95-752. Federal Motor Vehicle Safety Standards; Air Brake Systems; Long- Stroke Brake Chambers  

  • [Federal Register Volume 60, Number 8 (Thursday, January 12, 1995)]
    [Rules and Regulations]
    [Pages 2892-2896]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-752]
    
    
    
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    DEPARTMENT OF TRANSPORTATION
    National Highway Traffic Safety Administration
    
    49 CFR Part 571
    
    [Docket No. 93-54, Notice 2]
    RIN 2127-AE54
    
    
    Federal Motor Vehicle Safety Standards; Air Brake Systems; Long-
    Stroke Brake Chambers
    
    AGENCY: National Highway Traffic Safety Administration (NHTSA), 
    Department of Transportation.
    
    ACTION: Final rule.
    
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    SUMMARY: Consistent with a recommendation by the National 
    Transportation Safety Board and in response to a petition for 
    rulemaking from the American Trucking Associations (ATA), this final 
    rule amends the reservoir requirements in Standard No. 121, Air Brake 
    Systems, for trucks, buses, and trailers equipped with air brakes. The 
    agency believes that the amendments will improve the braking efficiency 
    of such vehicles and reduce the number of brakes found to be out of 
    adjustment during inspections. It will do this by removing a design 
    restriction that tends to discourage the use of long-stroke brake 
    chambers, a technology with potentially significant safety benefits.
    
    DATES: Effective Date: The amendments become effective on February 13, 
    1995.
        Petitions for Reconsideration: Any petitions for reconsideration of 
    this rule must be received by NHTSA no later than February 13, 1995.
    
    ADDRESSES: Petitions for reconsideration of this rule should refer to 
    Docket 93-54; Notice 2 and should be submitted to: Administrator, 
    National Highway Traffic Safety Administration, 400 Seventh Street SW., 
    Washington, D.C. 20590.
    
    FOR FURTHER INFORMATION CONTACT: Mr. Richard Carter, Office of Vehicle 
    Safety Standards, National Highway Traffic Safety Administration, 400 
    Seventh Street SW., Washington, D.C. 20590 (202-366-5274).
    
    SUPPLEMENTARY INFORMATION:
    
    I. Background
    
        Standard No. 121, Air Brake Systems, specifies performance 
    requirements applicable to vehicles equipped with air brakes. The 
    Standard also requires air-braked vehicles to be equipped with various 
    types of equipment, including an air compressor, reservoirs, and a 
    pressure gauge. (See section S5.1) Standard No. 121 does not specify 
    the length of stroke of brake chambers, but it establishes a ratio 
    between the volume of the service reservoirs and the volume of the 
    brake chambers. The reservoirs store energy, in the form of air at high 
    pressure that is used to apply the vehicle's brakes. Without such 
    reservoirs, the vehicle's air compressor could not maintain adequate 
    brake system pressure during successive rapid brake applications. The 
    effect of this ratio is that if the brake chamber stroke is lengthened, 
    thereby increasing its volume, it may be necessary to enlarge the 
    service reservoirs.
        With respect to trucks and buses, Section S5.1.2.1 currently 
    specifies that
    
        The combined volume of all service reservoirs and supply 
    reservoirs shall be at least 12 times the combined volume of all 
    service brake chambers at maximum travel of pistons or diaphragms. 
    However, the reservoirs on the truck portion of an auto transporter 
    need not meet this requirement.
    
        Similarly, with respect to trailers, section S5.2.1.1 specifies
    
        The total volume of each service reservoir shall be at least 
    eight times the combined volume of all service brake chambers 
    serviced by that reservoir at the maximum travel of the pistons or 
    diaphragms of those service brake chambers. However, the reservoirs 
    on a heavy hauler trailer and on the trailer portion of an auto 
    transporter need not meet the requirements specified in S5.2.1.1.
    
