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

SUMMARY: RSPA is amending the Hazardous Materials Regulations (HMR) to:

Require facilities that build, repair, and ensure the structural

integrity of tank cars, to develop and implement a quality assurance

program (QAP); allow the use of non-destructive testing (NDT)

techniques, in lieu of currently prescribed periodic hydrostatic

pressure tests, for fusion welded tank cars; require thickness

measurements of tank cars; allow the continued use of tank cars, with

limited reduced shell thicknesses, for certain hazardous materials;

increase the frequency for inspection and testing of tank cars for

added safety; clarify tank car pretrip inspection requirements; expand

the use of thermal protection systems and head protection on tank cars

to include certain other high hazard materials; add new requirements

for bottom-discontinuity protection; require the use of protective

coatings on insulated tank cars; prohibit the use of self-energized

manways located below the liquid level of the tank; remove

``grandfather'' provisions allowing certain uses of tank cars; and

improve the puncture resistance of tank cars used for certain high

hazard materials, including those that are poisonous-by-inhalation

(PIH) and those determined by the Environmental Protection Agency (EPA)

to pose health and environmental risks.

These actions are being taken to enhance the safe transportation of

hazardous materials in tank cars. The intended effects of these actions

are to improve the crashworthiness of tank cars and to increase the

probability of detecting critical tank car defects.

DATES: Effective date. The effective date of these amendments is July

1, 1996.

Compliance date. Voluntary compliance with the regulations, as

amended herein, is authorized November 1, 1995.

Incorporation by reference date. The incorporation by reference of

certain publications listed in these amendments is approved by the

Director of the Federal Register as of July 1, 1996.

FOR FURTHER INFORMATION CONTACT: Ed Pritchard (telephone 202-366-0509)

and James H. Rader (telephone 202-366-0510), Hazardous Materials

Division; or Thomas A. Phemister (telephone 202-366-0635), Office of

Chief Counsel, Federal Railroad Administration, 400 Seventh Street,

S.W., Washington, D.C. 20590-0001.

SUPPLEMENTARY INFORMATION:

I. Introduction

This final rule consolidates two related notices of proposed

rulemaking published under Docket HM-175A [58 FR 52574, October 8,

1993] and Docket No. HM-201 [58 FR 48485 September 16, 1993], that

address the safe performance of tank cars used to transport hazardous

materials. RSPA believes that, by consolidating these two rulemakings,

changes to sections that are affected by both rules will be more easily

understood by readers. This preamble discusses separately, for each

rulemaking, the notices of rulemaking and comments received in response

to these notices. A consolidated ``Review by Section Summary''

summarizes the changes made under this final rule.

The Federal Railroad Administration (FRA) has enforcement authority

for tank cars and rail transportation. FRA developed these rulemakings

jointly with RSPA.

II. Docket HM-175A--Crashworthiness Protection Requirements for

Tank Cars

A. Background

Based on research and on the FRA's continuing review of serious

accidents, involving the transportation of hazardous materials in tank

cars in the United States and Canada, RSPA issued a number of

regulations to improve the survivability of tank cars in

accidents.1 In these rulemakings, RSPA required the installation

of a tank-head puncture-resistance system (head protection), a coupler

vertical restraint system (shelf couplers), insulation, and a thermal

protection system for certain high-risk hazardous material ladings. The

difference between a ``thermal protection system'' and ``insulation''

is that a ``thermal protection system'' protects a tank from a pool or

torch-fire environment. In contrast, ``insulation'' protects the lading

inside the tank from ambient, temperature differentials, much like home

insulation. The record shows that these systems, working in

combination, have greatly reduced the potential harm to human health

and the environment when tank cars are involved in accidents.

\1\The discussions in the following rulemakings provide greater

detail about each of these safety system requirements: Interlocking

Couplers and Restrictions of Capacity of Tank Cars, Docket HM-38, 35

FR 14215 (September 9, 1970); Tank Car Tank Head Protection, Docket

HM-109, 41 FR 21475 (May 26, 1976); Shippers; Specifications for

Pressure Tank Cars, Docket HM-144, 42 FR 46306 (September 15, 1977);

Shippers, Specifications for Tank Cars, Docket HM-174, 49 FR 3473,

(January 27, 1984); Specifications for Railroad Tank Cars Used to

Transport Hazardous Materials, Docket HM-175, 49 FR 3468 (January

27, 1984); Transportation of Hazardous Materials, Miscellaneous

Amendments, Docket HM-166W, 54 FR 38790 (September 20, 1989); and

Performance-Oriented Packaging; Changes to Classification, Hazard

Communication, Packaging and Handling Requirements Based on UN

Standards and Agency Initiative, Docket HM-181, 55 FR 52402

(December 21, 1990).

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On October 8, 1993, RSPA published a notice of proposed rulemaking

(NPRM) under Docket HM-175A (58 FR 52574) based, in part, on

recommendations issued by the National Transportation Safety Board

(NTSB) and comments received in response to an advance notice of

proposal rulemaking published on May 15, 1990 [55 FR 20242], and a

supplemental advance notice of proposed rulemaking published on August

29, 1990 [55 FR 35327]. The NPRM solicited comments on the costs and

safety benefits that would be derived should the HMR be amended in the

following areas: (1) Tank-head protection; (2) thermal protection; (3)

self-energized manways below the tank liquid level; (4) non-pressure

tank cars for PIH materials; (5) grandfather provisions allowing use of

certain tank cars conforming to former standards; (6) bottom

discontinuity protection on tank cars; (7) protective coatings on

insulated tanks; and (8) tank cars of limited and designated

specifications, with greater protection in accidents for transporting

materials determined by EPA to pose health and environmental risks.

On January 6, 1994, FRA and RSPA held a public hearing to solicit

information to assist in deciding what actions, if any, should be taken

to improve the survivability of tank cars involved in hazardous

materials accidents. Twelve persons made presentations at the public

hearing. In addition, RSPA received 37 written comments in response to

the NPRM from representatives of trade associations and the various

industries that own, lease, transport, or use tank

[[Page 49049]]

cars. All written and oral comments were given full consideration.

B. Tank Cars Transporting ``Thermally Reactive Materials'' (Materials

That May Violently Decompose or Polymerize When Exposed to Fire)

In the NPRM, RSPA proposed to require the use of full-head

protection and thermal protection on tank cars used for certain

materials termed, ``thermally reactive.'' These materials, listed by

name, are thought by many to be capable of a violent decomposition or

polymerization reaction when exposed to fire. For these materials, the

critical temperature for the tank car, and its thermally reactive

lading, may be the heat at which the material undergoes decomposition

or polymerization--as opposed to the temperature at which the steel of

the tank becomes so plastic, it begins to lose tensile strength.

The proposal was based on several accidents involving thermally

reactive materials. For example, on August 2, 1988, at 9:00 p.m., in

Brazoria, Texas, 13 cars of a Union Pacific freight train

derailed.2 Seven of the derailed tank cars contained acetaldehyde,

and none of these tank cars had a thermal protection system, which was

not required. Two acetaldehyde tank cars sustained coupler punctures

and released their contents, which ignited. The resulting fire engulfed

four other acetaldehyde tank cars, and each of them had a total failure

or rupture of the tank shell within 5 to 10 minutes after the

derailment. Witnesses reported 3-4 explosions between 9:05 p.m. and

9:10 p.m.

\2\Union Pacific Derailment at Brazoria, Texas, FRA Accident

Investigation No. 137-88, Railroad Report No. 0888H0200, August 2,

1988.

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In another accident, NTSB found that the puncture of a tank car

containing hydrogen peroxide resulted in a release of lading and, when

the hydrogen peroxide combined with contaminants on the ground, a

chemical reaction occurred causing a fire.3 The fire heated and

ignited nearby polyethylene pellets, causing an explosion of the

hydrogen peroxide tank car and releasing a force equivalent to an

explosion of 10 tons of TNT (trinitrotoluene).

\3\Collision and Derailment of Montana Rail Link Freight Train

with Locomotive Units and Hazardous Materials Release, Helena,

Montana, February 2, 1989, National Transportation Safety Board

Report NTSB/RAR-89/05, National Transportation Safety Board,

Washington, D.C.

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Most commenters opposed the requirement for full-head protection or

thermal protection on tank cars used for thermally reactive materials.

In clarifying its comments on the NPRM, the Association of American

Railroads (AAR) stated that full-head protection is not necessary for

tank cars used for these materials, unless the materials pose another

hazard that warrants such protection. Other commenters, such as

American Petroleum Institute (API), Chemical Manufacturers Association

(CMA), and the Compressed Gas Association, Inc. (CGA), suggested that

RSPA open a new ANPRM to address these materials. A commenter stated--

the creation of this category has ramifications that reach far

beyond this particular rulemaking, which deals with one mode of

transportation (rail) and one type of packaging (tank cars). We are

concerned with the likelihood that, in the future, the Department

will expand the regulation of TRMs to affect other modes of

transportation and types of packaging.

Other commenters objected to the proposal to identify by list,

rather than by definition, certain existing hazardous materials that

would be designated ``thermally reactive.'' CMA challenged the

placement of several chemicals on the list, such as ``styrene, monomer

inhibited,'' ``vinyl toluene,'' ``vinylidene chloride,'' ``sulfur

trioxide,'' and ``hydrogen peroxide.'' CMA further stated that--

[s]tyrene, for example, is flammable and can polymerize in an

accident but solidifies causing little or no harm to the

environment. For hydrogen peroxide tank cars, the proposed rule

would create a safety hazard by requiring thermal protection.

Another commenter stated that ``[s]ome of the materials on the list

react violently when exposed to heat differentials and may decompose

with explosive force * * * Other materials, however, decompose through

polymerization into substances of relatively little hazard.'' The

commenter further explained that the key to the polymerization of

styrene is the absence of the inhibitor. Styrene is typically shipped

with inhibitor concentrations great enough to cover fairly lengthy,

unexpected delays in transportation. If a tank car of styrene is

exposed to extreme external heat, disregarding its flammable nature,

the inhibitor will dissipate rapidly as the temperature of the material

rises above 125 deg.F., which will allow the polymerization process to

begin. As a result of the polymerization, the internal heat of the

product will increase, and, with increasing temperature, the process

will accelerate.

Several commenters opposed the requirement for a thermal protection

system on tank cars used to transport ``hydrogen peroxide.'' One of the

commenters stated that hydrogen peroxide does not polymerize or burn,

and the products of decomposition--water and oxygen--are not toxic.

Two commenters, Eka Nobel and FMC Corporation (FMC), furnished

independent analyses of the fire effects on tank cars containing

``hydrogen peroxide.'' Eka Nobel contracted with the IIT Research

Institute (IITRI), which used FRA's computer model to analyze the fire

effects on a tank car containing hydrogen peroxide.4 The results

of IITRI's analysis indicate that a tank car constructed from stainless

steel will meet the thermal protection criterion for withstanding the

effects of a pool fire.

\4\``Temperatures, Pressures and Liquid Levels of Tank Cars

Engulfed in Fires,'' NTIS DOT/FRA/OR&D-84/08.11, (1984), Federal

Railroad Administration, Washington, DC.

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FMC furnished a detailed, mathematical heat transfer model using a

correlation contained in a National Fire Protection Association (NFPA)

publication, ``NFPA Pamphlet No. 30.'' FMC stated that for materials

that decompose exothermically, such as hydrogen peroxide, thermal

stability requires that the heat losses to the surroundings balance the

heat generated by the decomposition. Failure to remove the heat of

reaction could lead to runaway decomposition, and if the increased

pressure exceeds the burst pressure of the tank, the tank will fail.

Furthermore, heat input causes oxygen generation from thermal

decomposition of peroxide and vapor generation, by boiling off the

water-peroxide mixture. FMC further stated that because water is more

volatile than peroxide, the hydrogen peroxide concentration in the tank

will increase (although this may be compensated by water formation and

peroxide loss from thermal decomposition). If the peroxide

concentration reaches 74 percent by weight, the vapors in equilibrium

with the liquid (40 percent by weight of peroxide) can detonate, if

ignited, causing the tank car to fail.

The results of FMC's mathematical heat transfer model show that

tank cars containing hydrogen peroxide (having no less than a 7-percent

outage) will not fail and such tank cars will meet the thermal

protection criterion in Sec. 179.18 of this final rule for withstanding

the effects of a pool-fire. Readers who are interested in a detailed

discussion of Eka Nobel or FMC's fire studies on tank cars containing

hydrogen peroxide, should refer to the comments filed in the RSPA

Dockets Unit.

Many commenters suggested a performance-based definition as a means

to ensure the proper identification and packaging of thermally reactive

materials, because, with increasing temperature, all materials will

reach a stability limit.

[[Page 49050]]

These commenters suggested a performance-based definition that would

include the polymerization potential; the rate of the chemical reaction

(reaction kinetics); any highly exothermic reaction; the formation of

gases, vapors, or fumes in a quantity sufficient to present a danger to

human health and the environment; and any reactive by-products that

could lead to over-pressurization of the tank. Commenters stated that a

performance-based definition was the best way to ensure that the proper

packaging requirements are attached to the appropriate hazardous

materials.

