95-22771. Crashworthiness Protection Requirements for Tank Cars; Detection and Repair of Cracks, Pits, Corrosion, Lining Flaws, Thermal Protection Flaws and Other Defects of Tank Car Tanks  

  • [Federal Register Volume 60, Number 183 (Thursday, September 21, 1995)]
    [Rules and Regulations]
    [Pages 49048-49083]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-22771]
    
    
    
    
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    Part II
    
    
    
    
    
    Department of Transportation
    
    
    
    
    
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    Research and Special Programs Administration
    
    
    
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    49 CFR Part 171, et al.
    
    
    
    Crashworthiness Protection Requirements for Tank Cars; Detection and 
    Repair of Cracks, Pits, Corrosion, Lining Flaws, Thermal Protection 
    Flaws and Other Defects of Tank Car Tanks; Final Rule
    
    Federal Register / Vol. 60, No. 183 / Thursday, September 21, 1995 / 
    Rules and Regulations 
    
    [[Page 49048]]
    
    
    DEPARTMENT OF TRANSPORTATION
    
    Research and Special Programs Administration
    
    49 CFR Parts 171, 172, 173, 179, and 180
    
    [Docket Nos. HM-175A and HM-201; Amdt Nos. 171-137, 172-144, 173-245, 
    179-50, and 180-8]
    RIN 2137-AB89 and 2137-AB40
    
    
    Crashworthiness Protection Requirements for Tank Cars; Detection 
    and Repair of Cracks, Pits, Corrosion, Lining Flaws, Thermal Protection 
    Flaws and Other Defects of Tank Car Tanks
    
    AGENCY: Research and Special Programs Administration (RSPA), DOT.
    
    ACTION: Final rule.
    
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    SUMMARY: RSPA is amending the Hazardous Materials Regulations (HMR) to: 
    Require facilities that build, repair, and ensure the structural 
    integrity of tank cars, to develop and implement a quality assurance 
    program (QAP); allow the use of non-destructive testing (NDT) 
    techniques, in lieu of currently prescribed periodic hydrostatic 
    pressure tests, for fusion welded tank cars; require thickness 
    measurements of tank cars; allow the continued use of tank cars, with 
    limited reduced shell thicknesses, for certain hazardous materials; 
    increase the frequency for inspection and testing of tank cars for 
    added safety; clarify tank car pretrip inspection requirements; expand 
    the use of thermal protection systems and head protection on tank cars 
    to include certain other high hazard materials; add new requirements 
    for bottom-discontinuity protection; require the use of protective 
    coatings on insulated tank cars; prohibit the use of self-energized 
    manways located below the liquid level of the tank; remove 
    ``grandfather'' provisions allowing certain uses of tank cars; and 
    improve the puncture resistance of tank cars used for certain high 
    hazard materials, including those that are poisonous-by-inhalation 
    (PIH) and those determined by the Environmental Protection Agency (EPA) 
    to pose health and environmental risks.
        These actions are being taken to enhance the safe transportation of 
    hazardous materials in tank cars. The intended effects of these actions 
    are to improve the crashworthiness of tank cars and to increase the 
    probability of detecting critical tank car defects.
    
    DATES: Effective date. The effective date of these amendments is July 
    1, 1996.
        Compliance date. Voluntary compliance with the regulations, as 
    amended herein, is authorized November 1, 1995.
        Incorporation by reference date. The incorporation by reference of 
    certain publications listed in these amendments is approved by the 
    Director of the Federal Register as of July 1, 1996.
    
    FOR FURTHER INFORMATION CONTACT: Ed Pritchard (telephone 202-366-0509) 
    and James H. Rader (telephone 202-366-0510), Hazardous Materials 
    Division; or Thomas A. Phemister (telephone 202-366-0635), Office of 
    Chief Counsel, Federal Railroad Administration, 400 Seventh Street, 
    S.W., Washington, D.C. 20590-0001.
    
    SUPPLEMENTARY INFORMATION:
    
    I. Introduction
    
        This final rule consolidates two related notices of proposed 
    rulemaking published under Docket HM-175A [58 FR 52574, October 8, 
    1993] and Docket No. HM-201 [58 FR 48485 September 16, 1993], that 
    address the safe performance of tank cars used to transport hazardous 
    materials. RSPA believes that, by consolidating these two rulemakings, 
    changes to sections that are affected by both rules will be more easily 
    understood by readers. This preamble discusses separately, for each 
    rulemaking, the notices of rulemaking and comments received in response 
    to these notices. A consolidated ``Review by Section Summary'' 
    summarizes the changes made under this final rule.
        The Federal Railroad Administration (FRA) has enforcement authority 
    for tank cars and rail transportation. FRA developed these rulemakings 
    jointly with RSPA.
    
    II. Docket HM-175A--Crashworthiness Protection Requirements for 
    Tank Cars
    
    A. Background
    
        Based on research and on the FRA's continuing review of serious 
    accidents, involving the transportation of hazardous materials in tank 
    cars in the United States and Canada, RSPA issued a number of 
    regulations to improve the survivability of tank cars in 
    accidents.1 In these rulemakings, RSPA required the installation 
    of a tank-head puncture-resistance system (head protection), a coupler 
    vertical restraint system (shelf couplers), insulation, and a thermal 
    protection system for certain high-risk hazardous material ladings. The 
    difference between a ``thermal protection system'' and ``insulation'' 
    is that a ``thermal protection system'' protects a tank from a pool or 
    torch-fire environment. In contrast, ``insulation'' protects the lading 
    inside the tank from ambient, temperature differentials, much like home 
    insulation. The record shows that these systems, working in 
    combination, have greatly reduced the potential harm to human health 
    and the environment when tank cars are involved in accidents.
    
        \1\The discussions in the following rulemakings provide greater 
    detail about each of these safety system requirements: Interlocking 
    Couplers and Restrictions of Capacity of Tank Cars, Docket HM-38, 35 
    FR 14215 (September 9, 1970); Tank Car Tank Head Protection, Docket 
    HM-109, 41 FR 21475 (May 26, 1976); Shippers; Specifications for 
    Pressure Tank Cars, Docket HM-144, 42 FR 46306 (September 15, 1977); 
    Shippers, Specifications for Tank Cars, Docket HM-174, 49 FR 3473, 
    (January 27, 1984); Specifications for Railroad Tank Cars Used to 
    Transport Hazardous Materials, Docket HM-175, 49 FR 3468 (January 
    27, 1984); Transportation of Hazardous Materials, Miscellaneous 
    Amendments, Docket HM-166W, 54 FR 38790 (September 20, 1989); and 
    Performance-Oriented Packaging; Changes to Classification, Hazard 
    Communication, Packaging and Handling Requirements Based on UN 
    Standards and Agency Initiative, Docket HM-181, 55 FR 52402 
    (December 21, 1990).
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        On October 8, 1993, RSPA published a notice of proposed rulemaking 
    (NPRM) under Docket HM-175A (58 FR 52574) based, in part, on 
    recommendations issued by the National Transportation Safety Board 
    (NTSB) and comments received in response to an advance notice of 
    proposal rulemaking published on May 15, 1990 [55 FR 20242], and a 
    supplemental advance notice of proposed rulemaking published on August 
    29, 1990 [55 FR 35327]. The NPRM solicited comments on the costs and 
    safety benefits that would be derived should the HMR be amended in the 
    following areas: (1) Tank-head protection; (2) thermal protection; (3) 
    self-energized manways below the tank liquid level; (4) non-pressure 
    tank cars for PIH materials; (5) grandfather provisions allowing use of 
    certain tank cars conforming to former standards; (6) bottom 
    discontinuity protection on tank cars; (7) protective coatings on 
    insulated tanks; and (8) tank cars of limited and designated 
    specifications, with greater protection in accidents for transporting 
    materials determined by EPA to pose health and environmental risks.
        On January 6, 1994, FRA and RSPA held a public hearing to solicit 
    information to assist in deciding what actions, if any, should be taken 
    to improve the survivability of tank cars involved in hazardous 
    materials accidents. Twelve persons made presentations at the public 
    hearing. In addition, RSPA received 37 written comments in response to 
    the NPRM from representatives of trade associations and the various 
    industries that own, lease, transport, or use tank 
    
    [[Page 49049]]
    cars. All written and oral comments were given full consideration.
    
    B. Tank Cars Transporting ``Thermally Reactive Materials'' (Materials 
    That May Violently Decompose or Polymerize When Exposed to Fire)
    
        In the NPRM, RSPA proposed to require the use of full-head 
    protection and thermal protection on tank cars used for certain 
    materials termed, ``thermally reactive.'' These materials, listed by 
    name, are thought by many to be capable of a violent decomposition or 
    polymerization reaction when exposed to fire. For these materials, the 
    critical temperature for the tank car, and its thermally reactive 
    lading, may be the heat at which the material undergoes decomposition 
    or polymerization--as opposed to the temperature at which the steel of 
    the tank becomes so plastic, it begins to lose tensile strength.
        The proposal was based on several accidents involving thermally 
    reactive materials. For example, on August 2, 1988, at 9:00 p.m., in 
    Brazoria, Texas, 13 cars of a Union Pacific freight train 
    derailed.2 Seven of the derailed tank cars contained acetaldehyde, 
    and none of these tank cars had a thermal protection system, which was 
    not required. Two acetaldehyde tank cars sustained coupler punctures 
    and released their contents, which ignited. The resulting fire engulfed 
    four other acetaldehyde tank cars, and each of them had a total failure 
    or rupture of the tank shell within 5 to 10 minutes after the 
    derailment. Witnesses reported 3-4 explosions between 9:05 p.m. and 
    9:10 p.m.
    
        \2\Union Pacific Derailment at Brazoria, Texas, FRA Accident 
    Investigation No. 137-88, Railroad Report No. 0888H0200, August 2, 
    1988.
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        In another accident, NTSB found that the puncture of a tank car 
    containing hydrogen peroxide resulted in a release of lading and, when 
    the hydrogen peroxide combined with contaminants on the ground, a 
    chemical reaction occurred causing a fire.3 The fire heated and 
    ignited nearby polyethylene pellets, causing an explosion of the 
    hydrogen peroxide tank car and releasing a force equivalent to an 
    explosion of 10 tons of TNT (trinitrotoluene).
    
        \3\Collision and Derailment of Montana Rail Link Freight Train 
    with Locomotive Units and Hazardous Materials Release, Helena, 
    Montana, February 2, 1989, National Transportation Safety Board 
    Report NTSB/RAR-89/05, National Transportation Safety Board, 
    Washington, D.C.
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        Most commenters opposed the requirement for full-head protection or 
    thermal protection on tank cars used for thermally reactive materials. 
    In clarifying its comments on the NPRM, the Association of American 
    Railroads (AAR) stated that full-head protection is not necessary for 
    tank cars used for these materials, unless the materials pose another 
    hazard that warrants such protection. Other commenters, such as 
    American Petroleum Institute (API), Chemical Manufacturers Association 
    (CMA), and the Compressed Gas Association, Inc. (CGA), suggested that 
    RSPA open a new ANPRM to address these materials. A commenter stated--
    
    the creation of this category has ramifications that reach far 
    beyond this particular rulemaking, which deals with one mode of 
    transportation (rail) and one type of packaging (tank cars). We are 
    concerned with the likelihood that, in the future, the Department 
    will expand the regulation of TRMs to affect other modes of 
    transportation and types of packaging.
    
        Other commenters objected to the proposal to identify by list, 
    rather than by definition, certain existing hazardous materials that 
    would be designated ``thermally reactive.'' CMA challenged the 
    placement of several chemicals on the list, such as ``styrene, monomer 
    inhibited,'' ``vinyl toluene,'' ``vinylidene chloride,'' ``sulfur 
    trioxide,'' and ``hydrogen peroxide.'' CMA further stated that--
    
    [s]tyrene, for example, is flammable and can polymerize in an 
    accident but solidifies causing little or no harm to the 
    environment. For hydrogen peroxide tank cars, the proposed rule 
    would create a safety hazard by requiring thermal protection.
    
        Another commenter stated that ``[s]ome of the materials on the list 
    react violently when exposed to heat differentials and may decompose 
    with explosive force * * * Other materials, however, decompose through 
    polymerization into substances of relatively little hazard.'' The 
    commenter further explained that the key to the polymerization of 
    styrene is the absence of the inhibitor. Styrene is typically shipped 
    with inhibitor concentrations great enough to cover fairly lengthy, 
    unexpected delays in transportation. If a tank car of styrene is 
    exposed to extreme external heat, disregarding its flammable nature, 
    the inhibitor will dissipate rapidly as the temperature of the material 
    rises above 125  deg.F., which will allow the polymerization process to 
    begin. As a result of the polymerization, the internal heat of the 
    product will increase, and, with increasing temperature, the process 
    will accelerate.
        Several commenters opposed the requirement for a thermal protection 
    system on tank cars used to transport ``hydrogen peroxide.'' One of the 
    commenters stated that hydrogen peroxide does not polymerize or burn, 
    and the products of decomposition--water and oxygen--are not toxic.
        Two commenters, Eka Nobel and FMC Corporation (FMC), furnished 
    independent analyses of the fire effects on tank cars containing 
    ``hydrogen peroxide.'' Eka Nobel contracted with the IIT Research 
    Institute (IITRI), which used FRA's computer model to analyze the fire 
    effects on a tank car containing hydrogen peroxide.4 The results 
    of IITRI's analysis indicate that a tank car constructed from stainless 
    steel will meet the thermal protection criterion for withstanding the 
    effects of a pool fire.
    
        \4\``Temperatures, Pressures and Liquid Levels of Tank Cars 
    Engulfed in Fires,'' NTIS DOT/FRA/OR&D-84/08.11, (1984), Federal 
    Railroad Administration, Washington, DC.
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        FMC furnished a detailed, mathematical heat transfer model using a 
    correlation contained in a National Fire Protection Association (NFPA) 
    publication, ``NFPA Pamphlet No. 30.'' FMC stated that for materials 
    that decompose exothermically, such as hydrogen peroxide, thermal 
    stability requires that the heat losses to the surroundings balance the 
    heat generated by the decomposition. Failure to remove the heat of 
    reaction could lead to runaway decomposition, and if the increased 
    pressure exceeds the burst pressure of the tank, the tank will fail. 
    Furthermore, heat input causes oxygen generation from thermal 
    decomposition of peroxide and vapor generation, by boiling off the 
    water-peroxide mixture. FMC further stated that because water is more 
    volatile than peroxide, the hydrogen peroxide concentration in the tank 
    will increase (although this may be compensated by water formation and 
    peroxide loss from thermal decomposition). If the peroxide 
    concentration reaches 74 percent by weight, the vapors in equilibrium 
    with the liquid (40 percent by weight of peroxide) can detonate, if 
    ignited, causing the tank car to fail.
        The results of FMC's mathematical heat transfer model show that 
    tank cars containing hydrogen peroxide (having no less than a 7-percent 
    outage) will not fail and such tank cars will meet the thermal 
    protection criterion in Sec. 179.18 of this final rule for withstanding 
    the effects of a pool-fire. Readers who are interested in a detailed 
    discussion of Eka Nobel or FMC's fire studies on tank cars containing 
    hydrogen peroxide, should refer to the comments filed in the RSPA 
    Dockets Unit.
        Many commenters suggested a performance-based definition as a means 
    to ensure the proper identification and packaging of thermally reactive 
    materials, because, with increasing temperature, all materials will 
    reach a stability limit. 
    
    [[Page 49050]]
    These commenters suggested a performance-based definition that would 
    include the polymerization potential; the rate of the chemical reaction 
    (reaction kinetics); any highly exothermic reaction; the formation of 
    gases, vapors, or fumes in a quantity sufficient to present a danger to 
    human health and the environment; and any reactive by-products that 
    could lead to over-pressurization of the tank. Commenters stated that a 
    performance-based definition was the best way to ensure that the proper 
    packaging requirements are attached to the appropriate hazardous 
    materials.
        As evidenced from the comments, there is no single agreement on the 
    best approach to identify these materials, nor to ensure the proper 
    packaging requirements are assigned to these materials. Because of the 
    multiplicity of these yet unresolved issues, the packaging requirements 
    proposed in the NPRM for thermally reactive materials have not been 
    adopted in this final rule.
    
    C. Tank-Head Protection
    
        In the NPRM, RSPA proposed several changes relating to tank-head 
    protection. The proposal would require tank-head protection on tank 
    cars, used for all Class 2 materials and for tank cars constructed from 
    aluminum or nickel plate, when used to transport a hazardous material. 
    RSPA included Division 2.2 in its proposal to reduce the violent 
    rupture hazard and the asphyxiation potential to railroad workers or 
    bystanders exposed to the product if these tank cars are punctured. The 
    proposal to require full-head protection for tank cars constructed from 
    aluminum or nickel plate is based on the vulnerability of the tank head 
    to a puncture. The top-half of the tank head is vulnerable to puncture 
    in a derailment. Existing tank cars with half-head protection were 
    excluded, based on RSPA and FRA's regulatory analysis discussed later 
    in this preamble. Consistent with these proposed changes, RSPA also 
    proposed to eliminate a grandfather provision, in place since 1984, 
    following publication of a final rule under Docket HM-175, that permits 
    certain tank cars, with a capacity of less than 70 kiloliters (kl; 
    18,500 gallons), to continue in service without head protection.
        RSPA first introduced tank-head protection requirements after a 
    series of railroad accidents in the late 1960s and early 1970s 
    involving head punctures of tank cars (39 FR 27572 and 41 FR 21475). 
    The requirements of, and criteria for, head protection were based on 
    tests performed by FRA, the AAR, and the Railway Progress Institute 
    (RPI) Tank Car Safety Research and Test Project in the early 1970s. In 
    summary, these tests showed that head punctures, caused by over-speed 
    impacts in railroad classification yards, generally occurred at speeds 
    above 12 mph and often happened when a loaded tank car struck a 
    standing empty tank car, causing the empty car to ``jump'' and ram its 
    coupler into the head of the oncoming tank. A recent informal staff 
    analysis of data on main-line accidents showed that objects, such as 
    broken rails and couplers, may penetrate the top half of the tank head, 
    indicating that head protection is essential, even though not 100 
    percent effective, in a train derailment.
        The NPRM referenced the recent FRA research on puncture resistance, 
    which shows that puncture resistance is strongly influenced by impact 
    location, head and jacket thickness, and insulation thickness.5 
    Stated differently, research demonstrates that puncture resistance is 
    an inter-related function of head thickness, insulation thickness, and 
    jacket thickness, and that the concept of ``head protection'' must 
    include more than just traditional ``head shields.'' Based on the 
    results of this research, FRA expects that certain tank cars may meet 
    the 29 kilometers per hour (18-mph) threshold for puncture-resistance, 
    prescribed in Sec. 179.16 of this final rule, without further 
    modification.
    
        \5\Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture 
    Resistance Evaluation (1992), Federal Railroad Administration, 
    Washington, DC (NTIS DOT/FRA/ORD-92/11).
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        Tank cars currently equipped with half-head protection. Most 
    commenters agreed that there is no need to require full-head protection 
    on existing tank cars having only half-head protection.
        In comments filed in this docket, NTSB stated that the NPRM 
    addressed many of their concerns, but noted the proposal failed to 
    require existing tank cars used to transport Division 2.1 (flammable 
    gas) materials, or other materials with extreme hazards, to be modified 
    with full-head protection. Thus, these materials could be transported 
    indefinitely in tank cars without full-head protection modifications.
        While we appreciate the concerns of NTSB, we are not able to 
    establish a positive benefit/cost ratio by requiring modification of 
    the existing tank car fleet, primarily because the half-head protection 
    on existing cars is already about 95-percent effective. It is not 
    credible to argue that greater safety gains are realized by mandating 
    safety improvements on tank cars that currently have a 95-percent 
    effective protection system, than by requiring improvements on tank 
    cars without a head-protection system. The regulatory evaluation 
    considered both approaches, with emphasis being placed on choosing the 
    alternative offering maximum potential benefit to society, while 
    imposing the least net cost. Based on the regulatory evaluation, this 
    final rule does not require that existing half-head protection be 
    removed and replaced with full-head protection.
        Head protection systems for existing tank cars with capacities less 
    than 70 kl (18,500 gallons). RSPA received diverse comments in response 
    to this proposal in the NPRM. One commenter agreed that class DOT 105 
    tank cars having capacities less than 70 kl (18,500 gallons) and 
    transporting Division 2.1, 2.2, and 2.3 materials, should have full-
    head protection, unless already equipped with half-head protection.
        CMA supported the proposal to require full-head protection on newly 
    built class DOT 105A tank cars, regardless of tank capacity, when used 
    to transport a Division 2.1 or 2.3 material. The Reebie Associates 
    report, submitted as part of CMA's comments, assumed that all tank cars 
    would require head protection, except those that have a tank test 
    pressure of 41.4 Bar (600 pounds per square inch [psi]).
        The Chlorine Institute agreed that head protection systems are now 
    warranted for the transportation of chlorine, but recognized, based on 
    FRA research and the accident history, that many tank cars currently 
    used to transport chlorine meet the performance standard by virtue of a 
    thick tank-head and a tank jacket.
        NTSB commented that RSPA should require tank-head protection, 
    within 5 years, for all class 105 tank cars having capacities of less 
    than 70 kl (18,500 gallons) when used to transport a Division 2.1 
    (flammable gas) material as proposed in Option B of the NPRM.
        RPI commented that, except for the nominal 41 kl (11,000-gallon) 
    capacity tank cars, existing tank cars of less than 70 kl (18,500-
    gallon) capacity, transporting Division 2.1 materials or anhydrous 
    ammonia, should have head-protection, but only half-head protection. 
    RPI further commented that RSPA should exclude tank cars having a 
    nominal capacity of 41 kl (11,000 gallons) from any head protection 
    modification program, because most tank cars in this category are near 
    or exceed 30 years of age; consequently, the economic life of the tank 
    is nearing an end.
        RSPA and FRA believe that there is no longer a justification for 
    excluding tank cars having a capacity less than 70 
    
    [[Page 49051]]
    kl (18,500 gallons) from the modification requirements. While CMA's 
    report is not so optimistic on the use of DOT 105A500W specification 
    tank cars, RSPA and FRA believe that most of these tank cars will meet 
    the performance standard by virtue of their increased head thickness, 
    insulation, and metal jacket. Because of the small number of tank cars 
    in this category, and the small incremental cost to make such head 
    protection modifications for those tank cars that do not otherwise meet 
    the performance standard mandated by this rule, in this final rule RSPA 
    is removing the 70 kl (18,500-gallon) exception for existing tank cars 
    in current Secs. 173.314(c) and 173.323(c)(1).
        Further, while most commenters supported the 10-year modification 
    program for existing tank cars, we agree with NTSB, that when these 
    tank cars are used to transport Division 2.1 materials, a 5-year 
    modification program (as proposed in Option B of the NPRM) will ensure 
    that those cars presenting the greatest risk are modified first.
        Tank cars transporting materials in Division 2.2. A commenter 
    stated that the proposal to require full-head protection for Division 
    2.2 gases is sound and should be finalized. Several other commenters 
    disagreed with the proposal to require full-head protection for 
    Division 2.2 materials. The Reebie Associates report, submitted by CMA, 
    identified 467 Class 2 materials affected by the proposed rule, 11 of 
    which are Division 2.2 materials. The report shows that shippers used 
    1,448 tank cars in 1992 to transport these Division 2.2 materials, as 
    follows:
    
    ------------------------------------------------------------------------
                             Commodity                           Population 
    ------------------------------------------------------------------------
    Argon, refrigerated liquid................................             2
    Ammonia solutions.........................................            28
    Bromotrifluoromethane.....................................             1
    Carbon dioxide, refrigerated liquid.......................         1,016
    Chlorodifluoromethane.....................................           145
    Chlorotetrafluoroethane...................................            26
    Chloropentafluoroethane...................................            37
    Dichlorotetrafluoroethane.................................           164
    Fertilizer, ammoniating solutions.........................             4
    Trifluoromethane..........................................             1
    Xenon, refrigerated liquid................................            24
                                                               -------------
        Total.................................................         1,448
    ------------------------------------------------------------------------
    
        CGA opposed the full-head protection requirement for tank cars 
    transporting carbon dioxide. CGA referenced the testimony presented by 
    RPI at the January 6, 1994 public hearing concerning recent head impact 
    tests that verified the adequacy of the current head protection system 
    on DOT 105A500W specification tank cars.
        With regard to CMA's and CGA's comments, RSPA and FRA believe that 
    most tank cars used for ``carbon dioxide, refrigerated liquid,'' meet 
    the performance standard for head protection by virtue of their tank 
    head thickness and metal jacket. Tank cars used for ``argon, 
    refrigerated liquid,'' and ``xenon, refrigerated liquid,'' also meet 
    the head performance standard by virtue of the authorized class DOT 113 
    tank car specification. These tank cars must have a minimum outer 
    jacket tank head of not less than \1/2\-inch thick steel. See 
    Sec. 179.400-8(d). A total of 1,042 tank cars, or 72 percent of the 
    total Division 2.2 tank car population, are used to transport these 
    three commodities.
        A commenter opposed tank-head protection for Division 2.2 materials 
    stating, ``heavy walled tank and protective housing for the fittings is 
    adequate for the transportation environment.'' The commenter also 
    provided an in-house report using a computer model that claims the 
    asphyxiation potential from a punctured Division 2.2 refrigerant gas 
    tank car to be very low.'' Another commenter opposed applying head 
    protection to tank cars transporting Division 2.2 refrigerant gases. 
    This commenter stated that, in the past, DOT had judged a material 
    based on its hazards under normal conditions of transport, and that in 
    this rulemaking, DOT was over-assessing the potential for harm in a 
    low-probability event. RPI supported full-head protection on new, 
    insulated tank cars transporting Class 2 materials, but it opposed 
    full-head protection for new non-insulated tank cars or for existing 
    tank cars transporting these materials.
        We believe that even though the probability of an event occurring 
    with these materials is low, safety concerns still need to be 
    addressed, because the event may lead to high consequences, such as a 
    large scale evacuation or an oxygen deficient atmosphere in a 
    concentrated populated area. Taking the safety steps adopted in this 
    final rule will mitigate these hazards.
        We also believe that the transportation risks associated with 
    Division 2.2 gases are sufficient to require full-head protection for 
    new tank cars, and for existing tank cars without head protection, when 
    used to transport Division 2.2 materials. As noted above, this rule 
    does not require existing tank cars equipped with half-head protection 
    to be modified with full-head protection. RSPA and FRA are aware of 
    industry concerns that the attachment of full-head protection to non-
    jacketed cars is a feature not yet proven by long service. Similar 
    arguments were raised when head protection was first required almost 
    two decades ago [HM-144; 42 FR 46306, September 15, 1977]. FRA is aware 
    of companies with plans to attach full-head protection to their non-
    jacketed tank cars. As discussed later in this preamble, a phased-in 
    10-year modification program is provided for existing tank cars.
        Existing tank cars without head protection. Most commenters to the 
    NPRM supported the need to modify existing tank cars to meet the 
    current safety requirements. One commenter supported the need to modify 
    existing tank cars constructed from aluminum plate with half-head 
    protection, but believed full-head protection should be required when a 
    proven full-head shield design is available. Another commenter 
    suggested that DOT should specifically recognize that tank cars used in 
    ``chlorine'' service meet the performance requirements for head 
    protection and that DOT should not require any additional head 
    protection for these tank cars.
        As stated in the NPRM, the benefits of head protection are real, 
    predictable, and quantifiable. RSPA disagrees with commenters who state 
    that full-head protection is not warranted. Where earlier rules 
    required head protection on tank cars, it was a matter of recognizing 
    the highest priority needs first. The question is not one of demanding 
    low-priority, safety benefits, but the need to expand the safety base 
    of hazardous materials transportation in tank cars. Further, the small 
    additional cost of installing full-head protection on cars that now 
    have no head protection system, as compared with adding only half-head 
    protection, is justified on the basis of increased safety (see Chapter 
    V of the Economic Impact Assessment and Regulatory Flexibility 
    Analysis). In this final rule, RSPA requires existing tank cars that 
    currently have no head protection, to have full-head protection 
    installed when used to transport a Class 2 material. As explained 
    below, RSPA is also requiring full-head protection for tank cars 
    constructed from aluminum or nickel plate when used to transport 
    hazardous material.
        Tank cars constructed from aluminum and from nickel plate. 
    Commenters supported the need for head protection on tank cars 
    constructed from aluminum or nickel plate, but not the full-head 
    protection requirement proposed in the NPRM. Most commenters stated 
    that there is no design available for the securement of full-head 
    protection on tank cars without metal jackets. 
    
    [[Page 49052]]
    
        One commenter stated that his company's new aluminum tank cars, 
    constructed with greater tank shell and head dimensions than standard 
    tank cars, offer greater protection without head protection. The 
    commenter stated that further testing should be done and suggested that 
    RSPA and FRA submit more evidence to support the need for this 
    requirement.
        CMA supported requiring half-head protection for new tank cars 
    constructed from aluminum or nickel plate, and requiring half-head 
    protection for existing tank cars for certain hazardous materials. 
    Several commenters requested that RSPA consider the characteristics of 
    an individual Division 2.2 material, and that materials not subject to 
    the HMR, and low hazard materials should be excluded.
        We realize that the use of good engineering practice and design 
    specifications are needed to secure full-head protection to tank cars 
    without metal jackets. Although there is no service experience for a 
    full-head protection design on non-insulated tank cars, such designs 
    are certainly not unreachable within the years ahead. In rulemaking 
    proceedings under another docket [HM-144; 42 FR 46306, September 15, 
    1977] introducing half-head protection, commenters offered similar 
    arguments regarding head protection, for which solutions were later 
    found as a result of technological innovation. Currently, FRA is aware 
    of several companies that are nearing completion on their full-head 
    protection designs for aluminum and nickel tank cars. We, therefore, 
    believe that the introduction of this requirement will not adversely 
    affect industry. In this final rule, the use of full-head protection 
    for all tank cars constructed from aluminum or nickel plate is required 
    when used to transport a hazardous material. As discussed later in this 
    preamble, RSPA has provided for a phased-in 10-year modification 
    program.
    