        These provisions were intended to ensure that a vehicle's braking 
    system has sufficient compressed air to provide adequate brake pressure 
    after a number of brake applications.
        Brake chambers with longer strokes are commonly known as ``long-
    stroke'' chambers, in reference to the longer piston or pushrod travel 
    that they require. Reports\1\ by NHTSA and the National Transportation 
    Safety Board (NTSB) have indicated that long stroke chambers can help 
    improve brake adjustment on heavy vehicles. However, the reports also 
    note that the reservoir requirements in Standard No. 121 would 
    necessitate much larger reservoirs when long-stroke chambers are used. 
    Thus, while the current requirements do not prohibit long-stroke 
    chambers, the requirements for reservoir size significantly discourage 
    their use.
    
        \1\Automatic Slack Adjusters for Heavy Vehicle Brake Systems, 
    February 1991, DOT HS 724, and the National Transportation Safety 
    Board Heavy Vehicle Airbrake Performance, 1992, PB92-917003/NTSB/SS-
    92/01
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    II. Petition
    
        On March 17, 1992, the American Trucking Associations (ATA) 
    petitioned the agency to amend the reservoir requirements in Standard 
    No. 121 to facilitate the installation of long-stroke chambers. With 
    respect to trucks, buses, and trailers equipped with long-stroke 
    chambers, ATA recommended that the combined volume of all the 
    reservoirs be based on the ``rated volume'' of the service brake 
    chambers, rather than on the volume of the chambers at the maximum 
    travel of the piston. The ``rated volume'' of each brake chamber would 
    be determined pursuant to a table of specified values according to the 
    area of the brake diaphragm and the length of the stroke. In other 
    words, under ATA's recommended amendment, if a ``type 30'' brake 
    chamber (with a diaphragm of approximately 30 square inches) had a full 
    stroke of at least 2.50 inches, then the rated volume of the brake 
    chamber would have to be at least 84 cubic inches. As a practical 
    matter, the use of long stroke chambers should have a minimal effect on 
    reservoir capacity. For other types of brake chambers not presented on 
    the table, the rated volume would be the volume of the brake chamber at 
    maximum travel of the brake pistons or pushrods.
        In support of its petition, ATA argued that manufacturers would 
    have to incur unnecessary costs associated with increasing the size of 
    the reservoirs if standard brake chambers were replaced with long-
    stroke chambers. Along with these additional costs, some vehicle 
    configurations would have to be redesigned due to lack of adequate 
    locations with sufficient space to accommodate large reservoirs. The 
    lack of space is especially significant with short wheel base single 
    unit trucks equipped with extensive accessories (e.g., power-take-off 
    units (PTOs), tail gate lifts, refrigeration units, larger brakes) 
    which compete for undercarriage space.
    
    III. Notice of Proposed Rulemaking
    
        On August 2, 1993, NHTSA proposed amending Standard No. 121's 
    reservoir requirements for trucks, buses, and trailers to facilitate 
    the introduction of long-stroke brake chambers. (58 FR 41078). 
    Specifically, the agency proposed that the method for calculating air 
    reservoir requirements would be based on the ``rated volume'' 
    [[Page 2893]] of the brake chambers rather than on the volume of the 
    brake chambers at the maximum travel of the brake pistons or push rods. 
    The agency tentatively agreed with the petitioner that the proposed 
    amendments would make it easier for vehicle manufacturers to install 
    long-stroke brake chambers on air-braked vehicles, because extremely 
    large reservoirs would no longer be required. The agency stated that it 
    believed that long-stroke chambers would help improve the braking 
    efficiency of vehicles, significantly increase the reserve stroke, 
    reduce the number of brakes found to be out of adjustment during 
    inspections, and reduce the incidence of dragging brakes. NHTSA 
    referenced the Safety Board report, which concluded that ``* * * 
    combining a properly installed and maintained automatic slack adjuster 
    with a long-stroke chamber could reduce the percentage of brakes at or 
    past the limit of adjustment from the 26 percent figure for the manual 
    slack adjusters on a regular stroke chamber to the 4 percent figure for 
    the automatic adjusters installed on a long-stroke chamber.''
        In the NPRM, NHTSA explained its tentative determination that there 
    would be no safety problem with the amended reservoir requirements. The 
    agency cited tests conducted at NHTSA's Vehicle Research and Test 
    Center (VRTC) that indicated that there is sufficient reserve volume to 
    stop an air-braked vehicle even under worst-case conditions (i.e., the 
    engine was stalled so the compressor was not adding replacement air to 
    the system, the vehicle was equipped with long-stroke brake chambers 
    and antilock brake systems (ABS), and the vehicle was stopped on a very 
    low friction surface). The VRTC tests further indicated that while 
    multiple combination vehicles would experience an additional 10 psi 
    drop in air pressure because of the compressor's need to fill a greater 
    volume when the vehicle is equipped with long-stroke chambers, there 
    would still be adequate air pressure to safely stop a triple trailer 
    combination vehicle with ABS on a wet Jennite surface. The rapid 
    cycling produced by the ABS under this condition places severe demands 
    on reservoir capacity and is therefore a good measure of the reserve 
    pressure available from reservoirs meeting the revised volumes proposed 
    in the NPRM. Notwithstanding its tentative findings, NHTSA requested 
    comment about any potential safety problems that might result from 
    amending the reservoir requirements to facilitate the introduction of 
    long-stroke brake chambers.
    
