[Federal Register Volume 60, Number 65 (Wednesday, April 5, 1995)]
[Rules and Regulations]
[Pages 17398-17403]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-8349]
[[Page 17397]]
_______________________________________________________________________
Part III
Department of Transportation
_______________________________________________________________________
Research and Special Programs Administration
_______________________________________________________________________
49 CFR Parts 173, 178, and 180
Cargo Tanks; Miscellaneous Requirements; Revisions and Response to
Petitions for Reconsideration; Final Rule
Federal Register / Vol. 60, No. 65 / Wednesday, April 5, 1995 / Rules
and Regulations
[[Page 17398]]
DEPARTMENT OF TRANSPORTATION
Research and Special Programs Administration
49 CFR Parts 173, 178 and 180
[Docket No. HM-183C; Amdt. Nos. 173-240, 178-105 and 180-7]
RIN 2137-AC37
Cargo Tanks; Miscellaneous Requirements; Revisions and Response
to Petitions for Reconsideration
AGENCY: Research and Special Programs Administration (RSPA), DOT.
ACTION: Final rule; response to petitions for reconsideration.
-----------------------------------------------------------------------
SUMMARY: This document amends a final rule published on November 3,
1994, and concerns manufacture, qualification, and maintenance of DOT
specification cargo tank motor vehicles. In response to petitions for
reconsideration, RSPA is revising design loading requirements for MC
331 cargo tank motor vehicles and making other minor editorial and
technical changes for clarity. The changes made in this document are
intended to ease certain regulatory requirements where there will be no
adverse effect on safety.
DATES: Effective: May 22, 1995.
Compliance date: Compliance with the regulations, as amended
herein, is authorized as of April 5, 1995.
FOR FURTHER INFORMATION CONTACT: Ronald Kirkpatrick, telephone (202)
366-4545, Office of Hazardous Materials Technology, or Jennifer Karim,
(202) 366-4488, Office of Hazardous Materials Standards, Research and
Special Programs Administration, U.S. Department of Transportation,
Washington, DC 20590-0001.
SUPPLEMENTARY INFORMATION: On November 3, 1994, RSPA published in the
Federal Register a final rule, under Docket No. HM-183C (59 FR 55162),
amending certain requirements for the manufacture, qualification and
maintenance of cargo tank motor vehicles. Changes were made to relax
the requirements for structural integrity, accident damage protection,
welding and design quality control procedures, and pressure relief
based on comments from industry. Changes were also made to require
facilities repairing cargo tanks stamped as meeting the American
Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME
Code) to have a Certificate of Authorization for use of an ``R'' stamp
from the National Board of Boiler and Pressure Vessel Inspectors
(National Board) Code .
RSPA received five petitions for reconsideration of certain aspects
of the final rule. These petitions were submitted by the Cargo Tank
Manufacturers Association (CTMA), Cargo Tank Concepts, Ltd. (CTCL),
Truck Trailer Manufacturers Association (TTMA), National Propane Gas
Association (NPGA), and the Compressed Gas Association, Inc. (CGA).
CTMA opposed several provisions adopted in the final rule. First,
CTMA petitioned RSPA to reconsider its position on how the design
stress calculations, in 49 CFR 178.345-3(c), should be applied to cargo
tank loading conditions. Except for the loadings prescribed in
paragraph (c)(i), CTMA stated:
[T]he loads are extreme loads that will be experienced rarely if
at all during the life of a cargo tank and [the] ASME Code allowable
stresses should be based on the stress increase allowed for wind and
seismic loads which are also experienced rarely if at all in the
life of stationary vessels. Per UG-23 of the ASME Code, this
increase is 20 percent. CTMA believes that the loads specified in
building codes [are] applicable to pressure vessels in the same
manner. Using ASME allowable stresses for these load conditions is
too conservative since margins of safety are pyramided if rarely
occurring extreme loads cannot be resisted by emergency stresses as
recommended by CTMA.
As noted by RSPA in the preamble to the final rule (59 FR 55165),
discussions have been ongoing for a number of years on how to combine
the loadings in calculating the structural integrity requirements. The
concept of separating structural loadings into two categories, normal
operating loading and extreme dynamic loading, was proposed by several
cargo tank motor vehicle designers at a public meeting in February 1994
and more fully developed later. In normal operations, a cargo tank can
be expected to routinely experience relatively low dynamic forces;
these forces are to be considered to occur simultaneously. Under
extreme dynamic loadings, the cargo tank experiences relatively high
forces which occur rarely, if at all, during the life of a cargo tank;
these forces are considered to act independently, one at a time. This
approach has received wide acceptance and is the foundation for new
recommended practices under development by a TTMA engineering
committee.