    D. Thermal Protection Systems
    
        In the NPRM, RSPA proposed to require a thermal protection system 
    for a Class 2 material when a thermal analysis of the tank car and 
    lading shows that a release will occur other than through the safety 
    relief valve when the tank car is subjected to either a 100-minute pool 
    fire or a 30-minute torch fire. The current HMR require thermal 
    protection for Division 2.1 (flammable gas) materials (with limited car 
    capacity restrictions) and certain Division 2.3 (poison gas) materials. 
    RSPA proposed to expand the thermal protection requirements to include 
    Division 2.2 materials because, as stated by AAR, ``[a]t a chemical 
    accident, there are generally two reasons for an evacuation, one is to 
    protect the public from any toxic, poisonous, or noxious vapors or 
    fumes generated by the product itself . . ., the second is to protect 
    the public from thermal ruptures and the container debris that may be 
    hurled from an incident site'' [Emergency Action Guides, p. VII]. RSPA 
    also proposed to expand the thermal protection requirement to include 
    all Division 2.3 materials.
        RSPA began to require the application of a thermal protection 
    system on tank cars transporting Division 2.1 materials (flammable 
    gases) or ``ethylene oxide'' (Division 2.3) after a series of major 
    railroad accidents involving fires and ruptures of non-insulated 
    pressure tank cars. The design of and criteria for thermal protection 
    systems were based on tests performed by FRA at the U.S. Army 
    Ballistics Research Laboratory in White Sands, New Mexico, and at the 
    Transportation Test Center in Pueblo, Colorado. These tests revealed 
    that a 127.2 kl (33,600 gallon) non-protected tank car filled with 
    propane (Division 2.1) will rupture, with 40 percent of the lading 
    remaining in the tank car, within 24 minutes after exposure to a pool-
    fire. Rupture occurs when the residual strength of the tank shell falls 
    below the force generated by the vapor pressure of the lading exerted 
    on the inside surface of the tank shell. Further testing by FRA 
    demonstrated that a tank car filled with propane and equipped with a 
    thermal protection system delayed the thermal rupture of the tank car 
    for 94.5 minutes, by maintaining the shell temperature low enough to 
    vent 98 percent of the lading through the safety relief valve. The 
    current performance standard, requiring exposure to a 100-minute pool 
    fire and a 30-minute torch fire, was chosen because it provides 
    emergency response personnel time to assess the accident and to 
    initiate remedial actions, such as evacuating an area.
        Division 2.1 (flammable gas) and 2.3 (poisonous gas) materials: 
    Several commenters supported the need for a thermal protection system 
    on tank cars transporting Division 2.1 or 2.3 materials, regardless of 
    tank car capacity. The AAR and another commenter supported a thermal 
    protection system for all Class 2 materials, unless a shipper could 
    show that a release will not occur, other than through the safety 
    relief valve, when the tank and lading are subject to a fire. RPI also 
    concurred on the need for thermal protection for all Class 2 materials, 
    but, except for Division 2.1, but did not support the high-temperature 
    performance standard proposed in Sec. 179.18. RPI stated that most 
    insulation materials (e.g., 4 inches of glass-fiber insulation) are 
    adequate.
        In this regard, RSPA stated in the NPRM that many insulation 
    materials also provide good thermal protection. These insulation 
    materials, when analyzed with the tank and the lading, may show that 
    nothing further needs to be installed on the tank car to achieve 
    passage of the pool- and torch-fire performance tests. Research 
    sponsored by FRA on urethane-foam and glass-fiber insulation systems 
    show that urethane-foam insulation will pass the pool- and torch-fire 
    requirements and that glass-fiber insulation will also pass both tests, 
    provided the insulation is held in place with a plastic or wire scrim. 
    Owners of tank cars with either of these systems, or another comparable 
    system, may find that their thermal analysis of the tank car shows the 
    presence of sufficient thermal protection to meet the performance 
    standard. In this case, the tank car owner would have to verify only 
    that the insulation material installed on the tank car is capable of 
    passing the pool- and torch-fire verification or ``proof'' tests in 
    Appendix B to Part 179 of this final rule. Owners may find that a tank 
    car will pass the performance standard with only minor modifications, 
    such as applying a thermal protection system to the manway nozzle.
        Also in the NPRM, RSPA stated that, in 1981, a joint effort between 
    the Chlorine Institute and RPI-AAR Tank Car Safety Research and Test 
    Project resulted in the development of an insulation system to protect 
    a chlorine tank car involved in a fire. The insulation system developed 
    maintains back plate (inside surface of the tank car shell) 
    temperatures below 250.56  deg.C (483  deg.F). After reviewing the 
    thermal resistance capabilities of the insulation system used on 
    chlorine tank cars, RSPA incorporated it into the HMR in 1987. Readers 
    should refer for more information to Docket HM-166U, entitled 
    ``Transportation of Hazardous Materials; Miscellaneous Amendments'', 52 
    FR 13034, (April 20, 1987).
        Division 2.2 (nonflammable gas) materials. As noted earlier in the 
    preamble discussion on tank-head protection for Division 2.2 materials, 
    CMA commented that there were 1,448 tank cars allocated to Division 2.2 
    materials that had not already been captured in another service, such 
    as PIH. Of those, ``argon, refrigerated liquid,'' ``carbon dioxide, 
    refrigerated liquid,'' and ``xenon, refrigerated liquid,'' represent 
    1,042 tank cars, or 72 percent. CMA further commented that 
    
    [[Page 49053]]
    almost 100 percent of the total would need retrofitting and that the 
    overall economic impact of the new regulations on this group of tank 
    cars amounts to $26.0 million for retrofitting and $2.59 million for 
    higher lease rates and additional cars in the tenth year of the 
    implementation period.
        With regard to the issues raised by CMA, this final rule does not 
    contain any new thermal protection requirements for ``argon, 
    refrigerated liquid,'' ``carbon dioxide, refrigerated liquid,'' or 
    ``xenon, refrigerated liquid.'' Carbon dioxide is transported in DOT 
    105A500W tank cars equipped with two regulator valves, a reclosing 
    pressure-relief device, a frangible disc, and an insulation system with 
    good thermal performance (a thermal conductance of 0.03 British Thermal 
    Units [B.t.u.] per square foot per degree Fahrenheit differential). 
    Consequently, existing and new tank cars in carbon dioxide service have 
    sufficient thermal resistance when exposed to fire. Likewise, because 
    with argon and xenon, refrigerated liquids are packaged under the 
    exceptions for atmospheric gases in Sec. 173.320, this final rule does 
    not impose any new thermal protection requirements. This section 
    exempts cryogenic atmospheric gases from the packaging requirements 
    when the packagings are designed to maintain pressures below 1.74 Bar 
    (25.3 psi) under ambient temperature conditions.
        Another commenter opposed the use of thermal protection for 
    Division 2.2 materials on the basis that the hazards they pose do not 
    equate to those of Division 2.1 and 2.3 materials. The commenter 
    further stated that the thermal protection requirements proposed for 
    Division 2.2 materials do not appear to be justified by the hazards 
    posed, because, in many cases, these materials dissipate naturally with 
    little risk to the surroundings.
        A commenter, primarily addressing refrigerant gases, noted that an 
    analysis of each Division 2.2 material, to predict the behavior of a 
    tank car in a 100-minute pool-fire, seemed an unnecessary precaution 
    because the calculations, required by the current regulations, for 
    sizing safety relief valves accomplish the same purpose and meet this 
    same standard. RSPA and FRA disagree with this commenter's position 
    that the current regulations for sizing safety relief valves accomplish 
    the same purpose as the proposed Division 2.2 thermal protection 
    performance standard. The current safety relief valve-sizing 
    requirements make several assumptions. First, the valve sizing formula 
    assumes the exposure factor, that portion of the tank car exposed to 
    fire (represented as A0.82), is about one-fourth of the tank. The 
    pool-fire computer model in this final rule assumes total engulfment. 
    Second, the safety relief valve sizing formula assumes that flame 
    temperatures will reach approximately 650  deg.C (1,200  deg.F.). The 
    pool-fire standard assumes flame temperatures will reach 871  deg.C 
    (1,600  deg.F) for a pool-fire and 1,204  deg.C (2,200  deg.F) for a 
    torch fire at 40 miles per hour.6 Third, the safety relief valve-
    sizing formula does not take into consideration either an overturned 
    tank car venting liquid or a liquid-gas mixture (two phase flow) or the 
    diminished burst strength of the heated tank shell in the non-wetted 
    area, after prolonged fire exposure.
    
        \6\The pool-fire computer model assumes an average heat flux 
    over the entire tank surface, equivalent to complete engulfment in a 
    fire, where the flame temperature is 815.5  deg.C (1,500  deg.F). If 
    a higher or lower flame temperature were assumed, the parametric 
    analyses in the computer model would not match the actual field test 
    data.
    ---------------------------------------------------------------------------
    
        The Fertilizer Institute did not support the requirement for 
    thermal protection on tank cars transporting ``anhydrous ammonia''. It 
    stated that the likelihood of a fire-induced rupture of a tank car 
    carrying anhydrous ammonia has significantly decreased since 1980 
    because of added safety devices, safer placement in trains, and 
    improved emergency response procedures. Thus, there is little, if any, 
    increase to public safety by imposition of the proposed thermal 
    protection requirements on these tank cars.
        While RSPA and FRA agree with The Fertilizer Institute that the 
    safety record for tank cars transporting ``anhydrous ammonia'' is good, 
    these cars have a potential for violent rupture similar to compressed 
    gas tank cars, which received thermal protection many years ago. As The 
    Fertilizer Institute notes, the threat of a fire-induced violent 
    rupture of an anhydrous ammonia tank car is more than just a 
    theoretical potential. Since 1990, according to figures from the AAR, 
    ``anhydrous ammonia'' has been the sixth highest volume hazardous 
    material transported by railroad.
        AAR and two other commenters supported the need for thermal 
    protection for Class 2 materials, including Division 2.2. One of these 
    commenters stated: ``thermal protection systems are a good, simple idea 
    whose time has come. The purpose of the system is to prevent rupture of 
    the tank car in a fire with the release of its hazardous materials 
    contents to the environment. Uncontrolled release of almost any 
    hazardous material to the environment is objectionable whether due to 
    toxicity, flammability, or simply clean-up costs.'' This commenter 
    further stated that there can be little basis for exempting anhydrous 
    ammonia from the thermal protection requirements simply because it is 
    not likely to catch fire once released. Its PIH characteristic remains, 
    and the potential for rupturing in a non-insulated tank car is high.
        Although not all commenters agree on the need for thermal 
    protection for Division 2.2 materials, in this final rule RSPA requires 
    such a system if, after an analysis of the effects of a 100-minute pool 
    fire and a 30-minute torch fire, there will be a release of the tank 
    car lading other than through the safety relief valve. Because tank 
    cars may transport different ladings, and because changing ladings may 
    affect the whole system, owners or shippers may choose to perform a 
    ``worst case'' analysis based on all the commodities the car is likely 
    to carry.7
    
        \7\Owners are reminded that 49 CFR 173.31(a)(4) limits the use 
    of tank cars to those commodities for which they are authorized. 
    Authorized (or approved) commodities are those listed on the 
    certificate of construction or an AAR R-1 form. (See the AAR 
    Specifications for Tank Cars Section 1.4.3.1 and Appendix R, Section 
    R4.04.)
    ---------------------------------------------------------------------------
    
        Based on these comments and FRA's research, this final rule 
    requires the owner or the shipper of a Class 2 material, with the 
    exception of ``carbon dioxide, refrigerated liquid,'' ``chlorine,'' and 
    ``nitrous oxide, refrigerated liquid'' as explained above, to perform 
    an analysis of the characteristics of the material and of the thermal 
    resistance capabilities of the tank car, taking into consideration the 
    safety relief valve start-to-discharge pressure setting and relief 
    capacity and all areas of the tank car that are not afforded protection 
    from fire (such as stub sills, bolsters, and protective housings).
        Tank cars constructed from aluminum and nickel plate. Most 
    commenters said that the lading within a tank car constructed from 
    aluminum or nickel plate should determine the need for a thermal 
    protection system.
        We agree. The NPRM proposed to require a thermal protection 
    analysis for aluminum and nickel plate cars carrying Class 2 materials. 
    Based on the comments received, we believe that all such tank cars will 
    need protection and that such protection is essential.
        This final rule requires the owner of an aluminum or nickel plate 
    tank car used to transport a Class 2 material to perform an analysis of 
    the tank car in a 100-minute pool fire and in a 30-minute torch fire 
    using FRA's Tank Car Fire model. If the analysis shows that a release 
    of the lading from the tank car, 
    
    [[Page 49054]]
    will occur, other than through the safety relief valve, a thermal 
    protection system will be required. This final rule adopts a 10-year 
    phase-in period for those existing tank cars required to have thermal 
    protection.
    
    E. Shell Protection
    
        For tank cars transporting of a material poisonous by inhalation 
    (PIH), RSPA proposed that they have ``shell protection conforming to 
    Sec. 179.100-4.'' That is, the optional use of an insulated DOT 105S 
    tank car or a non-insulated, but thermally protected, DOT 112J or 114J 
    tank car having a metal jacket. Although RSPA used the term ``shell 
    protection'' to identify these systems, the intent of the NPRM was to 
    require tank cars transporting a PIH gas (Division 2.3) to conform to 
    the same requirements as tank cars transporting a PIH liquid. For a 
    complete discussion, see Performance-Oriented Packaging Standards; 
    Miscellaneous Amendments, Docket HM-181F, 58 FR 50224 (September 24, 
    1993). In the final rule issued under that docket, RSPA authorized the 
    optional use of an insulated DOT 105S tank car or a non-insulated, but 
    thermally protected, DOT 112J or 114J tank car for poisonous liquids 
    having a PIH hazard.
        In its comments to the NPRM, one commenter supported the need for 
    shell protection for PIH materials. Another commenter suggested that, 
    in lieu of a metal jacket, RSPA should establish a performance 
    standard, as with thermal and head protection. Until a performance 
    standard is established, shell-protection resistance should be 
    equivalent to a tank car having a tank test pressure of 20.7 Bar (300 
    psi) constructed from carbon steel and with a 1/8-inch carbon steel 
    jacket. The commenter stated that the shell-puncture resistance should 
    be based on either a total metal thickness, or an approved calculation. 
    We agree with this commenter that a performance-based standard for 
    shell-puncture resistance may have merit over specification-based 
    standard adopted in this final rule. However, such performance based 
    standards have not been proposed.
        Another commenter opposed the use of a metal jacket on pressure 
    tank cars transporting a PIH material on the basis that the FRA's 
    proposal did not support the conclusion that jacketing improves 
    puncture resistance. The commenter further questioned the use of a tank 
    jacket over thicker tank shells, since ``jackets provide thermal not 
    puncture protection.''
        In response to similar remarks, RSPA discussed in the NPRM a 1987 
    RPI report on the vulnerability of pressure tank car shells to 
    puncture.8 RPI found that shelf couplers, hardboard insulation 
    (cork), increased shell thickness, thermal protection, small tank car 
    size and increased jacket thickness proved effective towards reducing 
    the frequency of shell punctures. The RPI report summarizes a 20\1/2\-
    year history of accident data on shell punctures of pressure tank cars 
    and concludes that the 11-gauge steel jacket provides a measure of 
    shell protection. In addition to RPI's report, FRA also found, in a 
    research contract awarded to the AAR, that puncture resistance is 
    strongly influenced by impact location, by head and jacket thickness 
    and by insulation thickness.9
    
        \8\Phillips, E.A., Review of Pressure Car Shell Puncture 
    Vulnerability, RA-09-6-52, (1987), AAR-RPI Railway Tank Car Safety 
    Research and Test Project, AAR Technical Center, Chicago, Illinois.
        \9\[Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture 
    Resistance Evaluation, (1992) Federal Railroad Administration, 
    Washington, D.C. (NTIS DOT/FRA/ORD-92/11).
    ---------------------------------------------------------------------------
    
        RSPA explained earlier, in Docket HM-181, that the purpose of a 
    metal jacket is to provide ``both accident damage and fire protection'' 
    for certain [liquid] PIH materials.10 This final rule expands that 
    philosophy to all PIH materials [including compressed gases] and 
    authorizes the use of an insulated class DOT 105S tank car or a non-
    insulated, but thermally protected, class DOT 112J or 114J tank car.
    
        \10\See the final rule on Performance-Oriented Packaging 
    Standards; Miscellaneous Amendments, Docket HM-181F, 58 FR 50224 
    (September 24, 1993), and the NPRM, 58 FR 37612 (July 12, 1993).
    ---------------------------------------------------------------------------
    
    F. Self-Energized Manways Located Below the Liquid Level of the Lading
    
        RSPA proposed in the NPRM to prohibit the use on tank cars of a 
    self-energized manway located below the liquid level of the lading. The 
    proposal was based on a September 8, 1987 railroad yard incident in New 
    Orleans, Louisiana.11 In this incident, a tank car equipped with a 
    self-energized bottom manway and loaded with butadiene developed a leak 
    and caught fire. At one point during the incident, the flames were 
    large enough that both spans of a bridge on Interstate 10 were 
    engulfed. After the investigation, NTSB concluded that ``it is unlikely 
    that a hazardous material leak through a bottom manway during 
    transportation could be stopped.'' NTSB urged FRA to prohibit the 
    transportation of tank cars that have a manway opening located below 
    the liquid level of the lading in hazardous materials service. Because 
    the design of bottom manways depends in part on the weight of the 
    product and the pressure in the tank to make the seal fully effective, 
    this type of closure system becomes vulnerable to releasing product 
    when the lading is displaced within the tank. Therefore, we agree with 
    NTSB's conclusion.
    
        \11\Butadiene Release and Fire from GATX 55996 at the CSX 
    Terminal Junction Interchange, New Orleans, Louisiana, September 8, 
    1987, National Transportation Safety Board Report NTSB/HZM-88/01, 
    National Transportation Safety Board, Washington, D.C.
    ---------------------------------------------------------------------------
    
        In its comments to the NPRM, the AAR, RPI, and several other 
    commenters supported the proposal to remove self-energized manways 
    located below the liquid level of the lading. A commenter stated that 
    their design incorporates an externally elliptically shaped ring clamp 
    which is bolted to the manway closure plate with numerous closely-
    spaced studs around the circumference of the ring. This commenter holds 
    two DOT exemptions (DOT-E 5493 and DOT-E 6117) to operate tanks cars in 
    hydrogen sulphide service with this design. RSPA and FRA believe that 
    this design is certainly preferable to that used on the car that leaked 
    and burned in New Orleans and is similar to a more conventional 
    external flange, however, we believe this design still remains a 
    potential source of leaks since it is located below the liquid level of 
    the lading. Based on these reasons, RSPA will grant the exemption 
    holder a reasonable amount of time to phase out the use of these tank 
    cars.
        While some commenters agreed with a 2-year phase out program of 
    self-energized manways, NTSB stated that RSPA should immediately 
    prohibit such manways, and the AAR suggested a one-year phase-out 
    program.
        Based on these comments, this final rule prohibits the construction 
    of new tank cars having an internal self-energized manway located below 
    the liquid level of the lading. This prohibition is added in 
    Sec. 179.103-5. Based on NTSB's comments, compliance with this 
    provision is required beginning on the effective date of this final 
    rule.
    
    G. Non-Pressure Tank Cars for Materials Poisonous by Inhalation
    
        In the NPRM, RSPA proposed to prohibit the use of non-pressure tank 
    cars (e.g., class DOT 111A) for materials poisonous by inhalation.
        In a recent research report, FRA found that, in a single-car 
    national risk profile, the transportation of ethylene oxide in a DOT 
    111A100W4 tank car involves significantly greater risk than 
    transportation of the same material in a 
    
    [[Page 49055]]
    DOT 105J500W tank car.12 Characteristics and parameters evaluated 
    in this assessment included the toxicity, fire hazard, and explosion 
    hazard. In comments to the ANPRM, RPI reported that, during the time 
    period of 1965 through 1986, class DOT 111A tank cars involved in 
    accidents and damaged were slightly more than three times as likely to 
    lose lading as were class DOT 105 cars in similar situations.13
    
        \12\Raj, P.K., and Turner, C.K., Hazardous Materials 
    Transportation In Tank Cars/Analysis of Risks--Part 1, NTIS DOT/FRA/
    ORD-92/34, (1993), Federal Railroad Administration, Washington D.C.
        \13\Phillips, E.A., Analysis of Tank Cars Damaged in Accidents 
    1965 through 1986, RA-02-6-55, (1989), AAR-RPI Railway Tank Car 
    Safety Test and Research Project, AAR Technical Center, Chicago, 
    Illinois.
    ---------------------------------------------------------------------------
    
        The Raj/Turner report amply demonstrates (and AAR/RPI Tank Car 
    Safety Test and Research Project data support) that it is 
    ``improbable'' to assume that any single tank car (e.g., DOT 111A or 
    DOT 105) would be involved in an accident. However, based on FRA 
    accident data referenced earlier regarding DOT 111A and DOT 105 tank 
    cars, a significant number of such cars will be involved in accidents 
    during their service life.
        Several commenters supported disallowing the use of non-pressure 
    tank cars for the transportation of PIH materials. Because of the 
    hazards associated with PIH materials and the performance superiority 
    of the so-called ``pressure'' tank cars for this service, RSPA agrees 
    with the commenters. This final rule removes the class DOT 111A tank 
    car as an authorized packaging for Division 2.3 materials on the 
    effective date of this final rule.
    
    H. Phasing Out of Various ``Grandfather'' Provisions
    
        In the NPRM, RSPA proposed to remove from the HMR several 
    grandfather provisions that affect tank cars. The grandfather 
    provisions allow tank cars built before a certain date to remain in 
    service without modification. As an example, in Sec. 173.314(c), Notes 
    23 and 24 allow the continued use of class DOT 105A tank cars for 
    certain compressed and flammable gases if they were built before 
    September 1, 1981, while tank cars built after that date must meet a 
    more stringent class DOT 105S or 105J standard.
        NTSB stated, in a March 1, 1988 letter to RSPA, that tank cars 
    failing to meet current minimum safety requirements should no longer be 
    used for transportation of hazardous material under grandfather 
    provisions. NTSB stated that these grandfather provision could result 
    in a reduced level of safety. The AAR also petitioned RSPA to amend 
    Sec. 173.314(c) Note 30 (P-1138), stating that it does not provide any 
    assurance that tank cars with head protection will be used for PIH gas 
    service in the foreseeable future because companies will be able to use 
    tank cars without head protection for PIH compressed gas service for 
    the next 30 years. Other commenters agreed that the grandfather 
    provisions proposed for removal in the NPRM are no longer compatible 
    with the needs of safety.
        Based on these comments, RSPA is removing certain grandfather 
    provisions. In Sec. 171.102, special provision ``B63'' is removed to 
    disallow the use of DOT 105A100W, 111A100W4, 112A200W, and 114A340W 
    tank cars for ``ethyl chloride'' and ``ethyl methyl ether.'' Prior to 
    the issuance of Docket HM-181, these two materials were classed as 
    flammable liquids. Because these tank cars do not have head protection 
    or thermal protection systems, they do not provide an equivalent level 
    of safety compared to other tank cars used for Division 2.1 materials. 
    Also, special provision ``B63'' is removed from column 7 of the 
    Sec. 172.101 table entries for these two hazardous materials, thereby 
    prohibiting the use of non-protected tank cars.
        Other changes are made to disallow the use of class DOT 111A non-
    pressure tank cars for Class 2 (compressed gas) materials, such as 
    ``ammonia solutions,'' ``ethylamine,'' ``ethyl chloride,'' and ``ethyl 
    methyl ether.'' This final rule also removes the DOT 111A100W4 car as a 
    packaging for ``ethylene oxide'' in Sec. 173.323(c)(1).
    
    I. Bottom-Discontinuity Protection for Bottom Outlets
    
        In the NPRM, RSPA proposed to require bottom-discontinuity 
    protection (e.g., for bottom outlets) on tank cars. The proposed 
    requirements were intended to simply adopt the requirements published 
    by the AAR. In July of 1979, the AAR required bottom-discontinuity 
    protection for new tank car construction. Over a period of years, these 
    requirements were extended to existing tank cars on a priority schedule 
    determined by the nature of the commodity transported. The AAR's 
    program for bottom-discontinuity protection consists of either a metal 
    ``skid'' protecting the portion of the bottom outlet that protrudes 
    beyond the shell or the machining of a ``breakage groove'' in the valve 
    assembly.
        AAR, the Chlorine Institute, CMA, and several other commenters 
    supported the adoption of bottom-discontinuity protection for tank 
    cars, provided such protection was consistent with the AAR 
    requirements. API asked RSPA to clarify the requirements for bottom-
    discontinuity protection in this final rule. API and several other 
    commenters stated that the proposed rule would require the modification 
    of a number of tank cars, built before July 1, 1979, because most were 
    modified according to Appendix Y and not paragraphs E9.00 or E10.00 of 
    the AAR Specifications for Tank Cars. Appendix Y permits three levels 
    of protection for allowing the types of discontinuity: bottom outlets 
    that extend 1 inch or more; blind flanges and washouts that extend 2 
    and \5/8\ inches or more; and sumps and internally closed washouts that 
    extend 5 inches or more. Paragraphs E9.00 and E10.00 generally require 
    the protection of each valve and fitting from mechanical damage by the 
    tank, an another protective device, or the underframe.
        Several other commenters stated that the proposed rule would also 
    require the modification of all existing tank cars, including those 
    that do not transport hazardous materials. The Sulphur Institute and 
    another commenter opposed the need to add bottom-discontinuity 
    protection to existing tank cars that transport sulfur, molten, 
    claiming that such protection has little practical benefit.
        In the public hearing held on January 6, 1994, in Washington, D.C., 
    FRA stated that it was not the Department's intention to require the 
    modification of previously modified tank cars, nor to require bottom-
    discontinuity protection for tank cars that transport materials not 
    subject to the HMR.
        In this final rule, RSPA requires bottom-outlet protection that 
    conforms to paragraphs E9.00 and E10.00 of the AAR Specifications for 
    Tank Cars, M-1002, for all new tank cars equipped with bottom unloading 
    devices. Existing tank cars, without bottom-discontinuity protection, 
    used for the transportation of hazardous materials must conform to the 
    above paragraphs no later than 10 years after the effective date of 
    this final rule. Existing tank cars that conform to the bottom-
    discontinuity protection requirements of Appendix Y of the AAR 
    Specifications for Tank Cars, M-1002 may continue in use after the 
    effective date of this final rule. This final rule does not require the 
    modification of existing tank cars that transport materials not subject 
    to the HMR.
    
    J. Protective Coatings on Insulated Tank Cars
    
        In the NPRM, RSPA proposed use of protective coatings on the 
    exterior of a 
    
    [[Page 49056]]
    tank car and the interior of a tank car jacket to retard rust or 
    corrosion. The proposal was in response to an AAR petition (P-1050) and 
    FRA's findings of severe corrosion or pitting on the outer surface of 
    the tank shell, or the inner surface of the tank jacket, of insulated 
    tank cars. It is not known whether the corrosion stems from the 
    physical properties of the insulation itself or whether the corrosion 
    develops when insulation becomes impregnated or contaminated with water 
    or a chemical from the atmosphere in which the tank car operates. 
    Research within the industry has led to the development of protective 
    coating materials.
        Most commenters supported the proposal. One commenter stated that 
    acid-resistant protective coatings should be applied. The commenter 
    further stated that several manufacturing and repair shops are using 
    non-acid resistant latex coatings under polyurethane-foam insulations. 
    Another commenter suggested that the rule should be clarified to 
    exclude tanks or jackets manufactured with self-protective materials 
    such as stainless steel. Still another commenter asked RSPA to consider 
    adopting a recommended practice for applying protective coatings on 
    tank cars that is now under development by the National Association of 
    Corrosion Engineers.
        With regard to these comments, this final rule simply modifies 
    Secs. 179.100-4 and 179.200-4 by removing the exception for 
    polyurethane-foam insulations. Each of the current sections, and the 
    proposed rule, only require a protective coating on a carbon steel tank 
    shell and tank jacket. Concerning the comment on acid-resistant 
    coatings, RSPA agrees that applied coatings should prevent any 
    corrosive attack to the tank metal. RSPA and FRA will explore, in 
    cooperation with the AAR, CMA, and RPI, the need for and development of 
    acid-resistant coating standards.
        NTSB commented that the proposed rule does not sufficiently address 
    the potential problem of existing tank cars. NTSB further noted that a 
    requirement to apply a protective coating on an existing tank car, only 
    when the jacket is removed to repair a tank, cannot ensure that 
    corrosion problems will be detected before the tank corrodes through 
    and releases its lading. NTSB stated that, at a minimum, tank cars 
    currently in use without protective coatings should be inspected 
    periodically for corrosion damage and tank cars found with corrosion 
    damage should be required to have appropriate repairs.
        We agree with NTSB, and in this final rule require, under Docket 
    HM-201, new inspection intervals for materials that are corrosive to 
    the tank and a thickness performance measurement to ensure that the 
    tank shell is not corroded below the minimum shell thickness as 
    prescribed by the AAR. RSPA and FRA believe that HM-201 is responsive 
    to NTSB's concerns.
        In this final rule, RSPA is requiring protective coatings for all 
    new tank cars and for existing tank cars when a repair to the tank car 
    requires the complete removal of the jacket, as suggested by 
    commenters.
    