    IV. Comments to the NPRM
    
        NHTSA received 15 comments in response to the NPRM. Commenters 
    included vehicle manufacturers, brake manufacturers, truck equipment 
    suppliers, ATA, the Heavy Duty Brake Manufacturers Council (HDBMC) and 
    Advocates for Highway and Auto Safety (Advocates).
        Commenters addressed both the need for the proposal and recommended 
    various modifications to the proposed regulations.
        Midland-Grau, Rockwell, Allied Signal, HDBMC, Freightliner, 
    International Transquip Industries (ITI), MGM Brakes, Ford, and ATA 
    generally believed that the proposal to facilitate the use of long 
    stroke brake chambers is in the interest of safety. In contrast, while 
    WhiteGMC/Volvo, Haldex, Eaton, and Advocates, agreed that long stroke 
    brake chambers could enhance safety, they opposed the agency's specific 
    proposal which they believed would reduce the stringency of the 
    reservoir requirements and thus result in detriment to safety.
    
    V. Agency Determination
    
    A. Overview
    
        After reviewing the comments in light of the available information, 
    NHTSA has decided to amend Standard No. 121's reservoir requirements 
    for trucks, buses, and trailers to facilitate the introduction of long-
    stroke brake chambers. Specifically, under today's amendments, the 
    method for calculating air reservoir requirements is now based on 
    either the ``rated volume'' of the brake chambers or the volume of the 
    brake chambers at the maximum travel of the brake pistons or push rods, 
    whichever is less. As a result of these amendments, it will be easier 
    for vehicle manufacturers to install long-stroke brake chambers on air-
    braked vehicles, because extremely large reservoirs will no longer be 
    required to meet the reservoir requirements. The agency has determined 
    that long-stroke chambers will help improve the braking efficiency of 
    vehicles, increase the reserve stroke, reduce the number of brakes 
    found to be out of adjustment during inspections, and reduce the 
    incidence of dragging brakes.
        NHTSA has decided to modify the proposed Table V ``Brake Chamber 
    Rated Volumes'' by specifying upper limits to the stroke lengths for 
    which rated volumes may be used. As explained below, the agency has 
    determined that specifying an upper limit is necessary to preclude 
    manufacturers from extending stroke lengths beyond the point at which 
    adequate air pressure reserves are available to bring a vehicle to a 
    complete stop. Accordingly, the amendment would not affect extremely 
    long stroke chambers, the use of which could adversely affect air 
    reservoir capacity. Specifically, Table V has been modified such that a 
    vehicle manufacturer can use the ``rated volume'' rather than the 
    actual brake chamber volume, when determining minimum reservoir volume, 
    only when the maximum strokes for long stroke chambers are no more than 
    20 percent longer than the nominal stroke for standard stroke chambers. 
    In addition, the rated volumes have been increased to reflect the 
    largest volumes of standard stroke air brake chambers that are 
    available.
    
