Cargo Tanks; Miscellaneous Requirements; Revisions and 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