    K. Halogenated Organic Compounds (HOC)
    
        To address a 1991 NTSB safety recommendation,14 RSPA proposed 
    in the NPRM to require the use of a tank car with enhanced puncture 
    resistance if the tank is used to transport one or more of the 100 HOC 
    compounds listed in 40 CFR Part 268 Appendix III. The Appendix III list 
    was developed by EPA pursuant to statute (42 U.S.C. 6924) in order to 
    prohibit the land disposal of certain compounds having a carbon-halogen 
    bond, and that have the potential to harm human health and the 
    environment (these EPA compounds were identified as the ``California 
    List'' under the statute [See also 40 CFR 268.32]).
    
        \14\Transportation of Hazardous Materials by Rail, National 
    Transportation Safety Board Safety Study, Report NTSB/SS-91/01, 
    National Transportation Safety Board, Washington, D.C. (Safety 
    Recommendations R-91-11 and R-91-12).
    ---------------------------------------------------------------------------
    
        Many commenters opposing regulation of the EPA compounds suggested 
    that RSPA should continue to only regulate the compounds identified as 
    hazardous substances in Appendix A to Part 172. Commenters further 
    suggested that DOT should not consider the HOC concentration threshold 
    for those compounds. Several commenters stated that the regulatory 
    action proposed by RSPA is unnecessary, that RSPA should discontinue 
    its efforts to regulate these EPA compounds, and that RSPA should not 
    consider extending enhanced tank car standards to those carrying the 
    more than 1,000 chemicals prohibited from land disposal.
        API, CMA, and several other commenters suggested that the threshold 
    quantities for the EPA compounds are too low for transportation 
    purposes. The EPA threshold in 40 CFR 268.32 is 1,000 milligrams per 
    liter (mg/l) for liquids and 1,000 milligrams per kilogram (mg/kg) for 
    solids.
        CMA furnished a benefit/cost analysis, prepared by Reebie 
    Associates, that used 1992 TRAIN II data; thereby updating the previous 
    work performed by AAR, CMA, and RPI addressed in the NPRM. The CMA 
    report shows that a total of 3,893 tank cars transported an EPA 
    compound. CMA's list and the number of tank cars used for such 
    compounds follows:
    
    ------------------------------------------------------------------------
                                     AAR/CMA/RPI                            
        Hazardous      CMA's 1992     agreement   Currently in              
       substances      population     (based on     pressure      Remaining 
                                     1988 data)     tank cars               
    ------------------------------------------------------------------------
    1,1-                                                                    
     Dichloroethylen                                                        
     e..............             1  ............  ............             1
    1,2-                                                                    
     Dichloroethane.           236           236  ............  ............
    1,2-                                                                    
     Dichloropropane            31  ............  ............            31
    Carbon                                                                  
     tetrachloride..           312           312  ............  ............
    Chlordane.......            10  ............  ............            10
    Chlorobenzene...           105           105  ............  ............
    Chloroethane                                                            
     (ethyl                                                                 
     chloride)......           106  ............           106  ............
    Chloroform......           227           227  ............  ............
    Chloropropene...             7  ............  ............             7
    CIS 1,3-                                                                
     dichloropropane            42  ............  ............            42
    Dichlorodifluoro                                                        
     methane........           224  ............           224  ............
    Dichlorofinrorom                                                        
     ethane.........             2  ............  ............             2
    Dichlorofluorome                                                        
     thane..........             1  ............  ............             1
    Hexachlorocyclop                                                        
     entadiene......             8  ............             8  ............
    
    [[Page 49057]]
                                                                            
    Methylene                                                               
     chloride.......             2             2  ............  ............
    o-                                                                      
     Dichlorobenzene            15            15  ............  ............
    p-                                                                      
     Dichlorobenzene            82            82  ............  ............
    Pentachloropheno                                                        
     l..............            10  ............  ............            10
    Tetrachloroethan                                                        
     e..............            13            13  ............  ............
    Trichlorobenzene             6  ............  ............             6
    Trichloromonoflu                                                        
     oromethane.....             4  ............             4  ............
    Vinyl chloride..         2,449  ............         2,449  ............
                     -------------------------------------------------------
        Totals......         3,893           992         2,791           110
    ------------------------------------------------------------------------
    
    
    
        Commenters stated that RSPA should not include materials that are 
    transported as a solid because, when released, the clean up of these 
    materials is easily achieved. This statement assumes that accidents 
    will not occur near lakes, rivers or streams, or that rainfall will not 
    carry solid residue to such water sources. It is RSPA's and FRA's 
    experience that these types of accidents can occur as evidenced by the 
    metam sodium spill in the Sacramento River in California.
        As discussed in the NPRM, these materials were also evaluated by 
    the AAR in an effort to identify materials that have the potential to 
    harm human health and the environment. The AAR analyzed the EPA 
    compounds using a computer model based on EPA and standard chemical 
    dispersion equations. The AAR model describes a method of evaluating 
    the relative environmental hazard of chemicals shipped in tank 
    cars.15 In addition to the computer model, the AAR surveyed the 
    railroad industry for the clean-up costs associated with a spill of an 
    EPA compound. The AAR considered in their analysis: (1) Compounds that 
    were permitted in non-pressure tank cars by the DOT in 1988; (2) at 
    least one shipment of the compound reported to TRAIN II16 in 1988; 
    (3) the compounds with an EPA reportable quantity (RQ) of less than 
    1,000 pounds in 1988; (4) the compounds prohibited from land disposal 
    by the EPA; and (5) the compounds suggested by the railroads' hazardous 
    materials or environmental staff, or the AAR contractor on the project. 
    The results of the 1988 survey identified 10 compounds, transported in 
    class DOT 111A tank cars at that time, that pose a potential threat to 
    human health and the environment. These compounds were:
    
        \15\Lowenbach, William, A., Consequence Models of Hazardous 
    Materials Releases on Railroads, Association of American Railroads 
    (1989), Washington, D.C.
        \16\The Association of American Railroads (AAR) data network, 
    Tele-Rail Automated Information Network (TRAIN II), collects 
    information on approximately 90 percent of the rail traffic 
    originating and terminating in the United States. Users of the 
    network can trace individual car movements or gather information on 
    a particular cargo moving by rail. The AAR uses the data to develop 
    statistical trends in both car movement and commodity flow.
    
    Carbon tetrachloride
    Chlorobenzene
    Chloroform
    Dichlorobenzene
    Ethylene dibromide (1,2-Dibromomethane)
    Ethylene dichloride (1,2-Dichloroethane)
    Methyl chloroform (1,1,1-Trichloroethane)
    Methylene chloride (Dichloromethane)
    Perchloroethylene (Tetrachloroethene)
    Trichloroethylene (Trichloroethene)
    
        The results of AAR's analysis show that, within the last 10 years, 
    the release of these compounds in railroad accidents has resulted in 
    environmental clean-up costs exceeding $50 million. Even though these 
    materials accounted for less than one percent of the total volume of 
    hazardous materials, their releases accounted for 60 percent of all 
    railroad environmental clean-up costs. Based on the results of the 
    analysis, the AAR, CMA, and RPI have agreed that by January 1, 2000, 
    these 10 compounds should be transported only in a DOT 105S200W or a 
    DOT 112S200W tank car manufactured from AAR TC-128 normalized steel. 
    One of the 10 compounds, ``ethylene dibromide,'' is a compound that is 
    poisonous by inhalation (Zone B).
        As shown by CMA, 3,893 tank cars were used to transport these ``EPA 
    compounds''; of that total, ``chloroethane,'' 
    ``dichlorodifluoromethane,'' ``hexachlorocyclopentadiene,'' 
    ``trichloromonofluoromethane,'' and ``vinyl chloride'' represent 2,791 
    tank cars, or 72 percent of the total. Because the packaging 
    authorizations for these compounds currently require the use of classes 
    DOT 105J, 112J, 112T, 114J, 114T tank cars, these tank cars currently 
    meet the proposed standard.
        As noted above, AAR, CMA, and RPI agreed to use only DOT 105S200W 
    and 112S200W (or better) tank cars: These compounds are transported in 
    992 dedicated tank cars. CMA identified an additional 110 tank cars 
    that are used to transport an EPA compound, but lie outside of the 
    industry agreement. Because these 110 additional tank cars represent a 
    potential risk to human health and the environment, RSPA believes it is 
    reasonable to require the same level of protection for the additional 
    tank cars identified by CMA, based on the 1992 TRAIN II data, as those 
    identified by the AAR, CMA, and RPI, based on the 1988 TRAIN II data. 
    It simply cannot be argued that the shipment of an EPA compound 
    identified after 1988 poses less risk in transportation than if the EPA 
    compound would have been identified by the AAR, CMA, and RPI in 1988. 
    Furthermore, because the AAR, CMA, and RPI agreement does not preclude 
    the use of a non-protected tank car in transportation by any one member 
    or nonmember of the agreement, such cars may still be used.
        After considering each of the comments, RSPA agrees it should only 
    regulate those EPA compounds listed in the HMR. After reviewing the 100 
    EPA compounds (listed in 40 CFR 268 Appendix III), RSPA found that all 
    but 16 of the compounds are currently identified as a hazardous 
    substance. The 16 compounds are:
    
    Bis(2-chloroethoxy)ethane
    Bis(2-chloroethyl)ether
    Bromomethane
    2-Chloro-1,3-butadiene
    3-Chloropropene
    1,2-Dibromomethane
    Dibromomethane
    Hexachlorodibenzo-p-dioxins
    Hexachlorodibenzofuran
    Iodomethane
    Methylene chloride
    Pentachlorodibenzo-p-dioxins 
    
    [[Page 49058]]
    
    Pentachlorodibenzofuran
    Tetrachlorodibenzofuran
    Tribromomethane
    1,2,3-Trichloropropane
    
    More than 30 of the compounds are listed by proper shipping name in the 
    Sec. 172.101 Table. As a group, the EPA compounds include: volatiles 
    (35 compounds); semivolatiles (33 compounds); organochlorine pesticides 
    (20 compounds); phenoxyacetic acid herbicides (3 compounds); PCBs (all 
    PCBs); and dioxins and furans (7 compounds).
        Based on this review, this final rule requires that, when the EPA 
    compounds listed in the HMR are transported in large capacity tank 
    cars, the tank cars must conform to a limited and designated 
    specification with greater protection in accidents. Also, to ensure the 
    proper identification and packaging of these materials, RSPA is listing 
    (with the exception of Class 2 materials [compressed gases], PIH 
    materials, and the 16 materials not now identified as hazardous 
    substances) in Sec. 173.31(f), all EPA compounds listed in 40 CFR Part 
    268, Appendix III. As explained elsewhere in the preamble, RSPA is no 
    longer authorizing Class 2 materials or PIH materials in low-pressure 
    tank cars, e.g., class DOT 111A.
        Because RSPA is listing the EPA halogenated-organic compounds as 
    hazardous substances, in this final rule, the threshold quantity is the 
    reportable quantity of the hazardous substance. As an example, if the 
    material in the tank car (including its mixtures and solutions) (1) is 
    listed in Appendix A to Sec. 172.101, (2) is in a quantity that equals 
    or exceeds the reportable quantity (RQ) of the material listed in 
    Appendix A, and (3) is listed in Sec. 173.31(f), it must be transported 
    in a tank car of limited and designated specification to offer greater 
    protection in the event of an accident.
        In the NPRM, RSPA proposed that any of the halogenated organic 
    compounds identified by EPA must be transported in a tank car meeting 
    DOT 105S200W, DOT 112S200W with an 11-gauge metal jacket, or DOT 
    112S340W without a metal jacket. RSPA stated that the metal jacket and 
    head protection on these tank cars blunt the impacting forces from 
    couplers, wheels, track, and other objects along the carrier's right-
    of-way. According to FRA research, this blunting effect is directly 
    proportional to the thickness of the tank jacket or head shield and is 
    effective in preventing tank punctures.17 The NPRM would have 
    allowed the use of any class DOT 105 or DOT 112 tank car regardless of 
    its date of construction. Older tank cars would be allowed, including 
    those constructed with an older steel specification, such as ASTM A212 
    Grade B. Because the older steels have less puncture resistance than 
    the steels currently in use, the NPRM proposed the use of an external 
    metal jacket to help blunt any impacting force, as a result of an 
    accident, to the tank shell.
    
        \17\Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture 
    Resistance Evaluation, Report DOT/FRA/ORD-92-11, Federal Railroad 
    Administration (1992), Washington, D.C.
    ---------------------------------------------------------------------------
    
        At the January 6, 1994, public hearing, a commenter asked RSPA to 
    consider the use of a non-jacketed DOT 112S200W tank car, provided that 
    the tank car was constructed from an AAR normalized high-strength steel 
    specification, AAR TC-128. This steel specification has high tensile 
    and yield strength. In addition to the higher tensile and yield 
    strengths, commenters stated that normalization of the steel adds extra 
    puncture resistance. A commenter further stated that a tank car 
    constructed from the AAR's TC-128 steel specification would provide a 
    level of puncture resistance comparable to that of tank cars proposed 
    for use in the NPRM, and would also render a indisputable benefit/cost 
    ratio. Upon further review, RSPA agrees that a tank car constructed 
    from AAR TC-128, normalized, would provide a level of puncture 
    resistance equivalent to a tank car constructed from any steel 
    specification proposed in the NPRM. In this final rule, RSPA has 
    provided for the use of a DOT 112S200W (non-jacketed tank car) 
    constructed from AAR TC-128 normalized steel as an authorized 
    packaging, as suggested by the commenter.
    
    L. Implementation of New Requirements
    
        In the NPRM, RSPA proposed two implementation dates. Under ``Option 
    A,'' most of the compliance dates were set at 10 years from the 
    effective date of this final rule. This is a period that also coincides 
    with the duration frequently specified in typical full-term tank car 
    leases, whether a true lease or a financing vehicle; and with the 
    ``thorough inspection'' interval for tank cars in Interchange Rule 
    88.B.2.18 Under ``Option B,'' RSPA proposed that certain tank car 
    types and car/commodity combinations be considered for shorter retrofit 
    periods, with 5 years given to bring existing cars into compliance. For 
    instance, aluminum and nickel tank cars are more vulnerable to 
    puncture, and tanks used for transporting PIH materials present special 
    hazards.
    
        \18\Field Manual of the Interchange Rules, adopted by the 
    Association of American Railroads, Mechanical Division, Washington, 
    D.C., 1992. At intervals not to exceed 10 years, major components of 
    the car must be inspected, including body bolsters and center 
    plates, center sills, crossbearers, crossties, draft systems and 
    components, end sills, side sills, and trucks.
    ---------------------------------------------------------------------------
    
        Option A was supported by commenters. Although urging RSPA to adopt 
    the 10-year time limit, RPI stated that, because of start-up 
    complexities, it will not be reasonable to accomplish this on a 10-
    percent per year basis. Instead, RPI suggested that its members were 
    willing to modify 50 percent of the fleet in the first 5 years and 50 
    percent in the second 5 years. This accomplishes the desired goal while 
    minimizing scheduling problems and maximizing efficiency.
        Option B was supported by NTSB who stated that RSPA should require 
    tank-head protection, within 5 years, for all class DOT 105 tank cars 
    having capacities of less than 70 kl (18,500 gallons) when used to 
    transport a Division 2.1 material (flammable gas).
        Most commenters supported the 10-year modification program for 
    existing tank cars. RSPA believes, however, that a 5-year modification 
    program is more appropriate for class DOT 105 tank cars that have a 
    capacity less than 70 kl (18,500 gallons) when used to transport a 
    Division 2.1 material. Mandating an accelerated modification program 
    for these particular tank cars will ensure that those cars presenting 
    the greatest risk are modified first. Therefore, this final rule 
    requires that each tank car built on or after the effective date of 
    this final rule conform to this final rule. For tank cars built prior 
    to the effective date, the phase-in period is 10 years: at least 50 
    percent of the fleet in the first 5 years and the balance in the second 
    5 years. The phase-in-period for tank cars transporting a Division 2.1 
    material is 5 years, with at least 50 percent within 2\1/2\ years and 
    the balance in the second 2\1/2\ years. For existing tank cars 
    constructed with an internal self-energized manway located below the 
    liquid level of the lading, the compliance date is the effective date 
    of this final rule.
    
    III. Docket HM-201--Detection and Repair of Cracks, Pits, Corrosion, 
    Lining Flaws and Other Defects of Tank Car Tanks
    
    A. Background
    
        On September 16, 1993, RSPA published in the Federal Register a 
    NPRM under Docket HM-201; Notice No. 93-15 [58 FR 48485]. The NPRM 
    contained proposals to: (1) require the development and implementation 
    of a quality assurance program (QAP) at each facility that builds, 
    repairs, or ensures the structural integrity of tank 
    
    [[Page 49059]]
    cars; (2) require the use of non-destructive testing (NDT) techniques 
    in lieu of the current periodic hydrostatic pressure tests for fusion 
    welded tank cars to more adequately detect cracks in principal 
    structure elements (PSE), the failure of which could cause catastrophic 
    failure of the tank; (3) require thickness measurements of tank cars; 
    (4) allow for the continued use of tank cars with limited reduced shell 
    thicknesses; (5) increase the inspection and test intervals for tank 
    cars; and (6) clarify the tank car pretrip inspection requirements. 
    Readers are referred to the NPRM preamble for a complete background, 
    including a more extensive discussion of issues and citations to 
    research data summarized in the final rule.
        RSPA received 31 comments in response to the NPRM from members of 
    the various industries that own, lease, transport, or use tank cars. 
    RSPA and FRA have given full consideration to all comments in the 
    development of this final rule. Following is a summary of the written 
    comments, a summary of the final rule, and the actions taken by RSPA 
    and FRA in this final rule:
    
    B. Damage-Tolerance Fatigue Evaluations
    
        In 1992, the NTSB issued a report on the inspection and testing of 
    tank cars. The report disclosed that many tank car defects are not 
    routinely detected. These defects may suddenly grow to a critical size 
    resulting in failure of the tank car. The NTSB recommended that FRA and 
    RSPA develop requirements for the periodic inspection and tests of tank 
    cars to help ensure the detection of cracks before the cracks propagate 
    to a critical length. Such requirements would establish inspection and 
    test intervals based on the defect size detectable by the inspection 
    and test method used and on the stress level and crack propagation 
    characteristics of the PSE based on a ``damage-tolerance'' approach. 
    The Federal Aviation Administration (FAA) defines a structure as damage 
    tolerant if the structure has been evaluated to ensure that, should 
    serious fatigue, corrosion, or accidental damage occur within the 
    operational life of the structure, the remaining structure can 
    withstand reasonable loads without failure or excessive structural 
    deformation until the damage is detected (FAA Advisory Circular AC No. 
    25.571-1A). Damage-tolerance assumes that flaws exist in the structure 
    and that the design of the structure is such that these flaws will not 
    grow to a critical size and cause catastrophic failure to the structure 
    within a specified damage detection period. The damage detection period 
    depends on the characteristics of each PSE, each element's 
    susceptibility to severe corrosive environments, the inspectability of 
    each element, the inspection method, and procedures used and 
    maintenance practices.
        In the NPRM, RSPA proposed to allow tank car owners to use an 
    alternative inspection and test procedure or interval based on the 
    completion of a damage-tolerance fatigue evaluation. The evaluation 
    procedures would be reviewed by the AAR and approved by the Associate 
    Administrator for Safety, FRA. As stated in the NPRM, FRA believes that 
    some tank car owners may be able to reduce inspection and test costs by 
    using damage-tolerance fatigue evaluation procedures that incorporate: 
    (1) In-service inspection and test using techniques such as ultrasonic 
    or acoustic emission; (2) sampling of individual designs with a 100 
    percent inspection and test of the design if a crack is found; (3) 
    inspection and test intervals unique to each tank car component; and, 
    (4) inspection and test intervals based on the degree of risk a 
    material poses (i.e., high risk materials have shorter inspection and 
    test intervals than those with low risks).
        Most commenters stated that the damage-tolerance approach is a 
    significant step toward advancing the detectability of defects and well 
    suited to a tank car and its associated structure. They suggested that 
    RSPA and FRA expand the damage-tolerance approach, for fatigue, to 
    include other types of damage mechanisms, such as corrosion, corrosion 
    fatigue, original fabrication defects, stress corrosion cracking, 
    impact damage, and damage caused by an accident.
        RSPA and FRA agree that the use of a damage-tolerance approach to 
    periodic inspection and test of tank cars would substantially increase 
    the likelihood of the detection of cracks and crack-like defects before 
    such defects propagate to a critical size. RSPA and FRA also believe 
    that the inspection interval for each PSE should be based on the 
    inspection method used, the stress level in each PSE, and the crack 
    propagation characteristics of each PSE.
        The agencies realize, however, that in order to fully implement a 
    damage-tolerance program, it will take years for each owner or 
    manufacturer of a tank car to analyze each element on the tank car, and 
    to support the results of such analysis with test evidence and service 
    experience. FRA is currently working with the AAR Tank Car Committee, 
    the RPI, tank car owners, lessors, and manufacturers to develop 
    acceptable non-destructive testing techniques, and to develop an 
    inspection and test program based on damage-tolerance principles. These 
    programs include finite element analysis of the stub sill and its 
    attachment to the tank shell to identify the PSE on the tank car that 
    should be examined, over-the-road tests to define the typical 
    environmental loading spectrum expected in service, and a damage-
    tolerance evaluation of the structure.
        In this final rule, RSPA is revising the regulatory text for the 
    damage-tolerance fatigue evaluation proposed in Sec. 180.509(k). This 
    revised requirement provides that an acceptable damage-tolerance and 
    fatigue evaluation include other types of damage mechanisms and is 
    supported by test evidence and, if available, by service experience.
    
    C. Inspection and Test Intervals
    
        FRA found that cracks may reach a critical size in a PSE within 
    about 400,000 miles of railroad service [see ``Owners of Railroad Tank 
    Cars; Emergency Order Requiring Inspection and Repair of Stub Sill Tank 
    Cars,'' (Emergency Order Number 17) 57 FR 41799, September 11, 1992]. 
    To ensure against premature failure, common procedures for NDT allow 
    for two opportunities to inspect an item before predicted failure. 
    Because tank cars travel an average of about 18,000 miles per year and 
    most cracks become critical at about 400,000 miles of railroad service, 
    in the NPRM, RSPA proposed an inspection and test interval, based on a 
    simplified damage-tolerance evaluation, of 10 years to allow for two 
    opportunities to inspect an item before predicted failure.
        For the sake of efficiency, and to increase safety margins for most 
    cars, RSPA proposed to implement the 10-year inspection and test 
    interval starting at what would otherwise be the next scheduled tank 
    hydrostatic pressure test. For tank cars within a 20-year test cycle, 
    RSPA proposed that the next inspection and test date be the publication 
    date of this rule plus one half of the remaining years to what would 
    otherwise be the next scheduled tank hydrostatic test. After that the 
    tank would require an inspection and test on a 10-year interval.
        For materials corrosive to the tank and shipped in non-lined or 
    non-coated tank cars, RSPA proposed an inspection and test interval 
    based on the lower of (1) the corrosion rate of the material on the 
    tank shell or (2) the fatigue life of the tank structure as discussed 
    above. RSPA and FRA developed a test interval to ensure that the 
    calculated thickness of the tank at the next inspection and 
    
    [[Page 49060]]
    test will not fall below the proposed allowable minimum wall thickness. 
    The inspection and test interval in this case is calculated by 
    subtracting the actual thickness (measured at the time of construction 
    or any subsequent inspection and test) from the allowable minimum 
    thickness and then dividing that difference by the corrosion rate of 
    the hazardous material on the tank. Consequently, as the shell 
    thickness corrodes throughout the service-life of the tank, the tank 
    must receive an inspection and test more frequently.
        Commenters supported the proposed inspection and test program for 
    most tank cars. They suggested, however, that RSPA consider the 
    availability of tank car facility space and the practicality of 
    implementing the new inspection and test and quality assurance programs 
    without immobilizing a large number of tank cars. In particular, 
    commenters suggested that RSPA not reduce the inspection and test 
    intervals for tank cars constructed during the 1975-1979 period that 
    are now subject to a 20-year hydrostatic pressure test interval. As 
    proposed, these particular tank cars become due for inspection and test 
    during the years 1995 through 1997. A major oil company stated that 
    these particular tank cars represent at least 20 percent of its tank 
    car fleet.
        Several commenters stated tank cars used to transport chlorine, 
    unlike other tank cars, are currently tested every two years. As such, 
    all 8,000 tank cars in chlorine service would have to be brought in 
    conformance with the new inspection and test requirements within two 
    years. One company stated that it maintains 3,000 tank cars in chlorine 
    service and it would have to inspect 5.7 tank cars per day, which may 
    not be feasible because companies must first determine efficient 
    inspection techniques and provide training to inspection personnel. 
    Commenters further argue that because tank cars that transport chlorine 
    have an insulation system and a metal jacket, the inspectability of 
    certain PSE on these tank cars is difficult; accordingly, RSPA should 
    not mandate the new requirements in the short-term until the industry 
    and the government specify the acceptable NDT techniques for inspecting 
    tank cars that have metal jackets.
        The RPI suggested that RSPA phase in the new procedures slowly by 
    beginning with tank cars without a metal jacket and then tank cars 
    having a metal jacket when appropriate inspection techniques are 
    developed. Although RPI did not explain the basis for its comment, RSPA 
    and FRA assume that the reason behind RPI's comment is the difficulty 
    of inspecting PSE on a tank car having an insulation system covered by 
    a metal jacket or a thermal protection system; consequently, tank car 
    facilities will need time to develop the inspection methods and to 
    train inspection personnel on the use of those methods. Only after 
    identifying the appropriate inspection method and by training 
    inspection personnel, will there be a high probability of defect 
    detection.
        Several commenters requested that RSPA not require, in proposed 
    Sec. 180.509(b)(3), an inspection and test [requalification] of the 
    tank each time it is transferred into or out of a service that is 
    corrosive to the tank, which one commenter stated could occur 4 times 
    per month. Another commenter stated that the program is redundant with 
    proposed Sec. 180.509(c)(3)(ii) and, therefore, the section should be 
    deleted. The Chemical Manufacturers Association (CMA) suggested that 
    RSPA amend the proposal to allow for routine transfers, so long as the 
    tank car is within the established intervals for the periodic 
    inspection requirements. A commenter suggested that localized 
    modifications to a tank, such as modifying nozzles or bottom outlets, 
    should not subject the tank to a complete requalification.
        Based on the comments received, RSPA is not adopting proposed 
    paragraphs (b) (3) and (4). Paragraphs (b) (5) and (6) are renumbered 
    accordingly.
        RSPA and FRA also agree that local repairs or modifications should 
    not subject the tank to the full inspection and test program, because 
    the repair or modification must be done according to Appendix R of 
    AAR's Specifications for Tank Cars. Appendix R specifies the procedures 
    for repairs, alterations, and conversions of tank cars and the 
    appropriate non-destructive testing method to ensure that the repairs, 
    alterations, or conversions were performed correctly.
        RSPA and FRA agree that the new inspection and test methods, 
    combined with other FRA mandated inspection programs, may cause a 
    tremendous backlog of tank cars awaiting inspection. Therefore, to 
    maintain an acceptable level of safety, but also to allow for an 
    orderly and acceptable phased-in NDT inspection and test program, RSPA 
    will delay the compliance date of this final rule for 24 months for 
    tank cars without metal jackets and 48 months for tank cars having a 
    metal jacket or a thermal protection system. Before the compliance 
    date, tank cars may be given an inspection and hydrostatic test in 
    accordance with the current requirements or the requirements contained 
    in this final rule. After the compliance date, each tank car must be 
    given an inspection and test according to the requirements contained in 
    this final rule on or before the next scheduled tank hydrostatic 
    pressure test date.
    
    D. High-Mileage Tank Cars
    
        FRA realizes that some tank cars can travel in excess of 18,000 
    miles each year and, by doing so, the tank cars may reach 200,000 miles 
    of railroad service before their first periodic inspection and 400,000 
    miles before their second.
        The NTSB expressed its concerns that the proposed regulations 
    recommend, but do not require, more frequent inspections and tests for 
    tank cars with mileage rates that exceed the average. Further, because 
    there is no requirement to maintain cumulative mileage on individual 
    tank cars, the NTSB expressed concern that high-mileage tank cars would 
    not be identified for the more frequent inspections and tests, thereby 
    increasing the possibility of a non-detected fatigue crack propagating 
    and causing a structural failure within the 10-year inspection and test 
    cycle.
        RSPA and FRA agree with the NTSB that high-mileage tank cars should 
    receive an inspection and test prior to reaching 200,000 miles of 
    railroad service. However, no requirement for the maintenance or 
    retention of car mileage records was proposed. Because car owners keep 
    records of car mileage, the owners can ensure that tank cars having 
    high-mileage are inspected more frequently than the inspection and test 
    intervals adopted in this final rule. Current Sec. 173.24(b) provides 
    that each package used for the shipment of hazardous materials shall be 
    so designed, constructed, and maintained . . . so that under conditions 
    normally incident to transportation--the effectiveness of the package 
    will not be substantially reduced. Thus, an owner has an obligation to 
    ensure the continuing effectiveness of a tank car. This duty is not 
    unlike that of an owner of an automobile who replaces the tires on his 
    or her car when worn and not based on the warranty period. FRA will, 
    during its inspection activities, assess the need for a rulemaking (1) 
    to require owners to retain car mileage records and (2) to inspect 
    their tank cars before the cars accumulate more than 200,000 miles of 
    railroad service.
    