    B. Safety Consequences
    
        In the NPRM, NHTSA considered the safety implications of amending 
    the reservoir requirements to facilitate the installation of long-
    stroke brake chambers. The agency had tentatively determined that 
    relaxing the current reservoir volume requirements would not result in 
    any safety problems. Notwithstanding its tentative findings, the agency 
    requested comment about potential safety problems that might result 
    from decreasing the stringency of the reservoir requirements.
        Midland-Grau, Rockwell, Allied Signal, HDBMC, Freightliner, ITI, 
    MGM Brakes, Ford, and ATA generally believed that the proposal to 
    facilitate the use of long stroke brake chambers would have no 
    corresponding safety problems. HDBMC stated that long stroke brake 
    chambers will provide a significant improvement in maintaining a more 
    reliable level of automatic brake adjustment. Freightliner stated that 
    long stroke chambers will improve highway safety by providing 
    additional reserve stroke at force levels that will maintain brake 
    performances under extreme operating conditions. ATA stated that the 
    use of long stroke brake chambers will decrease the number of vehicles 
    with defective brakes and provide for more effective brakes, especially 
    when they are hot. Rockwell stated that the current regulations 
    unnecessarily impede the adoption of long stroke chambers and the 
    potential benefits they offer. It further stated that long stroke 
    chambers would keep the useful stroke of a vehicle's slack adjuster 
    within the acceptable stroke limits, reduce the number of out-of 
    adjustment vehicles, and the number of incidents of dragging brakes. 
    [[Page 2894]] 
        In contrast, WhiteGMC/Volvo, Haldex, Eaton, and Advocates believed 
    that the proposal would be detrimental to safety, primarily because the 
    proposed amendments would make the reservoir requirements less 
    stringent. WhiteGMC/Volvo stated that the proposal promotes less 
    reservoir volume and extended application times. Advocates had 
    ``misgivings about the regulatory approach'' in the NPRM which it 
    believed would significantly reduce the total operating reserve volume 
    of the brake reservoirs, thereby allowing manufacturers to install 
    undersized brake reservoirs. Haldex stated that the proposal was ill 
    advised and premature because it would result in a decrease in the 
    reserve air volume. Instead, it favored issuance of a ``performance 
    based standard.'' Eaton was concerned that the proposal was a ``quick 
    fix'' that would degrade heavy truck brake system performance.
        After reviewing testing conducted at VRTC, the comments, and other 
    available information, NHTSA has determined that the amendments to 
    Standard No. 121's reservoir requirements will ensure the safe braking 
    of air-braked vehicles, since it will not adversely affect their 
    reservoir capacity. Specifically, testing conducted at VRTC indicate 
    that today's amendments to Standard No. 121 will not cause a 
    significant reduction in a brake system's maintaining adequate pressure 
    even under adverse conditions, affect its application and release 
    times, or contribute to a vehicle's propensity to jackknife.
        With respect to a brake system's air reserves, VRTC and SAE testing 
    indicate that long stroke chambers perform safely, even if the volume 
    of the reservoirs are not increased to reflect the increased volume of 
    the long stroke chambers. In general, long stroke chambers use no more 
    air than standard length brake chambers, if they are properly adjusted. 
    This testing information has been placed in the public docket under 
    ``Reservoir Pressure Drop With ABS Cycling'' and ``SAE J1911 Tractor 
    and Trailer Tests.'' Similarly, long stroke chambers in SAE J1911 tests 
    show the same air consumption as a conventional brake chamber, when 
    properly adjusted.
        The only time a long stroke chamber will consume more air is when 
    the automatic adjuster is not functioning correctly and the stroke is 
    at the outer limit of adjustment. To protect against such situations, 
    the agency has decided to specify an upper limit for the maximum stroke 
    of brake chambers for which a vehicle manufacturer can use the ``rated 
    volume'' in determining the minimum reservoir volumes. The agency has 
    specified that the upper limit be 20 percent above the nominal stroke 
    for a normal stroke brake chamber. For instance, Type 9 brakes will be 
    allowed to have a stroke length of between 1.75 and 2.10 inches. The 
    agency has rejected the upper limits recommended by Midland-Grau which 
    in some cases would have increased the stroke length up to 40 percent. 
    The agency believes that using ``rated volumes'' for such long stroke 
    chambers might undermine the reservoir requirements.
        With respect to brake application times, NHTSA has determined that 
    long stroke brake chambers typically do not significantly affect brake 
    apply and release times. The effect of brake adjustment level on timing 
    is discussed in ``NHTSA Heavy-Duty Vehicle Brake Research Program 
    Report No. 5: Pneumatic Timing.'' DOT HS 806 897, December 1985. The 
    one exception is in the highly unusual situation in which all the 
    automatic brake adjusters on a vehicle fail and at the same time all of 
    the units operate at the outer limit of adjustment or beyond. Even 
    under this highly unlikely condition, the apply time would only 
    increase by approximately 0.040 second and the release time by 0.024 
    second. Moreover, standard stroke chambers would be ineffectual in this 
    situation. This equates to about three additional feet of stopping 
    distance on the apply time and two additional feet on the release 
    time.2 Any such increases can be minimized, since vehicle 
    manufacturers can change the apply and release times by modifying the 
    valving to adjust or remove air flow restrictions. Similarly, the 
    vehicle manufacturers could remove air flow restrictions to the glad 
    hand and pass the signal faster to the trailer.
    