RSPA does not believe the calculations for ``stress increase''
referred to by CTMA necessarily apply to dynamic loads experienced
either in normal operations or in extreme loading conditions
experienced by cargo tank motor vehicles. Two provisions for increased
allowable stresses are prescribed in the ASME Code, Section VIII,
Division 1, UG-23. In paragraph (c) of UG-23, a factor of 1.5 is
discussed for ``combined maximum primary membrane stress plus primary
bending stress across the thickness.'' Evidently, the 20 percent factor
referred to by CTMA is associated with the factor discussed in
paragraph (d) for the ``combination of earthquake loading, or wind
loading with other loadings in UG-22,'' with the stipulation that
earthquake and wind loadings need not be considered to act
simultaneously. RSPA believes the many years of experience accumulated
by cargo tank motor vehicle manufacturers support the approach adopted
in the final rule. The reference in the CTMA petition to other ``loads
specified in building codes'' may or may not pertain to this matter.
CTMA did not identify those codes and provided no information on
whether or how they have any application to cargo tank structural
integrity or accident damage protection. Therefore, CTMA's request is
denied.
Second, CTMA opposed the 2 ``g'' design load for rollover damage
protection devices specified in Sec. 178.345-8(c)(1). CTMA stated that
the loads on rollover devices, in the case of longitudinal sliding,
would be limited by the coefficient of sliding friction of the metal
rollover devices on the ground or pavement and, in the case of lateral
rollover, would be limited even further by the lateral force leading to
continued overturn of the tank. RSPA discussed commenters' requests to
reduce the 2 ``g'' design load for rollover protection at length in the
preamble of the final rule (59 FR 55166). RSPA recognizes that new
designs may be necessary to gain significant benefits in safety.
RSPA also recognizes that the amount of force currently imposed in
the horizontal plane is a simplification of many potential variables
which can come into play during an overturn accident. Many scenarios
are possible: the impact surface may be smooth or rough, horizontal or
sloping, as hard as concrete or as soft as sand or damp earth; the
vehicle may roll over an obstacle such as a guard rail; the cargo tank
may receive an impact over its entire length or on only a small part of
its exposed surface; etc. CTMA's comments on use of the coefficient of
sliding friction might be appropriate for overturn on a smooth, hard
highway surface, but would impose relatively moderate loads in
comparison to other rollover scenarios. Accident scenarios where the
rollover damage protection devices plow through earth or strike
[[Page 17399]] roadside obstacles impose much greater loadings on the
devices. Therefore, CTMA's petition for a reduction in the safety
performance of rollover damage protection is denied.
Third, CTMA repeated its position that it is difficult to design
rear-end protection devices in compliance with the loads prescribed in
Sec. 178.345-8(d), particularly devices which are offset from the load
path. CTMA repeated its belief previously expressed in comments that
the intent of the regulation is for the loads to be transmitted to the
tank structure and absorbed without exceeding the permitted stresses
anywhere along the load path. CTMA offered no new information to
support this position. The revised requirements were discussed in the
preamble of the final rule (59 FR 55167). RSPA believes that the
revised requirements for the DOT 400-series cargo tanks allow engineers
more freedom in the design of rear-end protection, including approaches
involving energy dissipation and dampening. Therefore, CTMA's petition
is denied.
Finally, CTMA commented on the suitability of applying ASME Code
standards to the cargo tank industry while not recognizing other
``alternative quality control program(s).'' This issue was fully
discussed in the preamble of the final rule (59 FR 55162). In addition,
this subject was addressed in previous notices and public meetings
under Docket HM-183 extending over a period of nearly ten years. CTMA
provided no additional data or information to support changing the
final rule. Therefore, RSPA's position remains unchanged and
requirements for using procedures established under the ASME Code and
the National Board of Boiler and Pressure Vessel Inspectors (National
Board) Code are retained, and CTMA's petition is denied.