    E. NDT Techniques
    
        In the NPRM, RSPA proposed to require that the bottom shell of 
    fusion welded tank cars be inspected periodically by appropriate NDT 
    techniques, such as optically aided visual inspections, ultrasonic, 
    
    [[Page 49061]]
    radiographic, magnetic particle, and dye penetrant testing methods, in 
    lieu of hydrostatic pressure tests.
        All commenters supported the use of NDT techniques to assess the 
    integrity of a tank car in lieu of a hydrostatic pressure test. Several 
    commenters stated that the use of qualification procedures will require 
    formal NDT techniques in defined areas where no previous requirements 
    existed and will improve the overall safety of tank cars.
        Several commenters suggested that RSPA should authorize the use of 
    acoustic emission testing to qualify tank cars for further use. One 
    commenter stated that acoustic emission testing is widely used in the 
    chemical process industry to assure the integrity of pressure vessels, 
    tanks, and piping. The commenter further stated that the overall 
    reliability of a series of local tests (ultrasonic, dye penetrant, 
    radiography, etc.) is incorrectly compared with the reliability of a 
    single global test (hydrostatic, acoustic emission) and that 
    substitution of multiple local tests for a single global test may 
    endanger, rather than enhance the safe transportation of hazardous 
    materials.
        RSPA and FRA do not agree with the commenters's conclusion about 
    the potential danger of multiple local tests as compared with a single 
    global test. RSPA and FRA believe that multiple local tests, focusing 
    on known areas of tank car stress, have a safety advantage over single 
    global tests, at least with the current state of development of 
    acoustic emission testing in the tank car industry. The NDT methods 
    mandated by this rule are a safety improvement. As noted immediately 
    below, the agencies have underscored their belief in the potential 
    benefits acoustic emission testing offers by granting an exemption that 
    will permit its development and refinement in a railroad industry 
    context.
        Outside the scope of this rulemaking, but related to it by means of 
    subject matter, Monsanto Chemical Company applied for a DOT exemption 
    to use acoustic emission technology, in lieu of the current hydrostatic 
    retest, for the tank cars it owns. The procedures developed by Monsanto 
    to support its exemption were recently evaluated under a research 
    contract administered by the government of Canada. (McBride, S. L., 
    Acoustic Emission Tank Car Test Method Review & Evaluation, Transport 
    Canada Report No. TP 12140E (1994) Montreal, Quebec). The results of 
    that research show that Monsanto's acoustic emission testing procedures 
    appear to be sound. The report suggests, however, minor refinements in 
    the acoustic emission procedures. Taking this into account, RSPA issued 
    Monsanto an exemption on September 9, 1994 (DOT-E 10589). The following 
    companies were granted ``party to'' status on the Monsanto exemption: 
    Union Tank Car Company, Testing Associates, and Physical Acoustics 
    Corporation.
        This final rule does not include acoustic emission testing as an 
    authorized NDT technique. RSPA and FRA are committed, however, to 
    explore new technologies for inspecting and testing tank cars and will 
    continue to evaluate the possibly of authorizing the acoustic emission 
    testing procedure in the future. In support of this commitment, FRA 
    issued a research contract to further explore and refine the use of 
    acoustic emission testing procedure and other NDT techniques in 
    determining the integrity of insulation and lining covered welds of 
    tank cars.
    
    F. Leakage Test
    
        In the NPRM, RSPA proposed a leakage test that would include all 
    product piping with all valves and accessories in place and operative, 
    except that during the test the tank car facility would remove or 
    render inoperative any venting devices set to discharge at less than 
    the test pressure. As proposed, the test pressure would be maintained 
    for at least 5 minutes at a pressure of not less than 50 percent of the 
    tank test pressure.
        Most commenters opposed the proposed change to use 50 percent of 
    the tank test pressure as the standard, because these pressures, some 
    as high as 300 psig, would constitute an unsafe maintenance practice. 
    RSPA proposed the leak test to ensure that when valves, fittings, and 
    manway cover plates are replaced on a tank car after an inspection and 
    test, that valves and fittings are securely applied and in a ``leak-
    free'' condition under normal operating pressures. This will help 
    ensure against product leakage from a valve, fitting, or manway cover 
    plate should the vapor pressure of the commodity rise after the shipper 
    loads the tank car, normally on its first trip after an inspection and 
    test at a tank car facility.
        Berwind Railway Service Company suggested conducting the leak test 
    at 30 psig for tank cars having a test pressure less than or equal to 
    200 psig and 50 psig for tank cars having a tank test pressure greater 
    than 200 psig. AAR and RPI supported similar pressures. In the 
    commenters experience, pressures of this magnitude are effective in 
    ensuring that tank cars are released from tank car facilities in a leak 
    free condition.
        The suggested leak test pressures are similar to the leak test 
    pressures currently used to qualify highway cargo tanks. For example, 
    the leak test for a cargo tank may not be less than 80 percent of the 
    tank design pressure (or its maximum allowable working pressure 
    [MAWP]); or, the maximum normal operating pressure when the cargo tank 
    has a MAWP equal to or greater than 6.9 Bar (100 psig); or, 4.1 Bar (60 
    psig) when the cargo tank is used to transport liquefied petroleum gas. 
    After considering the comments, RSPA and FRA agree that a lower leak 
    test pressure would provide an adequate leak test with less risk to 
    persons performing the test. In this final rule, RSPA is requiring a 
    leak test at 30 psig for tank cars having a test pressure less than or 
    equal to 200 psig and a leak test at 50 psig for tank cars having a 
    tank test pressure greater than 200 psig.
    
    G. Bottom Shell
    
        FRA has found that principal structural elements (PSE) located 
    within four feet of the bottom longitudinal centerline are susceptible 
    to fatigue cracking due to repeated loading conditions. Stress 
    concentrations in these areas may cause the formation of small cracks 
    that may not be detected under the current inspection and test 
    procedures. Because some defects may lie outside the area currently 
    defined as the bottom shell, such as those in the attachment welds of 
    bottom discontinuities, RSPA proposed, based on FRA's findings, to 
    revise the current definition of the bottom shell by enlarging the area 
    from 60.96 cm (two feet) to 121.92 cm (four feet) on each side of the 
    bottom longitudinal center line of the tank.
        The Chlorine Institute, CMA, and others agreed that experience has 
    shown that the bottom shell is prone to fatigue cracking. However, all 
    known fatigue-related defects have originated within two feet of the 
    bottom longitudinal centerline of the tank, which is the area most 
    highly stressed in train operation.
        RPI's comments referenced a report, ``Final Phase 14 Report on the 
    Stub Sill Buckling Study,'' that shows, when stub sill tank cars are 
    subjected to static and dynamic (impact) loads, a complex biaxial 
    stress field results in the shell area between the stub sills. The 
    report shows that measured strains are due to a combination of axial 
    compression and bending components and at high loads, high magnitude 
    strains occur over certain localized areas. The results of the RPI 
    report show that the stresses on the bottom longitudinal centerline of 
    the tank are about 1.8 times the magnitude of the stresses occurring 
    from two to 
    
    [[Page 49062]]
    four feet from the bottom longitudinal centerline.
        RPI further stated that fatigue damage increases exponentially with 
    the ratio of stress ranges and that crack initiation and propagation 
    within the area of two feet from the bottom longitudinal centerline is 
    much faster than the area two to four feet from the bottom longitudinal 
    centerline. Based on the Phase 14 report, RPI suggests that the bottom 
    shell definition should encompass an area that lies below the 
    horizontal plane of two longitudinal parallel lines extending two feet 
    on each side from the bottom longitudinal centerline, through the tank 
    heads. K & K Consultants, Incorporated, who also commented on the Phase 
    14 report provided a summary of the data and explained that the 
    principal stresses in the tank are approximately parallel to the bottom 
    longitudinal centerline, and that the stresses tend to decrease 
    circumferentially away from the bottom longitudinal centerline.
        After consideration of the comments, RSPA and FRA agree that four 
    feet on each side of the bottom longitudinal centerline is overly 
    restrictive. Therefore, the current definition of bottom shell in 
    Sec. 171.8 is retained.
    
    H. Structural Integrity Inspections
    
        In the NPRM, RSPA proposed a structural integrity inspection and 
    test on all circumferential and longitudinal welds and welded 
    attachments on the bottom of the tank, within 121.92 cm (4 feet) on 
    each side of the bottom tank centerline, using one or more non-
    destructive test methods. As explained above under the heading ``bottom 
    shell,'' several commenters stated that this area is more appropriately 
    defined as within 60.96 cm (2 feet) on each side of the bottom tank 
    centerline.
        FRA has learned that some high-stressed areas lie outside of the 
    60.96 cm (2 feet) bottom longitudinal centerline area. Brake pipe 
    supports, body stiffeners, tank anchors, and other attachments and 
    structures having large welds are examples of high-stressed areas that 
    may lie outside of this area. As a general matter, the HMR require 
    reinforcing pads for these high-stressed areas between external 
    brackets and tank shells if an attachment weld exceeds 6 linear inches 
    of 0.64 cm (0.25 inch) fillet weld per bracket or bracket leg 
    (Secs. 179.100-16 and 179.200-19). In its Tank Car Manual, AAR requires 
    the use of a reinforcing pad if a bracket or attachment welded directly 
    to the tank could cause damage to the tank, either through fatigue, 
    over-stressing, denting, or puncturing in the event of an accident. If 
    a reinforcing pad is used under a bracket or attachment, AAR specifies 
    that the pad shall not be less than 0.64 cm (0.25 inch) thick. For 
    further information, see sections E15.01 and E15.02 of AAR Tank Car 
    Manual.
        Further, in an investigation of tank shell cracking, FRA found that 
    local areas of the tank shell near tank discontinuities are subjected 
    to the combination of live-load stress in addition to the residual 
    stress induced by reinforcement pad welds, and that this combination 
    makes the sensitivity of the welded area near the discontinuity and 
    reinforcing pad weld susceptible to fatigue crack propagation. After 
    performing residual stress measurements of retro-fitted tank car 
    weldments, AAR confirmed FRA's findings that significant tensile 
    stresses (on the order of 30,000 psi) occur in the vicinity of the 
    fillet welds having a throat size (weld depth) greater than 0.64 cm 
    (0.25 inch). In general, fillet welds larger than 0.635 cm (0.25 inch) 
    are considered structural welds, and AAR requires post weld heat 
    treatment when these welds, such as interior brackets, supports, and 
    reinforcement bar pads, have a throat thickness exceeding 0.635 cm 
    (0.25 inch). For further information see R17.01 of AAR Tank Car Manual.
        In its comments to the NPRM, the Sulphur Institute stated that 
    stress type defects may originate in some attachment fillet welds, such 
    as those greater than 0.64 cm (0.25 inch) that are currently located 
    outside of the current bottom shell definition. Examples given were 
    body stiffener and brake pipe support fillet welds.
        RPI gave similar comments by suggesting that the inspection of 
    attachment welds on the bottom of the tank should be limited to 
    structure welds, such as transverse fillet welds larger than 0.64 cm 
    (0.25 inch), the terminations of longitudinal fillet welds larger than 
    0.64 cm (0.25 inch), and tank shell butt welds within 60.96 cm (24 
    inches) of the bottom longitudinal center line and between the body 
    bolsters. When asked to clarify its comments, RPI told FRA that a 0.64 
    cm (0.25 inch) fillet weld refers to the leg-length (see also the 
    definitions of ``Size [fillet]'' and ``Full Fillet Weld'' in Section 
    W2.00 of AAR Tank Car Manual). Furthermore, RPI stated that limiting 
    the inspection and test requirements to fillet welds greater than 0.64 
    cm (0.25 inch), would exclude non-structural fillet welds, such as 
    those used to attach exterior heater coils.
        RSPA and FRA agree that the stress concentration effects around 
    structural attachments will cause the formation of fatigue cracks and, 
    if these cracks are not detected and repaired during routine 
    maintenance of the tank car, such cracks will grow to failure. In this 
    final rule, RSPA requires a structural integrity inspection and test in 
    those areas known to develop cracks. Such an inspection and test 
    includes transverse fillet welds greater than 0.64 cm (0.25 inch) 
    within 121.92 cm (48 inches) of the bottom longitudinal center line, 
    the termination of longitudinal fillet welds greater than 0.64 cm (0.25 
    inch) within 121.92 cm (4 feet) of the bottom longitudinal center line, 
    and all tank shell butt welds within 60.96 cm (2 feet) of the bottom 
    longitudinal center line. By limiting the required inspection to known 
    areas of crack initiation, RSPA and FRA can expect an increase in the 
    probability of defect detection, as well as an improvement in the 
    reliability of the inspection results and a reduction in inspection 
    costs.
        The Sulphur Institute commented that if the integrity of the 
    coatings or linings applied to protect tank car tank metal remains 
    acceptable, there should be no need to remove the coating or lining to 
    inspect the tank for structural integrity. The purpose of the 
    structural integrity inspection is to ensure the detection of fatigue 
    cracks before the cracks progress to a dangerous size, thereby reducing 
    the residual strength of the tank. In order to inspect each PSE to 
    confirm structure integrity, tank car facilities may need to remove 
    portions of the lining or coating. Owners may choose, however, to use a 
    non-destructive testing method that interfaces between different 
    materials, with effective penetration, so that there will be no need to 
    remove the coating or lining. Such non-destructive testing methods 
    include radiography and ultrasonics.
    
    I. Minimum Shell Thickness
    
        Recognizing that a tank car shell tends to decrease in thickness 
    over time, RSPA proposed in the NPRM a definite service-life shell 
    thickness requirement for all areas of the tank shell and heads. The 
    proposed minimum in-service shell thickness requirement was based, in 
    part, on an AAR-RPI report, ``Allowable Thickness Reduction from 
    Minimum Prescribed Thickness of Carbon Steel Tank Car Tanks,'' that 
    discussed the investigation of shell thickness below the Part 179 
    construction standard in certain areas. The RPI-AAR report considered 
    the effects of an overall or localized reduction in the tank wall 
    thickness from a principal mode of failure--failure of a tank car due 
    to the effects of fire, fatigue crack growth leading to fracture, and 
    failure of the tank due to puncture of the heads. The results of the 
    RPI-AAR report show that 
    
    [[Page 49063]]
    the effects of a slightly reduced shell thickness on tank cars used to 
    transport ``ethylene oxide,'' ``butadienes, inhibited,'' ``vinyl 
    chloride,'' ``propane,'' and ``propylene'' will not have a significant 
    effect on safety. The NPRM also proposed to allow localized areas of 
    thickness reduction to have a total cumulative surface perimeter not 
    exceeding 182.88 cm (72 inches), consistent with the current provisions 
    in Sec. 173.31(a)(11)(iv).
        In its comments to the NPRM, RPI suggested that the 72-inch 
    cumulative perimeter should apply to the bottom shell only. RPI further 
    stated that RSPA should allow the rest of the tank shell, excluding the 
    tank heads, to have an unlimited number of two foot perimeter 
    reductions, provided such areas of reduction are separated by at least 
    16 inches (twice the diameter of a circle having a 24 inch 
    circumference).
        AAR also suggested that the permitted local thickness reductions 
    for non-pressure tank cars should depend on cause. AAR thickness 
    reduction tables, endorsed by many commenters under an earlier 
    rulemaking, differentiated between corrosion and mechanical damage for 
    non-pressure tank cars (see ``Shippers Use of Tank Cars with Localized 
    Reductions in Shell Thickness,'' 54 FR 8336, 8337, February 28, 1989). 
    AAR further commented that there is no need to make a distinction 
    between the cause of damage for pressure tank cars because of the 
    stricter limits imposed on such cars. AAR proposed that, for non-
    pressure tank cars, RSPA should permit a 0.48 cm (0.188 inch) local 
    thickness reduction in the top shell and 0.32 cm (0.125 inch) local 
    thickness reduction in the bottom shell for corrosive damage. For 
    mechanical damage, RSPA should permit 0.32 cm (0.125 inch) local 
    thickness reduction in the top shell and a 0.16 cm (0.063 inch) local 
    thickness reduction in the bottom shell. AAR asserts that the stresses 
    from a given thickness reduction attributed to mechanical damage can be 
    greater than the same reduction attributed to corrosion damage, because 
    mechanical damage causes a more abrupt change in the thickness.
        After full consideration of the merits of these comments, RSPA and 
    FRA agree that there should be no overall limit on the amount of 
    surface area with localized reduced shell thicknesses, provided such 
    limitations apply only to the top shell of the tank and such areas are 
    separated by at least 16 inches. Also, RSPA is modifying the thickness 
    reduction table, as recommended by AAR, and endorsed by several 
    commenters, to differentiate between corrosion and mechanical damage.
        AAR commented that RSPA proposed, in Sec. 180.509(g), maximum 
    thickness reductions from the original thickness of the tank and not 
    the required thickness of the tank: a thickness specified in a chart 
    summarizing specification requirements (e.g., Sec. 179.101-1(a)), or 
    the result of a calculation (e.g., Sec. 179.100-6(a)). RSPA disagrees. 
    The proposed section in the NPRM states that--
    
    [a] tank car found with a thickness below the required minimum 
    thickness after forming for its specification, as stated in Part 179 
    of this subchapter, may . . . [emphasis added]
    
    AAR further stated that RSPA should include an explicit provision 
    enabling the owner of a tank car to ``downgrade'' [downrate] the car to 
    the point where the loss of thickness exceeds the maximum allowed by 
    the regulation. As RSPA stated in the NPRM under the preamble heading, 
    ``Safety System Inspections,''
    
    [n]othing in the regulations would preclude a tank car owner from 
    marking a tank as meeting a less stringent specification, such as 
    re-marking a specification DOT 112J tank car to a DOT 112S or 
    112J400W tank specification to a DOT 112J340W tank specification 
    when the tank car no longer conforms to the marked specification.
    
        Downrating is permissible and a tank car owner may mark a tank as 
    meeting a less stringent specification, such as marking a specification 
    112A340W tank car to a DOT 111A100W1 tank car when the tank, because of 
    its shell thickness, no longer conforms to the marked specification. 
    Owners are reminded that changing the marked specification also changes 
    the certificate of construction and, when so doing, they must follow 
    the procedures in Appendix R of AAR's Specifications for Tank Cars (see 
    Sec. 173.31(a)(4) and (f), and Sec. 179.6).
        In its comments, RPI proposed a standardized minimum inspection 
    pattern for conducting thickness tests. RPI suggests that thickness 
    readings should be taken at the bottom, one side (90 deg.), and the top 
    within 6-inches of each circumferential weld for each plate. RPI 
    further states that corresponding readings should also be taken along 
    the head circumferential weld seam and another reading at the center of 
    the tank head. This would result in 32 thickness readings for a four-
    ring tank. In addition to the tank shell, two readings would be taken 
    on the manway nozzle, the top unloading nozzle, and the sump. According 
    to RPI, if an inspector finds corrosion or other damage that reduces 
    the shell thickness, additional readings must be taken to more 
    specifically identify the damaged area.
        RSPA is not incorporating a written procedure for conducting 
    thickness measurements throughout the tank shell to increase the 
    probability of defect or corrosion detection. RSPA and FRA believe that 
    such procedures belong in the tank car owner's written maintenance 
    plans or AAR Specifications for Tank Cars. Throughout this rulemaking, 
    RSPA and FRA have developed a course of action that outlines where and 
    what to inspect, but not how to inspect. This approach allows each tank 
    car owner the flexibility to develop inspection and test procedures 
    appropriate for each unique tank car, or a series of unique tank cars 
    based on operating and maintenance experience.
    
    J. Lining and Coating Inspections and Tests
    
        In the NPRM, RSPA proposed an inspection and test requirement for 
    tank cars with linings and coatings. This would ensure that the lining 
    or coating is in proper condition for the transportation of hazardous 
    materials. As proposed, owners of lined or coated tank cars must 
    determine the periodic inspection interval and inspection technique for 
    the lining and coating, based on the owner's knowledge of the material 
    used. The owner would also maintain all supporting documentation used 
    to make such a determination, such as the lining or coating 
    manufacturer's recommended inspection interval and inspection 
    technique, at the owner's principle place of business. Further, the 
    supporting documentation used to make such inspection interval 
    determinations and the inspection technique would have to be made 
    available to FRA upon request.
        All commenters supported RSPA's proposed inspection and test 
    requirement for tank cars with linings and coatings. RPI suggested that 
    RSPA should specify ``owners of linings and coatings,'' as opposed to 
    the ``tank car owner,'' to determine the inspection and test technique 
    and interval--since most shippers own the tank car lining or coating as 
    opposed to the tank car owner. Mobil Oil Corporation and others 
    suggested that the regulation should only apply to linings and coatings 
    installed to protect the tank shell, as opposed to those applied for 
    lading integrity or quality.
        RSPA and FRA agree with RPI and are revising the proposed 
    requirements to incorporate RPI's suggestions. In this final rule, 
    owners of linings and coatings in tank cars must determine the 
    
    [[Page 49064]]
    periodic inspection interval and inspection technique for the lining 
    and coating, based on the owner's knowledge of the material used. This 
    will ensure that the lining or coating is in proper condition for the 
    transportation of hazardous materials. The owner must also maintain all 
    supporting documentation used to make such a determination, such as the 
    lining or coating manufacturer's recommended inspection interval and 
    inspection technique, at the owner's principle place of business. The 
    supporting documentation used to make such inspection interval 
    determinations and the inspection technique must be made available to 
    FRA upon request.
        Further, in Sec. 180.509, RSPA is revising paragraphs (c)(3)(i) and 
    (iii)(A) to require an inspection and test of the lining or coating 
    only when the lining or coating is applied to protect the tank shell 
    from a lading such as hydrochloric acid.
    
    K. Safety System Inspections
    
        In the NPRM, RSPA proposed to add explicit requirements for the 
    inspection of thermal protection systems, tank head puncture resistance 
    systems, coupler vertical restraint systems, and devices used to 
    protect discontinuities. If, after an inspection, one or more of these 
    systems do not conform to the applicable specification requirements 
    contained in Part 179, renewal or repair of the system is necessary to 
    continue the qualification of the tank car. RSPA received two comments 
    on this proposal, both indicating support.
        In this final rule, RSPA is adopting the requirements for the 
    inspection of these safety systems.
    
    L. Quality Assurance Program (QAP)
    
        In the NPRM, RSPA proposed to require that each tank car facility 
    establish a Quality Assurance Program (QAP) to detect non-conformities 
    during the manufacturing, repair, or inspection and test process. A 
    tank car facility means an entity that manufactures, repairs, inspects, 
    or tests tank cars to ensure that the tank cars conform to Parts 179 
    and 180, that alters the certificate of construction of the tank car, 
    or that verifies that the tank car conforms to the specification.
        All commenters endorsed the QAP proposal; however, several 
    commenters suggested that RSPA delay the effective date for at least 18 
    months so that tank car repair facilities will have the opportunity to 
    develop a QAP. In its comments, AAR supported RSPA's QAP requirements 
    and further stated that the QAP developed by RSPA is consistent with 
    AAR's quality assurance requirements.
        Several commenters asked RSPA to clarify whether or not a tank car 
    facility includes a shipper's loading facility where items such as 
    gaskets and manway bolts are normally inspected and replaced as part of 
    a ``pre-trip'' inspection. It is not the intention of RSPA to include 
    within the definition of a tank car facility a shipper's facility where 
    pre-trip inspections are performed. Generally, a tank car facility 
    evaluates the tank structure to ensure that, if serious fatigue, 
    corrosion, or accidental damage occurs within the inspection and test 
    interval, the remaining structure can withstand reasonable loads 
    without failure or excessive structural deformation. A shipper, on the 
    other hand, ensures by inspection that the tank is in proper condition 
    for transportation from point of origin to destination.
        Based on the comments received, RSPA is requiring each tank car 
    repair facility to develop a QAP that has the means to detect any 
    nonconformity in the manufacturing, maintenance, or repair process and 
    that has the means to prevent its recurrence. Furthermore, the QAP must 
    ensure that the finished product conforms to the requirements of the 
    applicable specification and the regulations in the HMR. RSPA is also 
    clarifying the definition of a tank car facility to mean an entity that 
    manufactures, repairs, inspects, or tests tank cars to ensure that the 
    tank cars conform to Parts 179 and 180, that alters the certificate of 
    construction of the tank car, that ensures the continuing qualification 
    of a tank car by performing a function prescribed in Parts 179 or 180, 
    or that makes any representation indicating compliance with one or more 
    of the requirements of Parts 179 or 180. This language mirrors that for 
    the qualification of highway cargo tanks (see Sec. 180.2). A shipper 
    that inspects a tank car solely to ensure that the tank car is safe for 
    transportation is not performing a periodic qualification function. On 
    the other hand, a shipper who continues the qualification of a tank 
    car, by performing a function described in Parts 179 or 180, meets the 
    definition of a tank car facility.
    