        \2\NHTSA's Heavy-Duty Vehicle Research Program Report No. 5: 
    Pneumatic Timing. DOT HS 806 897, December 1985.
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        With respect to jackknifes, NHTSA disagrees with Eaton's claim that 
    equipping vehicles with long stroke chambers would increase the 
    likelihood of jackknifes. Jackknifes are caused by wheel lockup due to 
    hard brake applications on wet roads or when vehicles are empty or 
    lightly loaded. The presence or absence of long stroke chambers will 
    not affect the underlying foundation brakes. Specifically, VRTC 
    studies3 show that stroke lengths do not affect brake timing. The 
    agency further notes that long stroke chambers improve brake adjustment 
    and the resulting brake balance between tractors and trailers, thereby 
    improving a combination vehicle's directional stability and control and 
    decreasing the likelihood of jackknifing.
    
        \3\Id.
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    C. Changes to Proposed Regulatory Text
    
        Several commenters recommended that the proposed wording of Table V 
    and S5.1.2.1 and S5.2.1.2 be modified to provide greater flexibility to 
    manufacturers. For instance, ATA requested that the words ``on CAM 
    Brakes'' be deleted from the title in Table V so that it reads--``Brake 
    Chamber Rated Volumes.'' ATA also requested that the words ``brake 
    chamber'' be changed to ``brake actuator'' and that ``actuator'' be 
    inserted into Table V to clarify that the ``type'' is a brake actuator 
    classification and not a brake classification. Similarly, ITI 
    recommended that S5.1.2.1 and S5.2.1.2 be revised to permit brake 
    chambers that were not of the sizes specifically listed in Table V. 
    Allied recommended that the wording ``maximum travel of pistons or push 
    rod'' be replaced with ``full stroke of push rods.'' It also 
    recommended ``defining chamber type as being the nominal effective area 
    of a piston or diaphragm.''
        NHTSA has modified certain provisions in the regulatory text 
    pursuant to the comments. For instance, it has modified the title to 
    Table V to state ``Brake Chamber Rated Volumes'' instead of ``Brake 
    Chamber Rated Volumes on Cam Brakes.'' The agency agrees with the 
    commenters that including the reference to cam brakes was unnecessarily 
    narrow and might imply exclusion for use of other brake types such as 
    air disc, wedge, and air-over-hydraulic. NHTSA has also incorporated 
    Allied Signal's request for the regulation to indicate that chamber 
    type is the nominal effective area of a piston or diaphragm, by adding 
    this information to the top of column one in Table V.
        NHTSA decided not to modify other provisions in the regulatory 
    text, notwithstanding recommendations by commenters to the NPRM. For 
    instance, the agency decided not to adopt ATA's request to change the 
    phrase ``brake chamber'' to ``brake actuator.''
        There are numerous references to brake chamber throughout Standard 
    No. 121, which are well understood by the technical personnel who rely 
    on the requirements. ``Brake actuator'' may explain what an air-brake 
    chamber does (i.e., that it actuates the brakes when it fills with 
    air); however, it adds nothing to what is already understood. 
    Similarly, the agency decided not to adopt Allied Signal's request to 
    eliminate the term ``piston.'' While the [[Page 2895]] commenter 
    apparently believed that the use of the additional word ``piston'' 
    added nothing because every system has a push rod, the agency 
    nevertheless has decided to include this term to clarify that the 
    necessary measurements of stroke length can be measured at the piston 
    or the push rod. Accordingly, the regulatory text retains this word.
    