As evidenced from the comments, there is no single agreement on the

best approach to identify these materials, nor to ensure the proper

packaging requirements are assigned to these materials. Because of the

multiplicity of these yet unresolved issues, the packaging requirements

proposed in the NPRM for thermally reactive materials have not been

adopted in this final rule.

C. Tank-Head Protection

In the NPRM, RSPA proposed several changes relating to tank-head

protection. The proposal would require tank-head protection on tank

cars, used for all Class 2 materials and for tank cars constructed from

aluminum or nickel plate, when used to transport a hazardous material.

RSPA included Division 2.2 in its proposal to reduce the violent

rupture hazard and the asphyxiation potential to railroad workers or

bystanders exposed to the product if these tank cars are punctured. The

proposal to require full-head protection for tank cars constructed from

aluminum or nickel plate is based on the vulnerability of the tank head

to a puncture. The top-half of the tank head is vulnerable to puncture

in a derailment. Existing tank cars with half-head protection were

excluded, based on RSPA and FRA's regulatory analysis discussed later

in this preamble. Consistent with these proposed changes, RSPA also

proposed to eliminate a grandfather provision, in place since 1984,

following publication of a final rule under Docket HM-175, that permits

certain tank cars, with a capacity of less than 70 kiloliters (kl;

18,500 gallons), to continue in service without head protection.

RSPA first introduced tank-head protection requirements after a

series of railroad accidents in the late 1960s and early 1970s

involving head punctures of tank cars (39 FR 27572 and 41 FR 21475).

The requirements of, and criteria for, head protection were based on

tests performed by FRA, the AAR, and the Railway Progress Institute

(RPI) Tank Car Safety Research and Test Project in the early 1970s. In

summary, these tests showed that head punctures, caused by over-speed

impacts in railroad classification yards, generally occurred at speeds

above 12 mph and often happened when a loaded tank car struck a

standing empty tank car, causing the empty car to ``jump'' and ram its

coupler into the head of the oncoming tank. A recent informal staff

analysis of data on main-line accidents showed that objects, such as

broken rails and couplers, may penetrate the top half of the tank head,

indicating that head protection is essential, even though not 100

percent effective, in a train derailment.

The NPRM referenced the recent FRA research on puncture resistance,

which shows that puncture resistance is strongly influenced by impact

location, head and jacket thickness, and insulation thickness.5

Stated differently, research demonstrates that puncture resistance is

an inter-related function of head thickness, insulation thickness, and

jacket thickness, and that the concept of ``head protection'' must

include more than just traditional ``head shields.'' Based on the

results of this research, FRA expects that certain tank cars may meet

the 29 kilometers per hour (18-mph) threshold for puncture-resistance,

prescribed in Sec. 179.16 of this final rule, without further

modification.

\5\Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture

Resistance Evaluation (1992), Federal Railroad Administration,

Washington, DC (NTIS DOT/FRA/ORD-92/11).

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Tank cars currently equipped with half-head protection. Most

commenters agreed that there is no need to require full-head protection

on existing tank cars having only half-head protection.

In comments filed in this docket, NTSB stated that the NPRM

addressed many of their concerns, but noted the proposal failed to

require existing tank cars used to transport Division 2.1 (flammable

gas) materials, or other materials with extreme hazards, to be modified

with full-head protection. Thus, these materials could be transported

indefinitely in tank cars without full-head protection modifications.

While we appreciate the concerns of NTSB, we are not able to

establish a positive benefit/cost ratio by requiring modification of

the existing tank car fleet, primarily because the half-head protection

on existing cars is already about 95-percent effective. It is not

credible to argue that greater safety gains are realized by mandating

safety improvements on tank cars that currently have a 95-percent

effective protection system, than by requiring improvements on tank

cars without a head-protection system. The regulatory evaluation

considered both approaches, with emphasis being placed on choosing the

alternative offering maximum potential benefit to society, while

imposing the least net cost. Based on the regulatory evaluation, this

final rule does not require that existing half-head protection be

removed and replaced with full-head protection.

Head protection systems for existing tank cars with capacities less

than 70 kl (18,500 gallons). RSPA received diverse comments in response

to this proposal in the NPRM. One commenter agreed that class DOT 105

tank cars having capacities less than 70 kl (18,500 gallons) and

transporting Division 2.1, 2.2, and 2.3 materials, should have full-

head protection, unless already equipped with half-head protection.

CMA supported the proposal to require full-head protection on newly

built class DOT 105A tank cars, regardless of tank capacity, when used

to transport a Division 2.1 or 2.3 material. The Reebie Associates

report, submitted as part of CMA's comments, assumed that all tank cars

would require head protection, except those that have a tank test

pressure of 41.4 Bar (600 pounds per square inch [psi]).

The Chlorine Institute agreed that head protection systems are now

warranted for the transportation of chlorine, but recognized, based on

FRA research and the accident history, that many tank cars currently

used to transport chlorine meet the performance standard by virtue of a

thick tank-head and a tank jacket.

NTSB commented that RSPA should require tank-head protection,

within 5 years, for all class 105 tank cars having capacities of less

than 70 kl (18,500 gallons) when used to transport a Division 2.1

(flammable gas) material as proposed in Option B of the NPRM.

RPI commented that, except for the nominal 41 kl (11,000-gallon)

capacity tank cars, existing tank cars of less than 70 kl (18,500-

gallon) capacity, transporting Division 2.1 materials or anhydrous

ammonia, should have head-protection, but only half-head protection.

RPI further commented that RSPA should exclude tank cars having a

nominal capacity of 41 kl (11,000 gallons) from any head protection

modification program, because most tank cars in this category are near

or exceed 30 years of age; consequently, the economic life of the tank

is nearing an end.

RSPA and FRA believe that there is no longer a justification for

excluding tank cars having a capacity less than 70

[[Page 49051]]

kl (18,500 gallons) from the modification requirements. While CMA's

report is not so optimistic on the use of DOT 105A500W specification

tank cars, RSPA and FRA believe that most of these tank cars will meet

the performance standard by virtue of their increased head thickness,

insulation, and metal jacket. Because of the small number of tank cars

in this category, and the small incremental cost to make such head

protection modifications for those tank cars that do not otherwise meet

the performance standard mandated by this rule, in this final rule RSPA

is removing the 70 kl (18,500-gallon) exception for existing tank cars

in current Secs. 173.314(c) and 173.323(c)(1).

Further, while most commenters supported the 10-year modification

program for existing tank cars, we agree with NTSB, that when these

tank cars are used to transport Division 2.1 materials, a 5-year

modification program (as proposed in Option B of the NPRM) will ensure

that those cars presenting the greatest risk are modified first.

Tank cars transporting materials in Division 2.2. A commenter

stated that the proposal to require full-head protection for Division

2.2 gases is sound and should be finalized. Several other commenters

disagreed with the proposal to require full-head protection for

Division 2.2 materials. The Reebie Associates report, submitted by CMA,

identified 467 Class 2 materials affected by the proposed rule, 11 of

which are Division 2.2 materials. The report shows that shippers used

1,448 tank cars in 1992 to transport these Division 2.2 materials, as

follows:

------------------------------------------------------------------------

Commodity Population

------------------------------------------------------------------------

Argon, refrigerated liquid................................ 2

Ammonia solutions......................................... 28

Bromotrifluoromethane..................................... 1

Carbon dioxide, refrigerated liquid....................... 1,016

Chlorodifluoromethane..................................... 145

Chlorotetrafluoroethane................................... 26

Chloropentafluoroethane................................... 37

Dichlorotetrafluoroethane................................. 164

Fertilizer, ammoniating solutions......................... 4

Trifluoromethane.......................................... 1

Xenon, refrigerated liquid................................ 24

-------------

Total................................................. 1,448

------------------------------------------------------------------------

CGA opposed the full-head protection requirement for tank cars

transporting carbon dioxide. CGA referenced the testimony presented by

RPI at the January 6, 1994 public hearing concerning recent head impact

tests that verified the adequacy of the current head protection system

on DOT 105A500W specification tank cars.

With regard to CMA's and CGA's comments, RSPA and FRA believe that

most tank cars used for ``carbon dioxide, refrigerated liquid,'' meet

the performance standard for head protection by virtue of their tank

head thickness and metal jacket. Tank cars used for ``argon,

refrigerated liquid,'' and ``xenon, refrigerated liquid,'' also meet

the head performance standard by virtue of the authorized class DOT 113

tank car specification. These tank cars must have a minimum outer

jacket tank head of not less than \1/2\-inch thick steel. See

Sec. 179.400-8(d). A total of 1,042 tank cars, or 72 percent of the

total Division 2.2 tank car population, are used to transport these

three commodities.

A commenter opposed tank-head protection for Division 2.2 materials

stating, ``heavy walled tank and protective housing for the fittings is

adequate for the transportation environment.'' The commenter also

provided an in-house report using a computer model that claims the

asphyxiation potential from a punctured Division 2.2 refrigerant gas

tank car to be very low.'' Another commenter opposed applying head

protection to tank cars transporting Division 2.2 refrigerant gases.

This commenter stated that, in the past, DOT had judged a material

based on its hazards under normal conditions of transport, and that in

this rulemaking, DOT was over-assessing the potential for harm in a

low-probability event. RPI supported full-head protection on new,

insulated tank cars transporting Class 2 materials, but it opposed

full-head protection for new non-insulated tank cars or for existing

tank cars transporting these materials.

We believe that even though the probability of an event occurring

with these materials is low, safety concerns still need to be

addressed, because the event may lead to high consequences, such as a

large scale evacuation or an oxygen deficient atmosphere in a

concentrated populated area. Taking the safety steps adopted in this

final rule will mitigate these hazards.

We also believe that the transportation risks associated with

Division 2.2 gases are sufficient to require full-head protection for

new tank cars, and for existing tank cars without head protection, when

used to transport Division 2.2 materials. As noted above, this rule

does not require existing tank cars equipped with half-head protection

to be modified with full-head protection. RSPA and FRA are aware of

industry concerns that the attachment of full-head protection to non-

jacketed cars is a feature not yet proven by long service. Similar

arguments were raised when head protection was first required almost

two decades ago [HM-144; 42 FR 46306, September 15, 1977]. FRA is aware

of companies with plans to attach full-head protection to their non-

jacketed tank cars. As discussed later in this preamble, a phased-in

10-year modification program is provided for existing tank cars.

Existing tank cars without head protection. Most commenters to the

NPRM supported the need to modify existing tank cars to meet the

current safety requirements. One commenter supported the need to modify

existing tank cars constructed from aluminum plate with half-head

protection, but believed full-head protection should be required when a

proven full-head shield design is available. Another commenter

suggested that DOT should specifically recognize that tank cars used in

``chlorine'' service meet the performance requirements for head

protection and that DOT should not require any additional head

protection for these tank cars.

As stated in the NPRM, the benefits of head protection are real,

predictable, and quantifiable. RSPA disagrees with commenters who state

that full-head protection is not warranted. Where earlier rules

required head protection on tank cars, it was a matter of recognizing

the highest priority needs first. The question is not one of demanding

low-priority, safety benefits, but the need to expand the safety base

of hazardous materials transportation in tank cars. Further, the small

additional cost of installing full-head protection on cars that now

have no head protection system, as compared with adding only half-head

protection, is justified on the basis of increased safety (see Chapter

V of the Economic Impact Assessment and Regulatory Flexibility

Analysis). In this final rule, RSPA requires existing tank cars that

currently have no head protection, to have full-head protection

installed when used to transport a Class 2 material. As explained

below, RSPA is also requiring full-head protection for tank cars

constructed from aluminum or nickel plate when used to transport

hazardous material.

Tank cars constructed from aluminum and from nickel plate.

Commenters supported the need for head protection on tank cars

constructed from aluminum or nickel plate, but not the full-head

protection requirement proposed in the NPRM. Most commenters stated

that there is no design available for the securement of full-head

protection on tank cars without metal jackets.

[[Page 49052]]

One commenter stated that his company's new aluminum tank cars,

constructed with greater tank shell and head dimensions than standard

tank cars, offer greater protection without head protection. The

commenter stated that further testing should be done and suggested that

RSPA and FRA submit more evidence to support the need for this

requirement.

CMA supported requiring half-head protection for new tank cars

constructed from aluminum or nickel plate, and requiring half-head

protection for existing tank cars for certain hazardous materials.

Several commenters requested that RSPA consider the characteristics of

an individual Division 2.2 material, and that materials not subject to

the HMR, and low hazard materials should be excluded.

We realize that the use of good engineering practice and design

specifications are needed to secure full-head protection to tank cars

without metal jackets. Although there is no service experience for a

full-head protection design on non-insulated tank cars, such designs

are certainly not unreachable within the years ahead. In rulemaking

proceedings under another docket [HM-144; 42 FR 46306, September 15,

1977] introducing half-head protection, commenters offered similar

arguments regarding head protection, for which solutions were later

found as a result of technological innovation. Currently, FRA is aware

of several companies that are nearing completion on their full-head

protection designs for aluminum and nickel tank cars. We, therefore,

believe that the introduction of this requirement will not adversely

affect industry. In this final rule, the use of full-head protection

for all tank cars constructed from aluminum or nickel plate is required

when used to transport a hazardous material. As discussed later in this

preamble, RSPA has provided for a phased-in 10-year modification

program.