CTCL petitioned RSPA to reconsider amendments allowing a small
release of certain types of ladings from the pressure relief system, in
overturn accidents, before reclosing to a leak-tight position. CTCL
stated that it has designed a vent which releases vapors instead of
lading in an overturn accident situation, and that this information was
not presented RSPA earlier because the technology had not yet been
developed. RSPA welcomes the development by industry of improved valve
designs. RSPA solicited information during the HM-183C rulemaking
proceeding on the existence of reclosing pressure relief devices
capable of reseating with no loss of lading and not subject to clogging
and sticking during field service. However, RSPA believes CTCL has not
provided sufficient information to support excluding the use of other
valve designs at this time, and CTCL's petition is denied.
TTMA petitioned RSPA to continue allowing a cargo tank manufacturer
holding an ASME ``U'' stamp to make repairs to ASME stamped cargo
tanks. TTMA stated that an ASME ``U'' stamp holder should not be
required to obtain an ``R'' stamp from the National Board and there is
no reason why the National Board cannot continue to inspect repairs
made by a ``U'' stamp holder. Furthermore, the National Board
Inspection Code allows repairs to be made on ASME stamped cargo tanks
by a facility holding an ``R'' stamp or by a facility working within an
individual governmental jurisdiction where that jurisdiction has issued
authorization for the facility to perform repairs.
RSPA explained in the preambles of the notice of proposed
rulemaking (March 3, 1993; 58 FR 12316) and the final rule (59 FR
55170) that the National Board has control over the quality of work
performed by an ``R'' stamp holder. Jurisdictional authorization is
recognized only within the governmental boundaries where the repair
facility is located. This type of authorization may be appropriate for
work performed on stationary vessels, but not for mobile systems such
as cargo tank motor vehicles. RSPA believes it is essential to apply a
nationally recognized consensus standard in a uniform manner regardless
of jurisdiction. Therefore, the requirement that repairs on DOT
specification cargo tanks certified to the ASME Code must be performed
only by a facility holding a valid ``R'' stamp is retained and TTMA's
petition is denied.
CGA petitioned RSPA to remove the word ``internal'' in the first
sentence in Sec. 178.338-11(c) specifying that each filling and
discharge line for liquids must be provided with a remotely controlled
internal self-closing stop valve. CGA pointed out that the word
``internal'' did not appear in the provision in the notice of proposed
rulemaking and that requiring internal valves would bring the cryogenic
flammable lading industry to a standstill because of the inner tank/
outer jacket configuration of these cargo tanks. RSPA agrees. It was
not RSPA's intent to require an ``internal'' self-closing valve on
these tanks, but to broaden the requirement to include all flammable
ladings. Therefore, the word ``internal'' is removed.
NPGA asked RSPA to reconsider its decision in the final rule that a
future rulemaking would address design loading requirements for MC 331
specification cargo tanks. The preamble to the final rule (59 FR 55163)
noted NPGA's recommendation for uniformity in design loading
requirements for all DOT specification cargo tanks. In its petitions,
NPGA asked RSPA to extend, until March 1, 1997, the compliance date for
construction of MC 331 cargo tank motor vehicles conforming to the
structural integrity requirements contained in Sec. 178.337-3. It also
urged RSPA to make resolution of stress analysis a priority project.
RSPA has reviewed the report previously submitted by NPGA and found
that NPGA's proposed loadings for the MC 331 cargo tank are very
similar to the loadings adopted for the DOT 400-series cargo tanks.
This supports NPGA's position that cargo tank motor vehicles encounter
similar loadings regardless of whether the cargo tank is used to
transport a liquid or gas lading. Therefore, for greater consistency,
RSPA is amending the structural integrity requirements in Sec. 178.337-
3 by adopting the same loadings as specified for the DOT 400-series
cargo tank specifications. In view of this change, a new paragraph (f)
is added in Sec. 178.23 to provide for a MC 331 specification cargo
tank conforming to the structural integrity requirements contained in
Sec. 178.337-3 or to the corresponding requirements in effect at the
time of manufacture. However, the material thickness may not be less
than that required by the ASME Code.
Based on comments received from CGA that design loadings specified
for MC 338 cargo tanks should not be revised for consistency with the
MC 331 specification, RSPA is not making any change to Sec. 178.338-3.
CGA has advised it is developing a document to provide additional
guidance to its members on the design and construction of MC 338 cargo
tanks.
The amendment to Sec. 178.337-3 eliminates any need for a delay in
the compliance date for construction of MC 331 cargo tank motor
vehicles conforming to the structural integrity requirements, and this
part of NPGA's petition is denied.