    D. Future Rulemaking
    
        NHTSA notes that it is considering rulemaking consistent with the 
    draft SAE Recommended Practice J1609X, Air Reservoir Capacity 
    Performance Guide--Commercial Vehicles. The purpose of such a 
    rulemaking would be to establish a performance requirement addressing 
    the minimum air storage capacity for air-braked vehicles. If the agency 
    determined that such a performance requirement were appropriate, it 
    would issue a proposal in the Federal Register on which the public 
    could comment. A considerable amount of testing needs to be completed 
    before a viable set of performance requirements are established.
    
    E. Miscellaneous Issues
    
        Commenters raised a number of issues that were not mentioned in the 
    NPRM. These include testing trucks on down-hill grades, the consistency 
    of the amendment to the agency's statutory mandate, marking 
    requirements, and the rule's effective date.
        With respect to testing truck descents on downhill grades, NHTSA 
    disagrees with comments by Advocates and Haldex that the air reservoir 
    requirements should be based on such testing and that such testing 
    represents worst-case situations. Braking on ice, snow, and rain 
    covered roads with low coefficient of friction surfaces is more severe 
    than mountain grade braking. The air pressure remaining after a 
    complete antilock cycling stop on ice or wet Jennite is substantially 
    less than that remaining in the air brake system at the bottom of a 
    long mountain grade. Moreover, VRTC studies clearly show that there is 
    sufficient air remaining in the air brake system, after stopping on low 
    coefficient of friction surfaces or mountain grades using either 
    snubbing or steady pressure. Similarly, testing performed by the 
    University of Michigan Transportation Research Institute (UMTRI) shows 
    sufficient air supply reserves on long down hill grades to make a 60 
    psi full braking stop at the bottom of the grade.4 Advocates 
    appears to misunderstand how downhill braking affects an air brake 
    system's reservoirs. Consumption and apply and release times, which are 
    important concerns for long stroke chambers, are not important concerns 
    with downhill braking. The major consideration in downhill braking is 
    overheated brakes and brake fade caused by brakes that are not in 
    adjustment, since improperly adjusted brakes must be applied for longer 
    periods of time. As a result, the vehicle will have either no brakes or 
    very limited braking. The use of long stroke brake chambers together 
    with automatic adjusters will reduce the incidence of out-of-
    adjustment, and thus not degrade the performance on downhill braking.
    