D. Thermal Protection Systems

In the NPRM, RSPA proposed to require a thermal protection system

for a Class 2 material when a thermal analysis of the tank car and

lading shows that a release will occur other than through the safety

relief valve when the tank car is subjected to either a 100-minute pool

fire or a 30-minute torch fire. The current HMR require thermal

protection for Division 2.1 (flammable gas) materials (with limited car

capacity restrictions) and certain Division 2.3 (poison gas) materials.

RSPA proposed to expand the thermal protection requirements to include

Division 2.2 materials because, as stated by AAR, ``[a]t a chemical

accident, there are generally two reasons for an evacuation, one is to

protect the public from any toxic, poisonous, or noxious vapors or

fumes generated by the product itself . . ., the second is to protect

the public from thermal ruptures and the container debris that may be

hurled from an incident site'' [Emergency Action Guides, p. VII]. RSPA

also proposed to expand the thermal protection requirement to include

all Division 2.3 materials.

RSPA began to require the application of a thermal protection

system on tank cars transporting Division 2.1 materials (flammable

gases) or ``ethylene oxide'' (Division 2.3) after a series of major

railroad accidents involving fires and ruptures of non-insulated

pressure tank cars. The design of and criteria for thermal protection

systems were based on tests performed by FRA at the U.S. Army

Ballistics Research Laboratory in White Sands, New Mexico, and at the

Transportation Test Center in Pueblo, Colorado. These tests revealed

that a 127.2 kl (33,600 gallon) non-protected tank car filled with

propane (Division 2.1) will rupture, with 40 percent of the lading

remaining in the tank car, within 24 minutes after exposure to a pool-

fire. Rupture occurs when the residual strength of the tank shell falls

below the force generated by the vapor pressure of the lading exerted

on the inside surface of the tank shell. Further testing by FRA

demonstrated that a tank car filled with propane and equipped with a

thermal protection system delayed the thermal rupture of the tank car

for 94.5 minutes, by maintaining the shell temperature low enough to

vent 98 percent of the lading through the safety relief valve. The

current performance standard, requiring exposure to a 100-minute pool

fire and a 30-minute torch fire, was chosen because it provides

emergency response personnel time to assess the accident and to

initiate remedial actions, such as evacuating an area.

Division 2.1 (flammable gas) and 2.3 (poisonous gas) materials:

Several commenters supported the need for a thermal protection system

on tank cars transporting Division 2.1 or 2.3 materials, regardless of

tank car capacity. The AAR and another commenter supported a thermal

protection system for all Class 2 materials, unless a shipper could

show that a release will not occur, other than through the safety

relief valve, when the tank and lading are subject to a fire. RPI also

concurred on the need for thermal protection for all Class 2 materials,

but, except for Division 2.1, but did not support the high-temperature

performance standard proposed in Sec. 179.18. RPI stated that most

insulation materials (e.g., 4 inches of glass-fiber insulation) are

adequate.

In this regard, RSPA stated in the NPRM that many insulation

materials also provide good thermal protection. These insulation

materials, when analyzed with the tank and the lading, may show that

nothing further needs to be installed on the tank car to achieve

passage of the pool- and torch-fire performance tests. Research

sponsored by FRA on urethane-foam and glass-fiber insulation systems

show that urethane-foam insulation will pass the pool- and torch-fire

requirements and that glass-fiber insulation will also pass both tests,

provided the insulation is held in place with a plastic or wire scrim.

Owners of tank cars with either of these systems, or another comparable

system, may find that their thermal analysis of the tank car shows the

presence of sufficient thermal protection to meet the performance

standard. In this case, the tank car owner would have to verify only

that the insulation material installed on the tank car is capable of

passing the pool- and torch-fire verification or ``proof'' tests in

Appendix B to Part 179 of this final rule. Owners may find that a tank

car will pass the performance standard with only minor modifications,

such as applying a thermal protection system to the manway nozzle.

Also in the NPRM, RSPA stated that, in 1981, a joint effort between

the Chlorine Institute and RPI-AAR Tank Car Safety Research and Test

Project resulted in the development of an insulation system to protect

a chlorine tank car involved in a fire. The insulation system developed

maintains back plate (inside surface of the tank car shell)

temperatures below 250.56 deg.C (483 deg.F). After reviewing the

thermal resistance capabilities of the insulation system used on

chlorine tank cars, RSPA incorporated it into the HMR in 1987. Readers

should refer for more information to Docket HM-166U, entitled

``Transportation of Hazardous Materials; Miscellaneous Amendments'', 52

FR 13034, (April 20, 1987).

Division 2.2 (nonflammable gas) materials. As noted earlier in the

preamble discussion on tank-head protection for Division 2.2 materials,

CMA commented that there were 1,448 tank cars allocated to Division 2.2

materials that had not already been captured in another service, such

as PIH. Of those, ``argon, refrigerated liquid,'' ``carbon dioxide,

refrigerated liquid,'' and ``xenon, refrigerated liquid,'' represent

1,042 tank cars, or 72 percent. CMA further commented that

[[Page 49053]]

almost 100 percent of the total would need retrofitting and that the

overall economic impact of the new regulations on this group of tank

cars amounts to $26.0 million for retrofitting and $2.59 million for

higher lease rates and additional cars in the tenth year of the

implementation period.

With regard to the issues raised by CMA, this final rule does not

contain any new thermal protection requirements for ``argon,

refrigerated liquid,'' ``carbon dioxide, refrigerated liquid,'' or

``xenon, refrigerated liquid.'' Carbon dioxide is transported in DOT

105A500W tank cars equipped with two regulator valves, a reclosing

pressure-relief device, a frangible disc, and an insulation system with

good thermal performance (a thermal conductance of 0.03 British Thermal

Units [B.t.u.] per square foot per degree Fahrenheit differential).

Consequently, existing and new tank cars in carbon dioxide service have

sufficient thermal resistance when exposed to fire. Likewise, because

with argon and xenon, refrigerated liquids are packaged under the

exceptions for atmospheric gases in Sec. 173.320, this final rule does

not impose any new thermal protection requirements. This section

exempts cryogenic atmospheric gases from the packaging requirements

when the packagings are designed to maintain pressures below 1.74 Bar

(25.3 psi) under ambient temperature conditions.

Another commenter opposed the use of thermal protection for

Division 2.2 materials on the basis that the hazards they pose do not

equate to those of Division 2.1 and 2.3 materials. The commenter

further stated that the thermal protection requirements proposed for

Division 2.2 materials do not appear to be justified by the hazards

posed, because, in many cases, these materials dissipate naturally with

little risk to the surroundings.

A commenter, primarily addressing refrigerant gases, noted that an

analysis of each Division 2.2 material, to predict the behavior of a

tank car in a 100-minute pool-fire, seemed an unnecessary precaution

because the calculations, required by the current regulations, for

sizing safety relief valves accomplish the same purpose and meet this

same standard. RSPA and FRA disagree with this commenter's position

that the current regulations for sizing safety relief valves accomplish

the same purpose as the proposed Division 2.2 thermal protection

performance standard. The current safety relief valve-sizing

requirements make several assumptions. First, the valve sizing formula

assumes the exposure factor, that portion of the tank car exposed to

fire (represented as A0.82), is about one-fourth of the tank. The

pool-fire computer model in this final rule assumes total engulfment.

Second, the safety relief valve sizing formula assumes that flame

temperatures will reach approximately 650 deg.C (1,200 deg.F.). The

pool-fire standard assumes flame temperatures will reach 871 deg.C

(1,600 deg.F) for a pool-fire and 1,204 deg.C (2,200 deg.F) for a

torch fire at 40 miles per hour.6 Third, the safety relief valve-

sizing formula does not take into consideration either an overturned

tank car venting liquid or a liquid-gas mixture (two phase flow) or the

diminished burst strength of the heated tank shell in the non-wetted

area, after prolonged fire exposure.

\6\The pool-fire computer model assumes an average heat flux

over the entire tank surface, equivalent to complete engulfment in a

fire, where the flame temperature is 815.5 deg.C (1,500 deg.F). If

a higher or lower flame temperature were assumed, the parametric

analyses in the computer model would not match the actual field test

data.

---------------------------------------------------------------------------

The Fertilizer Institute did not support the requirement for

thermal protection on tank cars transporting ``anhydrous ammonia''. It

stated that the likelihood of a fire-induced rupture of a tank car

carrying anhydrous ammonia has significantly decreased since 1980

because of added safety devices, safer placement in trains, and

improved emergency response procedures. Thus, there is little, if any,

increase to public safety by imposition of the proposed thermal

protection requirements on these tank cars.

While RSPA and FRA agree with The Fertilizer Institute that the

safety record for tank cars transporting ``anhydrous ammonia'' is good,

these cars have a potential for violent rupture similar to compressed

gas tank cars, which received thermal protection many years ago. As The

Fertilizer Institute notes, the threat of a fire-induced violent

rupture of an anhydrous ammonia tank car is more than just a

theoretical potential. Since 1990, according to figures from the AAR,

``anhydrous ammonia'' has been the sixth highest volume hazardous

material transported by railroad.

AAR and two other commenters supported the need for thermal

protection for Class 2 materials, including Division 2.2. One of these

commenters stated: ``thermal protection systems are a good, simple idea

whose time has come. The purpose of the system is to prevent rupture of

the tank car in a fire with the release of its hazardous materials

contents to the environment. Uncontrolled release of almost any

hazardous material to the environment is objectionable whether due to

toxicity, flammability, or simply clean-up costs.'' This commenter

further stated that there can be little basis for exempting anhydrous

ammonia from the thermal protection requirements simply because it is

not likely to catch fire once released. Its PIH characteristic remains,

and the potential for rupturing in a non-insulated tank car is high.

Although not all commenters agree on the need for thermal

protection for Division 2.2 materials, in this final rule RSPA requires

such a system if, after an analysis of the effects of a 100-minute pool

fire and a 30-minute torch fire, there will be a release of the tank

car lading other than through the safety relief valve. Because tank

cars may transport different ladings, and because changing ladings may

affect the whole system, owners or shippers may choose to perform a

``worst case'' analysis based on all the commodities the car is likely

to carry.7

\7\Owners are reminded that 49 CFR 173.31(a)(4) limits the use

of tank cars to those commodities for which they are authorized.

Authorized (or approved) commodities are those listed on the

certificate of construction or an AAR R-1 form. (See the AAR

Specifications for Tank Cars Section 1.4.3.1 and Appendix R, Section

R4.04.)

---------------------------------------------------------------------------

Based on these comments and FRA's research, this final rule

requires the owner or the shipper of a Class 2 material, with the

exception of ``carbon dioxide, refrigerated liquid,'' ``chlorine,'' and

``nitrous oxide, refrigerated liquid'' as explained above, to perform

an analysis of the characteristics of the material and of the thermal

resistance capabilities of the tank car, taking into consideration the

safety relief valve start-to-discharge pressure setting and relief

capacity and all areas of the tank car that are not afforded protection

from fire (such as stub sills, bolsters, and protective housings).

Tank cars constructed from aluminum and nickel plate. Most

commenters said that the lading within a tank car constructed from

aluminum or nickel plate should determine the need for a thermal

protection system.

We agree. The NPRM proposed to require a thermal protection

analysis for aluminum and nickel plate cars carrying Class 2 materials.

Based on the comments received, we believe that all such tank cars will

need protection and that such protection is essential.

This final rule requires the owner of an aluminum or nickel plate

tank car used to transport a Class 2 material to perform an analysis of

the tank car in a 100-minute pool fire and in a 30-minute torch fire

using FRA's Tank Car Fire model. If the analysis shows that a release

of the lading from the tank car,

[[Page 49054]]

will occur, other than through the safety relief valve, a thermal

protection system will be required. This final rule adopts a 10-year

phase-in period for those existing tank cars required to have thermal

protection.

E. Shell Protection

For tank cars transporting of a material poisonous by inhalation

(PIH), RSPA proposed that they have ``shell protection conforming to

Sec. 179.100-4.'' That is, the optional use of an insulated DOT 105S

tank car or a non-insulated, but thermally protected, DOT 112J or 114J

tank car having a metal jacket. Although RSPA used the term ``shell

protection'' to identify these systems, the intent of the NPRM was to

require tank cars transporting a PIH gas (Division 2.3) to conform to

the same requirements as tank cars transporting a PIH liquid. For a

complete discussion, see Performance-Oriented Packaging Standards;

Miscellaneous Amendments, Docket HM-181F, 58 FR 50224 (September 24,

1993). In the final rule issued under that docket, RSPA authorized the

optional use of an insulated DOT 105S tank car or a non-insulated, but

thermally protected, DOT 112J or 114J tank car for poisonous liquids

having a PIH hazard.

In its comments to the NPRM, one commenter supported the need for

shell protection for PIH materials. Another commenter suggested that,

in lieu of a metal jacket, RSPA should establish a performance

standard, as with thermal and head protection. Until a performance

standard is established, shell-protection resistance should be

equivalent to a tank car having a tank test pressure of 20.7 Bar (300

psi) constructed from carbon steel and with a 1/8-inch carbon steel

jacket. The commenter stated that the shell-puncture resistance should

be based on either a total metal thickness, or an approved calculation.