Additionally, CGA petitioned RSPA to allow modifications on
cryogenic cargo tanks originally authorized by exemption prior to
introduction of the MC 338 specification. In accordance with
Sec. 180.405(d), such cargo tanks must be marked ``DOT MC 338-E''
followed by the exemption number. CGA contends that modifications such
as adding a manhole may require removal of the outer jacket and
installation of a new shell course to the inner vessel; only local
reinforcement of the inner vessel was required
[[Page 17400]] previously. After further consideration, RSPA agrees
with CGA. In establishing the MC 338 specification, the final rule
(June 16, 1983; 48 FR 27674) stated ``[T]his grandfathering of existing
tanks is necessary to avoid potential severe economic consequences to
some exemption holders and can be justified from a safety point of view
because of the thorough technical review involved in the exemption
process, notwithstanding the fact that certain aspects of certain
exemptions may differ from this final rule.'' Nothing in subsequent
rulemakings has changed this premise. Therefore, in this final rule, in
Sec. 180.413, in paragraph (d)(3), the introductory text is revised,
and a new paragraph (v) is added to allow MC 338 cargo tanks authorized
under Sec. 180.405(d) to be structurally modified provided that no
reduction in structural integrity is incurred and that any modification
is in accordance with the ASME Code or with the MC 338 specification.
Finally, RSPA has made the following editorial revisions for
clarity: In Sec. 178.345-3, in paragraphs (c)(1)(iii)(B) and
(c)(2)(iii)(B), in the second sentence, the wording ``horizontal pivot
of the tractor'' is revised to read ``horizontal pivot of the truck
tractor''. In Sec. 178.345-14, in paragraph (b)(3), the wording ``Tank
MAWP'' is revised to read ``Tank maximum allowable working pressure
(MAWP)''. In Sec. 180.403, a sentence is added to the definition of
modification. In Sec. 180.405, in paragraph (h)(2), reference to 40 CFR
60.601 is deleted. In Sec. 180.407, in the table in paragraph (c),
under the subheading ``Thickness Test'' in the first column, the
wording ``in corrosive service, except'' is revised to read
``transporting lading corrosive to the tank, except''; and paragraphs
(d)(1) (i) and (ii) are revised to remove duplicative language. In
Sec. 180.413, paragraphs (b)(6) and (d)(10) are revised to clarify that
a repair or modification affecting the structural integrity of a
pressure cargo tank, with respect to pressure, must be determined by
testing required by the specification or by Sec. 180.407(g)(1)(iv).
Rulemaking Analyses and Notices
1. Executive Order 12866 and DOT Regulatory Policies and Procedures
This final rule is not considered a significant regulatory action
under section 3(f) of Executive Order 12866 and was not reviewed by the
Office of Management and Budget. The rule is not considered significant
under the Regulatory Policies and Procedures of the Department of
Transportation (44 FR 11034). This amendment imposes no new
requirements on affected persons. The final regulatory evaluation for
the November 1994 final rule is available for review in the docket.
Changes in this final rule did not warrant revision of the regulatory
evaluation.
2. 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, and certain
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 July 5, 1995.
Because RSPA lacks discretion in this area, preparation of a
federalism assessment is not warranted.
3. Regulatory Flexibility Act
I certify that this final rule will not have a significant economic
impact on a substantial number of small entities. This rule applies to
manufacturers, shippers, carriers, and owners of cargo tanks, some of
which are small entities. There are no direct or indirect adverse
economic impacts for small units of government, businesses, or other
organizations.
4. Paperwork Reduction Act
This amendment imposes no changes to the information collection and
recordkeeping requirements contained in the June 12, 1989 final rule,
which were approved by the Office of Management and Budget (OMB) under
the provisions of 44 U.S.C. chapter 35 and assigned control number
2137-0014.
5. 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 number 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 173
Hazardous materials transportation, Packaging and containers,
Radioactive materials, Reporting and recordkeeping requirements,
Uranium.
49 CFR Part 178
Hazardous materials transportation, Motor vehicles safety,
Packaging and containers, Reporting and recordkeeping requirements.
49 CFR Part 180
Hazardous materials transportation, Motor carriers, Motor vehicle
safety, Packaging and containers, Reporting and recordkeeping
requirements.