        \4\``The Influence of Braking Strategy on Brake Temperatures in 
    Mountain Descents,'' March 1992, Federal Highway Administration 
    Report DTFH61-89-C-00106. Report available through the National 
    Technical Information Service. NTIS accession number PB 93-137032.
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        Advocates stated that the petitioner's ``rated volume'' approach to 
    establish the air reservoir volumes is equivalent to the European type 
    approval approach for establishing compliance. Accordingly, it believed 
    that the proposal was inconsistent with the National Traffic and Motor 
    Vehicle Safety Act (now codified as chapter 301 of Title 49, United 
    States Code). NHTSA believes that Advocates has misinterpreted both the 
    proposal and the law. Unlike European type approval, the proposal is 
    not for a single manufacturer's product. Rather, it regulates all 
    manufacturers' brake chambers of a specific type. Accordingly, today's 
    requirements are consistent with the law.
        Rockwell and HDBMC recommended that the agency require the 
    identification of long stroke chambers through marking requirements. 
    Notwithstanding this request, NHTSA notes that the agency cannot 
    include a marking requirement in this final rule that it did not 
    propose in the NPRM. Nevertheless, the agency will monitor the progress 
    made by the Federal Highway Administration which is working with the 
    SAE, Commercial Vehicle Safety Alliance, and brake equipment 
    manufacturers to establish an acceptable marking system that can easily 
    be identified under the difficult visual conditions on the underside of 
    air braked vehicles. If NHTSA determines that Federal marking 
    requirements are needed, then it would propose marking requirements in 
    a future rulemaking.
        The same problem with inadequate notice is relevant to Midland-
    Grau's recommendation to raise the minimum governor cut-in pressure to 
    100 psi. The agency may consider such a requirement in a separate 
    rulemaking, depending on tests to be conducted at VRTC.
        In response to requests by Freightliner and ATA for NHTSA to make 
    the final rule effective upon publication, the agency notes that the 
    Administrative Procedure Act generally requires a leadtime of at least 
    30 days, unless the agency finds ``good cause'' to issue the rule 
    sooner. Since, NHTSA typically makes a finding of good cause only in 
    emergency situations, the agency cannot accommodate this request. The 
    final rule will take effect 30 days after its publication in the 
    Federal Register.
    
    Rulemaking Analyses and Notices
    
    Executive Order 12866 (Federal Regulation) and DOT Regulatory Policies 
    and Procedures
    
        NHTSA has considered the impact of this rulemaking action under 
    E.O. 12866, ``Regulatory Planning and Review'' and the Department of 
    Transportation's regulatory policies and procedures. This rulemaking 
    document was not reviewed under E.O. 12866. This action has been 
    determined to be not ``significant'' under the Department of 
    Transportation's regulatory policies and procedures. A full regulatory 
    evaluation is not required because the rule will not impose any special 
    requirements on manufacturers. Instead, the rule will facilitate the 
    introduction of a new brake design by removing a design restriction. 
    Therefore, the agency believes that this rulemaking will not result in 
    significant additional costs or cost savings.
    
    Regulatory Flexibility Act
    
        In accordance with the Regulatory Flexibility Act, NHTSA has 
    evaluated the effects of this action on small entities. Based upon this 
    evaluation, I certify that the amendments will not have a significant 
    economic impact on a substantial number of small entities. Vehicle and 
    brake manufacturers typically do not qualify as small entities. As 
    discussed above, the agency's assessment is that this amendment will 
    have no cost impact to the industry. For these reasons, vehicle 
    manufacturers, small businesses, small organizations, and small 
    governmental units which purchase motor vehicles will not be affected 
    by the requirements. Accordingly, no regulatory flexibility analysis 
    has been prepared.
    
    Executive Order 12612 (Federalism)
    
        This action has been analyzed in accordance with the principles and 
    criteria contained in Executive Order 12612, and it has been determined 
    that the rule will not have sufficient [[Page 2896]] Federalism 
    implications to warrant preparation of a Federalism Assessment. No 
    State laws will be affected.
    
    National Environmental Policy Act
    
        Finally, the agency has considered the environmental implications 
    of this final rule in accordance with the National Environmental Policy 
    Act of 1969 and determined that the rule will not significantly affect 
    the human environment.
    
    F. Civil Justice Reform
    
        This final rule does not have any retroactive effect. Under 49 
    U.S.C. 30103, whenever a Federal motor vehicle safety standard is in 
    effect, a State may not adopt or maintain a safety standard applicable 
    to the same aspect of performance which is not identical to the Federal 
    standard, except to the extent that the State requirement imposes a 
    higher level of performance and applies only to vehicles procured for 
    the State's use. 49 U.S.C. 30161 sets forth a procedure for judicial 
    review of final rules establishing, amending or revoking Federal motor 
    vehicle safety standards. That section does not require submission of a 
    petition for reconsideration or other administrative proceedings before 
    parties may file suit in court.
    