We agree with this commenter that a performance-based standard for

shell-puncture resistance may have merit over specification-based

standard adopted in this final rule. However, such performance based

standards have not been proposed.

Another commenter opposed the use of a metal jacket on pressure

tank cars transporting a PIH material on the basis that the FRA's

proposal did not support the conclusion that jacketing improves

puncture resistance. The commenter further questioned the use of a tank

jacket over thicker tank shells, since ``jackets provide thermal not

puncture protection.''

In response to similar remarks, RSPA discussed in the NPRM a 1987

RPI report on the vulnerability of pressure tank car shells to

puncture.8 RPI found that shelf couplers, hardboard insulation

(cork), increased shell thickness, thermal protection, small tank car

size and increased jacket thickness proved effective towards reducing

the frequency of shell punctures. The RPI report summarizes a 20\1/2\-

year history of accident data on shell punctures of pressure tank cars

and concludes that the 11-gauge steel jacket provides a measure of

shell protection. In addition to RPI's report, FRA also found, in a

research contract awarded to the AAR, that puncture resistance is

strongly influenced by impact location, by head and jacket thickness

and by insulation thickness.9

\8\Phillips, E.A., Review of Pressure Car Shell Puncture

Vulnerability, RA-09-6-52, (1987), AAR-RPI Railway Tank Car Safety

Research and Test Project, AAR Technical Center, Chicago, Illinois.

\9\[Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture

Resistance Evaluation, (1992) Federal Railroad Administration,

Washington, D.C. (NTIS DOT/FRA/ORD-92/11).

---------------------------------------------------------------------------

RSPA explained earlier, in Docket HM-181, that the purpose of a

metal jacket is to provide ``both accident damage and fire protection''

for certain [liquid] PIH materials.10 This final rule expands that

philosophy to all PIH materials [including compressed gases] and

authorizes the use of an insulated class DOT 105S tank car or a non-

insulated, but thermally protected, class DOT 112J or 114J tank car.

\10\See the final rule on Performance-Oriented Packaging

Standards; Miscellaneous Amendments, Docket HM-181F, 58 FR 50224

(September 24, 1993), and the NPRM, 58 FR 37612 (July 12, 1993).

---------------------------------------------------------------------------

F. Self-Energized Manways Located Below the Liquid Level of the Lading

RSPA proposed in the NPRM to prohibit the use on tank cars of a

self-energized manway located below the liquid level of the lading. The

proposal was based on a September 8, 1987 railroad yard incident in New

Orleans, Louisiana.11 In this incident, a tank car equipped with a

self-energized bottom manway and loaded with butadiene developed a leak

and caught fire. At one point during the incident, the flames were

large enough that both spans of a bridge on Interstate 10 were

engulfed. After the investigation, NTSB concluded that ``it is unlikely

that a hazardous material leak through a bottom manway during

transportation could be stopped.'' NTSB urged FRA to prohibit the

transportation of tank cars that have a manway opening located below

the liquid level of the lading in hazardous materials service. Because

the design of bottom manways depends in part on the weight of the

product and the pressure in the tank to make the seal fully effective,

this type of closure system becomes vulnerable to releasing product

when the lading is displaced within the tank. Therefore, we agree with

NTSB's conclusion.

\11\Butadiene Release and Fire from GATX 55996 at the CSX

Terminal Junction Interchange, New Orleans, Louisiana, September 8,

1987, National Transportation Safety Board Report NTSB/HZM-88/01,

National Transportation Safety Board, Washington, D.C.

---------------------------------------------------------------------------

In its comments to the NPRM, the AAR, RPI, and several other

commenters supported the proposal to remove self-energized manways

located below the liquid level of the lading. A commenter stated that

their design incorporates an externally elliptically shaped ring clamp

which is bolted to the manway closure plate with numerous closely-

spaced studs around the circumference of the ring. This commenter holds

two DOT exemptions (DOT-E 5493 and DOT-E 6117) to operate tanks cars in

hydrogen sulphide service with this design. RSPA and FRA believe that

this design is certainly preferable to that used on the car that leaked

and burned in New Orleans and is similar to a more conventional

external flange, however, we believe this design still remains a

potential source of leaks since it is located below the liquid level of

the lading. Based on these reasons, RSPA will grant the exemption

holder a reasonable amount of time to phase out the use of these tank

cars.

While some commenters agreed with a 2-year phase out program of

self-energized manways, NTSB stated that RSPA should immediately

prohibit such manways, and the AAR suggested a one-year phase-out

program.

Based on these comments, this final rule prohibits the construction

of new tank cars having an internal self-energized manway located below

the liquid level of the lading. This prohibition is added in

Sec. 179.103-5. Based on NTSB's comments, compliance with this

provision is required beginning on the effective date of this final

rule.

G. Non-Pressure Tank Cars for Materials Poisonous by Inhalation

In the NPRM, RSPA proposed to prohibit the use of non-pressure tank

cars (e.g., class DOT 111A) for materials poisonous by inhalation.

In a recent research report, FRA found that, in a single-car

national risk profile, the transportation of ethylene oxide in a DOT

111A100W4 tank car involves significantly greater risk than

transportation of the same material in a

[[Page 49055]]

DOT 105J500W tank car.12 Characteristics and parameters evaluated

in this assessment included the toxicity, fire hazard, and explosion

hazard. In comments to the ANPRM, RPI reported that, during the time

period of 1965 through 1986, class DOT 111A tank cars involved in

accidents and damaged were slightly more than three times as likely to

lose lading as were class DOT 105 cars in similar situations.13

\12\Raj, P.K., and Turner, C.K., Hazardous Materials

Transportation In Tank Cars/Analysis of Risks--Part 1, NTIS DOT/FRA/

ORD-92/34, (1993), Federal Railroad Administration, Washington D.C.

\13\Phillips, E.A., Analysis of Tank Cars Damaged in Accidents

1965 through 1986, RA-02-6-55, (1989), AAR-RPI Railway Tank Car

Safety Test and Research Project, AAR Technical Center, Chicago,

Illinois.

---------------------------------------------------------------------------

The Raj/Turner report amply demonstrates (and AAR/RPI Tank Car

Safety Test and Research Project data support) that it is

``improbable'' to assume that any single tank car (e.g., DOT 111A or

DOT 105) would be involved in an accident. However, based on FRA

accident data referenced earlier regarding DOT 111A and DOT 105 tank

cars, a significant number of such cars will be involved in accidents

during their service life.

Several commenters supported disallowing the use of non-pressure

tank cars for the transportation of PIH materials. Because of the

hazards associated with PIH materials and the performance superiority

of the so-called ``pressure'' tank cars for this service, RSPA agrees

with the commenters. This final rule removes the class DOT 111A tank

car as an authorized packaging for Division 2.3 materials on the

effective date of this final rule.

H. Phasing Out of Various ``Grandfather'' Provisions

In the NPRM, RSPA proposed to remove from the HMR several

grandfather provisions that affect tank cars. The grandfather

provisions allow tank cars built before a certain date to remain in

service without modification. As an example, in Sec. 173.314(c), Notes

23 and 24 allow the continued use of class DOT 105A tank cars for

certain compressed and flammable gases if they were built before

September 1, 1981, while tank cars built after that date must meet a

more stringent class DOT 105S or 105J standard.

NTSB stated, in a March 1, 1988 letter to RSPA, that tank cars

failing to meet current minimum safety requirements should no longer be

used for transportation of hazardous material under grandfather

provisions. NTSB stated that these grandfather provision could result

in a reduced level of safety. The AAR also petitioned RSPA to amend

Sec. 173.314(c) Note 30 (P-1138), stating that it does not provide any

assurance that tank cars with head protection will be used for PIH gas

service in the foreseeable future because companies will be able to use

tank cars without head protection for PIH compressed gas service for

the next 30 years. Other commenters agreed that the grandfather

provisions proposed for removal in the NPRM are no longer compatible

with the needs of safety.

Based on these comments, RSPA is removing certain grandfather

provisions. In Sec. 171.102, special provision ``B63'' is removed to

disallow the use of DOT 105A100W, 111A100W4, 112A200W, and 114A340W

tank cars for ``ethyl chloride'' and ``ethyl methyl ether.'' Prior to

the issuance of Docket HM-181, these two materials were classed as

flammable liquids. Because these tank cars do not have head protection

or thermal protection systems, they do not provide an equivalent level

of safety compared to other tank cars used for Division 2.1 materials.

Also, special provision ``B63'' is removed from column 7 of the

Sec. 172.101 table entries for these two hazardous materials, thereby

prohibiting the use of non-protected tank cars.

Other changes are made to disallow the use of class DOT 111A non-

pressure tank cars for Class 2 (compressed gas) materials, such as

``ammonia solutions,'' ``ethylamine,'' ``ethyl chloride,'' and ``ethyl

methyl ether.'' This final rule also removes the DOT 111A100W4 car as a

packaging for ``ethylene oxide'' in Sec. 173.323(c)(1).

I. Bottom-Discontinuity Protection for Bottom Outlets

In the NPRM, RSPA proposed to require bottom-discontinuity

protection (e.g., for bottom outlets) on tank cars. The proposed

requirements were intended to simply adopt the requirements published

by the AAR. In July of 1979, the AAR required bottom-discontinuity

protection for new tank car construction. Over a period of years, these

requirements were extended to existing tank cars on a priority schedule

determined by the nature of the commodity transported. The AAR's

program for bottom-discontinuity protection consists of either a metal

``skid'' protecting the portion of the bottom outlet that protrudes

beyond the shell or the machining of a ``breakage groove'' in the valve

assembly.

AAR, the Chlorine Institute, CMA, and several other commenters

supported the adoption of bottom-discontinuity protection for tank

cars, provided such protection was consistent with the AAR

requirements. API asked RSPA to clarify the requirements for bottom-

discontinuity protection in this final rule. API and several other

commenters stated that the proposed rule would require the modification

of a number of tank cars, built before July 1, 1979, because most were

modified according to Appendix Y and not paragraphs E9.00 or E10.00 of

the AAR Specifications for Tank Cars. Appendix Y permits three levels

of protection for allowing the types of discontinuity: bottom outlets

that extend 1 inch or more; blind flanges and washouts that extend 2

and \5/8\ inches or more; and sumps and internally closed washouts that

extend 5 inches or more. Paragraphs E9.00 and E10.00 generally require

the protection of each valve and fitting from mechanical damage by the

tank, an another protective device, or the underframe.

Several other commenters stated that the proposed rule would also

require the modification of all existing tank cars, including those

that do not transport hazardous materials. The Sulphur Institute and

another commenter opposed the need to add bottom-discontinuity

protection to existing tank cars that transport sulfur, molten,

claiming that such protection has little practical benefit.

In the public hearing held on January 6, 1994, in Washington, D.C.,

FRA stated that it was not the Department's intention to require the

modification of previously modified tank cars, nor to require bottom-

discontinuity protection for tank cars that transport materials not

subject to the HMR.

In this final rule, RSPA requires bottom-outlet protection that

conforms to paragraphs E9.00 and E10.00 of the AAR Specifications for

Tank Cars, M-1002, for all new tank cars equipped with bottom unloading

devices. Existing tank cars, without bottom-discontinuity protection,

used for the transportation of hazardous materials must conform to the

above paragraphs no later than 10 years after the effective date of

this final rule. Existing tank cars that conform to the bottom-

discontinuity protection requirements of Appendix Y of the AAR

Specifications for Tank Cars, M-1002 may continue in use after the

effective date of this final rule. This final rule does not require the

modification of existing tank cars that transport materials not subject

to the HMR.

J. Protective Coatings on Insulated Tank Cars

In the NPRM, RSPA proposed use of protective coatings on the

exterior of a

[[Page 49056]]

tank car and the interior of a tank car jacket to retard rust or

corrosion. The proposal was in response to an AAR petition (P-1050) and

FRA's findings of severe corrosion or pitting on the outer surface of

the tank shell, or the inner surface of the tank jacket, of insulated

tank cars. It is not known whether the corrosion stems from the

physical properties of the insulation itself or whether the corrosion

develops when insulation becomes impregnated or contaminated with water

or a chemical from the atmosphere in which the tank car operates.

Research within the industry has led to the development of protective

coating materials.

Most commenters supported the proposal. One commenter stated that

acid-resistant protective coatings should be applied. The commenter

further stated that several manufacturing and repair shops are using

non-acid resistant latex coatings under polyurethane-foam insulations.

Another commenter suggested that the rule should be clarified to

exclude tanks or jackets manufactured with self-protective materials

such as stainless steel. Still another commenter asked RSPA to consider

adopting a recommended practice for applying protective coatings on

tank cars that is now under development by the National Association of

Corrosion Engineers.

With regard to these comments, this final rule simply modifies

Secs. 179.100-4 and 179.200-4 by removing the exception for

polyurethane-foam insulations. Each of the current sections, and the

proposed rule, only require a protective coating on a carbon steel tank

shell and tank jacket. Concerning the comment on acid-resistant

coatings, RSPA agrees that applied coatings should prevent any

corrosive attack to the tank metal. RSPA and FRA will explore, in

cooperation with the AAR, CMA, and RPI, the need for and development of

acid-resistant coating standards.