In consideration of the foregoing, title 49, chapter I of the Code
of Federal Regulations, is amended as set forth below:
PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENTS AND
PACKAGINGS
1. The authority citation for part 173 continues to read as
follows:
Authority: 49 U.S.C. 5101-5127, 49 CFR 1.53.
2. In Sec. 173.23, a new paragraph (f) is added to read as follows:
Sec. 173.23 Previously authorized packaging.
* * * * * [[Page 17401]]
(f) An MC 331 cargo tank motor vehicle must conform to structural
integrity requirements in Sec. 178.337-3 or to corresponding
requirements in effect at the time of manufacture.
PART 178--SPECIFICATIONS FOR PACKAGINGS
3. The authority citation for part 178 continues to read as
follows:
Authority: 49 U.S.C. 5101-5127, 49 CFR 1.53.
4. In Sec. 178.337-3, paragraph (c) is revised to read as follows:
Sec. 178.337-3 Structural integrity.
* * * * *
(c) Shell design. Shell stresses resulting from static or dynamic
loadings, or combinations thereof, are not uniform throughout the cargo
tank motor vehicle. The vertical, longitudinal, and lateral normal
operating loadings can occur simultaneously and must be combined. The
vertical, longitudinal and lateral extreme dynamic loadings occur
separately and need not be combined.
(1) Normal operating loadings. The following procedure addresses
stress in the tank shell resulting from normal operating loadings. The
effective stress (the maximum principal stress at any point) must be
determined by the following formula:
S = 0.5(Sy + Sx) [0.25(Sy -
Sx)2 + Ss2]0.5
Where:
(i) S = effective stress at any given point under the combination of
static and normal operating loadings that can occur at the same time,
in psi.
(ii) Sy = circumferential stress generated by the MAWP and
external pressure, when applicable, plus static head, in psi.
(iii) Sx = The following net longitudinal stress generated by the
following static and normal operating loading conditions, in psi:
(A) The longitudinal stresses resulting from the MAWP and external
pressure, when applicable, plus static head, in combination with the
bending stress generated by the static weight of the fully loaded cargo
tank, all structural elements, equipment and appurtenances supported by
the cargo tank wall;
(B) The tensile or compressive stress resulting from normal
operating longitudinal acceleration or deceleration. In each case, the
forces applied must be 0.35 times the vertical reaction at the
suspension assembly, applied at the road surface, and as transmitted to
the cargo tank wall through the suspension assembly of a trailer during
deceleration; or the horizontal pivot of the truck tractor or converter
dolly fifth wheel, or the drawbar hinge on the fixed dolly during
acceleration; or anchoring and support members of a truck during
acceleration and deceleration, as applicable. The vertical reaction
must be calculated based on the static weight of the fully loaded cargo
tank, all structural elements, equipment and appurtenances supported by
the cargo tank wall. The following loadings must be included:
(1) The axial load generated by a decelerative force;
(2) The bending moment generated by a decelerative force;
(3) The axial load generated by an accelerative force; and
(4) The bending moment generated by an accelerative force; and
(C) The tensile or compressive stress generated by the bending
moment resulting from normal operating vertical accelerative force
equal to 0.35 times the vertical reaction at the suspension assembly of
a trailer; or the horizontal pivot of the upper coupler (fifth wheel)
or turntable; or anchoring and support members of a truck, as
applicable. The vertical reaction must be calculated based on the
static weight of the fully loaded cargo tank, all structural elements,
equipment and appurtenances supported by the cargo tank wall.
(iv) Ss = The following shear stresses generated by the following
static and normal operating loading conditions, in psi:
(A) The static shear stress resulting from the vertical reaction at
the suspension assembly of a trailer, and the horizontal pivot of the
upper coupler (fifth wheel) or turntable; or anchoring and support
members of a truck, as applicable. The vertical reaction must be
calculated based on the static weight of the fully loaded cargo tank,
all structural elements, equipment and appurtenances supported by the
cargo tank wall;
(B) The vertical shear stress generated by a normal operating
accelerative force equal to 0.35 times the vertical reaction at the
suspension assembly of a trailer; or the horizontal pivot of the upper
coupler (fifth wheel) or turntable; or anchoring and support members of
a truck, as applicable. The vertical reaction must be calculated based
on the static weight of the fully loaded cargo tank, all structural
elements, equipment and appurtenances supported by the cargo tank wall;
(C) The lateral shear stress generated by a normal operating
lateral accelerative force equal to 0.2 times the vertical reaction at
each suspension assembly of a trailer, applied at the road surface, and
as transmitted to the cargo tank wall through the suspension assembly
of a trailer, and the horizontal pivot of the upper coupler (fifth
wheel) or turntable; or anchoring and support members of a truck, as
applicable. The vertical reaction must be calculated based on the
static weight of the fully loaded cargo tank, all structural elements,
equipment and appurtenances supported by the cargo tank wall; and
(D) The torsional shear stress generated by the same lateral forces
as described in paragraph (c)(1)(iv)(C) of this section.