    List of Subjects in 49 CFR Part 571
    
        Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber 
    products, Tires.
    
        In consideration of the foregoing, 49 CFR part 571 is amended to 
    read as follows:
    
    PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
    
        1. The authority citation for part 571 continues to read as 
    follows:
    
        Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
    delegation of authority at 49 CFR 1.50.
    
        2. Section 571.121 is amended by revising S5.1.2.1 and S5.2.1.1 to 
    read as follows:
    
    
    Sec. 571.121  Standard No. 121; Air brake systems.
    
    * * * * *
        S5.1.2.1   The combined volume of all service reservoirs and supply 
    reservoirs shall be at least 12 times the combined volume of all 
    service brake chambers. For each brake chamber type having a full 
    stroke at least as great as the first number in Column 1 of Table V, 
    but no more than the second number in Column 1 of Table V, the volume 
    of each brake chamber for purposes of calculating the required combined 
    service and supply reservoir volume shall be either that specified in 
    Column 2 of Table V or the actual volume of the brake chamber at 
    maximum travel of the brake piston or pushrod, whichever is lower. The 
    volume of a brake chamber not listed in Table V is the volume of the 
    brake chamber at maximum travel of the brake piston or pushrod. The 
    reservoirs of the truck portion of an auto transporter need not meet 
    this requirement for reservoir volume.
    * * * * *
        S5.2.1.1  The total volume of each service reservoir shall be at 
    least eight times the combined volume of all service brake chambers 
    serviced by that reservoir. For each brake chamber type having a full 
    stroke at least as great as the first number in Column 1 of Table V, 
    but no more than the second number in column 1, the volume of each 
    brake chamber for purposes of calculating the required total service 
    reservoir volume shall be either that number specified in Column 2 of 
    Table V or the actual volume of the brake chamber at maximum travel of 
    the brake piston or pushrod, whichever is lower. The volume of a brake 
    chamber not listed in Table V is the volume of the brake chamber at 
    maximum travel of the brake piston or pushrod. The reservoirs on a 
    heavy hauler trailer and the trailer portion of an auto transporter 
    need not meet this requirement for reservoir volume.
    * * * * *
    
    
    Sec. 571.121  [Amended]
    
        3. Section 571.121 is amended to include the following table to be 
    placed after Figure 3.
    
                      Table V.--Brake Chamber Rated Volumes                 
    ------------------------------------------------------------------------
                                                                     Column 
                                                        Column 1,   2, rated
      Brake chamber type (nominal area of piston or    full stroke   volume 
               diaphragm in square inches)               (inches)    (cubic 
                                                                     inches)
    ------------------------------------------------------------------------
    Type 9...........................................    1.75/2.10        25
    Type 12..........................................    1.75/2.10        30
    Type 14..........................................    2.25/2.70        40
    Type 16..........................................    2.25/2.70        50
    Type 18..........................................    2.25/2.70        55
    Type 20..........................................    2.25/2.70        60
    Type 24..........................................    2.25/2.70        70
    Type 30..........................................    2.50/3.20        95
    Type 36..........................................    3.00/3.60       135
    ------------------------------------------------------------------------
    
        Issued on January 5, 1995.
    Ricardo Martinez,
    Administrator.
    [FR Doc. 95-752 Filed 1-11-95; 8:45 am]
    BILLING CODE 4910-59-P
    
    

Document Information

Published:
01/12/1995
Department:
National Highway Traffic Safety Administration
Entry Type:
Rule
Action:
Final rule.
Document Number:
95-752
Pages:
2892-2896 (5 pages)
Docket Numbers:
Docket No. 93-54, Notice 2
RINs:
2127-AE54
PDF File:
95-752.pdf
CFR: (1)
49 CFR 571.121