NTSB commented that the proposed rule does not sufficiently address

the potential problem of existing tank cars. NTSB further noted that a

requirement to apply a protective coating on an existing tank car, only

when the jacket is removed to repair a tank, cannot ensure that

corrosion problems will be detected before the tank corrodes through

and releases its lading. NTSB stated that, at a minimum, tank cars

currently in use without protective coatings should be inspected

periodically for corrosion damage and tank cars found with corrosion

damage should be required to have appropriate repairs.

We agree with NTSB, and in this final rule require, under Docket

HM-201, new inspection intervals for materials that are corrosive to

the tank and a thickness performance measurement to ensure that the

tank shell is not corroded below the minimum shell thickness as

prescribed by the AAR. RSPA and FRA believe that HM-201 is responsive

to NTSB's concerns.

In this final rule, RSPA is requiring protective coatings for all

new tank cars and for existing tank cars when a repair to the tank car

requires the complete removal of the jacket, as suggested by

commenters.

K. Halogenated Organic Compounds (HOC)

To address a 1991 NTSB safety recommendation,14 RSPA proposed

in the NPRM to require the use of a tank car with enhanced puncture

resistance if the tank is used to transport one or more of the 100 HOC

compounds listed in 40 CFR Part 268 Appendix III. The Appendix III list

was developed by EPA pursuant to statute (42 U.S.C. 6924) in order to

prohibit the land disposal of certain compounds having a carbon-halogen

bond, and that have the potential to harm human health and the

environment (these EPA compounds were identified as the ``California

List'' under the statute [See also 40 CFR 268.32]).

\14\Transportation of Hazardous Materials by Rail, National

Transportation Safety Board Safety Study, Report NTSB/SS-91/01,

National Transportation Safety Board, Washington, D.C. (Safety

Recommendations R-91-11 and R-91-12).

---------------------------------------------------------------------------

Many commenters opposing regulation of the EPA compounds suggested

that RSPA should continue to only regulate the compounds identified as

hazardous substances in Appendix A to Part 172. Commenters further

suggested that DOT should not consider the HOC concentration threshold

for those compounds. Several commenters stated that the regulatory

action proposed by RSPA is unnecessary, that RSPA should discontinue

its efforts to regulate these EPA compounds, and that RSPA should not

consider extending enhanced tank car standards to those carrying the

more than 1,000 chemicals prohibited from land disposal.

API, CMA, and several other commenters suggested that the threshold

quantities for the EPA compounds are too low for transportation

purposes. The EPA threshold in 40 CFR 268.32 is 1,000 milligrams per

liter (mg/l) for liquids and 1,000 milligrams per kilogram (mg/kg) for

solids.

CMA furnished a benefit/cost analysis, prepared by Reebie

Associates, that used 1992 TRAIN II data; thereby updating the previous

work performed by AAR, CMA, and RPI addressed in the NPRM. The CMA

report shows that a total of 3,893 tank cars transported an EPA

compound. CMA's list and the number of tank cars used for such

compounds follows:

------------------------------------------------------------------------

AAR/CMA/RPI

Hazardous CMA's 1992 agreement Currently in

substances population (based on pressure Remaining

1988 data) tank cars

------------------------------------------------------------------------

1,1-

Dichloroethylen

e.............. 1 ............ ............ 1

1,2-

Dichloroethane. 236 236 ............ ............

1,2-

Dichloropropane 31 ............ ............ 31

Carbon

tetrachloride.. 312 312 ............ ............

Chlordane....... 10 ............ ............ 10

Chlorobenzene... 105 105 ............ ............

Chloroethane

(ethyl

chloride)...... 106 ............ 106 ............

Chloroform...... 227 227 ............ ............

Chloropropene... 7 ............ ............ 7

CIS 1,3-

dichloropropane 42 ............ ............ 42

Dichlorodifluoro

methane........ 224 ............ 224 ............

Dichlorofinrorom

ethane......... 2 ............ ............ 2

Dichlorofluorome

thane.......... 1 ............ ............ 1

Hexachlorocyclop

entadiene...... 8 ............ 8 ............

[[Page 49057]]

Methylene

chloride....... 2 2 ............ ............

o-

Dichlorobenzene 15 15 ............ ............

p-

Dichlorobenzene 82 82 ............ ............

Pentachloropheno

l.............. 10 ............ ............ 10

Tetrachloroethan

e.............. 13 13 ............ ............

Trichlorobenzene 6 ............ ............ 6

Trichloromonoflu

oromethane..... 4 ............ 4 ............

Vinyl chloride.. 2,449 ............ 2,449 ............

-------------------------------------------------------

Totals...... 3,893 992 2,791 110

------------------------------------------------------------------------

Commenters stated that RSPA should not include materials that are

transported as a solid because, when released, the clean up of these

materials is easily achieved. This statement assumes that accidents

will not occur near lakes, rivers or streams, or that rainfall will not

carry solid residue to such water sources. It is RSPA's and FRA's

experience that these types of accidents can occur as evidenced by the

metam sodium spill in the Sacramento River in California.

As discussed in the NPRM, these materials were also evaluated by

the AAR in an effort to identify materials that have the potential to

harm human health and the environment. The AAR analyzed the EPA

compounds using a computer model based on EPA and standard chemical

dispersion equations. The AAR model describes a method of evaluating

the relative environmental hazard of chemicals shipped in tank

cars.15 In addition to the computer model, the AAR surveyed the

railroad industry for the clean-up costs associated with a spill of an

EPA compound. The AAR considered in their analysis: (1) Compounds that

were permitted in non-pressure tank cars by the DOT in 1988; (2) at

least one shipment of the compound reported to TRAIN II16 in 1988;

(3) the compounds with an EPA reportable quantity (RQ) of less than

1,000 pounds in 1988; (4) the compounds prohibited from land disposal

by the EPA; and (5) the compounds suggested by the railroads' hazardous

materials or environmental staff, or the AAR contractor on the project.

The results of the 1988 survey identified 10 compounds, transported in

class DOT 111A tank cars at that time, that pose a potential threat to

human health and the environment. These compounds were:

\15\Lowenbach, William, A., Consequence Models of Hazardous

Materials Releases on Railroads, Association of American Railroads

(1989), Washington, D.C.

\16\The Association of American Railroads (AAR) data network,

Tele-Rail Automated Information Network (TRAIN II), collects

information on approximately 90 percent of the rail traffic

originating and terminating in the United States. Users of the

network can trace individual car movements or gather information on

a particular cargo moving by rail. The AAR uses the data to develop

statistical trends in both car movement and commodity flow.

Carbon tetrachloride

Chlorobenzene

Chloroform

Dichlorobenzene

Ethylene dibromide (1,2-Dibromomethane)

Ethylene dichloride (1,2-Dichloroethane)

Methyl chloroform (1,1,1-Trichloroethane)

Methylene chloride (Dichloromethane)

Perchloroethylene (Tetrachloroethene)

Trichloroethylene (Trichloroethene)

The results of AAR's analysis show that, within the last 10 years,

the release of these compounds in railroad accidents has resulted in

environmental clean-up costs exceeding $50 million. Even though these

materials accounted for less than one percent of the total volume of

hazardous materials, their releases accounted for 60 percent of all

railroad environmental clean-up costs. Based on the results of the

analysis, the AAR, CMA, and RPI have agreed that by January 1, 2000,

these 10 compounds should be transported only in a DOT 105S200W or a

DOT 112S200W tank car manufactured from AAR TC-128 normalized steel.

One of the 10 compounds, ``ethylene dibromide,'' is a compound that is

poisonous by inhalation (Zone B).

As shown by CMA, 3,893 tank cars were used to transport these ``EPA

compounds''; of that total, ``chloroethane,''

``dichlorodifluoromethane,'' ``hexachlorocyclopentadiene,''

``trichloromonofluoromethane,'' and ``vinyl chloride'' represent 2,791

tank cars, or 72 percent of the total. Because the packaging

authorizations for these compounds currently require the use of classes

DOT 105J, 112J, 112T, 114J, 114T tank cars, these tank cars currently

meet the proposed standard.

As noted above, AAR, CMA, and RPI agreed to use only DOT 105S200W

and 112S200W (or better) tank cars: These compounds are transported in

992 dedicated tank cars. CMA identified an additional 110 tank cars

that are used to transport an EPA compound, but lie outside of the

industry agreement. Because these 110 additional tank cars represent a

potential risk to human health and the environment, RSPA believes it is

reasonable to require the same level of protection for the additional

tank cars identified by CMA, based on the 1992 TRAIN II data, as those

identified by the AAR, CMA, and RPI, based on the 1988 TRAIN II data.

It simply cannot be argued that the shipment of an EPA compound

identified after 1988 poses less risk in transportation than if the EPA

compound would have been identified by the AAR, CMA, and RPI in 1988.

Furthermore, because the AAR, CMA, and RPI agreement does not preclude

the use of a non-protected tank car in transportation by any one member

or nonmember of the agreement, such cars may still be used.

After considering each of the comments, RSPA agrees it should only

regulate those EPA compounds listed in the HMR. After reviewing the 100

EPA compounds (listed in 40 CFR 268 Appendix III), RSPA found that all

but 16 of the compounds are currently identified as a hazardous

substance. The 16 compounds are:

Bis(2-chloroethoxy)ethane

Bis(2-chloroethyl)ether

Bromomethane

2-Chloro-1,3-butadiene

3-Chloropropene

1,2-Dibromomethane

Dibromomethane

Hexachlorodibenzo-p-dioxins

Hexachlorodibenzofuran

Iodomethane

Methylene chloride

Pentachlorodibenzo-p-dioxins

[[Page 49058]]

Pentachlorodibenzofuran

Tetrachlorodibenzofuran

Tribromomethane

1,2,3-Trichloropropane

More than 30 of the compounds are listed by proper shipping name in the

Sec. 172.101 Table. As a group, the EPA compounds include: volatiles

(35 compounds); semivolatiles (33 compounds); organochlorine pesticides

(20 compounds); phenoxyacetic acid herbicides (3 compounds); PCBs (all

PCBs); and dioxins and furans (7 compounds).

Based on this review, this final rule requires that, when the EPA

compounds listed in the HMR are transported in large capacity tank

cars, the tank cars must conform to a limited and designated

specification with greater protection in accidents. Also, to ensure the

proper identification and packaging of these materials, RSPA is listing

(with the exception of Class 2 materials [compressed gases], PIH

materials, and the 16 materials not now identified as hazardous

substances) in Sec. 173.31(f), all EPA compounds listed in 40 CFR Part

268, Appendix III. As explained elsewhere in the preamble, RSPA is no

longer authorizing Class 2 materials or PIH materials in low-pressure

tank cars, e.g., class DOT 111A.

Because RSPA is listing the EPA halogenated-organic compounds as

hazardous substances, in this final rule, the threshold quantity is the

reportable quantity of the hazardous substance. As an example, if the

material in the tank car (including its mixtures and solutions) (1) is

listed in Appendix A to Sec. 172.101, (2) is in a quantity that equals

or exceeds the reportable quantity (RQ) of the material listed in

Appendix A, and (3) is listed in Sec. 173.31(f), it must be transported

in a tank car of limited and designated specification to offer greater

protection in the event of an accident.

In the NPRM, RSPA proposed that any of the halogenated organic

compounds identified by EPA must be transported in a tank car meeting

DOT 105S200W, DOT 112S200W with an 11-gauge metal jacket, or DOT

112S340W without a metal jacket. RSPA stated that the metal jacket and

head protection on these tank cars blunt the impacting forces from

couplers, wheels, track, and other objects along the carrier's right-

of-way. According to FRA research, this blunting effect is directly

proportional to the thickness of the tank jacket or head shield and is

effective in preventing tank punctures.17 The NPRM would have

allowed the use of any class DOT 105 or DOT 112 tank car regardless of

its date of construction. Older tank cars would be allowed, including

those constructed with an older steel specification, such as ASTM A212

Grade B. Because the older steels have less puncture resistance than

the steels currently in use, the NPRM proposed the use of an external

metal jacket to help blunt any impacting force, as a result of an

accident, to the tank shell.

\17\Coltman, M., & Hazel, M., Jr., Chlorine Tank Car Puncture

Resistance Evaluation, Report DOT/FRA/ORD-92-11, Federal Railroad

Administration (1992), Washington, D.C.

---------------------------------------------------------------------------

At the January 6, 1994, public hearing, a commenter asked RSPA to

consider the use of a non-jacketed DOT 112S200W tank car, provided that

the tank car was constructed from an AAR normalized high-strength steel

specification, AAR TC-128. This steel specification has high tensile

and yield strength. In addition to the higher tensile and yield

strengths, commenters stated that normalization of the steel adds extra

puncture resistance. A commenter further stated that a tank car

constructed from the AAR's TC-128 steel specification would provide a

level of puncture resistance comparable to that of tank cars proposed

for use in the NPRM, and would also render a indisputable benefit/cost

ratio. Upon further review, RSPA agrees that a tank car constructed

from AAR TC-128, normalized, would provide a level of puncture

resistance equivalent to a tank car constructed from any steel

specification proposed in the NPRM. In this final rule, RSPA has

provided for the use of a DOT 112S200W (non-jacketed tank car)

constructed from AAR TC-128 normalized steel as an authorized

packaging, as suggested by the commenter.