    M. Inspection Requirements Prior to Transportation
    
        The current regulations, at Sec. 173.31(b)(3), require that the 
    shipper inspect a tank car before releasing it into transportation to 
    ensure that, among other things, the closures are in a ``tool-tight,'' 
    secure condition. Further, closures on the tank (under 
    Sec. 173.24(f)(1)(ii)) must be so designed and closed that ``under 
    conditions (including the effects of temperature and vibration) 
    normally incident to transportation . . . the closure is secure and 
    leakproof.''
        RSPA and FRA proposed in Sec. 174.68 that tank cars be inspected 
    prior to transportation as an amendment to the current requirements 
    because of their concerns about tank cars in transportation with loose 
    closures. Since 1989, FRA inspectors have found loose closures on tank 
    cars containing hazardous materials more than 23,000 times. In that 
    same period, RSPA has received about 1,100 to 1,200 incident reports 
    each year on tank cars that had released product, often as a result of 
    a loose closure. Those releases resulted in injury to 85 railroad 
    employees. This history shows that more needs to be done to ensure that 
    tank cars conform to the regulations when offered for transportation. 
    It is FRA's experience that properly designed and secured closures 
    (closures meeting the standards of Secs. 173.24 and 173.31) do not 
    become loose during transportation and that most of the incidents 
    reported to RSPA reflect poor pre-trip preparation of the tank car 
    prior to offering it for transportation. In order to clearly state the 
    offerors responsibility for pre-trip inspection of a tank car, 
    Sec. 174.68 in the NPRM proposed a rebuttable presumption against a 
    proper pre-trip inspection if unsecured closures were found in transit.
        RSPA and FRA believe that aligning the inspection requirements in 
    current Sec. 173.31(b) with the design and operations requirements in 
    Sec. 173.24 will clarify their full intent, foster compliance with 
    safety standards, and improve hazardous materials transportation 
    safety. Comments on the proposed Sec. 174.68 came from most of those 
    filing responses to the NPRM and they covered five aspects of the 
    proposal. First, several commenters argued that Sec. 174.68 was the 
    wrong place for pre-trip inspection requirements, that, as shipper 
    responsibilities, they belonged in Part 173. RSPA and FRA agree and the 
    final rule includes pre-trip inspection in Sec. 173.31.
        Second, several commenters said that the proposal raised the duty 
    of care for pre-trip car preparation to an all but impossible level. 
    Current Sec. 173.31(b)(1) requires that ``the shipper must determine to 
    the extent practicable, that . . . fittings are in proper condition. . 
    . .'' [emphasis added] The origin of the phrase ``to the extent 
    practicable'' in Sec. 173.31(b) has its roots in the Interstate 
    Commerce Commission's (ICC) regulations prior to 1960. In those 
    
    [[Page 49065]]
    regulations, the ICC required shippers, before loading the tank car, to 
    examine the tank and each appurtenance to see that the safety and 
    outlet valves, safety vents, the excess flow valves (if any), the 
    closures of all openings, and the protective covers of all 
    appurtenances were in proper condition.
        In a letter dated July 10, 1959, to AAR, the Manufacturing 
    Chemists' Association (MCA) stated that the addition of the words ``to 
    the extent practicable'' in the tank car loading section was to clarify 
    the purpose of the regulations and to make the regulation more 
    realistic and to eliminate from the regulation items which were either 
    very difficult to inspect or very expensive to inspect such as a full 
    inspection of safety relief valves or excess flow valves. Read 
    literally, the regulation at that time would impose a duty on the 
    shipper to disassemble and inspect safety valves and excess flow valves 
    prior to each trip.
        As a result of the MCA letter in 1959, AAR petitioned the ICC to 
    amend the current regulations by inserting the phrase ``to the extent 
    practicable'' in the tank car loading section. The ICC agreed and the 
    new phrase went into the regulations on March 23, 1960, under Order 
    Number 42. From the beginning, this phrase was meant to reflect the 
    practical impossibility of, for instance, taking the valves apart 
    before each trip; the additional language was not intended to excuse 
    poor pre-trip preparation. This final rule does not enlarge the ``to 
    the extent practicable'' standard.
        Third, several commenters seemed to confuse the essential elements 
    of the loose closure violation by arguing that evidence of a leak (or 
    release of product) in transit does not necessarily prove the lack of a 
    pre-trip inspection. They mistakenly believed that the proposal focused 
    on releases of hazardous materials rather than the broader fault: loose 
    fittings and closures. FRA and RSPA agree that leaks can develop in 
    transit from sources other that insecure closures, the failure of a 
    rubber lining and the failure of a frangible disc are two possible 
    examples. This provision was developed from the requirement in the 
    current Sec. 173.31(b) that closures must be secured in place with an 
    appropriate tool, and the final rule makes no changes in that 
    requirement.
        Fourth, many commenters argued that the condition of tank cars in 
    transit is the responsibility of the railroads, that it is their duty 
    to ensure that the closures are, and remain, tight. RSPA and FRA note 
    that current Sec. 173.31(b)(3) requires the shipper to make closures 
    ``tool tight'' prior to shipping and that Sec. 173.24(b) and (f) 
    require closures to be designed, maintained, and closed so that ``under 
    conditions (including the effects of temperature and vibration) 
    normally incident to transportation'' they will remain secure. 
    Responsibility for tight closures must rest primarily with the offeror. 
    The railroads' duty to inspect a tank car is aimed at detecting obvious 
    leaks and defects in the running gear of the vehicle. FRA's pre-
    departure inspection requirements--applicable to all trains whether or 
    not carrying hazardous materials--are found at 49 CFR 215.13. Appendix 
    D to Part 215 describes the inspection to be performed by a train crew, 
    ``At each location where a freight car is placed in a train and 
    [designated inspectors] are not on duty. . . .'' Appendix D requires 
    the train crew to reject a placarded hazardous materials tank car from 
    which lading is leaking. As the National Industrial Transportation 
    League said in its comments, ``The key issue in determining the 
    regulatory responsibilities under the HMR should be to determine which 
    functions parties actually performed, or should have performed.'' This 
    final rule is not intended to, nor does it, change these essential 
    relationships.
        Fifth, several commenters argued that the proposed rebuttable 
    presumption will be impossible to meet. The proposed rule states 
    examples (derailment and vandalism) that will rebut the presumption, 
    but they are not intended to be exclusive. In FRA's experience in 
    discussing alleged violations with shippers over the past few years, 
    the following circumstances have led to either termination or a penalty 
    amount significantly reduced from that originally proposed, depending 
    on the facts and circumstances of each case:
         Delivery to a mistaken destination and subsequent 
    rerouting to the original destination,
         Erroneous spotting at a repair facility,
         Actual delivery to the consignee prior to inspection,
         Abnormally rough handling by a railroad,
         Gaskets, otherwise secure at the start of the trip, 
    deteriorating enroute in a manner the offeror could not have foreseen.
        One commenter cited case law on irrebuttable presumptions. RSPA and 
    FRA agree with the commenter that a presumption impossible to rebut 
    would not be proper; for the reasons given, RSPA and FRA do not view 
    the presumption in the regulation published today as impossible to 
    rebut.
        In some cases, FRA has seen pre-trip inspection check lists that 
    were at obvious odds with the conditions discovered on the car. The 
    rebuttable presumption stated today is not designed to make enforcement 
    ``easier,'' it is designed to make responsibility more certain. For 
    most shippers of hazardous materials, today's rule will not mean a 
    change in the regulator/regulated relationship.
        When FRA issues a Notice of Proposed Violation for an alleged 
    violation of the HMR, the respondent (railroad, shipper, or 
    manufacturer) is afforded the opportunity to investigate the charges 
    and to collect factual evidence to mitigate or dismiss the case. 
    Respondent has the opportunity for a hearing. FRA, or an Administrative 
    Law Judge, considers respondent's submissions, together with the 
    factors in 49 U.S.C. Sec. 5123(c), before reaching a decision. The 
    standard in this final rule does not change the process by which FRA 
    enforces railroad related hazardous materials violations. FRA expects 
    that, by clarifying the responsibility of the shipper, there will be 
    fewer loose closures on tank cars and fewer injured railroad employees.
        Several commenters mentioned mishandling, even abusive handling, by 
    the railroads. FRA's own studies have demonstrated that overspeed 
    impacts in railroad switching operations are far from a rarity, but FRA 
    is not aware that overspeed impacts will loosen the threaded fasteners 
    securing lading retention fittings on a tank car. Overspeed impacts can 
    cause severe structural damage, lessen the service life of the car, and 
    cause frangible safety vent discs to rupture. In such cases, 
    enforcement actions against the railroads are appropriate, and FRA 
    pursues them. One shipper, PPG Industries, Inc., put impact recorders 
    on a test fleet of 50 tank cars operated out of its Lake Charles, 
    Louisiana plant. The impacts in excess of 6G's (about 8 miles per hour) 
    between July 1992 and December 1993 are documented in PPG's comments in 
    this docket. Because they are limited in geographic scope, RSPA and FRA 
    cannot say that this data presents a typical picture, nation-wide, but 
    PPG's charts are graphic evidence, arranged by railroad and by 
    terminal, that railroad tank cars are subject to stresses well above 
    their optimum operating environment.
        In the final rule, RSPA is articulating a rebuttable presumption 
    standard aimed specifically at loose closures on tank cars. The 
    statement of this presumption in Sec. 173.31(d)(2) does not mean, 
    however, that there is a different standard for railroad tank cars than 
    for 
    
    [[Page 49066]]
    other packagings used to transport hazardous materials. The ``secure 
    and leakproof'' standard established in Sec. 173.24(f) applies to 
    closures on all packagings used for transportation. If a hazardous 
    materials package is discovered with loose closures, either the 
    closures were not designed properly or they were not tightened 
    properly. Neither RSPA nor FRA are aware of hazardous materials 
    packagings designs that allow closures to loosen in transit. Hence the 
    presumption that, when an inspector discovers a loose closure, it was 
    not tightened properly. RSPA has made the presumption explicit for 
    railroad transportation because FRA's enforcement experience, discussed 
    earlier, proves the need to focus responsibility on those who prepare 
    hazardous materials for transportation.
        The following table lists the adopted paragraphs or sections and, 
    where applicable, the corresponding paragraph or section contained in 
    the current HMR. In some cases, the cross-references are to provisions 
    which are similar to, but not identical with current provisions.
    
    ------------------------------------------------------------------------
           New section                          Old section                 
    ------------------------------------------------------------------------
    173.31(a)(2).............  173.31(a)(4) [except 4th and 5th sentence].  
    173.31(a)(3).............                                               
    173.31(a)(4).............  173.31(a)(7) [1st sentence after ``Effective 
                                July 1, 1991...'' and preceding ``..., as in
                                effect on November 16, 1990''].             
    173.31(a)(5)                                                            
    173.31(a)(6).............  173.31(a)(3) [1st sentence].                 
                               173.31(a)(3)(i).                             
    173.31(b)(1).............  173.31(a)(5) [except last sentence].         
    173.31(b)(2).............  173.31(a)(12).                               
                               173.31(a)(15) [1st sentence preceding        
                                ``...nonreclosing pressure relief           
                                devices.''] [2nd preceding ``...provided    
                                that the liquid...''] [3rd sentence         
                                preceding ``...breather holes are not...''].
    173.31(b)(3)                                                            
    173.31(b)(4)                                                            
    173.31(b)(5)               .............................................
    173.31(b)(6)                                                            
    173.31(c)................  173.31(a)(14) [1st sentence preceding        
                                ``...equal to or greater than...''].        
                               173.31(a)(14)(i) [1st sentence preceding     
                                ``...ullage space or dome of tank.''].      
                               173.31(a)(14)(ii).                           
                               173.31(a)(14)(iii).                          
    173.31(d)(1)                                                            
    173.31(e)(1).............  173.31(a)(17).                               
    173.31(e)(2)                                                            
    173.31(f)                                                               
    173.314(c), Note 2.......  173.314(c), Note 25.                         
    173.314(c), Note 3.......  173.314(c), Note 21.                         
    173.314(c), Note 4.......  173.314(c), Note 20.                         
    173.314(c), Note 6.......  173.314(c), Note 12 [except 1st and last     
                                sentence].                                  
    173.314(c), Note 7.......  173.314(c), Note 18 [1st sentence preceding  
                                ``...g, when offered for transportation.''].
    173.314(c), Note 8.......  173.314(c), Note 19 [1st sentence preceding  
                                ``...g, when offered for transportation.''].
    179.7                                                                   
    179.16...................  179.100-5.                                   
    179.18...................  179.100-4.                                   
    179.20                                                                  
    179.22...................  179.100-21.                                  
                               179.105-8.                                   
                               179.200-25.                                  
                               179.203-3.                                   
    Appendix A to Part 179...  179.105-5 (b) and (c).                       
    Appendix B to Part 179...  179.105-4 (d) and (e).                       
    Subpart F to Part 180                                                   
    180.501                                                                 
    180.503                                                                 
    180.505                                                                 
    180.507                                                                 
    180.509                                                                 
    180.511                                                                 
    180.513                                                                 
    180.515                                                                 
    180.517                                                                 
    180.519                                                                 
    ------------------------------------------------------------------------
    
    IV. Review by Section Summary
    
    Part 171
    
        Section 171.7(a)(3). The 49 CFR reference sections for the 
    Association of American Railroads standards and for a Compressed Gas 
    Association standard are added, revised or removed, as appropriate, to 
    reflect the changes in this rulemaking.
    
    Part 172
    
        Section 172.101. In the HMT, three special provisions are removed. 
    Special Provision ``B41,'' appearing in column (7) of the entries for 
    benzyl chloride, fluorosulfonic acid, and titanium tetrachloride is no 
    longer necessary due to the new inspection and test intervals adopted 
    in this final rule. Special Provision ``B43,'' appearing in column (7) 
    of the entries for carbon dioxide, refrigerated liquid, hydrogen 
    chloride, refrigerated liquid, and vinyl fluoride, 
    
    [[Page 49067]]
    inhibited, also is no longer necessary because of the new inspection 
    and test requirements. For the Division 2.1 (flammable gas) entries 
    ethyl chloride and ethyl methyl ether, Special Provision ``B63'' is 
    removed, thus prohibiting the use of tank cars without head protection 
    or thermal protection.
        Section 172.102. As discussed above, Special Provisions ``B41'' and 
    ``B43'' are removed. The inspection and test intervals (i.e., 5-3-1) 
    specified in Special Provision ``B41'' and the nondestructive test 
    requirements specified in Special Provision ``B43'' are incorporated 
    into Subpart F of Part 180. Special Provision ``B63'' appears only in 
    the entries ethyl chloride and ethyl methyl ether and, therefore, in 
    paragraph (c), is removed. Special Provision ``B64'' is amended by 
    changing the head-protection section reference ``Sec. 179.105-5'' to 
    read ``Sec. 179.16,'' and Special Provision ``B79'' is amended by 
    changing the head- and thermal-protection section references 
    ``Secs. 179.105-4 and 179.105-5'' to read ``Sec. 179.16 and 179.18''.
    
    Part 173
    
        Section 173.31. The section heading is revised to read ``Use of 
    Tank Cars.'' This section also is completely revised and reorganized 
    for clarity.
        New paragraph (a)(1) corresponds to the language in the HMR for 
    cargo tanks and portable tanks (see Secs. 173.32c(a) and 173.33(a)). 
    The section also includes reference to certain ``AAR'' specification 
    tank cars that are authorized for hazardous materials service in the 
    HMR (see Secs. 173.241 and 173.242). When these tank cars are used for 
    the transportation of hazardous materials, the tank cars must meet the 
    minimum specification for new construction as required by AAR.
        New paragraph (a)(2) is essentially current Sec. 173.31(a)(4). The 
    first, second, and third sentences are revised to clarify the use of 
    the term ``authorized.'' Prior to December 19, 1957 (ICC Order No. 33), 
    the regulations stated that:
    
        [T]ank cars and appurtenances may be used for the transportation 
    of any commodity for which they are authorized, as indicated on the 
    certificate of construction. When a car is to be used for the 
    transportation of a commodity other than those approved on the 
    certificate of construction, it must be approved for such loading by 
    the A.A.R. Tank Car Committee. Changes in fittings or commodity 
    stencilling required to transfer a car from one service to another 
    as authorized on the certificate of construction, may be made only 
    be the owner or owner's authorized agent * * *.
    
        As evidenced by the language above, the term ``authorized'' means 
    those commodities designated on the certificate of construction and 
    approved by the AAR Tank Car Committee. Order No. 33 changed the 
    regulation by removing the phrase ``as indicated on the certificate of 
    construction'' because many car owners did not have a certificate for 
    older Class ARA-II (built prior to 1917), ARA-III (built prior to 
    1927), and some ICC-103 (built after 1927) tank cars. Because this 
    final rule requires that the original and subsequent tank car 
    certificates must be maintained for the life of the car and transferred 
    with ownership, RSPA is clarifying the purpose of this paragraph by 
    inserting the phrase ``in this part and specified on its certificate of 
    construction'' at the end of the first sentence. See Sec. 180.517. The 
    second and third sentences are modified accordingly. Provisions 
    contained in the fourth and fifth sentences of current 
    Sec. 173.31(a)(4), stating that DOT 105A-W, 109A-W, 111A100W4, 112A-W, 
    and 114A-W tank cars may be used for any commodity for which it is 
    approved and may be stencilled accordingly, and that a tank car 
    stencilled to indicate that it is authorized for one commodity may not 
    be used for any other service, are removed. The stencilling requirement 
    for these cars is optional and, therefore, not enforceable.
        New paragraph (a)(3) provides that no person may fill a tank car 
    with a hazardous material when the tank car is overdue for periodic 
    inspection and test. This provision allows the movement of tank cars 
    containing hazardous material residue to a tank car facility for 
    inspection and testing.
        New paragraph (a)(4) is current Sec. 173.31(a)(7). It removes 
    reference to a compliance date, now past, and establishes that air 
    brake equipment support attachments must be welded to pads instead of 
    directly to the tank shell in conformance with Secs. 179.100-16 and 
    179.200-19.
        New paragraph (a)(5) prohibits the use of an internal self-
    energized manway that is located below the liquid level of the lading 
    on a tank car, beginning on the effective date of this final rule. 
    After the effective date of this final rule, an exemption would be 
    required in order to continue to operate such a tank car. This 
    provision was proposed paragraph (a)(22) in HM-175A.
        New paragraph (a)(6) is current Sec. 173.31(a)(3). It removes 
    specific ``DOT'' class references and explains that any tank car of the 
    same class with a higher tank test pressure than the tank car 
    authorized in the HMR may be used. The paragraph is also simplified by 
    specifying the hierarchy of the letters in the specification marking 
    that describe special protective systems (e.g., ``J'' for thermally 
    protected, jacketed cars; ``T'' for thermally protected, non-jacketed 
    cars; ``S'' for cars with head shields but without thermal protection; 
    and ``A'' for cars without protective systems).
        New paragraph (b)(1), concerning the use of coupler vertical 
    restraint systems, is current Sec. 173.31(a)(5). It is revised to 
    require all DOT specification tank cars and any other tank car used to 
    transport hazardous material to be equipped with a coupler vertical 
    restraint system. This revision also removes reference to a compliance 
    date, now past, excepting DOT specification tank cars in nonhazardous 
    materials service from being equipped with a coupler vertical restraint 
    system.
        New paragraph (b)(2), concerning pressure relief devices, is 
    current Secs. 173.31(a)(12) and 173.31(a)(15). This revision is 
    simplified by using the term ``poisonous by inhalation'' (see 
    Sec. 171.8) in place of the defining criteria.
        New paragraph (b)(3) requires head protection for all tank cars 
    transporting Class 2 materials and tank cars constructed from aluminum 
    or nickel plate. Tank cars currently equipped with half-head protection 
    are excluded. The compliance period is 10 years from the effective date 
    of this rule, except for class DOT 105 tank cars with less than 70 kl 
    (18,500 gallon) capacity when used to transport a Division 2.1 
    material, which have a compliance period of 5 years. This provision was 
    proposed paragraph (a)(19) in HM-175A.
        New paragraph (b)(4) requires tank cars transporting Class 2 
    materials to have thermal protection. Exceptions from the thermal 
    protection standard are granted for ``chlorine,'' ``carbon dioxide, 
    refrigerated liquid,'' and ``nitrous oxide, refrigerated liquid,'' and 
    for tank car tank classes DOT 106, 107A, 110, and 113. This provision 
    was proposed paragraph (a)(20) in HM-175A. In the NPRM, RSPA did not 
    propose thermal protection for the commodities identified above (see 
    proposed Sec. 173.314(k) and (o)). The compliance period is 10 years 
    from the effective date of this final rule.
        New paragraph (b)(5) requires bottom-discontinuity protection for 
    all existing tank cars transporting a hazardous material. The new 
    protection requirements conform to paragraphs E9.00 and E10.00 of the 
    AAR Specifications for Tank Cars, M-1002. Existing tank cars that 
    conform to Appendix Y of the AAR Specifications for Tank Cars, M-1002, 
    may continue in use. The compliance period is 10 years from the 
    effective date of this final rule. 
    
    [[Page 49068]]
    This provision was proposed paragraph (a)(23) in HM-175A.
        New paragraph (b)(6) is added to require tank car owners to 
    implement measures to ensure the phased-in completion of the 
    modifications on each tank car subject to this final rule. As discussed 
    earlier in this preamble, RSPA and FRA have several programs in place 
    to improve the tank car fleet. Owners, therefore, should develop 
    careful plans, procedures, and schedules to assure completion of the 
    modifications before the regulatory compliance date. Paragraph (b)(6) 
    also requires submission of a yearly progress report to FRA that shows 
    the reporting mark of each tank car requiring modification, the type of 
    modification required for each tank car during the previous year, and 
    the total number of tank cars modified the previous year.
        New paragraph (c) was proposed as paragraph (d) in HM-201. This 
    final rule revises the terms ``un-insulated'' to ``non-insulated,'' 
    ``ullage space or dome'' to ``vacant,'' and clarifies that this 
    provision applies to cars in hazardous materials service only. A new 
    provision is added in paragraph (c)(3) to require all tank cars 
    transporting a PIH material to have a tank test pressure of at least 
    20.7 Bar (300 psi). This provision is consistent with other regulations 
    adopted under Docket HM-181 for PIH liquids.\19\ Also, several shipping 
    names appearing in the opening paragraph are revised for consistency 
    with the proper shipping name as shown in the Sec. 172.101 table.
    
        \19\For further information see Performance-Oriented Packaging, 
    Docket HM-181, 55 FR 52402 (December 21, 1990). In general, liquid 
    materials PIH in Hazard Zone A are assigned Special Provision B72 
    and those in Hazard Zone B are assigned Special Provision B74. These 
    two special provisions require the use of a 105S, 112J, or a 114J 
    tank car having a tank test pressure greater than 18 Bar (300 psi).
    ---------------------------------------------------------------------------
    
        New paragraph (d) reinforces the inspection requirements that must 
    be fulfilled before a tank car of hazardous materials is offered for 
    transportation. These provisions were proposed paragraph (a)(4) and 
    Sec. 174.68 in HM-201. These proposed requirements were revised and 
    combined based on suggestions made by the commenters.
        In new paragraph (e), to clarify that the paragraph applies to 
    materials that are poisonous by inhalation, the paragraph heading is 
    revised to read ``Special requirements for materials poisonous by 
    inhalation.''
        New paragraph (e)(1) concerns the use of heater coils. This 
    provision is essentially current paragraph Sec. 173.31(a)(17). This 
    provision was proposed paragraph (e) in HM-201.
        New paragraph (e)(2) requires that tank cars used for materials 
    poisonous by inhalation must conform to at least a DOT 105S300W, 
    105S300ALW, 112J340W, or 114J340W. This provision was proposed 
    paragraph (a)(21) in HM-175A. It is made consistent with Special 
    Provision B74 for liquid PIH materials in Zone B. The compliance period 
    is 10 years from the effective date of this final rule.
        New paragraph (f) requires the use of a DOT 105S200W; a DOT 
    112S200W with an 11-gauge steel jacket conforming to Sec. 179.100-4; a 
    DOT 112S340W; or a DOT 112S200W tank car constructed from AAR steel 
    specification TC-128, normalized, for the transportation of certain 
    listed hazardous substances in Sec. 173.31(f) that pose a potential 
    threat to human health and the environment. This provision was proposed 
    paragraph (a)(24) in HM-175A.
        Section 173.314. In the table in paragraph (c), the entries are 
    amended by removing references to the individual tank car 
    specifications and adding references to the authorized tank car 
    classes. This change ensures that Sec. 173.314 does not authorize a 
    tank car having a tank test pressure below the regulatory minimum in 
    Sec. 173.31(c). The current notes following the table are amended by 
    redesignating, revising, or removing all tank car ``design 
    requirements'' as follows (notes that apply to filling limits are 
    retained):
        Note 1, no change.
        Note 2 is restated without substantial change and moved to 
    Sec. 173.314(n).
        Note 3 and Note 4 are restated without substantial change and moved 
    to Sec. 173.314(j), which is applicable to all materials having a 
    primary or secondary Division 2.1 (flammable gas) hazard.
        Note 5 is restated without substantial change for clarity.
        Note 6 is restated without substantial change and moved to 
    Sec. 173.314(o).
        Note 7, which restricts the transportation of multi-unit tank cars 
    tanks (ton containers) to rail and highway only, is removed. RSPA 
    believes no valid reason exists to restrict the transport of these 
    units by water. A provision restricting the transport of multi-unit 
    tank car tanks by air is unnecessary because all multi-unit tank car 
    tanks exceed the maximum quantity limitations allowed by air.
        Note 8 is restated without substantial change and moved to 
    Sec. 173.314(l).
        Note 9 is moved to Sec. 173.314(j) and made applicable to all 
    materials with a primary or secondary Division 2.1 (flammable gas) 
    hazard.
        Note 10 is restated without substantial change and moved to 
    Sec. 173.314(m).
        Note 11 is restated without substantial change and included in 
    Sec. 173.314(m).
        Note 12 is restated without substantial change. The filling density 
    requirements are moved to Note 6, and the design requirements are moved 
    to Sec. 173.314(k).
        Note 13 is removed to eliminate duplication of the marking 
    requirements prescribed in Special Provision B12, Secs. 173.314(a)(5) 
    and 172.330(a)(1)(i).
        Note 14 is removed because it is not referenced in the table.
        Note 15 is removed since it is included with the other design 
    requirements applicable to tank cars used for materials having a 
    primary or secondary Division 2.1 (flammable gas) hazard in 
    Sec. 173.314(j).
        Note 16, which is currently reserved, is removed.
        Note 17, which references Sec. 173.314(g) is removed.
        Note 18 is restated without substantial change and moved to Note 7.
        Note 19 is restated without substantial change and moved to Note 8.
        Note 20 is restated without substantial change and moved to Note 4.
        Note 21 is restated without substantial change and moved to Note 3.
        Note 22, referencing the requirements in Sec. 173.245, is 
    incorporated into the table under the entry ``Division 2.3, Zone A 
    materials.''
        Note 23 and Note 24 are removed based on other changes in this 
    final rule concerning the elimination of grandfather provisions.
        Note 25 is restated without substantial change and moved to Note 2.
        Note 29 and Note 30 are removed based on other changes in this 
    final rule concerning the elimination of grandfather provisions.
        In addition, the table in Sec. 173.314(c) will reflect the tank car 
    classes and not the specifications.
        Section 173.319. Paragraph (a)(4)(iii) is revised by removing a 
    parenthetical reference to current Sec. 173.31(c)(13). A requirement 
    contained in Sec. 173.31(c)(13) prescribing special retest requirements 
    for class DOT-113 tank cars is revised and moved to new paragraph 
    Sec. 173.319(e).
        Section 173.323. Paragraph (c)(1) is revised to require a tank test 
    pressure of at least 20.7 Bar (300 psi) for ethylene oxide no later 
    then 10 years after the effective date of this final rule. 
    Authorization for the use of a DOT 111A100W4 and 111J100W4 tank car is 
    removed.
    
    Part 179
    
        Section 179.1. In paragraph (c), the section reference 
    ``Sec. 173.31'' is revised to read ``Sec. 180.507''. 
    
    [[Page 49069]]
    
        Section 179.2. This section is amended by adding a definition for 
    ``Tank car facility.''
        Section 179.7. This section requires tank car facilities to have a 
    Quality Assurance Program (QAP). Paragraph (a) sets forth performance 
    standard for the program. Paragraphs (b)(1) through (b)(13) require 
    that the QAP have certain minimum requirements. The term ``Enhanced 
    visual imagery'' in paragraph (b)(10) is changed to read ``Optically-
    aided visual inspection'' to correctly identify that the visual 
    inspection method is ``optically aided.'' Optically-aided visual 
    methods include the use of magnifiers, borescopes, fiberscopes, and 
    machine vision technology (e.g., a video digitizer that converts images 
    into digital form, and through image enhancement, image segmentation, 
    and feature extraction, the computer classifies objects within the 
    image). Paragraph (c) requires tank car facilities to ensure that only 
    personnel qualified to perform a particular nondestructive inspection 
    and test perform that operation. Paragraph (d) requires each tank car 
    facility to have written procedures, covering inspection, fabrication, 
    and repair operations as appropriate, for their employees. Paragraph 
    (e) cross-references the training requirements in Subpart H of Part 
    172. (Section 172.702 requires that a hazmat employer train each of its 
    hazmat employees.) Paragraph (f) specifies the compliance date by which 
    tank car facilities must have a QAP and written procedures in effect.
        Section 179.16. This new section contains the tank-head puncture-
    resistance requirements found in current Secs. 179.100-23 and 179.105-
    5.
        Section 179.18. This new section contains the thermal protection 
    requirements found in current Sec. 179.105-4(a), (b), and (c). A 
    requirement that the exterior of the tank car must be painted white in 
    proposed Sec. 179.18(d) is moved to Sec. 179.101-1, Note 4 in this 
    final rule. Editorial revisions are made to these requirements for 
    clarity and for consistency with other changes in this final rule.
        Section 179.20. This new section contains bottom-discontinuity 
    protection requirements. For new tank cars, bottom-discontinuity 
    protection must conform to paragraphs E9.00 and E10.00 of the AAR 
    Specifications for Tank Cars, M-1002.
        Section 179.22. New section 179.22 consolidates the marking 
    requirements contained in current Secs. 179.100-21, 179.105-8, 179.200-
    25, and 179.203-3. Based on this consolidation, Secs. 179.100-21, 
    179.105-8, 179.200-25, and 179.203-3 are removed.
        Section 179.100-4. This section is amended by removing the phrase 
    ``except that a protective coating is not required when foam-in-place 
    insulation that adheres to the tank or jacket is applied'' at the end 
    of the first paragraph. This change is based on an AAR petition (P-
    1050) to require protective coatings on the outside surface of the tank 
    shell and the inside surface of the jacket.
        Section 179.100-21. The marking requirements contained in this 
    section are consolidated with other marking requirements in new 
    Sec. 179.22 and, as discussed earlier, Sec. 179.100-21 is removed.
        Section 179.100-23. The head protection requirements contained in 
    this section are moved to Sec. 179.16(b), and, as discussed earlier, 
    Sec. 179.100-23 is removed.
        Section 179.101-1. Certain editorial changes are made in 
    Sec. 179.101-1, Note 4, for clarity and consistency with other changes 
    made in this final rule. In the first sentence in Note 4, the section 
    reference ``Sec. 179.100-4,'' which addresses insulated tank cars, is 
    removed because Note 4 applies to non-insulated cars only. Note 4 is 
    revised to clarify that there is no need to paint the tank white when a 
    ``thermal protection'' system is applied (consistent with current 
    Sec. 179.105-4(g) and proposed Sec. 179.16 (d)), and to remove a 
    requirement that tank cars in hydrogen fluoride service need to have a 
    dark colored band in the top platform and fitting area because hydrogen 
    fluoride is not a Class 2 (compressed gas) material. The last sentence 
    is also removed because it is not a mandatory requirement.
        Section 179.103-1. Current paragraph (c), providing that a manway 
    may be located other than at the top of the tank is no longer valid 
    and, therefore, is removed and reserved.
        Section 179.103-2. Current paragraph (a) containing manway cover 
    plate requirements is revised by removing the phrase ``may be of the 
    self-energizing type and''. This change would prohibit the construction 
    of tank cars with a self-energized manway located below the liquid 
    level of the lading.
        Section 179.103-5. In current paragraph (a)(1), the first two 
    sentences authorizing the location of a self-energizing manway below 
    the liquid level of the tank is no longer valid and, therefore are 
    removed.
        Section 179.105. Current Secs. 179.105 through 179.105-8 containing 
    special requirements for class DOT 105S, 105J, 111J, 112S, 112J, 112T, 
    114S, 114J, and 114T specification tank cars are removed because they 
    are unnecessary. The applicable requirements concerning head protection 
    and thermal protection are moved to Secs. 179.16, 179.18, and 
    Appendices A and B to Part 179, as appropriate. The marking 
    requirements are consolidated into Sec. 179.22. The requirement for 
    exterior tank color was moved to footnote 4 of the Sec. 179.101-1 
    table.
        Section 179.200-4. This section is amended by removing the phrase 
    ``except that a protective coating is not required when foam-in-place 
    insulation that adheres to the tank or jacket is applied'' at the end 
    of the first paragraph. This change is based on an AAR petition (P-
    1050) to require protective coatings on the outside surface of the tank 
    shell and the inside surface of the jacket.
        Section 179.200-25. The marking requirements contained in this 
    section are consolidated with other marking requirements in 
    Sec. 179.22, and, as discussed earlier, Sec. 179.200-25 is removed.
        Section 179.200-27. The head protection requirements are 
    consolidated into Sec. 179.16. Therefore, current Sec. 179.200-27 is 
    removed.
        Section 179.203. Current Secs. 179.203, 179.203-1, 179.203-2, and 
    179.203-3 containing special requirements for class DOT 111 tank cars 
    are unnecessary and are removed. The restriction in paragraph (c) 
    against the use of class DOT 111 tank cars built after March 1, 1984, 
    for the transportation of flammable gases or ethylene oxide is 
    incorporated into Secs. 173.314 and 173.323. The applicable head-
    protection and thermal-protection requirements are consolidated into 
    Secs. 179.16 and 179.18, respectively. The marking requirements are 
    consolidated into Sec. 179.22.
        Appendix A. The tank-head puncture-resistance test verification 
    requirements in Sec. 179.105-5 paragraphs (b) and (c) are moved to this 
    Appendix.
        Appendix B. This appendix contains the thermal-protection test-
    verification requirements found in current Sec. 179.105-4(d), (e) and 
    (f). These requirements are editorially revised for clarity.
    