(2) Extreme dynamic loadings. The following procedure addresses
stress in the tank shell resulting from extreme dynamic loadings. The
effective stress (the maximum principal stress at any point) must be
determined by the following formula:
S = 0.5(Sy + Sx) [0.25(Sy - Sx)2
+ Ss2]0.5
Where:
(i) S = effective stress at any given point under a combination of
static and extreme dynamic loadings that can occur at the same time, in
psi.
(ii) Sy = circumferential stress generated by MAWP and external
pressure, when applicable, plus static head, in psi.
(iii) Sx = the following net longitudinal stress generated by the
following static and extreme dynamic loading conditions, in psi:
(A) The longitudinal stresses resulting from the MAWP and external
pressure, when applicable, plus static head, in combination with the
bending stress generated by the static weight of the fully loaded cargo
tank, all structural elements, equipment and appurtenances supported by
the tank wall;
(B) The tensile or compressive stress resulting from extreme
longitudinal acceleration or deceleration. In each case the forces
applied must be 0.7 times the vertical reaction at the suspension
assembly, applied at the road surface, and as transmitted to the cargo
tank wall through the suspension assembly of a trailer during
deceleration; or the horizontal pivot of the truck tractor or converter
dolly fifth wheel, or the drawbar hinge on the fixed dolly during
acceleration; or the anchoring and support members of a truck during
acceleration and deceleration, as applicable. The vertical reaction
must be calculated based on the static weight of the fully loaded cargo
tank, all structural elements, equipment and appurtenances supported by
the cargo tank wall. The following loadings must be included:
[[Page 17402]]
(1) The axial load generated by a decelerative force;
(2) The bending moment generated by a decelerative force;
(3) The axial load generated by an accelerative force; and
(4) The bending moment generated by an accelerative force; and
(C) The tensile or compressive stress generated by the bending
moment resulting from an extreme vertical accelerative force equal to
0.7 times the vertical reaction at the suspension assembly of a
trailer, and the horizontal pivot of the upper coupler (fifth wheel) or
turntable; or the anchoring and support members of a truck, as
applicable. The vertical reaction must be calculated based on the
static weight of the fully loaded cargo tank, all structural elements,
equipment and appurtenances supported by the cargo tank wall.
(iv) Ss = The following shear stresses generated by static and
extreme dynamic loading conditions, in psi:
(A) The static shear stress resulting from the vertical reaction at
the suspension assembly of a trailer, and the horizontal pivot of the
upper coupler (fifth wheel) or turntable; or anchoring and support
members of a truck, as applicable. The vertical reaction must be
calculated based on the static weight of the fully loaded cargo tank,
all structural elements, equipment and appurtenances supported by the
cargo tank wall;
(B) The vertical shear stress generated by an extreme vertical
accelerative force equal to 0.7 times the vertical reaction at the
suspension assembly of a trailer, and the horizontal pivot of the upper
coupler (fifth wheel) or turntable; or anchoring and support members of
a truck, as applicable. The vertical reaction must be calculated based
on the static weight of the fully loaded cargo tank, all structural
elements, equipment and appurtenances supported by the cargo tank wall;
(C) The lateral shear stress generated by an extreme lateral
accelerative force equal to 0.4 times the vertical reaction at the
suspension assembly of a trailer, applied at the road surface, and as
transmitted to the cargo tank wall through the suspension assembly of a
trailer, and the horizontal pivot of the upper coupler (fifth wheel) or
turntable; or anchoring and support members of a truck, as applicable.
The vertical reaction must be calculated based on the static weight of
the fully loaded cargo tank, all structural elements, equipment and
appurtenances supported by the cargo tank wall; and
(D) The torsional shear stress generated by the same lateral forces
as described in paragraph (c)(2)(iv)(C) of this section.