L. Implementation of New Requirements

In the NPRM, RSPA proposed two implementation dates. Under ``Option

A,'' most of the compliance dates were set at 10 years from the

effective date of this final rule. This is a period that also coincides

with the duration frequently specified in typical full-term tank car

leases, whether a true lease or a financing vehicle; and with the

``thorough inspection'' interval for tank cars in Interchange Rule

88.B.2.18 Under ``Option B,'' RSPA proposed that certain tank car

types and car/commodity combinations be considered for shorter retrofit

periods, with 5 years given to bring existing cars into compliance. For

instance, aluminum and nickel tank cars are more vulnerable to

puncture, and tanks used for transporting PIH materials present special

hazards.

\18\Field Manual of the Interchange Rules, adopted by the

Association of American Railroads, Mechanical Division, Washington,

D.C., 1992. At intervals not to exceed 10 years, major components of

the car must be inspected, including body bolsters and center

plates, center sills, crossbearers, crossties, draft systems and

components, end sills, side sills, and trucks.

---------------------------------------------------------------------------

Option A was supported by commenters. Although urging RSPA to adopt

the 10-year time limit, RPI stated that, because of start-up

complexities, it will not be reasonable to accomplish this on a 10-

percent per year basis. Instead, RPI suggested that its members were

willing to modify 50 percent of the fleet in the first 5 years and 50

percent in the second 5 years. This accomplishes the desired goal while

minimizing scheduling problems and maximizing efficiency.

Option B was supported by NTSB who stated that RSPA should require

tank-head protection, within 5 years, for all class DOT 105 tank cars

having capacities of less than 70 kl (18,500 gallons) when used to

transport a Division 2.1 material (flammable gas).

Most commenters supported the 10-year modification program for

existing tank cars. RSPA believes, however, that a 5-year modification

program is more appropriate for class DOT 105 tank cars that have a

capacity less than 70 kl (18,500 gallons) when used to transport a

Division 2.1 material. Mandating an accelerated modification program

for these particular tank cars will ensure that those cars presenting

the greatest risk are modified first. Therefore, this final rule

requires that each tank car built on or after the effective date of

this final rule conform to this final rule. For tank cars built prior

to the effective date, the phase-in period is 10 years: at least 50

percent of the fleet in the first 5 years and the balance in the second

5 years. The phase-in-period for tank cars transporting a Division 2.1

material is 5 years, with at least 50 percent within 2\1/2\ years and

the balance in the second 2\1/2\ years. For existing tank cars

constructed with an internal self-energized manway located below the

liquid level of the lading, the compliance date is the effective date

of this final rule.

III. Docket HM-201--Detection and Repair of Cracks, Pits, Corrosion,

Lining Flaws and Other Defects of Tank Car Tanks

A. Background

On September 16, 1993, RSPA published in the Federal Register a

NPRM under Docket HM-201; Notice No. 93-15 [58 FR 48485]. The NPRM

contained proposals to: (1) require the development and implementation

of a quality assurance program (QAP) at each facility that builds,

repairs, or ensures the structural integrity of tank

[[Page 49059]]

cars; (2) require the use of non-destructive testing (NDT) techniques

in lieu of the current periodic hydrostatic pressure tests for fusion

welded tank cars to more adequately detect cracks in principal

structure elements (PSE), the failure of which could cause catastrophic

failure of the tank; (3) require thickness measurements of tank cars;

(4) allow for the continued use of tank cars with limited reduced shell

thicknesses; (5) increase the inspection and test intervals for tank

cars; and (6) clarify the tank car pretrip inspection requirements.

Readers are referred to the NPRM preamble for a complete background,

including a more extensive discussion of issues and citations to

research data summarized in the final rule.

RSPA received 31 comments in response to the NPRM from members of

the various industries that own, lease, transport, or use tank cars.

RSPA and FRA have given full consideration to all comments in the

development of this final rule. Following is a summary of the written

comments, a summary of the final rule, and the actions taken by RSPA

and FRA in this final rule:

B. Damage-Tolerance Fatigue Evaluations

In 1992, the NTSB issued a report on the inspection and testing of

tank cars. The report disclosed that many tank car defects are not

routinely detected. These defects may suddenly grow to a critical size

resulting in failure of the tank car. The NTSB recommended that FRA and

RSPA develop requirements for the periodic inspection and tests of tank

cars to help ensure the detection of cracks before the cracks propagate

to a critical length. Such requirements would establish inspection and

test intervals based on the defect size detectable by the inspection

and test method used and on the stress level and crack propagation

characteristics of the PSE based on a ``damage-tolerance'' approach.

The Federal Aviation Administration (FAA) defines a structure as damage

tolerant if the structure has been evaluated to ensure that, should

serious fatigue, corrosion, or accidental damage occur within the

operational life of the structure, the remaining structure can

withstand reasonable loads without failure or excessive structural

deformation until the damage is detected (FAA Advisory Circular AC No.

25.571-1A). Damage-tolerance assumes that flaws exist in the structure

and that the design of the structure is such that these flaws will not

grow to a critical size and cause catastrophic failure to the structure

within a specified damage detection period. The damage detection period

depends on the characteristics of each PSE, each element's

susceptibility to severe corrosive environments, the inspectability of

each element, the inspection method, and procedures used and

maintenance practices.

In the NPRM, RSPA proposed to allow tank car owners to use an

alternative inspection and test procedure or interval based on the

completion of a damage-tolerance fatigue evaluation. The evaluation

procedures would be reviewed by the AAR and approved by the Associate

Administrator for Safety, FRA. As stated in the NPRM, FRA believes that

some tank car owners may be able to reduce inspection and test costs by

using damage-tolerance fatigue evaluation procedures that incorporate:

(1) In-service inspection and test using techniques such as ultrasonic

or acoustic emission; (2) sampling of individual designs with a 100

percent inspection and test of the design if a crack is found; (3)

inspection and test intervals unique to each tank car component; and,

(4) inspection and test intervals based on the degree of risk a

material poses (i.e., high risk materials have shorter inspection and

test intervals than those with low risks).

Most commenters stated that the damage-tolerance approach is a

significant step toward advancing the detectability of defects and well

suited to a tank car and its associated structure. They suggested that

RSPA and FRA expand the damage-tolerance approach, for fatigue, to

include other types of damage mechanisms, such as corrosion, corrosion

fatigue, original fabrication defects, stress corrosion cracking,

impact damage, and damage caused by an accident.

RSPA and FRA agree that the use of a damage-tolerance approach to

periodic inspection and test of tank cars would substantially increase

the likelihood of the detection of cracks and crack-like defects before

such defects propagate to a critical size. RSPA and FRA also believe

that the inspection interval for each PSE should be based on the

inspection method used, the stress level in each PSE, and the crack

propagation characteristics of each PSE.

The agencies realize, however, that in order to fully implement a

damage-tolerance program, it will take years for each owner or

manufacturer of a tank car to analyze each element on the tank car, and

to support the results of such analysis with test evidence and service

experience. FRA is currently working with the AAR Tank Car Committee,

the RPI, tank car owners, lessors, and manufacturers to develop

acceptable non-destructive testing techniques, and to develop an

inspection and test program based on damage-tolerance principles. These

programs include finite element analysis of the stub sill and its

attachment to the tank shell to identify the PSE on the tank car that

should be examined, over-the-road tests to define the typical

environmental loading spectrum expected in service, and a damage-

tolerance evaluation of the structure.

In this final rule, RSPA is revising the regulatory text for the

damage-tolerance fatigue evaluation proposed in Sec. 180.509(k). This

revised requirement provides that an acceptable damage-tolerance and

fatigue evaluation include other types of damage mechanisms and is

supported by test evidence and, if available, by service experience.

C. Inspection and Test Intervals

FRA found that cracks may reach a critical size in a PSE within

about 400,000 miles of railroad service [see ``Owners of Railroad Tank

Cars; Emergency Order Requiring Inspection and Repair of Stub Sill Tank

Cars,'' (Emergency Order Number 17) 57 FR 41799, September 11, 1992].

To ensure against premature failure, common procedures for NDT allow

for two opportunities to inspect an item before predicted failure.

Because tank cars travel an average of about 18,000 miles per year and

most cracks become critical at about 400,000 miles of railroad service,

in the NPRM, RSPA proposed an inspection and test interval, based on a

simplified damage-tolerance evaluation, of 10 years to allow for two

opportunities to inspect an item before predicted failure.

For the sake of efficiency, and to increase safety margins for most

cars, RSPA proposed to implement the 10-year inspection and test

interval starting at what would otherwise be the next scheduled tank

hydrostatic pressure test. For tank cars within a 20-year test cycle,

RSPA proposed that the next inspection and test date be the publication

date of this rule plus one half of the remaining years to what would

otherwise be the next scheduled tank hydrostatic test. After that the

tank would require an inspection and test on a 10-year interval.

For materials corrosive to the tank and shipped in non-lined or

non-coated tank cars, RSPA proposed an inspection and test interval

based on the lower of (1) the corrosion rate of the material on the

tank shell or (2) the fatigue life of the tank structure as discussed

above. RSPA and FRA developed a test interval to ensure that the

calculated thickness of the tank at the next inspection and

[[Page 49060]]

test will not fall below the proposed allowable minimum wall thickness.

The inspection and test interval in this case is calculated by

subtracting the actual thickness (measured at the time of construction

or any subsequent inspection and test) from the allowable minimum

thickness and then dividing that difference by the corrosion rate of

the hazardous material on the tank. Consequently, as the shell

thickness corrodes throughout the service-life of the tank, the tank

must receive an inspection and test more frequently.

Commenters supported the proposed inspection and test program for

most tank cars. They suggested, however, that RSPA consider the

availability of tank car facility space and the practicality of

implementing the new inspection and test and quality assurance programs

without immobilizing a large number of tank cars. In particular,

commenters suggested that RSPA not reduce the inspection and test

intervals for tank cars constructed during the 1975-1979 period that

are now subject to a 20-year hydrostatic pressure test interval. As

proposed, these particular tank cars become due for inspection and test

during the years 1995 through 1997. A major oil company stated that

these particular tank cars represent at least 20 percent of its tank

car fleet.

Several commenters stated tank cars used to transport chlorine,

unlike other tank cars, are currently tested every two years. As such,

all 8,000 tank cars in chlorine service would have to be brought in

conformance with the new inspection and test requirements within two

years. One company stated that it maintains 3,000 tank cars in chlorine

service and it would have to inspect 5.7 tank cars per day, which may

not be feasible because companies must first determine efficient

inspection techniques and provide training to inspection personnel.

Commenters further argue that because tank cars that transport chlorine

have an insulation system and a metal jacket, the inspectability of

certain PSE on these tank cars is difficult; accordingly, RSPA should

not mandate the new requirements in the short-term until the industry

and the government specify the acceptable NDT techniques for inspecting

tank cars that have metal jackets.

The RPI suggested that RSPA phase in the new procedures slowly by

beginning with tank cars without a metal jacket and then tank cars

having a metal jacket when appropriate inspection techniques are

developed. Although RPI did not explain the basis for its comment, RSPA

and FRA assume that the reason behind RPI's comment is the difficulty

of inspecting PSE on a tank car having an insulation system covered by

a metal jacket or a thermal protection system; consequently, tank car

facilities will need time to develop the inspection methods and to

train inspection personnel on the use of those methods. Only after

identifying the appropriate inspection method and by training

inspection personnel, will there be a high probability of defect

detection.

Several commenters requested that RSPA not require, in proposed

Sec. 180.509(b)(3), an inspection and test [requalification] of the

tank each time it is transferred into or out of a service that is

corrosive to the tank, which one commenter stated could occur 4 times

per month. Another commenter stated that the program is redundant with

proposed Sec. 180.509(c)(3)(ii) and, therefore, the section should be

deleted. The Chemical Manufacturers Association (CMA) suggested that

RSPA amend the proposal to allow for routine transfers, so long as the

tank car is within the established intervals for the periodic

inspection requirements. A commenter suggested that localized

modifications to a tank, such as modifying nozzles or bottom outlets,

should not subject the tank to a complete requalification.

Based on the comments received, RSPA is not adopting proposed

paragraphs (b) (3) and (4). Paragraphs (b) (5) and (6) are renumbered

accordingly.

RSPA and FRA also agree that local repairs or modifications should

not subject the tank to the full inspection and test program, because

the repair or modification must be done according to Appendix R of

AAR's Specifications for Tank Cars. Appendix R specifies the procedures

for repairs, alterations, and conversions of tank cars and the

appropriate non-destructive testing method to ensure that the repairs,

alterations, or conversions were performed correctly.

RSPA and FRA agree that the new inspection and test methods,

combined with other FRA mandated inspection programs, may cause a

tremendous backlog of tank cars awaiting inspection. Therefore, to

maintain an acceptable level of safety, but also to allow for an

orderly and acceptable phased-in NDT inspection and test program, RSPA

will delay the compliance date of this final rule for 24 months for

tank cars without metal jackets and 48 months for tank cars having a

metal jacket or a thermal protection system. Before the compliance

date, tank cars may be given an inspection and hydrostatic test in

accordance with the current requirements or the requirements contained

in this final rule. After the compliance date, each tank car must be

given an inspection and test according to the requirements contained in

this final rule on or before the next scheduled tank hydrostatic

pressure test date.