    Part 180
    
        Subpart F of Part 180. This subpart contains the qualification and 
    maintenance requirements for tank cars.
        Section 180.501. Paragraph (a) specifies the applicability of the 
    Subpart. Paragraph (b) specifies that any person who performs a 
    function required by Subpart F of Part 180 must perform that function 
    according to the regulations. 
    
    [[Page 49070]]
    
        Section 180.503. This section defines certain terms used throughout 
    the subpart.
        Section 180.505. This section requires each tank car facility 
    performing repair work to have a QAP based on requirements in 
    Sec. 179.7 for new car construction.
        Section 180.507. This section contains the continuing 
    qualifications for existing tank cars that are no longer authorized for 
    new construction, such as a class DOT 113A175W tank car. Paragraph (a) 
    is essentially current Sec. 173.31(a)(1) except that it is revised to 
    include non-specification tank cars that are currently authorized for 
    the transportation of hazardous materials. Paragraphs (b)(1), (2), (3), 
    and (4) are current Sec. 173.31(a)(2), (8), (9), and (10).
        Section 180.509. This section specifies the requirements for the 
    periodic inspection and testing of tank cars. Paragraph (a)(1) requires 
    each tank car facility to evaluate the tank car according to the 
    ``Acceptable results of inspections and tests'' as prescribed in 
    Sec. 180.511. Paragraph (a)(2) requires marking each tank car passing a 
    periodic inspection and test to indicate the date it passed this review 
    and the due dates for the next inspection and test required in the new 
    Sec. 180.515. Paragraph (a)(3) requires a written report for each tank 
    car after it successfully passes an inspection and test. Paragraph (b) 
    specifies unusual conditions that may require an inspection and test of 
    tank cars. Paragraph (b)(1) requires an inspection and test if the tank 
    shows evidence of abrasion, corrosion, cracks, dents, distortions, 
    defects in welds, or any other condition unsafe for transportation. 
    Paragraph (b)(2) requires an inspection and test if the tank car was in 
    an accident and damaged to the extent that may adversely affect its 
    capability to retain its contents (e.g., large dent or gouge in the 
    tank shell). Paragraph (b)(3) requires an inspection and test if the 
    tank was involved in a fire. Paragraph (b)(4) requires an inspection 
    and test of either a single tank car or a design of tank cars operating 
    in an unsafe condition, if required by FRA, based on the existence of a 
    probable cause. Probable cause may include an inspection and test where 
    FRA discovers a crack in a welded area, a wheel burn, or a large dent 
    or bulge in the tank shell; it may also include a group of cars of a 
    given design if FRA discovers problems apparently related to cars of 
    that design.
        Paragraph (c) specifies the frequency with which inspections and 
    tests must be performed on tank cars. Paragraph (c)(1) specifies the 
    requirements for the inspection and hydrostatic test of class DOT 107 
    tank cars and riveted tank cars. As noted above, the hydrostatic test 
    is still effective for these tank cars since it will detect loose 
    rivets and areas of metal distress. Paragraph (c)(2) requires an 
    inspection for thermal integrity of class DOT 113 tank cars in place of 
    the inspection and testing requirements in Subpart F of Part 180. This 
    paragraph cross-references the requirements in Sec. 173.319(e). 
    Paragraph (c)(3) specifies the inspection and test requirements for 
    fusion welded tank cars. The intervals would vary depending upon 
    whether or not the tank car was lined or coated and upon whether or not 
    the car was transporting materials corrosive to the tank. For linings 
    and coatings, this final rule requires a tank car facility to inspect 
    the lining or coating based on the inspection and test intervals and 
    techniques established by the lining or coating owner. The owner must 
    establish an inspection interval and test technique based on the 
    manufacturer's recommendations or the owner's knowledge of the life-
    expectancy of the lining or coating.
        Paragraph (d) specifies the manner for conducting a visual 
    inspection for each tank car. Paragraph (d)(1) requires an inspection 
    of the tank car internally and externally for abrasion, corrosion, 
    cracks, dents, distortions, defects in welds, or any other conditions 
    unsafe for transportation. Paragraph (d)(2) requires the inspection of 
    all piping, valves, fittings, and gaskets for corrosion and any other 
    condition unsafe for transportation. Paragraph (d)(3) requires an 
    inspection of the tank cars for missing or loose bolts, nuts, or other 
    elements. Paragraph (d)(4) requires an inspection of all closures on 
    the tank car for proper securement. The tank car facility would also 
    inspect the protective housings for proper securement. Paragraph (d)(5) 
    requires an inspection of the seats on excess flow valves. Paragraph 
    (d)(6) requires an inspection of the markings on the tank car for 
    legibility.
        Paragraph (e) requires that a structural integrity inspection and 
    test shall include all transverse fillet welds greater than 0.64 cm 
    (0.25 inch) within four feet of the bottom longitudinal center line; 
    the termination of longitudinal fillet welds greater than 0.64 cm (0.25 
    inch) within four feet of the bottom longitudinal center line; and all 
    tank shell butt welds within two feet of the bottom longitudinal center 
    line using one or more nondestructive test methods. The term ``Enhanced 
    visual imagery'' is changed to read ``Optically-aided visual 
    inspection'' to correctly identify that the visual inspection method is 
    ``optically aided.''
        Paragraph (f) requires thickness measurements to determine that the 
    tank car is not below the minimum shell thickness.
        Paragraph (g) specifies the allowable shell thickness reductions. 
    Paragraph (g)(1)(i) allows thickness reductions on carbon steel, 
    stainless steel, aluminum, nickel, and manganese-molybdenum steels. 
    Paragraph (g)(1)(ii) specifies the minimum shell and head thickness 
    reductions for uniform and localized areas and Note 5 of the table is 
    removed to disallow any reduction in the shell thickness for class DOT 
    111A tank cars transporting ethylene oxide. As discussed earlier, this 
    final rule prohibits the transportation of ethylene oxide in a class 
    DOT 111 tank car.
        Paragraph (h)(1) requires the inspection of the safety systems on 
    the tank, such as thermal protection systems, tank-head puncture-
    resistance systems, and coupler vertical restraint systems, to ensure 
    their integrity. Paragraph (h)(2) requires the inspection and test of 
    re-closing pressure relief devices (safety valves).
        Paragraph (i) requires an inspection and test of tank cars with a 
    lining or coating on the tank car. The inspection interval is 
    determined by the owner based on the type of testing technique used, 
    and knowledge of the material and tank car, but cannot exceed 10 years.
        Paragraph (j) requires a leakage pressure test of the tank car and 
    appurtenances.
        Paragraph (k) allows the use of an alternative inspection and test 
    procedure provided the procedure is based on a damage-tolerance 
    evaluation, examined by the AAR Tank Car Committee, and approved by the 
    Associate Administrator for Safety FRA.
        Paragraph (l) specifies the compliance date for the new inspection 
    and test requirements.
        Section 180.511. This section specifies the acceptable results of 
    inspections and tests. Paragraph (a) establishes that an acceptable 
    visual inspection as one that shows no structural defect that may cause 
    the tank car to fail (including leak) before the next inspection and 
    test interval.
        Paragraph (b) establishes that an acceptable structural integrity 
    inspection and test is one that shows no structural defect that may 
    initiate cracks or propagate cracks and cause the tank car to fail 
    before the next inspection and test interval.
        Paragraph (c) establishes that an acceptable service life shell 
    thickness is one that shows no areas of the tank car 
    
    [[Page 49071]]
    below the minimum shell or head thickness allowed in Sec. 180.509(g).
        Paragraph (d) establishes that an acceptable safety system 
    inspection is one that shows the systems (e.g., a thermal protection 
    system) conform to Part 179.
        Paragraph (e) establishes that an acceptable inspection and test 
    for lining and coatings as one that shows no holes or degraded areas.
        Paragraph (f) establishes that an acceptable inspection and test 
    for a leakage pressure test as one that shows no indications of leakage 
    in any product piping, fitting, or closure.
        Paragraph (g) establishes that an acceptable hydrostatic test, for 
    class DOT 107 tank cars and riveted tank cars, is one that shows no 
    leakage or deformations (i.e., distress) in the tank.
        Section 180.513. This section specifies that tank car repairs must 
    conform to the requirements of Appendix R of AAR Specifications for 
    Tank Cars. As proposed in HM-175A, the introductory text becomes 
    paragraph (a), and Sec. 173.31 paragraph (f)(3) becomes Sec. 180.513 
    paragraph (b). Section 180.513(b) requires that, unless the exterior 
    tank car shell or interior tank car jacket has a protective coating, 
    when the complete tank car jacket is removed to effect a repair, the 
    exterior tank car shell and the interior tank car jacket must have a 
    protective coating applied to prevent the deterioration of the tank 
    shell and tank jacket.
        Section 180.515. This section specifies the marking requirements 
    for tank cars after a successful tank inspection and test.
        Section 180.517. This section specifies the reporting and record 
    retention requirements after a tank car has successfully completed its 
    required inspection and test. Paragraph (a) requires the tank car owner 
    to retain the certificate of construction of the tank car (AAR Form 4-
    2) and related documentation certifying that the tank car conforms to 
    the specification. The owner shall retain the documents for the period 
    of ownership. Upon a change in ownership, Section 1.3.15 of AAR 
    Specifications for Tank Cars requires the transfer of these documents 
    to the new owner. Paragraph (b) specifies the inspection and test 
    reporting requirements.
        Section 180.519. This section specifies the periodic test and 
    inspection requirements for multi-unit tank cars (e.g., class DOT 106 
    and 110 multi-unit tank cars).
    
    V. Regulatory Analysis and Notices
    
    A. Executive Order 12866 and DOT Regulatory Policies and Procedures
    
        This final rule is considered a significant regulatory action under 
    section 3(f) of Executive Order 12866 and was reviewed by the Office of 
    Management and Budget. The rule is considered significant under the 
    Regulatory policies and Procedures of the Department of Transportation 
    (44 FR 11034) because it affects a significant segment of the tank car 
    industry. A regulatory evaluation is available for review in the 
    docket.
    
    B. Executive Order 12612
    
        This final rule has been analyzed in accordance with the principles 
    and criteria contained in Executive Order 12612 (``Federalism''). 
    Federal law expressly preempts State, local, and Indian tribe 
    requirements applicable to the transportation of hazardous material 
    that cover certain subjects and are not ``substantively the same'' as 
    the Federal requirements. 49 U.S.C. 5125(b)(1). These covered subjects 
    are:
        (A) the designation, description, and classification of hazardous 
    material;
        (B) the packing, repacking, handling, labeling, marking, and 
    placarding of hazardous material;
        (C) the preparation, execution, and use of shipping documents 
    related to hazardous material and requirements respecting the number, 
    contents, and placement of those documents;
        (D) the written notification, recording, and reporting of the 
    unintentional release in transportation of hazardous material; or
        (E) the design, manufacturing, fabricating, marking, maintenance, 
    reconditioning, repairing, or testing of a packaging or a container 
    which is represented, marked, certified, or sold as qualified for use 
    in transporting hazardous material.
        This final rule addresses the design, manufacturing, repairing, and 
    other requirements for packages represented as qualified for use in the 
    transportation of hazardous material. Therefore, this final rule 
    preempts State, local, or Indian tribe requirements that are not 
    ``substantively the same'' as Federal requirements on these subjects. 
    Section 5125(b)(2) of Title 49 U.S.C. provides that when DOT issues a 
    regulation concerning any of the covered subjects after November 16, 
    1990, DOT must determine and publish in the Federal Register the 
    effective date of Federal preemption. The effective date may not be 
    earlier that the 90th day following the date of issuance of the final 
    rule and no later than two years after the date of issuance. RSPA has 
    determined that the effective date of Federal preemption of this final 
    rule will be 90 days after publication in the Federal Register.
        Because RSPA lacks discretion in this area, preparation of a 
    federalism assessment is not warranted.
    
    C. Regulatory Flexibility Act
    
        I certify that this final rule will not have a significant economic 
    impact on a substantial number of small entities. The entities affected 
    by the rule are involved in tank car leasing, maintenance, repair and 
    use. There are no direct or indirect adverse economic impacts for small 
    units of government, businesses, or other organizations.
    
    D. Paperwork Reduction Act
    
        The requirements for information collection have been approved by 
    the Office of Management and Budget (OMB) under the provision of the 
    Paperwork Reduction Act of 1980 (Pub. L. 95-511) under OMB control 
    number 2137-0559.
    
    E. Regulation Identifier Number (RIN)
    
        A regulation identifier number (RIN) is assigned to each regulatory 
    action listed in the Unified Agenda of Federal Regulations. The 
    Regulatory Information Service Center publishes the Unified Agenda in 
    April and October of each year. The RIN numbers contained in the 
    heading of this document can be used to cross-reference this action 
    with the Unified Agenda.
    
    List of Subjects
    
    49 CFR Part 171
    
        Exports, Hazardous materials transportation, Hazardous waste, 
    Imports, Incorporation by reference, Reporting and recordkeeping 
    requirements.
    
    49 CFR Part 172
    
        Hazardous materials transportation, Hazardous waste, Labels, 
    Markings, Packaging and containers, Reporting and recordkeeping 
    requirements.
    
    49 CFR Part 173
    
        Hazardous materials transportation, Incorporation by reference, 
    Packaging and containers, Radioactive materials, Reporting and 
    recordkeeping requirements, Uranium.
    
    49 CFR Part 179
    
        Hazardous materials transportation, Incorporation by reference, 
    Railroad safety, Reporting and recordkeeping requirements. 
    
    [[Page 49072]]
    
    
    49 CFR Part 180
    
        Hazardous materials transportation, Incorporation by reference, 
    Motor carriers, Motor vehicle safety, Packaging and containers, 
    Railroad safety, Reporting and recordkeeping requirements.
        In consideration of the foregoing, 49 CFR Chapter I is amended as 
    follows:
    
    PART 171--GENERAL INFORMATION, REGULATIONS, AND DEFINITIONS
    
        1. The authority citation for part 171 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.
    
    
    Sec. 171.7  [Amended]
    
        2. In Sec. 171.7, in paragraph (a)(3) Table, the following changes 
    are made:
        a. Under the Association of American Railroads, for the entry ``AAR 
    Manual of Standards and Recommended Practices, Section C-Part III, 
    Specifications for Tank Cars, Specification M-1002, September, 1992'' 
    in column 2, the references are revised to read ``173.31; 174.63; 
    179.6; 179.7; 179.12; 179.16; 179.20; 179.22; 179.100; 179.101; 
    179.102; 179.103; 179.200; 179.201; 179.220; 179.300; 179.400; 180.509; 
    180.513; 180.515; 180.517.''.
        b. Under the Association of American Railroads, for the entry ``AAR 
    Specifications for Design, Fabrication and Construction of Freight 
    Cars, Volume 1, 1988'' in column 2, the reference is revised to read 
    ``179.16.''.
        c. Under the Compressed Gas Association, Inc., for the entry ``CGA 
    Pamphlet C-6, Standards for Visual Inspection of Compressed Gas 
    Cylinders, 1984'' in column 2, the reference is revised to read 
    ``173.34; 180.519.''.
    
    PART 172--HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS 
    MATERIALS COMMUNICATIONS, EMERGENCY RESPONSE INFORMATION, AND 
    TRAINING REQUIREMENTS
    
        3. The authority citation for part 172 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.
    
    
    Sec. 172.101  [Amended]
    
        4. In Sec. 172.101, in the Hazardous Materials Table, the following 
    changes are made:
        a. For the entries ``Benzyl chloride'', ``Fluorosulfonic acid'', 
    and ``Titanium tetrachloride'', in Column (7), Special Provision 
    ``B41,'' is removed.
        b. For the entries ``Carbon dioxide, refrigerated liquid'' and 
    ``Vinyl fluoride inhibited'', in Column (7), Special Provision ``B43'' 
    is removed.
        c. For the entry ``Hydrogen chloride, refrigerated liquid'', in 
    Column (7), Special Provision ``, B43'' is removed.
        d. For the entry ``Ethyl methyl ether'', in column (7), Special 
    Provision ``B63'' is removed.
        e. For the entry ``Ethyl chloride'', in column (7), Special 
    Provision ``B63,'' is removed.
    
    
    Sec. 172.102  [Amended]
    
        5. In Sec. 172.102, in paragraph (c)(3), the following changes are 
    made:
        a. Special Provision ``B41'' is removed.
        b. Special Provision ``B43'' is removed.
        c. Special Provision ``B63'' is removed.
        d. Special Provision ``B64'' is amended by revising the section 
    reference ``Sec. 179.105-5'' to read ``Sec. 179.16''.
        e. Special Provision ``B79'' is amended by revising the section 
    references ``Secs. 179.105-4 and 179.105-5'' to read ``Secs. 179.16 and 
    179.18''.
    
    PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENTS AND 
    PACKAGINGS
    
        6. The authority citation for part 173 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.
    
        7. Section 173.31 is revised to read as follows:
    
    
    Sec. 173.31  Use of tank cars.
    
        (a) General. (1) No person may offer a hazardous material for 
    transportation in a tank car unless the tank car meets the applicable 
    specification and packaging requirements of this subchapter or, when 
    this subchapter authorizes the use of an non-DOT specification tank 
    car, the applicable specification to which the tank was constructed.
        (2) Tank cars and appurtenances may be used for the transportation 
    of any commodity for which they are authorized in this part and 
    specified on the certificate of construction (AAR Form 4-2 or by 
    addendum on Form R-1). See Sec. 179.5 of this subchapter. Transfer of a 
    tank car from one specified service on its certificate of construction 
    to another may be made only by the owner or with the owner's 
    authorization. A tank car proposed for a commodity service other than 
    specified on its certificate of construction must be approved for such 
    service by the AAR's Tank Car Committee.
        (3) No person may fill a tank car overdue for periodic inspection 
    with a hazardous material and then offer it for transportation. Any 
    tank car marked as meeting a DOT specification and any non-
    specification tank car transporting a hazardous material must have a 
    periodic inspection and test conforming to Subpart F of Part 180 of 
    this subchapter.
        (4) No railroad tank car, regardless of its construction date, may 
    be used for the transportation in commerce of any hazardous material 
    unless the air brake equipment support attachments of such tank car 
    conform to the standards for attachments set forth in Secs. 179.100-16 
    and 179.200-19 of this subchapter.
        (5) No railroad tank car, regardless of its construction date, may 
    be used for the transportation in commerce of any hazardous material 
    with a self-energized manway located below the liquid level of the 
    lading.
        (6) Unless otherwise specifically provided in this part:
        (i) When this subchapter designates a specific specification tank 
    car, the same class tank car with a higher marked test pressure also 
    may be used.
        (ii) When the tank car specification delimiter is an ``A,'' 
    offerors may also use tank cars with a delimiter ``S,'' ``J'' or ``T''.
        (iii) When the tank car specification delimiter is an ``S,'' 
    offerors may also use tank cars with a delimiter ``J'' or ``T''.
        (iv) When a tank car specification delimiter is a ``T'' offerors 
    may also use tank cars with a delimiter of ``J''.
        (v) When a tank car specification delimiter is a ``J'', offerors 
    may not use a tank car with any other specification delimiter.
        (b) Safety systems--(1) Coupler vertical restraint. Each tank car 
    conforming to a DOT specification and any other tank car used for 
    transportation of a hazardous material must be equipped with a coupler 
    vertical restraint system that meets the requirements of Sec. 179.14 of 
    this subchapter.
        (2) Pressure relief devices. (i) Pressure relief devices on tank 
    cars must conform to Part 179 of this subchapter.
        (ii) Except for shipments of chloroprene, inhibited, in class DOT 
    115 tank cars, tank cars used for materials meeting the definition for 
    Division 6.1 liquid, Packing Group I or II, Class 2 materials, or Class 
    3 or 4 liquids, must have self-closing pressure relief devices. 
    However, a tank car built before January 1, 1991, and equipped with a 
    non-closing pressure relief device may be used to transport a Division 
    6.1 or Class 4 liquid if the liquid is not poisonous by inhalation. 
    Unless otherwise specifically provided in this 
    
    [[Page 49073]]
    subchapter, frangible discs may not have breather holes.
        (3) Tank-head puncture-resistance requirements. The following tank 
    cars must have a tank-head puncture-resistance system that conforms to 
    the requirements in Sec. 179.16 of this subchapter, or to the 
    corresponding requirements in effect at the time of installation:
        (i) Tank cars transporting a Class 2 material.
        (ii) Tank cars constructed from aluminum or nickel plate that are 
    used to transport hazardous material.
        (iii) Except as provided in paragraph (b)(3)(iv) of this section, 
    tank cars not requiring a tank-head puncture-resistance system prior to 
    July 1, 1996, must have a tank-head puncture-resistance system 
    installed no later than July 1, 2006.
        (iv) Class DOT 105A tank cars built prior to September 1, 1981, 
    having a tank capacity less than 70 kl (18,500 gallons), and used to 
    transport a Division 2.1 (flammable gas) material, must have a tank-
    head puncture-resistant system installed no later than July 1, 2001.
        (4) Thermal protection requirements. The following tank cars must 
    have thermal protection that conforms to the requirements of 
    Sec. 179.18 of this subchapter:
        (i) Tank cars transporting a Class 2 material, except for class DOT 
    105A tank cars transporting chlorine, carbon dioxide refrigerated 
    liquid, or nitrous oxide refrigerated liquid, and class DOT 106, 107A, 
    110, and 113 tank cars.
        (ii) Tank cars not requiring thermal protection prior to July 1, 
    1996, must conform to this section no later than July 1, 2006.
        (5) Bottom-discontinuity protection requirements. No person may 
    offer for transportation a hazardous material in a tank car unless the 
    tank car has bottom-discontinuity protection that conforms to the 
    requirements of E9.00 and E10.00 of the AAR Specifications for Tank 
    Cars. Tank cars not requiring bottom-discontinuity protection under the 
    terms of Appendix Y of the AAR Specifications for Tank Cars as of July 
    1, 1996, must conform to these requirements no later than July 1, 2006. 
    Tank cars modified before July 1, 1996, may conform to the bottom-
    discontinuity protection requirements of Appendix Y of the 1992 edition 
    of the AAR Specifications for Tank Cars.
        (6) Scheduling of modifications and progress reporting. The date of 
    conformance for the continued use of tank cars subject to paragraphs 
    (b)(3), (b)(4), (b)(5), (e)(2), and (f) of this section and 
    Secs. 173.314(j) and 173.323(c)(1) is subject to the following 
    conditions and limitations.
        (i) Each tank car owner shall modify, reassign, retire, or remove 
    at least 50 percent of their in-service tank car fleet within the first 
    half of the compliance period and the remainder of their in-service 
    tank car fleet during the second half of the compliance period.
        (ii) Before July 1 of each year, each owner shall submit to the 
    Associate Administrator for Safety, FRA (Attention: RRS-12) a progress 
    report that shows the reporting mark of each tank car, the status of 
    each tank car during the previous year, and the total number of those 
    tank cars modified reassigned, retired, or removed the previous year.
        (c) Tank car test pressure. A tank car used for the transportation 
    of a hazardous material must have a tank test pressure equal to or 
    greater than the greatest of the following:
        (1) Except for shipments of carbon dioxide, anhydrous hydrogen 
    chloride, vinyl fluoride, ethylene, or hydrogen, 133 percent of the sum 
    of lading vapor pressure at the reference temperature of 46  deg.C (115 
     deg.F) for non-insulated tank cars or 41  deg.C (105  deg.F) for 
    insulated tank cars plus static head, plus gas padding pressure in the 
    vacant space of a tank car;
        (2) 133 percent of the maximum loading or unloading pressure, 
    whichever is greater;
        (3) 20.7 Bar (300 psi) for materials that are poisonous by 
    inhalation;
        (4) The minimum pressure prescribed by the specification in Part 
    179 of this subchapter; or
        (5) The minimum test pressure prescribed for the specific hazardous 
    material in the applicable packaging section in Subpart F or G of this 
    Part.
        (d) Examination before shipping. (1) No person may offer for 
    transportation a tank car containing a hazardous material or a residue 
    of a hazardous material unless that person determines that the tank car 
    is in proper condition and safe for transportation. As a minimum, each 
    person offering a tank car for transportation must perform an external 
    visual inspection that includes:
        (i) Except where insulation or a thermal protection system 
    precludes an inspection, the tank shell and heads for abrasion, 
    corrosion, cracks, dents, distortions, defects in welds, or any other 
    condition that makes the tank car unsafe for transportation;
        (ii) The piping, valves, fittings, and gaskets for corrosion, 
    damage, or any other condition that makes the tank car unsafe for 
    transportation;
        (iii) For missing or loose bolts, nuts, or elements that make the 
    tank car unsafe for transportation;
        (iv) All closures on tank cars and determine that the closures and 
    all fastenings securing them are properly tightened in place by the use 
    of a bar, wrench, or other suitable tool;
        (v) Protective housings for proper securement;
        (vi) The pressure relief device, including a careful inspection of 
    the frangible disc in non-closing pressure relief devices, for 
    corrosion or damage that may alter the intended operation of the 
    device;
        (vii) Each tell-tale indicator after filling and prior to 
    transportation to ensure the integrity of the frangible disc;
        (viii) The external thermal protection system, tank head puncture 
    resistance system, coupler vertical restraint system, and other safety 
    systems for conditions that make the tank car unsafe for 
    transportation;
        (ix) The required markings on the tank car for legibility; and
        (x) The periodic inspection date markings to ensure that the 
    inspection and test intervals are within the prescribed intervals.
        (2) Closures on tank cars are required, under this subchapter, to 
    be designed and closed so that under conditions normally incident to 
    transportation, including the effects of temperature and vibration, 
    there will be no identifiable release of a hazardous material to the 
    environment. In any action brought to enforce this section, the lack of 
    securement of any closure to a tool-tight condition, detected at any 
    point, will establish a rebuttable presumption that a proper inspection 
    was not performed by the offeror of the car. That presumption may be 
    rebutted only by evidence establishing that the car was subjected to 
    abnormal treatment, e.g., a derailment or vandalism.
        (e) Special requirements for materials poisonous by inhalation--(1) 
    Interior heater coils. Tank cars used for materials poisonous by 
    inhalation may not have interior heater coils.
        (2) Tank car specifications. Except as otherwise provided in this 
    subchapter, tank cars used for materials poisonous by inhalation must 
    conform to at least a DOT 105S300W, 105S300ALW, 112J340W, or 114J340W 
    specification. Hazardous materials not requiring the use of a class DOT 
    105S300W, 105S300ALW, 112J340W, or 114J340W tank car prior to July 1, 
    1996, must be transported in one of these specifications no later than 
    July 1, 2006.
        (f) Special requirements for hazardous substances. (1) Before July 
    1, 2006, each tank car used for transportation of a 
    
    [[Page 49074]]
    hazardous substance listed in paragraph (f)(2) of this section must 
    conform to DOT 105S200W, DOT 112S200W with an 11-gauge steel jacket, 
    DOT 112S340W, or DOT 112S200W constructed from AAR steel specification 
    TC-128, normalized.
        (2) List of hazardous substances. Hazardous substances for which 
    the provisions of this paragraph (f) apply are as follows:
    
    Aldrin
    Allyl chloride
    alpha-BHC
    beta-BHC
    delta-BHC
    gamma-BHC
    Bis(2-chloroethyl) ether
    Bromoform
    Carbon tetrachloride
    Chlordane
    p-Chloroaniline
    Chlorobenzene
    Chlorobenzilate
    p-Chloro-m-cresol
    2-Chloroethyl vinyl ether
    Chloroform
    2-Chloronapthalene
    o-Chlorophenol
    3-Chloropropionitrile
    DDE
    DDT
    1,2-Dibromo-3-chloropropane
    m-Dichlorobenzene
    o-Dichlorobenzene
    p-Dichlorobenzene
    3,3'-Dichlorobenzidine
    1,4-Dichloro-2-butene
    1,1-Dichloroethane
    1,2-Dichloroethane
    1,1-Dichloroethylene
    Dichloroisopropyl ether
    Dichloromethane @
    2,4-Dichlorophenol
    2,6-Dichlorophenol
    1,2-Dichloropropane
    1,3-Dichloropropene
    Dieldrin
    alpha-Endosulfan
    beta-Endosulfan
    Endrin
    Endrin aldehyde
    Heptachlor
    Heptachlor epoxide
    Hexachlorobenzene
    Hexachlorobutadiene
    Hexachloroethane
    Hexachlorophene
    Hexachloropropene
    Isodrin
    Kepone
    Methoxychlor
    4,4'-Methylenebis(2-chloroaniline)
    Methylene bromide
    Pentachlorobenzene
    Pentachloroethane
    Pentachloronitrobenzene (PCNB)
    Pentachlorophenol
    Polychlorinated biphenyls (PCBs)
    Pronamide
    Silvex (2,4,5-TP)
    2,4,5-T
    TDE
    1,2,4,5-Tetrachlorobenzene
    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
    Tetrachloroethane
    Tetrachloroethylene
    2,3,4,6-Tetrachlorophenol
    Toxaphene
    1,2,4-Trichlorobenzene
    1,1,1-Trichloroethane
    1,1,2-Trichloroethane
    Trichloroethylene
    2,4,5-Trichlorophenol
    2,4,6-Trichlorophenol
    Tris(2,3-dibromopropyl) phosphate
    
        8. In Sec. 173.314, the section heading and paragraph (c) are 
    revised, and paragraphs (j) through (o) are added to read as follows:
    
    
    Sec. 173.314  Compressed gases in tank cars and multi-unit tank cars.
    