* * * * *
Sec. 178.338-11 [Amended]
5. In Sec. 178.338-11, in paragraph (c) introductory text, in the
first sentence, the wording ``remotely controlled internal self-closing
stop valve'' is revised to read ``remotely controlled self-closing
shut-off valve''.
Sec. 178.345-3 [Amended]
6. In Sec. 178.345-3, in paragraphs (c)(1)(iii)(B) and
(c)(2)(iii)(B), in the second sentence, the wording ``horizontal pivot
of the tractor'' is revised to read ``horizontal pivot of the truck
tractor''.
Sec. 178.345-14 [Amended]
7. In Sec. 178.345-14, in paragraph (b)(3), the wording ``Tank
(MAWP)'' is revised to read ``Tank maximum allowable working pressure
(MAWP)''.
PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS
8. The authority citation for part 180 continues to read as
follows:
Authority: 49 U.S.C. 5101-5127, 49 CFR 1.53.
9. In Sec. 180.403, the introductory text in the definition for
``modification'' is revised to read as follows:
Sec. 180.403 Definitions.
* * * * *
Modification means any change to the original design and
construction of a cargo tank or a cargo tank motor vehicle which
affects its structural integrity or lading retention capability. Any
modification which involves welding on the cargo tank wall also must
meet all requirements for ``Repair'' as defined in this section. * * *
* * * * *
Sec. 180.405 [Amended]
10. In Sec. 180.407, in paragraph (h)(2), in the second sentence,
the reference ``40 CFR 60.501 and 60.601'' is revised to read ``40 CFR
60.501''.
11. In Sec. 180.407, paragraphs (d)(1)(i) and (ii) are revised to
read as follows:
Sec. 180.407 Requirements for test and inspection of specification
cargo tanks.
* * * * *
(d) * * *
(1) * * *
(i) Visual inspection is precluded by internal lining or coating,
or
(ii) The cargo tank is not equipped with a manhole or inspection
opening.
* * * * *
Sec. 180.407 [Amended]
11a. In addition, in Sec. 180.407, in the table in paragraph (c),
under the subheading ``Thickness Test'' in the first column, the
wording ``in corrosive service, except'' is revised to read
``transporting material corrosive to the tank, except''.
12. In Sec. 180.413, paragraphs (b)(6), ((d)(3) introductory text
and (d)(10) are revised, and a new paragraph (d)(3)(v) is added to read
as follows:
Sec. 180.413 Repair, modification, stretching, or rebarrelling of
cargo tanks.
* * * * *
(b) * * *
(6) The suitability of any repair affecting the structural
integrity of the cargo tank must be determined by the testing required
either in the applicable manufacturing specification, or in
Sec. 180.407(g)(1)(iv).
* * * * *
(d) * * *
(3) Except as provided in paragraph (d)(3)(v) in this section, all
new material and equipment, and equipment affected by modification,
stretching or rebarrelling must meet the requirements of the
specification in effect at the time such work is performed, and must
meet the applicable structural integrity requirements (Secs. 178.337-3,
178.338-3, or 178.345-3 of this subchapter). The work must conform to
the requirements of the applicable specification as follows:
* * * * *
(v) For Specification MC 338 cargo tanks, the provisions of
specification MC 338. However, structural modifications to MC 338 cargo
tanks authorized under Sec. 180.405(d) may conform to applicable
provisions of the ASME Code instead of specification MC 338, provided
the structural integrity of the modified cargo tank is at least
equivalent to that of the original cargo tank.
* * * * *
(10) The suitability of any modification affecting the structural
integrity of the cargo tank, with respect to pressure, must be
determined by the testing required either in the applicable
manufacturing specification, or in Sec. 180.407(g)(1)(iv).
* * * * *
Sec. 180.413 [Amended]
13. In addition, in Sec. 180.413, the following changes are made:
a. In paragraph (d)(3)(iii), at the end of the paragraph, the word
``and'' is removed.
b. In paragraph (d)(3)(iv), at the end of the paragraph, the period
is removed and ``; and'' is added in its place.
[[Page 17403]] Issued in Washington, DC on March 30, 1995, under
authority delegated in 49 CFR Part 1.
Ana Sol Gutierrez,
Deputy Administrator, Research and Special Programs Administration.
[FR Doc. 95-8349 Filed 4-4-95; 8:45 am]
BILLING CODE 4910-60-P