D. High-Mileage Tank Cars

FRA realizes that some tank cars can travel in excess of 18,000

miles each year and, by doing so, the tank cars may reach 200,000 miles

of railroad service before their first periodic inspection and 400,000

miles before their second.

The NTSB expressed its concerns that the proposed regulations

recommend, but do not require, more frequent inspections and tests for

tank cars with mileage rates that exceed the average. Further, because

there is no requirement to maintain cumulative mileage on individual

tank cars, the NTSB expressed concern that high-mileage tank cars would

not be identified for the more frequent inspections and tests, thereby

increasing the possibility of a non-detected fatigue crack propagating

and causing a structural failure within the 10-year inspection and test

cycle.

RSPA and FRA agree with the NTSB that high-mileage tank cars should

receive an inspection and test prior to reaching 200,000 miles of

railroad service. However, no requirement for the maintenance or

retention of car mileage records was proposed. Because car owners keep

records of car mileage, the owners can ensure that tank cars having

high-mileage are inspected more frequently than the inspection and test

intervals adopted in this final rule. Current Sec. 173.24(b) provides

that each package used for the shipment of hazardous materials shall be

so designed, constructed, and maintained . . . so that under conditions

normally incident to transportation--the effectiveness of the package

will not be substantially reduced. Thus, an owner has an obligation to

ensure the continuing effectiveness of a tank car. This duty is not

unlike that of an owner of an automobile who replaces the tires on his

or her car when worn and not based on the warranty period. FRA will,

during its inspection activities, assess the need for a rulemaking (1)

to require owners to retain car mileage records and (2) to inspect

their tank cars before the cars accumulate more than 200,000 miles of

railroad service.

E. NDT Techniques

In the NPRM, RSPA proposed to require that the bottom shell of

fusion welded tank cars be inspected periodically by appropriate NDT

techniques, such as optically aided visual inspections, ultrasonic,

[[Page 49061]]

radiographic, magnetic particle, and dye penetrant testing methods, in

lieu of hydrostatic pressure tests.

All commenters supported the use of NDT techniques to assess the

integrity of a tank car in lieu of a hydrostatic pressure test. Several

commenters stated that the use of qualification procedures will require

formal NDT techniques in defined areas where no previous requirements

existed and will improve the overall safety of tank cars.

Several commenters suggested that RSPA should authorize the use of

acoustic emission testing to qualify tank cars for further use. One

commenter stated that acoustic emission testing is widely used in the

chemical process industry to assure the integrity of pressure vessels,

tanks, and piping. The commenter further stated that the overall

reliability of a series of local tests (ultrasonic, dye penetrant,

radiography, etc.) is incorrectly compared with the reliability of a

single global test (hydrostatic, acoustic emission) and that

substitution of multiple local tests for a single global test may

endanger, rather than enhance the safe transportation of hazardous

materials.

RSPA and FRA do not agree with the commenters's conclusion about

the potential danger of multiple local tests as compared with a single

global test. RSPA and FRA believe that multiple local tests, focusing

on known areas of tank car stress, have a safety advantage over single

global tests, at least with the current state of development of

acoustic emission testing in the tank car industry. The NDT methods

mandated by this rule are a safety improvement. As noted immediately

below, the agencies have underscored their belief in the potential

benefits acoustic emission testing offers by granting an exemption that

will permit its development and refinement in a railroad industry

context.

Outside the scope of this rulemaking, but related to it by means of

subject matter, Monsanto Chemical Company applied for a DOT exemption

to use acoustic emission technology, in lieu of the current hydrostatic

retest, for the tank cars it owns. The procedures developed by Monsanto

to support its exemption were recently evaluated under a research

contract administered by the government of Canada. (McBride, S. L.,

Acoustic Emission Tank Car Test Method Review & Evaluation, Transport

Canada Report No. TP 12140E (1994) Montreal, Quebec). The results of

that research show that Monsanto's acoustic emission testing procedures

appear to be sound. The report suggests, however, minor refinements in

the acoustic emission procedures. Taking this into account, RSPA issued

Monsanto an exemption on September 9, 1994 (DOT-E 10589). The following

companies were granted ``party to'' status on the Monsanto exemption:

Union Tank Car Company, Testing Associates, and Physical Acoustics

Corporation.

This final rule does not include acoustic emission testing as an

authorized NDT technique. RSPA and FRA are committed, however, to

explore new technologies for inspecting and testing tank cars and will

continue to evaluate the possibly of authorizing the acoustic emission

testing procedure in the future. In support of this commitment, FRA

issued a research contract to further explore and refine the use of

acoustic emission testing procedure and other NDT techniques in

determining the integrity of insulation and lining covered welds of

tank cars.

F. Leakage Test

In the NPRM, RSPA proposed a leakage test that would include all

product piping with all valves and accessories in place and operative,

except that during the test the tank car facility would remove or

render inoperative any venting devices set to discharge at less than

the test pressure. As proposed, the test pressure would be maintained

for at least 5 minutes at a pressure of not less than 50 percent of the

tank test pressure.

Most commenters opposed the proposed change to use 50 percent of

the tank test pressure as the standard, because these pressures, some

as high as 300 psig, would constitute an unsafe maintenance practice.

RSPA proposed the leak test to ensure that when valves, fittings, and

manway cover plates are replaced on a tank car after an inspection and

test, that valves and fittings are securely applied and in a ``leak-

free'' condition under normal operating pressures. This will help

ensure against product leakage from a valve, fitting, or manway cover

plate should the vapor pressure of the commodity rise after the shipper

loads the tank car, normally on its first trip after an inspection and

test at a tank car facility.

Berwind Railway Service Company suggested conducting the leak test

at 30 psig for tank cars having a test pressure less than or equal to

200 psig and 50 psig for tank cars having a tank test pressure greater

than 200 psig. AAR and RPI supported similar pressures. In the

commenters experience, pressures of this magnitude are effective in

ensuring that tank cars are released from tank car facilities in a leak

free condition.

The suggested leak test pressures are similar to the leak test

pressures currently used to qualify highway cargo tanks. For example,

the leak test for a cargo tank may not be less than 80 percent of the

tank design pressure (or its maximum allowable working pressure

[MAWP]); or, the maximum normal operating pressure when the cargo tank

has a MAWP equal to or greater than 6.9 Bar (100 psig); or, 4.1 Bar (60

psig) when the cargo tank is used to transport liquefied petroleum gas.

After considering the comments, RSPA and FRA agree that a lower leak

test pressure would provide an adequate leak test with less risk to

persons performing the test. In this final rule, RSPA is requiring a

leak test at 30 psig for tank cars having a test pressure less than or

equal to 200 psig and a leak test at 50 psig for tank cars having a

tank test pressure greater than 200 psig.

G. Bottom Shell

FRA has found that principal structural elements (PSE) located

within four feet of the bottom longitudinal centerline are susceptible

to fatigue cracking due to repeated loading conditions. Stress

concentrations in these areas may cause the formation of small cracks

that may not be detected under the current inspection and test

procedures. Because some defects may lie outside the area currently

defined as the bottom shell, such as those in the attachment welds of

bottom discontinuities, RSPA proposed, based on FRA's findings, to

revise the current definition of the bottom shell by enlarging the area

from 60.96 cm (two feet) to 121.92 cm (four feet) on each side of the

bottom longitudinal center line of the tank.

The Chlorine Institute, CMA, and others agreed that experience has

shown that the bottom shell is prone to fatigue cracking. However, all

known fatigue-related defects have originated within two feet of the

bottom longitudinal centerline of the tank, which is the area most

highly stressed in train operation.

RPI's comments referenced a report, ``Final Phase 14 Report on the

Stub Sill Buckling Study,'' that shows, when stub sill tank cars are

subjected to static and dynamic (impact) loads, a complex biaxial

stress field results in the shell area between the stub sills. The

report shows that measured strains are due to a combination of axial

compression and bending components and at high loads, high magnitude

strains occur over certain localized areas. The results of the RPI

report show that the stresses on the bottom longitudinal centerline of

the tank are about 1.8 times the magnitude of the stresses occurring

from two to

[[Page 49062]]

four feet from the bottom longitudinal centerline.

RPI further stated that fatigue damage increases exponentially with

the ratio of stress ranges and that crack initiation and propagation

within the area of two feet from the bottom longitudinal centerline is

much faster than the area two to four feet from the bottom longitudinal

centerline. Based on the Phase 14 report, RPI suggests that the bottom

shell definition should encompass an area that lies below the

horizontal plane of two longitudinal parallel lines extending two feet

on each side from the bottom longitudinal centerline, through the tank

heads. K & K Consultants, Incorporated, who also commented on the Phase

14 report provided a summary of the data and explained that the

principal stresses in the tank are approximately parallel to the bottom

longitudinal centerline, and that the stresses tend to decrease

circumferentially away from the bottom longitudinal centerline.

After consideration of the comments, RSPA and FRA agree that four

feet on each side of the bottom longitudinal centerline is overly

restrictive. Therefore, the current definition of bottom shell in

Sec. 171.8 is retained.

H. Structural Integrity Inspections

In the NPRM, RSPA proposed a structural integrity inspection and

test on all circumferential and longitudinal welds and welded

attachments on the bottom of the tank, within 121.92 cm (4 feet) on

each side of the bottom tank centerline, using one or more non-

destructive test methods. As explained above under the heading ``bottom

shell,'' several commenters stated that this area is more appropriately

defined as within 60.96 cm (2 feet) on each side of the bottom tank

centerline.

FRA has learned that some high-stressed areas lie outside of the

60.96 cm (2 feet) bottom longitudinal centerline area. Brake pipe

supports, body stiffeners, tank anchors, and other attachments and

structures having large welds are examples of high-stressed areas that

may lie outside of this area. As a general matter, the HMR require

reinforcing pads for these high-stressed areas between external

brackets and tank shells if an attachment weld exceeds 6 linear inches

of 0.64 cm (0.25 inch) fillet weld per bracket or bracket leg

(Secs. 179.100-16 and 179.200-19). In its Tank Car Manual, AAR requires

the use of a reinforcing pad if a bracket or attachment welded directly

to the tank could cause damage to the tank, either through fatigue,

over-stressing, denting, or puncturing in the event of an accident. If

a reinforcing pad is used under a bracket or attachment, AAR specifies

that the pad shall not be less than 0.64 cm (0.25 inch) thick. For

further information, see sections E15.01 and E15.02 of AAR Tank Car

Manual.

Further, in an investigation of tank shell cracking, FRA found that

local areas of the tank shell near tank discontinuities are subjected

to the combination of live-load stress in addition to the residual

stress induced by reinforcement pad welds, and that this combination

makes the sensitivity of the welded area near the discontinuity and

reinforcing pad weld susceptible to fatigue crack propagation. After

performing residual stress measurements of retro-fitted tank car

weldments, AAR confirmed FRA's findings that significant tensile

stresses (on the order of 30,000 psi) occur in the vicinity of the

fillet welds having a throat size (weld depth) greater than 0.64 cm

(0.25 inch). In general, fillet welds larger than 0.635 cm (0.25 inch)

are considered structural welds, and AAR requires post weld heat

treatment when these welds, such as interior brackets, supports, and

reinforcement bar pads, have a throat thickness exceeding 0.635 cm

(0.25 inch). For further information see R17.01 of AAR Tank Car Manual.

In its comments to the NPRM, the Sulphur Institute stated that

stress type defects may originate in some attachment fillet welds, such

as those greater than 0.64 cm (0.25 inch) that are currently located

outside of the current bottom shell definition. Examples given were

body stiffener and brake pipe support fillet welds.

RPI gave similar comments by suggesting that the inspection of

attachment welds on the bottom of the tank should be limited to

structure welds, such as transverse fillet welds larger than 0.64 cm

(0.25 inch), the terminations of longitudinal fillet welds larger than

0.64 cm (0.25 inch), and tank shell butt welds within 60.96 cm (24

inches) of the bottom longitudinal center line and between the body

bolsters. When asked to clarify its comments, RPI told FRA that a 0.64

cm (0.25 inch) fillet weld refers to the leg-length (see also the

definitions of ``Size [fillet]'' and ``Full Fillet Weld'' in Section

W2.00 of AAR Tank Car Manual). Furthermore, RPI stated that limiting

the inspection and test requirements to fillet welds greater than 0.64

cm (0.25 inch), would exclude non-structural fillet welds, such as

those used to attach exterior heater coils.

RSPA and FRA agree that the stress concentration effects around

structural attachments will cause the formation of fatigue cracks and,

if these cracks are not detected and repaired during routine

maintenance of the tank car, such cracks will grow to failure. In this

final rule, RSPA requires a structural integrity inspection and test in

those areas known to develop cracks. Such an inspection and test

includes transverse fillet welds greater than 0.64 cm (0.25 inch)

within 121.92 cm (48 inches) of the bottom longitudinal center line,

the termination of longitudinal fillet welds greater than 0.64 cm (0.25

inch) within 121.92 cm (4 feet) of the bottom longitudinal center line,

and all tank shell butt welds within 60.96 cm (2 feet) of the bottom

longitudinal center line. By limiting the required inspection to known

areas of crack initiation, RSPA and FRA can expect an increase in the

probability of defect detection, as well as an improvement in the

reliability of the inspection results and a reduction in inspection

costs.