    * * * * *
        (c) Authorized gases, filling limits for tank cars. A compressed 
    gas in a tank car or a multi-unit tank car must be offered for 
    transportation in accordance with Sec. 173.31 and this section. The 
    named gases must be loaded and offered for transportation in accordance 
    with the following table:
    
    ----------------------------------------------------------------------------------------------------------------
                                                              Outage and filling                                    
                      Proper shipping name                    limits (see note 1)      Authorized tank car class    
    ----------------------------------------------------------------------------------------------------------------
    Ammonia, anhydrous, or ammonia solutions > 50 percent    Note 2..............  105, 112, 114.                   
     ammonia.                                                                                                       
                                                             Note 3..............  106.                             
    Ammonia solutions with > 35 percent, but  50  Note 3..............  105, 109, 112, 114.              
     percent ammonia by mass.                                                                                       
    Argon, compressed......................................  Note 4..............  107.                             
    Boron trichloride......................................  Note 3..............  105, 106.                        
    Carbon dioxide, refrigerated liquid....................  Note 5..............  105.                             
    Chlorine...............................................  Note 6..............  105.                             
                                                             125.................  106.                             
    Chlorine trifluoride...................................  Note 3..............  106, 110.                        
    Chlorine pentafluoride.................................  Note 3..............  106, 110.                        
    Dimethyl ether.........................................  Note 3..............  105, 106, 110.                   
    Dimethylamine, anhydrous...............................  Note 3..............  105, 106, 112.                   
    Dinitrogen tetroxide, inhibited........................  Note 3..............  105, 106, 110.                   
    Division 2.1 materials not specifically identified in    Note 3..............  105, 106, 110, 112, 114.         
     this table.                                                                                                    
    Division 2.2 materials not specifically identified in    Note 3..............  105, 106, 109, 110, 112, 114.    
     this table.                                                                                                    
    Division 2.3 Zone A materials not specifically           None................  See Sec. 173.245.                
     identified in this table.                                                                                      
    Division 2.3 Zone B materials not specifically           Note 3..............  105, 106, 110, 112, 114.         
     identified in this table.                                                                                      
    Division 2.3 Zone C materials not specifically           Note 3..............  105, 106, 110, 112, 114.         
     identified in this table.                                                                                      
    Division 2.3 Zone D materials not specifically           Note 3..............  105, 106, 109, 110, 112, 114.    
     identified in this table.                                                                                      
    Ethylamine.............................................  Note 3..............  105, 106, 110, 112, 114.         
    Helium, compressed.....................................  Note 4..............  107.                             
    Hydrogen...............................................  Note 4..............  107.                             
    Hydrogen chloride, refrigerated liquid.................  Note 7..............  105.                             
    Hydrogen sulphide, liquified...........................  68..................  106.                             
    Methyl bromide.........................................  Note 3..............  105, 106.                        
    Methyl chloride........................................  Note 3..............  105, 106, 112.                   
    Methyl mercaptan.......................................  Note 3..............  105, 106.                        
    Methylamine, anhydrous.................................  Note 3..............  105, 106, 112.                   
    Nitrogen, compressed...................................  Note 4..............  107.                             
    Nitrosyl chloride......................................  124.................  105.                             
                                                             110.................  106.                             
    
    [[Page 49075]]
                                                                                                                    
    Nitrous oxide, refrigerated liquid.....................  Note 5..............  105.                             
    Oxygen, compressed.....................................  Note 4..............  107.                             
    Phosgene...............................................  Note 3..............  106.                             
    Sulfur dioxide, liquified..............................  125.................  105, 106, 110.                   
    Sulfuryl fluoride......................................  120.................  105.                             
    Vinyl fluoride, inhibited..............................  Note 8..............  105.                             
    ----------------------------------------------------------------------------------------------------------------
    Notes:                                                                                                          
    1. The percent filling density for liquefied gases is hereby defined as the ratio of the mass of gas in the tank
      to the mass of water the tank will hold. For determining the water capacity of the tank in kilograms, the mass
      of one liter (0.264 gallons) of water at 15.55  deg.C (60  deg.F.) in air is 1 kg (2.204 pounds).             
    2. The liquefied gas must be so loaded so that the outage is at least two percent of the total capacity of the  
      tank at the reference temperature of 46  deg.C (115  deg.F.) for non-insulated tanks and 41  deg.C (105       
      deg.F.) for insulated tanks.                                                                                  
    3. The requirements of Sec. 173.24b(a) apply.                                                                   
    4. The gas pressure at 54.44  deg.C (130  deg.F.) in any non-insulated tank car may not exceed 7/10 of the      
      marked test pressure, except that a tank may be charged with helium to a pressure 10 percent in excess of the 
      marked maximum gas pressure at 54.44  deg.C (130  deg.F.) of each tank.                                       
    5. The liquid portion of the gas at -17.77  deg.C (0  deg.F.) must not completely fill the tank.                
    6. The maximum permitted filling density is 125 percent. The quantity of chlorine loaded into a single unit-tank
      car may not be loaded in excess of the normal lading weights nor in excess of 81.65 Mg (90 tons).             
    7. 89 percent maximum to 80.1 percent minimum at a test pressure of 6.2 Bar (90 psi).                           
    8. 59.6 percent maximum to 53.6 percent minimum at a test pressure of 7.2 Bar (105 psi).                        
    
    
    * * * * *
        (j) Special requirements for materials having a primary or 
    secondary Division 2.1 (flammable gas) hazard. For single unit tank 
    cars, interior pipes of loading and unloading valves, sampling devices, 
    and gauging devices with an opening for the passage of the lading 
    exceeding 1.52 mm (0.060 inch) diameter must be equipped with excess 
    flow valves. For single unit tank cars constructed before January 1, 
    1972, gauging devices must conform to this paragraph by no later than 
    July 1, 2006. The protective housing cover must be provided with an 
    opening, with a weatherproof cover, above each safety relief valve that 
    is concentric with the discharge of the safety relief valve and that 
    has an area at least equal to the valve outlet area. Class DOT 109 tank 
    cars and tank cars manufactured from aluminum or nickel plate are not 
    authorized.
        (k) Special requirements for chlorine. Tank cars built after 
    September 30, 1991, must have an insulation system consisting of 5.08 
    cm (2 inches) glass fiber placed over 5.08 cm (2 inches) of ceramic 
    fiber. Tank cars must have excess flow valves on the interior pipes of 
    liquid discharge valves. Tank cars constructed to a DOT 105A500W 
    specification may be marked as a DOT 105A300W specification with the 
    size and type of safety relief valves required by the marked 
    specification.
        (l) Special requirements for hydrogen sulphide. Each multi-unit 
    tank car must be equipped with adequate safety relief devices of the 
    fusible plug type having a yield temperature not over 76.66  deg.C (170 
     deg.F.), and not less than 69.44  deg.C (157  deg.F.). Each device 
    must be resistant to extrusion of the fusible alloy and leak tight at 
    55  deg.C (130  deg.F.). Each valve outlet must be sealed by a threaded 
    solid plug. In addition, all valves must be protected by a metal cover.
        (m) Special requirements for nitrosyl chloride. Single unit tank 
    cars and their associated service equipment, such as venting, loading 
    and unloading valves, and safety relief valves, must be made of metal 
    or clad with a material that is not subject to rapid deterioration by 
    the lading. Multi-unit tank car tanks must be nickel-clad and have 
    safety relief devices incorporating a fusible plug having a yield 
    temperature of 79.44  deg.C (175  deg.F.). Safety relief devices must 
    be vapor tight at 54.44  deg.C (130  deg.F.).
        (n) Special requirements for hydrogen chloride. Each tank car must 
    be equipped with one or more safety relief devices. The discharge 
    outlet for each safety relief device must be connected to a manifold 
    having a non-obstructed discharge area of at least 1.5 times the total 
    discharge area of the safety relief devices connected to the manifold. 
    All manifolds must be connected to a single common header having a non-
    obstructed discharge pointing upward and extending above the top of the 
    car. The header and the header outlet must each have a non-obstructed 
    discharge area at least equal to the total discharge area of the 
    manifolds connected to the header. The header outlet must be equipped 
    with an ignition device that will instantly ignite any hydrogen 
    discharged through the safety relief device.
        (o) Special requirements for carbon dioxide, refrigerated liquid 
    and nitrous oxide, refrigerated liquid. Each tank car must have an 
    insulation system so that the thermal conductance is not more than 
    0.613 kilojoules per hour, per square meter, per degree Celsius (0.03 
    B.t.u. per square foot per hour, per degree Fahrenheit) temperature 
    differential. Each tank car must be equipped with one safety relief 
    valve set to open at a pressure not exceeding 75 percent of the tank 
    test pressure and one frangible disc design to burst at a pressure less 
    than the tank test pressure. The discharge capacity of each safety 
    relief device must be sufficient to prevent building up of pressure in 
    the tank in excess of 82.5 percent of the test pressure of the tank. 
    Tanks must be equipped with two regulating valves set to open at a 
    pressure not to exceed 24.1 Bar (350 psi) on DOT 105A500W tanks and at 
    a pressure not to exceed 27.6 Bar (400 psi) on DOT 105A600W tanks. Each 
    regulating valve and safety relief device must have its final discharge 
    piped to the outside of the protective housing.
        9. In Sec. 173.319, new paragraph (e) is added to read as follows:
    
    
    Sec. 173.319  Cryogenic liquids in tank cars.
    
    * * * * *
        (e) Special requirements for class DOT 113 tank cars. (1) A class 
    DOT-113 tank car need not be periodically pressure tested; however, 
    each shipment must be monitored to determine the average daily pressure 
    rise in the tank car. If the average daily pressure rise during any 
    shipment exceeds 0.2 Bar (3 psi) per day, the tank must be tested for 
    thermal integrity prior to any subsequent shipment.
        (2) Thermal integrity test. When required by paragraph (e)(1) of 
    this section, either of the following thermal integrity tests may be 
    used:
        (i) Pressure rise test. The pressure rise in the tank may not 
    exceed 0.34 Bar (5 psi) in 24 hours. When the pressure rise test is 
    performed, the absolute pressure in the annular space of the loaded 
    tank car may not exceed 75 microns of 
    
    [[Page 49076]]
    mercury at the beginning of the test and may not increase more than 25 
    microns during the 24-hour period; or
        (ii) Calculated heat transfer rate test. The insulation system must 
    be performance tested as prescribed in Sec. 179.400-4 of this 
    subchapter. When the calculated heat transfer rate test is performed, 
    the absolute pressure in the annular space of the loaded tank car may 
    not exceed 75 microns of mercury at the beginning of the test and may 
    not increase more than 25 microns during the 24-hour period. The 
    calculated heat transfer rate in 24 hours may not exceed:
        (A) 120 percent of the appropriate standard heat transfer rate 
    specified in Sec. 179.401-1 of this subchapter, for DOT-113A60W and 
    DOT-113C120W tank cars;
        (B) 122.808 joules (0.1164 Btu/day/lb.) of inner tank car water 
    capacity, for DOT-113A175W tank cars;
        (C) 345.215 joules (0.3272 Btu/day/lb.) of inner tank car water 
    capacity, for DOT-113C60W and 113D60W tank cars; or
        (D) 500.09 joules (0.4740 Btu/day/lb.) of inner tank car water 
    capacity, for DOT-113D120W tank cars.
        (3) A tank car that fails a test prescribed in paragraph (e)(2) of 
    this section must be removed from hazardous materials service. A tank 
    car removed from hazardous materials service because it failed a test 
    prescribed in paragraph (e)(2) of this section may not be used to 
    transport a hazardous material unless the tank car conforms to all 
    applicable requirements of this subchapter.
        (4) Each frangible disc must be replaced with a new frangible disc 
    every 12 months, and the replacement date must be marked on the car 
    near the pressure relief valve information.
        (5) Pressure relief valves and alternate pressure relief valves 
    must be tested every five years. The start-to-discharge pressure and 
    vapor tight pressure requirements for the pressure relief valves must 
    be as specified in Sec. 179.401-1 of this subchapter. The alternate 
    pressure relief device values specified in Sec. 179.401-1 of this 
    subchapter for a DOT-113C120W tank car apply to a DOT-113D120W tank 
    car.
    
    
    Sec. 173.319  [Amended]
    
        10. In addition, in Sec. 173.319, in paragraph (a)(4)(iii), the 
    parenthetical reference ``(see Sec. 173.31(c)(13))'' is removed.
        11. In Sec. 173.323, paragraph (c)(1) is revised to read as 
    follows:
    
    
    Sec. 173.323  Ethylene oxide.
    
    * * * * *
        (c) * * *
        (1) Tank cars. Class DOT 105J tank cars: Notwithstanding the 
    requirements of Sec. 173.31(c), each tank car must have a tank test 
    pressure of at least 20.7 Bar (300 psi) no later than July 1, 2006.
    * * * * *
    
    PART 179--SPECIFICATIONS FOR TANK CARS
    
        2. The authority citation for part 179 continues to read as 
    follows:
    
        Authority: 49 App. U.S.C. 5101-5127; 49 CFR 1.53.
    
    
    Sec. 179.1  [Amended]
    
        13. In Sec. 179.1, in paragraph (c), the section reference 
    ``Sec. 173.31'' is revised to read ``Sec. 180.507''.
        14. In Sec. 179.2, paragraph (a)(10) is redesignated as paragraph 
    (a)(11) and a new paragraph (a)(10) is added to read as follows:
    
    
    Sec. 179.2  Definitions and abbreviations.
    
        (a) * * *
        (10) Tank car facility means an entity that manufactures, repairs, 
    inspects, or tests a tank car to ensure that the tank car conforms to 
    this part and subpart F of part 180 of this subchapter, that alters the 
    certificate of construction of the tank car, that ensures the 
    continuing qualification of a tank car by performing a function 
    prescribed in parts 179 or 180 of this subchapter, or that makes any 
    representation indicating compliance with one or more of the 
    requirements of parts 179 or 180 of this subchapter.
    * * * * *
        15. Section 179.7 is added to subpart A to read as follows:
    
    
    Sec. 179.7 Quality assurance program.
    
        (a) At a minimum, each tank car facility shall have a quality 
    assurance program, approved by AAR, that--
        (1) Ensures the finished product conforms to the requirements of 
    the applicable specification and regulations of this subchapter;
        (2) Has the means to detect any nonconformity in the manufacturing, 
    repair, or testing of the tank car; and
        (3) Prevents non-conformities from recurring.
        (b) At a minimum, the quality assurance program must have the 
    following elements
        (1) Statement of authority and responsibility for those persons in 
    charge of the quality assurance program.
        (2) An organizational chart showing the interrelationship between 
    managers, engineers, purchasing, construction, inspection, testing, and 
    quality control personnel.
        (3) Procedures to ensure that the latest applicable drawings, 
    design calculations, specifications, and instructions are used in 
    manufacture, inspection, testing, and repair.
        (4) Procedures to ensure that the fabrication and construction 
    materials received are properly identified and documented.
        (5) A description of the manufacturing, inspection, and testing 
    program so that an inspector can determine specific inspection and test 
    intervals.
        (6) Monitoring and control of processes and product characteristics 
    during production.
        (7) Procedures for correction of imperfections.
        (8) Provisions indicating that the requirements of the AAR 
    Specifications for Tank Cars, Specification M-1002, apply.
        (9) Qualification requirements of personnel performing ultrasonic, 
    radiographic, dye penetrant, magnetic particle, or other non-
    destructive inspections and tests.
        (10) Qualification requirements of personnel performing optically 
    aided visual inspections (including fiber optic, borescope, and video-
    image-scope systems). Under these requirements, the examiner must have 
    the capability to consistently and repetitively find flaws under test 
    conditions. Furthermore, the requirements must include visual acuity 
    criteria where detectability (minimum size of a flaw that an examiner 
    can find); resolution (minimum distance at which two flaws may be seen 
    separately); and contrast sensitivity (minimum detectable thickness 
    change (convolutions) over a surface area) further define the 
    qualifications of the examiner.
        (11) Procedures for evaluating the inspection and test technique 
    employed, including the accessibility of the area and the sensitivity 
    of the inspection and test technique and minimum detectable crack 
    length.
        (12) Procedures for the periodic calibration and measurement of 
    inspection and test equipment.
        (13) A system for the maintenance of records, inspections, tests, 
    and the interpretation of inspection and test results.
        (c) Each tank car facility shall ensure that only personnel 
    qualified for each non-destructive inspection and test perform that 
    particular operation.
        (d) Each tank car facility shall establish written procedures for 
    their employees to ensure that the work performed on the tank car 
    conforms to the specification and AAR approval for the tank car.
        (e) Each tank car facility shall train its employees in accordance 
    with Subpart 
    
    [[Page 49077]]
    H of part 172 of this subchapter on the program and procedures 
    specified in paragraph (b) of this section to ensure quality.
        (f) Date of conformance. After July 1, 1998, no tank car facility 
    may manufacture, repair, inspect, or test tank cars subject to 
    requirements of this subchapter, unless it is operating in conformance 
    with a quality assurance program and written procedures required by 
    paragraphs (a) and (b) of this section.
        16. Section 179.16 is added to subpart B to read as follows:
    
    
    Sec. 179.16  Tank-head puncture-resistance systems.
    
        (a) Performance standard. When the regulations in this subchapter 
    require a tank-head puncture-resistance system, the system shall be 
    capable of sustaining, without any loss of lading, coupler-to-tank-head 
    impacts at relative car speeds of 29 km/hour (18 mph) when:
        (1) The weight of the impact car is at least 119,295 kg (263,000 
    pounds);
        (2) The impacted tank car is coupled to one or more backup cars 
    that have a total weight of at least 217,724 kg (480,000 pounds) and 
    the hand brake is applied on the last ``backup'' car; and
        (3) The impacted tank car is pressurized to at least 6.9 Bar (100 
    psi).
        (b) Compliance with the requirements of paragraph (a) of this 
    section shall be verified by full-scale testing according to Appendix A 
    of this part or by installing full-head protection (shields) or full 
    tank-head jackets on each end of the tank car conforming to the 
    following
        (1) The tank-head puncture-resistance system must be at least 1.27 
    cm (0.5 inch) thick, shaped to the contour of the tank head and made 
    from steel having a tensile strength greater than 379.21 N/mm\2\ 
    (55,000 psi).
        (2) The design and test requirements of the tank-head puncture-
    resistance system must meet the impact test requirements of Section 5.3 
    of the AAR Specifications for Tank Cars.
        (3) The workmanship must meet the requirements of Section C, Part 
    II, Chapter 5 of the AAR Specifications for Design, Fabrication, and 
    Construction of Freight Cars.
        17. Section 179.18 is added to subpart B to read as follows:
    
    
    Sec. 179.18  Thermal protection systems.
    
        (a) Performance standard. When the regulations in this subchapter 
    require thermal protection on a tank car, the tank car must have 
    sufficient thermal resistance so that there will be no release of any 
    lading within the tank car, except release through the safety relief 
    valve, when subjected to:
        (1) A pool fire for 100 minutes; and
        (2) A torch fire for 30 minutes.
        (b) Thermal analysis. (1) Compliance with the requirements of 
    paragraph (a) of this section shall be verified by modeling the fire 
    effects on the entire surface of the tank car according to the 
    procedures outlined in ``Temperatures, Pressures and Liquid Levels of 
    Tank Cars Engulfed in Fires,'' DOT/FRA/OR&D-84/08.11, (1984), Federal 
    Railroad Administration, Washington D.C. (available from National 
    Technical Information Service, Springfield, VA 22161), or other 
    procedure approved by the AAR Committee on Tank Cars. The analysis must 
    also consider the fire effects on and the heat flux through tank 
    discontinuities, protective housings, underframes, metal jackets, 
    insulation, and thermal protection. A complete record of each analysis 
    shall be made, retained and, upon request, made available for 
    inspection and copying by an authorized representative of the 
    Department.
        (2) When the analysis shows the thermal resistance of the tank car 
    does not conform to paragraph (a) of this section, the thermal 
    resistance of the tank car must be increased by using a system listed 
    by the Department under paragraph (c) of this section or by testing an 
    unlisted system and verifying it according to appendix B of this part.
        (c) Systems that no longer require test verification. The 
    Department maintains a list of thermal protection systems that comply 
    with the requirements of appendix B of this part and that no longer 
    require test verification. Information necessary to equip tank cars 
    with one of these systems is available in the Dockets Unit, Research 
    and Special Programs Administration, 400 Seventh Street, SW., 
    Washington, D.C. 20590-0001.
        18. Section 179.20 is added to subpart B to read as follows:
    
    
    Sec. 179.20  Service equipment; protection systems.
    
        If an applicable tank car specification authorizes location of 
    filling or discharge connections in the bottom shell, the connections 
    must be designed, constructed, and protected according to paragraphs 
    E9.00 and E10.00 of the AAR Specifications for Tank Cars, M-1002.
        19. Section 179.22 is added to subpart B to read as follows:
    
    
    Sec. 179.22  Marking.
    
        In addition to any other marking requirement in this subchapter, 
    the following marking requirements apply:
        (a) Each tank car must be marked according to the requirements in 
    Appendix C of the AAR Specifications for Tank Cars.
        (b) Each tank car that is equipped with a tank-head puncture-
    resistance system must have the letter ``S'' substituted for the letter 
    ``A'' in the specification marking.
        (c) Each tank car that is equipped with a tank-head puncture-
    resistance system, a thermal protection system, and a metal jacket must 
    have the letter ``J'' substituted for the letter ``A'' or ``S'' in the 
    specification marking.
        (d) Each tank car that is equipped with a tank-head puncture-
    resistance system, a thermal protection system, and no metal jacket 
    must have the letter ``T'' substituted for the letter ``A'' or ``S'' in 
    the specification marking.
    
    
    Sec. 179.100-4  [Amended]
    
        20. In Sec. 179.100-4, in paragraph (a), the last sentence is 
    amended by removing the phrase ``except that a protective coating is 
    not required when foam-in-place insulation that adheres to the tank or 
    jacket is applied''.
    
    
    Secs. 179.100-21 and 179.100-23  [Removed]
    
        21. Sections 179.100-21 and 179.100-23 are removed.
        22. In Sec. 179.101-1, in paragraph (a), Note 4 following the table 
    is revised to read as follows:
    
    
    Sec. 179.101-1  Individual specification requirements.
    
        (a) * * *
        \4\ Tank cars not equipped with a thermal protection or an 
    insulation system used for the transportation of a Class 2 
    (compressed gas) material must have at least the upper two-thirds of 
    the exterior of the tank, including manway nozzle and all 
    appurtenances in contact with this area, finished with a reflective 
    coat of white paint.
    * * * * *
    
    
    Sec. 179.103-1  [Amended]
    
        23. In Sec. 179.103-1, paragraph (c) is removed and reserved.
        24. In Sec. 179.103-2, paragraph (a) is revised to read as follows:
    
    
    Sec. 179.103-2  Manway cover.
    
        (a) The manway cover must be an approved design.
    * * * * *
    
    
    Sec. 179.103-5  [Amended]
    
        25. In Sec. 179.103-5, paragraph (a)(1) is amended by removing the 
    first two sentences.
    
    
    Secs. 179.105, 179.105-1--179.105-8  [Removed]
    
        26. Sections 179.105, 179.105-1 through 179.105-8 are removed.
        27. In Sec. 179.200-4, in paragraph (a), the last sentence is 
    revised to read as follows:
    
    [[Page 49078]]
    
    
    
    Sec. 179.200-4  Insulation.
    
        (a) * * * The exterior surface of a carbon steel tank and the 
    inside surface of a carbon steel jacket must be given a protection 
    coating.
    * * * * *
    
    
    Secs. 179.200-25 and 179.200-27  [Removed]
    
        28. Sections 179.200-25 and 179.200-27 are removed.
    
    
    Secs. 179.203, 179.203-1--179.203-3  [Removed]
    
        29. Sections 179.203, 179.203-1 through 179.203-2 are removed.
        30. Appendixes A and B are added to Part 179 to read as follows:
    
    Appendix A to Part 179--Procedures for Tank-Head Puncture-Resistance 
    Test
    
        1. This test procedure is designed to verify the integrity of 
    new or untried tank-head puncture-resistance systems and to test for 
    system survivability after coupler-to-tank-head impacts at relative 
    speeds of 29 km/hour (18 mph).
        2. Tank-head puncture-resistance test. A tank-head puncture-
    resistance system must be tested under the following conditions:
        a. The ram car used must weigh at least 119,295 kg (263,000 
    pounds), be equipped with a coupler, and duplicate the condition of 
    a conventional draft sill including the draft yoke and draft gear. 
    The coupler must protrude from the end of the ram car so that it is 
    the leading location of perpendicular contact with the impacted test 
    car.
        b. The impacted test car must be loaded with water at six 
    percent outage with internal pressure of at least 6.9 Bar (100 psi) 
    and coupled to one or more ``backup'' cars which have a total weight 
    of 217,724 kg (480,000 pounds) with hand brakes applied on the last 
    ``backup'' car.
        c. At least two separate tests must be conducted with the 
    coupler on the vertical centerline of the ram car. One test must be 
    conducted with the coupler at a height of 53.3 cm (21 inches), plus-
    or-minus 2.5 cm (1 inch), above the top of the sill; the other test 
    must be conducted with the coupler height at 79 cm (31 inches), 
    plus-or-minus 2.5 cm (1 inch), above the top of the sill. If the 
    combined thickness of the tank head and any additional shielding 
    material is less than the combined thickness on the vertical 
    centerline of the car, a third test must be conducted with the 
    coupler positioned so as to strike the thinnest point of the tank 
    head.
        3. One of the following test conditions must be applied:
    
    ------------------------------------------------------------------------
                                     Minimum                                
     Minimum weight of attached    velocity of                              
       ram cars in kg (pounds)    impact in km/          Restrictions       
                                    hour (mph)                              
    ------------------------------------------------------------------------
    119,295 (263,000)...........  29 (18)......  One ram car only.          
    155,582 (343,000)...........  25.5 (16)....  One ram car or one car plus
                                                  one rigidly attached car. 
    311,164 (686,000)...........  22.5 (14)....  One ram car plus one or    
                                                  more rigidly attached     
                                                  cars.                     
    ------------------------------------------------------------------------
    
        4. A test is successful if there is no visible leak from the 
    standing tank car for at least one hour after impact.
    
    Appendix B to Part 179--Procedures for Simulated Pool and Torch-Fire 
    Testing
    
        1. This test procedure is designed to measure the thermal 
    effects of new or untried thermal protection systems and to test for 
    system survivability when exposed to a 100-minute pool fire and a 
    30-minute torch fire.
        2. Simulated pool fire test. 
        a. A pool-fire environment must be simulated in the following 
    manner:
        (1) The source of the simulated pool fire must be hydrocarbon 
    fuel with a flame temperature of 871  deg.C (1,600  deg.F), plus-or-
    minus 37.8  deg.C (100  deg.F), throughout the duration of the test.
        (2) A square bare plate with thermal properties equivalent to 
    the material of construction of the tank car must be used. The plate 
    dimensions must be not less than one foot by one foot by nominal 1.6 
    cm (0.625 inch) thick. The bare plate must be instrumented with not 
    less than nine thermocouples to record the thermal response of the 
    bare plate. The thermocouples must be attached to the surface not 
    exposed to the simulated pool fire and must be divided into nine 
    equal squares with a thermocouple placed in the center of each 
    square.
        (3) The pool-fire simulator must be constructed in a manner that 
    results in total flame engulfment of the front surface of the bare 
    plate. The apex of the flame must be directed at the center of the 
    plate.
        (4) The bare plate holder must be constructed in such a manner 
    that the only heat transfer to the back side of the bare plate is by 
    heat conduction through the plate and not by other heat paths.
        (5) Before the bare plate is exposed to the simulated pool fire, 
    none of the temperature recording devices may indicate a plate 
    temperature in excess of 37.8  deg.C (100  deg.F) nor less than 0 
    deg.C (32  deg.F).
        (6) A minimum of two thermocouple devices must indicate 427 
    deg.C (800  deg.F) after 13 minutes, plus-or-minus one minute, of 
    simulated pool-fire exposure.
        b. A thermal protection system must be tested in the simulated 
    pool-fire environment described in paragraph 2a of this appendix in 
    the following manner:
        (1) The thermal protection system must cover one side of a bare 
    plate as described in paragraph 2a(2) of this appendix.
        (2) The non-protected side of the bare plate must be 
    instrumented with not less than nine thermocouples placed as 
    described in paragraph 2a(2) of this appendix to record the thermal 
    response of the plate.
        (3) Before exposure to the pool-fire simulation, none of the 
    thermocouples on the thermal protection system configuration may 
    indicate a plate temperature in excess of 37.8  deg.C (100  deg.F) 
    nor less than 0  deg.C (32  deg.F).
        (4) The entire surface of the thermal protection system must be 
    exposed to the simulated pool fire.
        (5) A pool-fire simulation test must run for a minimum of 100 
    minutes. The thermal protection system must retard the heat flow to 
    the plate so that none of the thermocouples on the non-protected 
    side of the plate indicate a plate temperature in excess of 427 
    deg.C (800  deg.F).
        (6) A minimum of three consecutive successful simulation fire 
    tests must be performed for each thermal protection system.
        3. Simulated torch fire test. 
        a. A torch-fire environment must be simulated in the following 
    manner:
        (1) The source of the simulated torch must be a hydrocarbon fuel 
    with a flame temperature of 1,204  deg.C (2,200  deg.F), plus-or-
    minus 37.8  deg.C (100  deg.F), throughout the duration of the test. 
    Furthermore, torch velocities must be 64.4 km/h  16 km/h 
    (40 mph  10 mph) throughout the duration of the test.
        (2) A square bare plate with thermal properties equivalent to 
    the material of construction of the tank car must be used. The plate 
    dimensions must be at least four feet by four feet by nominal 1.6 cm 
    (0.625 inch) thick. The bare plate must be instrumented with not 
    less than nine thermocouples to record the thermal response of the 
    plate. The thermocouples must be attached to the surface not exposed 
    to the simulated torch and must be divided into nine equal squares 
    with a thermocouple placed in the center of each square.
        (3) The bare plate holder must be constructed in such a manner 
    that the only heat transfer to the back side of the plate is by heat 
    conduction through the plate and not by other heat paths. The apex 
    of the flame must be directed at the center of the plate.
        (4) Before exposure to the simulated torch, none of the 
    temperature recording devices may indicate a plate temperature in 
    excess of 37.8  deg.C (100  deg.F) or less than 0  deg.C (32 
    deg.F).
        (5) A minimum of two thermocouples must indicate 427  deg.C (800 
     deg.F) in four minutes, plus-or-minus 30 seconds, of torch 
    simulation exposure.
        b. A thermal protection system must be tested in the simulated 
    torch-fire environment described in paragraph 3a of this appendix in 
    the following manner:
        (1) The thermal protection system must cover one side of the 
    bare plate identical to that used to simulate a torch fire under 
    paragraph 3a(2) of this appendix.
        (2) The back of the bare plate must be instrumented with not 
    less than nine thermocouples placed as described in 
    
    [[Page 49079]]
    paragraph 3a(2) of this appendix to record the thermal response of the 
    material.
        (3) Before exposure to the simulated torch, none of the 
    thermocouples on the back side of the thermal protection system 
    configuration may indicate a plate temperature in excess of 37.8 
    deg.C (100  deg.F) nor less than 0  deg.C (32  deg.F).
        (4) The entire outside surface of the thermal protection system 
    must be exposed to the simulated torch-fire environment.
        (5) A torch-simulation test must be run for a minimum of 30 
    minutes. The thermal protection system must retard the heat flow to 
    the plate so that none of the thermocouples on the backside of the 
    bare plate indicate a plate temperature in excess of 427  deg.C (800 
     deg.F).
        (6) A minimum of two consecutive successful torch-simulation 
    tests must be performed for each thermal protection system.
    PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS
        31. The authority citation for part 180 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.
    
        32. A new Subpart F is added to part 180 to read as follows:
    Subpart F--Qualification and Maintenance of Tank Cars
    Sec.
    180.501  Applicability.
    180.503  Definitions.
    180.505  Quality assurance program.
    180.507  Qualification of tank cars.
    180.509  Requirements for inspection and test of specification tank 
    cars.
    180.511  Acceptable results of inspections and tests.
    180.513  Repairs, alterations, conversions, and modifications.
    180.515  Markings.
    180.517  Reporting and record retention requirements.
    180.519  Periodic retest and inspection of tank cars other than 
    single-unit tank car tanks.
    Subpart F--Qualification and Maintenance of Tank Cars
    Sec. 180.501  Applicability.
    
        (a) This subpart prescribes requirements, in addition to those 
    contained in parts 107, 171, 172, 173, and 179 of this subchapter, 
    applicable to any person who manufactures, fabricates, marks, 
    maintains, repairs, inspects, or services tank cars to ensure that the 
    tank cars are in proper condition for transportation.
        (b) Any person who performs a function prescribed in this part 
    shall perform that function in accordance with this part.
    Sec. 180.503  Definitions.
    
        The definitions contained in Secs. 171.8 and 179.2 of this 
    subchapter apply.
    
    
    Sec. 180.505  Quality assurance program.
    
        The quality assurance program requirements of Sec. 179.7 of this 
    subchapter apply.
    
    
    Sec. 180.507  Qualification of tank cars.
    
        (a) Each tank car marked as meeting a ``DOT'' specification or any 
    other tank car used for the transportation of a hazardous material must 
    meet the requirements of this subchapter or the applicable 
    specification to which the tank was constructed.
        (b) Tank car specifications no longer authorized for construction. 
    (1) Tank cars prescribed in the following table are authorized for 
    service provided they conform to all applicable safety requirements of 
    this subchapter:
    
    ------------------------------------------------------------------------
    Specification prescribed in the                                         
          current regulations         Other specifications permitted   Notes
    ------------------------------------------------------------------------
    105A200W.......................  105A100W.......................       1
    105A200ALW.....................  105A100ALW.....................       1
    105A300W.......................  ICC-105, 105A300...............        
    105A400W.......................  105A400........................        
    105A500W.......................  105A500........................        
    105A600W.......................  105A600........................        
    106A500X.......................  ICC-27, BE-27, 106A500.........        
    106A800X.......................  106A800........................        
    107A * * * *...................  ...............................       2
    ------------------------------------------------------------------------
    Note 1: Tanks built as Specification DOT 105A100W or DOT 105A100ALW may 
      be altered and converted to DOT 105A200W and DOT 105A200ALW,          
      respectively.                                                         
    Note 2: The test pressures of tanks built in the United States between  
      January 1, 1941 and December 31, 1955, may be increased to conform to 
      Specification 107A. Original and revised test pressure markings must  
      be indicated and may be shown on the tank or on a plate attached to   
      the bulkhead of the car. Tanks built before 1941 are not authorized.  
    
        (2) For each tank car conforming to and used under an exemption 
    issued before October 1, 1984, which authorized the transportation of a 
    cryogenic liquid in a tank car, the owner or operator shall remove the 
    exemption number stenciled on the tank car and stamp the tank car with 
    the appropriate Class DOT-113 specification followed by the applicable 
    exemption number. For example: DOT-113D60W-E * * * * (asterisks to be 
    replaced by the exemption number). The owner or operator marking a tank 
    car in this manner shall retain on file a copy of the last exemption in 
    effect during the period the tank car is in service. No person may 
    modify a tank car marked under this paragraph unless the modification 
    is in compliance with an applicable requirement or provision of this 
    subchapter.
        (3) Specification DOT-113A175W, DOT-113C60W, DOT-113D60W, and DOT-
    113D120W tank cars may continue in use, but new construction is not 
    authorized.
        (4) Class DOT 105A and 105S tank cars used to transport hydrogen 
    chloride, refrigerated liquid under the terms of DOT-E 3992 may 
    continue in service, but new construction is not authorized.
    
    
    Sec. 180.509  Requirements for inspection and test of specification 
    tank cars.
    
        (a) General. (1) Each tank car facility shall evaluate a tank car 
    according to the requirements specified in Sec. 180.511.
        (2) Each tank car that successfully passes a periodic inspection 
    and test must be marked as prescribed in Sec. 180.515.
        (3) A written report as specified in Sec. 180.517(b) must be 
    prepared for each tank car that is inspected and tested under this 
    section.
        (b) Conditions requiring inspection and test of tank cars. Without 
    regard to any other periodic inspection and test requirement, a tank 
    car must have an inspection and test according to this section if:
        (1) The tank car shows evidence of abrasion, corrosion, cracks, 
    dents, distortions, defects in welds, or any other condition that makes 
    the tank car unsafe for transportation.
        (2) The tank car was in an accident and damaged to an extent that 
    may adversely affect its capability to retain its contents.
        (3) The tank bears evidence of damage caused by fire.
        (4) The Associate Administrator for Safety, FRA, requires it based 
    on the existence of probable cause that a tank car or a class or design 
    of tank cars may be in an unsafe operating condition.
        (c) Frequency of inspection and tests. Each tank car shall have an 
    inspection and test according to the requirements of this paragraph.
        (1) For Class 107 tank cars and tank cars of riveted construction, 
    the tank car must have a hydrostatic pressure test and visual 
    inspection conforming to the requirements in effect prior to July 1, 
    1996, for the tank specification.
        (2) For Class DOT 113 tank cars, see Sec. 173.319(e) of this 
    subchapter.
        (3) For fusion welded tank cars, each tank car must have an 
    inspection and test in accordance with paragraphs (d) through (k) of 
    this section.
        (i) For cars transporting materials not corrosive to the tank, 
    every 10 years for the tank and service equipment (i.e., filling and 
    discharge, venting, safety, heating, and measuring devices).
        (ii) For non-lined or non-coated tank cars transporting materials 
    corrosive to the tank, an interval based on the following formula, but 
    in no case shall 
    
    [[Page 49080]]
    the interval exceed 10 years for the tank and 5 years for service 
    equipment:
    
                                                                            
                                          t1-t2                             
                                  i =  ----------                           
                                            r                               
                                                                            
    
    where:
    i  is the inspection and test interval.
    t1  is the actual thickness.
    t2  is the allowable minimum thickness under paragraph (g) of this 
    section.
    r  is the corrosion rate per year.
    
        (iii) For lined or coated tank cars transporting a material 
    corrosive to the tank, every 10 years for the tank, 5 years for the 
    service equipment, and when a lining or coating is applied to protect 
    the tank shell from the lading, an interval based on the owner's 
    determination for the lining or coating, but not greater than every 10 
    years.
        (A) When a lining or coating is applied to protect the tank shell 
    from the lading, each owner of a lining or coating shall determine the 
    periodic inspection interval and test technique for the lining or 
    coating. The owner must maintain all supporting documentation used to 
    make such a determination, such as the lining or coating manufacturer's 
    recommended inspection interval and test technique, at the owner's 
    principal place of business.
        (B) The supporting documentation used to make such inspection and 
    test interval determinations and technique must be made available to 
    FRA upon request.
        (d) Visual inspection. At a minimum, each tank car facility must 
    visually inspect the tank externally and internally as follows:
        (1) An internal inspection of the tank shell and heads for 
    abrasion, corrosion, cracks, dents, distortions, defects in welds, or 
    any other condition that makes the tank car unsafe for transportation, 
    and except in the areas where insulation or a thermal protection system 
    precludes it, an external inspection of the tank shell and heads for 
    abrasion, corrosion, cracks, dents, distortions, defects in welds, or 
    any other condition that makes the tank car unsafe for transportation;
        (2) An inspection of the piping, valves, fittings, and gaskets for 
    indications of corrosion and other conditions that make the tank car 
    unsafe for transportation;
        (3) An inspection for missing or loose bolts, nuts, or elements 
    that make the tank car unsafe for transportation;
        (4) An inspection of all closures on the tank car for proper 
    securement in a tool tight condition and an inspection of the 
    protective housings for proper securement;
        (5) An inspection of excess flow valves having threaded seats for 
    tightness; and
        (6) An inspection of the required markings on the tank car for 
    legibility.
        (e) Structural integrity inspections and tests. At a minimum, each 
    tank car facility shall inspect the tank car for structural integrity 
    as specified in this section. The structural integrity inspection and 
    test shall include all transverse fillet welds greater than 0.64 cm 
    (0.25 inch) within 121.92 cm (4 feet) of the bottom longitudinal center 
    line; the termination of longitudinal fillet welds greater than 0.64 cm 
    (0.25 inch) within 121.92 cm (4 feet) of the bottom longitudinal center 
    line; and all tank shell butt welds within 60.96 cm (2 feet) of the 
    bottom longitudinal center line by one or more of the following 
    inspection and test methods to determine that the welds are in proper 
    condition:
        (1) Dye penetrant test;
        (2) Radiography test;
        (3) Magnetic particle test;
        (4) Ultrasonic test; or
        (5) Optically-aided visual inspection (e.g., magnifiers, 
    fiberscopes, borescopes, and machine vision technology).
        (f) Thickness tests. (1) Each tank car facility shall measure the 
    thickness of the tank car shell, heads, sumps, domes, and nozzles on 
    each tank car by using a device capable of accurately measuring the 
    thickness to within 0.05 mm (0.002 inch).
        (2) After repairs, alterations, conversions or modifications of a 
    tank car that result in a reduction to the tank car shell thickness, 
    the tank car facility shall measure the thickness of the tank car shell 
    in the area of reduced shell thickness to ensure that the shell 
    thickness conforms to paragraph (g) of this section.
        (g) Service life shell thickness allowance. (1) A tank car found 
    with a shell thickness below the required minimum thickness after 
    forming for its specification, as stated in part 179 of this 
    subchapter, may continue in service if:
         (i) Construction of the tank car shell and heads is from carbon 
    steel, stainless steel, aluminum, nickel, or manganese-molybdenum 
    steel; and
         (ii) Any reduction in thickness of the tank shell or head is not 
    more than that provided in the following table:
    
                                          Allowable Shell Thickness Reductions                                      
    ----------------------------------------------------------------------------------------------------------------
                         Class DOT 103, 104, 111, and 115 tank       Class DOT 105, 109, 112, and 114 tank cars     
                                         cars                  -----------------------------------------------------
        Damage type    ----------------------------------------                                                     
                             Top shell         Bottom shell         Top shell                 Bottom shell          
    ----------------------------------------------------------------------------------------------------------------
    Corrosion.........  3.17 mm (0.125      1.58 mm (0.063      0.79 mm (0.031     0.79 mm (0.031 inch).            
                         inch).              inch).              inch).                                             
    Corrosion and       3.17 mm (0.125      1.58 mm (0.063      0.79 mm (0.031     0.79 mm (0.031 inch).            
     mechanical.         inch).              inch).              inch).                                             
    Corrosion, local..  4.76 mm (\3/16\     3.17 mm (0.125      1.58 mm (0.063     1.58 mm (0.063 inch).            
                         inch).              inch).              inch).                                             
    Mechanical, local.  3.17 mm (0.125      1.58 mm (0.063      1.58 mm (0.063     1.58 mm (0.063 inch).            
                         inch).              inch).              inch).                                             
    Corrosion and       4.76 mm (\3/16\     3.17 mm (0.125      1.58 mm (0.063     1.58 mm (0.063 inch).            
     mechanical, local.  inch).              inch).              inch).                                             
    ----------------------------------------------------------------------------------------------------------------
    Notes:                                                                                                          
    1. The perimeter for a local reduction may not exceed a 60.96 cm (24 inch) perimeter. Local reductions in the   
      top shell must be separated from other reductions in the top shell by at least 40.64 cm (16 inches). The      
      cumulative perimeter for local reductions in the bottom shell may not exceed 182.88 cm (72 inches).           
    2. Any reduction in the tank car shell may not affect the structural strength of the tank car so that the tank  
      car shell no longer conforms to Section 6.2 of the AAR Specifications for Tank Cars.                          
    3. Any reduction applies only to the outer shell for Class DOT 115 tank cars.                                   
    4. For Class DOT 103 and 104 tank cars, the inside diameter may not exceed 243.84 cm (96 inches).               
    
         (h) Safety system inspections. At a minimum, each tank car 
    facility must inspect:
        (1) Tank car thermal protection systems, tank head puncture 
    resistance systems, coupler vertical restraint systems, and systems 
    used to protect discontinuities (i.e., skid protection and protective 
    housings) to ensure their integrity. 
    
    [[Page 49081]]
    
         (2) Reclosing pressure relief devices by:
        (i) Removing the safety relief device from the tank car for 
    inspection; and
        (ii) Testing the safety relief device with air or another gas to 
    ensure that it conforms to the start-to-discharge pressure for the 
    specification or hazardous material in this subchapter.
        (i) Lining and coating inspection and test. When this subchapter 
    requires a lining or coating, at a minimum, each tank car facility must 
    inspect the lining or coating installed on the tank car according to 
    the inspection interval and test technique established by the owner of 
    the lining or coating in accordance with paragraph (c)(3)(iii) of this 
    section.
        (j) Leakage pressure test. (1) At a minimum, each tank car facility 
    shall perform a leakage pressure test on the tank fittings and 
    appurtenances. The leakage pressure test must include product piping 
    with all valves and accessories in place and operative, except that 
    during the pressure test the tank car facility shall remove or render 
    inoperative any venting devices set to discharge at less than the test 
    pressure. Test pressure must be maintained for at least 5 minutes. 
    Leakage test pressure may not be less than 2.1 Bar (30 psig) for tank 
    cars having a test pressure less than or equal to 13.8 Bar (200 psig), 
    or 3.4 Bar (50 psig) for tank cars having a tank test pressure greater 
    than 13.8 Bar (200 psig).
        (2) Interior heater systems must be tested hydrostatically at 13.87 
    Bar (200 psi) and must show no signs of leakage.
        (k) Alternative inspection and test procedures. In lieu of the 
    other requirements of this section, a person may use an alternative 
    inspection and test procedure or interval based on a damage-tolerance 
    fatigue evaluation (that includes a determination of the probable 
    locations and modes of damage due to fatigue, corrosion, or accidental 
    damage), when the evaluation is examined by the Association of American 
    Railroads Tank Car Committee and approved by the Associate 
    Administrator for Safety, FRA.
        (l) Inspection and test compliance date for tank cars with metal 
    jackets or thermal protection systems. (1) After July 1, 2000, each 
    tank car with a metal jacket or with a thermal protection system shall 
    have an inspection and test conforming to this section no later than 
    the date the tank car requires a periodic hydrostatic pressure test 
    (i.e., the marked due date on the tank car for the hydrostatic test).
        (2) After July 1, 1998, each tank car without a metal jacket shall 
    have an inspection and test conforming to this section no later than 
    the date the tank car requires a periodic hydrostatic pressure test 
    (i.e., the marked due date on the tank car for the hydrostatic test).
        (3) For tank cars on a 20-year periodic hydrostatic pressure test 
    interval (i.e., Class DOT 103W, 104W, 111A60W1, 111A100W1, and 
    111A100W3 tank cars), the next inspection and test date is the midpoint 
    between the compliance date in paragraph (l)(1) or (2) of this section 
    and the remaining years until the tank would have had a hydrostatic 
    pressure test.
    
    
    Sec. 180.511  Acceptable results of inspections and tests.
    
        Provided it conforms with other applicable requirements of this 
    subchapter, a tank car is qualified for use if it successfully passes 
    the following inspections and tests conducted in accordance with this 
    subpart:
        (a) Visual inspection. A tank car successfully passes the visual 
    inspection when the inspection shows no structural defect that may 
    cause leakage from or failure of the tank before the next inspection 
    and test interval.
        (b) Structural integrity inspection and test. A tank car 
    successfully passes the structural integrity inspection and test when 
    it shows no structural defect that may initiate cracks or propagate 
    cracks and cause failure of the tank before the next inspection and 
    test interval.
        (c) Service life shell thickness. A tank car successfully passes 
    the service life shell thickness inspection when the tank shell and 
    heads show no thickness reduction below that allowed in 
    Sec. 180.509(g).
        (d) Safety system inspection. A tank car successfully passes the 
    safety system inspection when each thermal protection system, tank head 
    puncture resistance system, coupler vertical restraint system, and 
    system used to protect discontinuities (e.g., breakage grooves on 
    bottom outlets and protective housings) on the tank car conform to this 
    subchapter.
        (e) Lining and coating inspection. A tank car successfully passes 
    the lining and coating inspection and test when the lining or coating 
    shows no evidence of holes or degraded areas.
        (f) Leakage pressure test. A tank car successfully passes the 
    leakage pressure test when all product piping, fittings and closures 
    show no indication of leakage.
        (g) Hydrostatic test. A Class 107 tank car or a riveted tank car 
    successfully passes the hydrostatic test when it shows no leakage, 
    distortion, excessive permanent expansion, or other evidence of 
    weakness that might render the tank car unsafe for transportation 
    service.
    
    
    Sec. 180.513  Repairs, alterations, conversions, and modifications.
    
        (a) In order to repair tank cars, the tank car facility must comply 
    with the requirements of Appendix R of the AAR Specifications for Tank 
    Cars.
        (b) Unless the exterior tank car shell or interior tank car jacket 
    has a protective coating, after a repair that requires the complete 
    removal of the tank car jacket, the exterior tank car shell and the 
    interior tank car jacket must have a protective coating applied to 
    prevent the deterioration of the tank shell and tank jacket.
    
    
    Sec. 180.515  Markings.
    
        (a) When a tank car passes the required inspection and test with 
    acceptable results, the tank car facility shall mark the date of the 
    inspection and test and the due date of the next inspection and test on 
    the tank car in accordance with paragraph (b) of this section. When a 
    tank car facility performs multiple inspection and test at the same 
    time, one date may be used to satisfy the requirements of this section. 
    One date also may be shown when multiple inspection and test have the 
    same due date.
        (b) The tank car facility must comply with the marking requirements 
    of Appendix C of the AAR Specifications for Tank Cars.
        (c) Converted tank cars must have the new specification and 
    conversion date permanently marked in letters and figures at least 0.95 
    cm (0.375 inch) high on the outside of the manway nozzle or the edge of 
    the manway nozzle flange on the left side of the car. The marking may 
    have the last numeral of the specification number omitted (e.g., ``DOT 
    111A100W'' instead of ``DOT 111A100W1'').
        (d) When pressure tested within six months of installation and 
    protected from deterioration, the test date marking of a safety relief 
    device is the installation date on the tank car.
    
    
    Sec. 180.517  Reporting and record retention requirements.
    
        (a) Certification and representation. Each owner of a specification 
    tank car shall retain the certificate of construction (AAR Form 4-2) 
    and related papers certifying that the manufacture of the specification 
    tank car identified in the documents is in accordance with the 
    applicable specification. The owner shall retain the documents 
    throughout the period of ownership of the specification tank car and 
    for one year thereafter. Upon a 
    
    [[Page 49082]]
    change of ownership, the requirements of Section 1.3.15 of the AAR 
    Specifications for Tank Cars apply.
        (b) Inspection and test reporting. Each tank car that is inspected 
    as specified in Sec. 180.509 must have a written report, in English, 
    prepared according to this paragraph. The owner must retain a copy of 
    the inspection and test reports until successfully completing the next 
    inspection and test of the same type. The inspection and test report 
    must include the following:
        (1) Type of inspection and test performed (a checklist is 
    acceptable);
        (2) The results of each inspection and test performed;
        (3) Owner's reporting mark;
        (4) DOT Specification;
        (5) Inspection and test date (month and year);
        (6) Location and description of defects found and method used to 
    repair each defect;
        (7) The name and address of the tank car facility and the signature 
    of inspector.
    
    
    Sec. 180.519  Periodic retest and inspection of tank cars other than 
    single-unit tank car tanks.
    
        (a) General. Unless otherwise provided in this subpart, tanks 
    designed to be removed from cars for filling and emptying and tanks 
    built to a Class DOT 107A specification and their safety relief devices 
    must be retested periodically as specified in Retest Table 1 of 
    paragraph (b)(5) of this section. Retests may be made at any time 
    during the calendar year the retest falls due.
        (b) Pressure test. (1) Each tank, except as provided in paragraph 
    (b)(8) of this section, must be subjected to the specified hydrostatic 
    pressure and its permanent expansion determined. Pressure must be 
    maintained for 30 seconds and far as long as necessary to secure 
    complete expansion of the tank. Before testing, the pressure gauge must 
    be shown to be accurate within 1 percent at test measure. The expansion 
    gauge must be shown to be accurate, at test pressure, to within 1 
    percent. Expansion must be recorded in cubic centimeters. Permanent 
    volumetric expansion may not exceed 10 percent of total volumetric 
    expansion at test pressure and the tank must not leak or show evidence 
    of distress.
        (2) Each tank, except tanks built to specification DOT 107A, must 
    also be subjected to interior air pressure test of at least 100 psi 
    under conditions favorable to detection of any leakage. No leaks may 
    appear.
        (3) Safety relief valves must be retested by air or gas, must start 
    to discharge at or below the prescribed pressure and must be vapor 
    tight at or above the prescribed pressure.
        (4) Frangible discs and fusible plugs must be removed from the tank 
    and visually inspected.
        (5) Tanks must be retested as specified in Retest Table 1 of this 
    paragraph (b)(5), and before returning to service after repairs 
    involving welding or heat treatment:
    
                                                     Retest Table 1                                                 
    ----------------------------------------------------------------------------------------------------------------
                                         Retest interval--years   Minimum Retest pressure--    Safety relief valve  
                                       --------------------------          p.s.i.               pressure--p.s.i.    
                                                                 ---------------------------------------------------
               Specification                            Safety        Tank                                          
                                            Tank        relief    hydrostatic    Tank air    Start-to-   Vapor tight
                                                       devicesd    expansionc      test      discharge              
    ----------------------------------------------------------------------------------------------------------------
    DOT 27............................            5            2          500          100          375          300
    106A500...........................            5            2          500          100          375          300
    106A500X..........................            5            2          500          100          375          300
    106A800...........................            5            2          800          100          600          480
    106A800X..........................            5            2          800          100          600          480
    106A800NCI........................            5            2          800          100          600          480
    107A * * * *......................           d5           a2          (b)         None         None         None
    110A500-W.........................            5            2          500          100          375          300
    110A600-W.........................            5            2          600          100          500          360
    110A800-W.........................            5            2          800          100          600          480
    110A1000-W........................            5            2        1,000          100          750          600
    BE-275............................            5            2          500          100          375          300
    ----------------------------------------------------------------------------------------------------------------
    Notes:                                                                                                          
    aIf DOT 107A * * * * tanks are used for transportation of flammable gases, one frangible disc from each car must
      be burst at the interval prescribed. The sample disc must burst at a pressure not exceeding the marked test   
      pressure of the tank and not less than 70 percent of the marked test pressure. If the sample disc does not    
      burst within the prescribed limits, all discs on the car must be replaced.                                    
    bThe hydrostatic expansion test pressure must at least equal the marked test pressure.                          
    cSee Sec. 180.519(b)(1).                                                                                        
    dSafety relief valves of the spring-loaded type on tanks used exclusively for fluorinated hydrocarbons and      
      mixtures thereof which are free from corroding components may be retested every 5 years.                      
    
        (6) The month and year of test, followed by a ``V'' if visually 
    inspected as described in paragraph (d)(8) of this section, must be 
    plainly and permanently stamped into the metal of one head or chime of 
    each tank with successful test results; for example, 1-60 for January 
    1960. On DOT 107A**** tanks, the date must be stamped into the metal of 
    the marked end, except that if all tanks mounted on a car have been 
    tested, the date may be stamped into the metal of a plate permanently 
    applied to the bulkhead on the ``A'' end of the car. Dates of previous 
    tests and all prescribed markings must be kept legible.
        (c) Visual inspection. Tanks of Class DOT 106A and DOT 110A-Z 
    specifications (Secs. 179.300, 179.301, 179.302 of this subchapter) 
    used exclusively for transporting fluorinated hydrocarbons and mixtures 
    thereof, and that are free from corroding components, may be given a 
    periodic complete internal and external visual inspection in place of 
    the periodic hydrostatic retest. Visual inspections shall be made only 
    by competent persons. The tank must be accepted or rejected in 
    accordance with the criteria in CGA Pamphlet C-6.
        (d) Written records. The results of the pressure test and visual 
    inspection must be recorded on a suitable data sheet. Completed copies 
    of these reports must be retained by the owner and by the person 
    performing the pressure test and visual inspection as long as the tank 
    is in service. The information to be recorded and checked on these data 
    
    
    [[Page 49083]]
    sheets are: Date of test and inspection; DOT specification number; tank 
    identification (registered symbol and serial number, date of 
    manufacture and ownership symbol); type of protective coating (painted, 
    etc., and statement as to need for refinishing or recoating); 
    conditions checked (leakage, corrosion, gouges, dents or digs, broken 
    or damaged chime or protective ring, fire, fire damage, internal 
    condition); test pressure; results of tests; and disposition of tank 
    (returned to service, returned to manufacturer for repair, or 
    scrapped); and identification of the person conducting the retest or 
    inspection.
    
        Issued in Washington, DC, on September 7, 1995 under authority 
    delegated in 49 CFR Part 1.
    D.K. Sharma,
    Administrator.
    [FR Doc. 95-22771 Filed 9-20-95; 8:45 am]
    BILLING CODE 4910-60-P
    
    

Document Information

Published:
09/21/1995
Department:
Research and Special Programs Administration
Entry Type:
Rule
Action:
Final rule.
Document Number:
95-22771
Dates:
Effective date. The effective date of these amendments is July 1, 1996.
Pages:
49048-49083 (36 pages)
Docket Numbers:
Docket Nos. HM-175A and HM-201, Amdt Nos. 171-137, 172-144, 173-245, 179-50, and 180-8
RINs:
2137-AB40, 2137-AB89
PDF File:
95-22771.pdf
CFR: (45)
49 CFR 171.8)
49 CFR 173.31(a)(4)
49 CFR 173.31(c)
49 CFR 173.319(e)
49 CFR 179.105-4(g)
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