The Sulphur Institute commented that if the integrity of the

coatings or linings applied to protect tank car tank metal remains

acceptable, there should be no need to remove the coating or lining to

inspect the tank for structural integrity. The purpose of the

structural integrity inspection is to ensure the detection of fatigue

cracks before the cracks progress to a dangerous size, thereby reducing

the residual strength of the tank. In order to inspect each PSE to

confirm structure integrity, tank car facilities may need to remove

portions of the lining or coating. Owners may choose, however, to use a

non-destructive testing method that interfaces between different

materials, with effective penetration, so that there will be no need to

remove the coating or lining. Such non-destructive testing methods

include radiography and ultrasonics.

I. Minimum Shell Thickness

Recognizing that a tank car shell tends to decrease in thickness

over time, RSPA proposed in the NPRM a definite service-life shell

thickness requirement for all areas of the tank shell and heads. The

proposed minimum in-service shell thickness requirement was based, in

part, on an AAR-RPI report, ``Allowable Thickness Reduction from

Minimum Prescribed Thickness of Carbon Steel Tank Car Tanks,'' that

discussed the investigation of shell thickness below the Part 179

construction standard in certain areas. The RPI-AAR report considered

the effects of an overall or localized reduction in the tank wall

thickness from a principal mode of failure--failure of a tank car due

to the effects of fire, fatigue crack growth leading to fracture, and

failure of the tank due to puncture of the heads. The results of the

RPI-AAR report show that

[[Page 49063]]

the effects of a slightly reduced shell thickness on tank cars used to

transport ``ethylene oxide,'' ``butadienes, inhibited,'' ``vinyl

chloride,'' ``propane,'' and ``propylene'' will not have a significant

effect on safety. The NPRM also proposed to allow localized areas of

thickness reduction to have a total cumulative surface perimeter not

exceeding 182.88 cm (72 inches), consistent with the current provisions

in Sec. 173.31(a)(11)(iv).

In its comments to the NPRM, RPI suggested that the 72-inch

cumulative perimeter should apply to the bottom shell only. RPI further

stated that RSPA should allow the rest of the tank shell, excluding the

tank heads, to have an unlimited number of two foot perimeter

reductions, provided such areas of reduction are separated by at least

16 inches (twice the diameter of a circle having a 24 inch

circumference).

AAR also suggested that the permitted local thickness reductions

for non-pressure tank cars should depend on cause. AAR thickness

reduction tables, endorsed by many commenters under an earlier

rulemaking, differentiated between corrosion and mechanical damage for

non-pressure tank cars (see ``Shippers Use of Tank Cars with Localized

Reductions in Shell Thickness,'' 54 FR 8336, 8337, February 28, 1989).

AAR further commented that there is no need to make a distinction

between the cause of damage for pressure tank cars because of the

stricter limits imposed on such cars. AAR proposed that, for non-

pressure tank cars, RSPA should permit a 0.48 cm (0.188 inch) local

thickness reduction in the top shell and 0.32 cm (0.125 inch) local

thickness reduction in the bottom shell for corrosive damage. For

mechanical damage, RSPA should permit 0.32 cm (0.125 inch) local

thickness reduction in the top shell and a 0.16 cm (0.063 inch) local

thickness reduction in the bottom shell. AAR asserts that the stresses

from a given thickness reduction attributed to mechanical damage can be

greater than the same reduction attributed to corrosion damage, because

mechanical damage causes a more abrupt change in the thickness.

After full consideration of the merits of these comments, RSPA and

FRA agree that there should be no overall limit on the amount of

surface area with localized reduced shell thicknesses, provided such

limitations apply only to the top shell of the tank and such areas are

separated by at least 16 inches. Also, RSPA is modifying the thickness

reduction table, as recommended by AAR, and endorsed by several

commenters, to differentiate between corrosion and mechanical damage.

AAR commented that RSPA proposed, in Sec. 180.509(g), maximum

thickness reductions from the original thickness of the tank and not

the required thickness of the tank: a thickness specified in a chart

summarizing specification requirements (e.g., Sec. 179.101-1(a)), or

the result of a calculation (e.g., Sec. 179.100-6(a)). RSPA disagrees.

The proposed section in the NPRM states that--

[a] tank car found with a thickness below the required minimum

thickness after forming for its specification, as stated in Part 179

of this subchapter, may . . . [emphasis added]

AAR further stated that RSPA should include an explicit provision

enabling the owner of a tank car to ``downgrade'' [downrate] the car to

the point where the loss of thickness exceeds the maximum allowed by

the regulation. As RSPA stated in the NPRM under the preamble heading,

``Safety System Inspections,''

[n]othing in the regulations would preclude a tank car owner from

marking a tank as meeting a less stringent specification, such as

re-marking a specification DOT 112J tank car to a DOT 112S or

112J400W tank specification to a DOT 112J340W tank specification

when the tank car no longer conforms to the marked specification.

Downrating is permissible and a tank car owner may mark a tank as

meeting a less stringent specification, such as marking a specification

112A340W tank car to a DOT 111A100W1 tank car when the tank, because of

its shell thickness, no longer conforms to the marked specification.

Owners are reminded that changing the marked specification also changes

the certificate of construction and, when so doing, they must follow

the procedures in Appendix R of AAR's Specifications for Tank Cars (see

Sec. 173.31(a)(4) and (f), and Sec. 179.6).

In its comments, RPI proposed a standardized minimum inspection

pattern for conducting thickness tests. RPI suggests that thickness

readings should be taken at the bottom, one side (90 deg.), and the top

within 6-inches of each circumferential weld for each plate. RPI

further states that corresponding readings should also be taken along

the head circumferential weld seam and another reading at the center of

the tank head. This would result in 32 thickness readings for a four-

ring tank. In addition to the tank shell, two readings would be taken

on the manway nozzle, the top unloading nozzle, and the sump. According

to RPI, if an inspector finds corrosion or other damage that reduces

the shell thickness, additional readings must be taken to more

specifically identify the damaged area.

RSPA is not incorporating a written procedure for conducting

thickness measurements throughout the tank shell to increase the

probability of defect or corrosion detection. RSPA and FRA believe that

such procedures belong in the tank car owner's written maintenance

plans or AAR Specifications for Tank Cars. Throughout this rulemaking,

RSPA and FRA have developed a course of action that outlines where and

what to inspect, but not how to inspect. This approach allows each tank

car owner the flexibility to develop inspection and test procedures

appropriate for each unique tank car, or a series of unique tank cars

based on operating and maintenance experience.

J. Lining and Coating Inspections and Tests

In the NPRM, RSPA proposed an inspection and test requirement for

tank cars with linings and coatings. This would ensure that the lining

or coating is in proper condition for the transportation of hazardous

materials. As proposed, owners of lined or coated tank cars must

determine the periodic inspection interval and inspection technique for

the lining and coating, based on the owner's knowledge of the material

used. The owner would also maintain all supporting documentation used

to make such a determination, such as the lining or coating

manufacturer's recommended inspection interval and inspection

technique, at the owner's principle place of business. Further, the

supporting documentation used to make such inspection interval

determinations and the inspection technique would have to be made

available to FRA upon request.

All commenters supported RSPA's proposed inspection and test

requirement for tank cars with linings and coatings. RPI suggested that

RSPA should specify ``owners of linings and coatings,'' as opposed to

the ``tank car owner,'' to determine the inspection and test technique

and interval--since most shippers own the tank car lining or coating as

opposed to the tank car owner. Mobil Oil Corporation and others

suggested that the regulation should only apply to linings and coatings

installed to protect the tank shell, as opposed to those applied for

lading integrity or quality.

RSPA and FRA agree with RPI and are revising the proposed

requirements to incorporate RPI's suggestions. In this final rule,

owners of linings and coatings in tank cars must determine the

[[Page 49064]]

periodic inspection interval and inspection technique for the lining

and coating, based on the owner's knowledge of the material used. This

will ensure that the lining or coating is in proper condition for the

transportation of hazardous materials. The owner must also maintain all

supporting documentation used to make such a determination, such as the

lining or coating manufacturer's recommended inspection interval and

inspection technique, at the owner's principle place of business. The

supporting documentation used to make such inspection interval

determinations and the inspection technique must be made available to

FRA upon request.

Further, in Sec. 180.509, RSPA is revising paragraphs (c)(3)(i) and

(iii)(A) to require an inspection and test of the lining or coating

only when the lining or coating is applied to protect the tank shell

from a lading such as hydrochloric acid.

K. Safety System Inspections

In the NPRM, RSPA proposed to add explicit requirements for the

inspection of thermal protection systems, tank head puncture resistance

systems, coupler vertical restraint systems, and devices used to

protect discontinuities. If, after an inspection, one or more of these

systems do not conform to the applicable specification requirements

contained in Part 179, renewal or repair of the system is necessary to

continue the qualification of the tank car. RSPA received two comments

on this proposal, both indicating support.

In this final rule, RSPA is adopting the requirements for the

inspection of these safety systems.

L. Quality Assurance Program (QAP)

In the NPRM, RSPA proposed to require that each tank car facility

establish a Quality Assurance Program (QAP) to detect non-conformities

during the manufacturing, repair, or inspection and test process. A

tank car facility means an entity that manufactures, repairs, inspects,

or tests tank cars to ensure that the tank cars conform to Parts 179

and 180, that alters the certificate of construction of the tank car,

or that verifies that the tank car conforms to the specification.

All commenters endorsed the QAP proposal; however, several

commenters suggested that RSPA delay the effective date for at least 18

months so that tank car repair facilities will have the opportunity to

develop a QAP. In its comments, AAR supported RSPA's QAP requirements

and further stated that the QAP developed by RSPA is consistent with

AAR's quality assurance requirements.

Several commenters asked RSPA to clarify whether or not a tank car

facility includes a shipper's loading facility where items such as

gaskets and manway bolts are normally inspected and replaced as part of

a ``pre-trip'' inspection. It is not the intention of RSPA to include

within the definition of a tank car facility a shipper's facility where

pre-trip inspections are performed. Generally, a tank car facility

evaluates the tank structure to ensure that, if serious fatigue,

corrosion, or accidental damage occurs within the inspection and test

interval, the remaining structure can withstand reasonable loads

without failure or excessive structural deformation. A shipper, on the

other hand, ensures by inspection that the tank is in proper condition

for transportation from point of origin to destination.

Based on the comments received, RSPA is requiring each tank car

repair facility to develop a QAP that has the means to detect any

nonconformity in the manufacturing, maintenance, or repair process and

that has the means to prevent its recurrence. Furthermore, the QAP must

ensure that the finished product conforms to the requirements of the

applicable specification and the regulations in the HMR. RSPA is also

clarifying the definition of a tank car facility to mean an entity that

manufactures, repairs, inspects, or tests tank cars to ensure that the

tank cars conform to Parts 179 and 180, that alters the certificate of

construction of the tank car, that ensures the continuing qualification

of a tank car by performing a function prescribed in Parts 179 or 180,

or that makes any representation indicating compliance with one or more

of the requirements of Parts 179 or 180. This language mirrors that for

the qualification of highway cargo tanks (see Sec. 180.2). A shipper

that inspects a tank car solely to ensure that the tank car is safe for

transportation is not performing a periodic qualification function. On

the other hand, a shipper who continues the qualification of a tank

car, by performing a function described in Parts 179 or 180, meets the

definition of a tank car facility.

M. Inspection Requirements Prior to Transportation

The current regulations, at Sec. 173.31(b)(3), require that the

shipper inspect a tank car before releasing it into transportation to

ensure that, among other things, the closures are in a ``tool-tight,''

secure condition. Further, closures on the tank (under

Sec. 173.24(f)(1)(ii)) must be so designed and closed that ``under

conditions (including the effects of temperature and vibration)

normally incident to transportation . . . the closure is secure and

leakproof.''

RSPA and FRA proposed in Sec. 174.68 that tank cars be inspected

prior to transportation as an amendment to the current requirements

because of their concerns about tank cars in transportation with loose

closures. Since 1989, FRA inspectors have found loose closures on tank

cars containing hazardous materials more than 23,000 times. In that

same period, RSPA has received about 1,100 to 1,200 incident reports

each year on tank cars that had released product, often as a result of

a loose closure. Those releases resulted in injury to 85 railroad

employees. This history shows that more needs to be done to ensure that

tank cars conform to the regulations when offered for transportation.

It is FRA's experience that properly designed and secured closures

(closures meeting the standards of Secs. 173.24 and 173.31) do not

become loose during transportation and that most of the incidents

reported to RSPA reflect poor pre-trip preparation of the tank car

prior to offering it for transportation. In order to clearly state the

offerors responsibility for pre-trip inspection of a tank car,

Sec. 174.68 in the NPRM proposed a rebuttable presumption against a

proper pre-trip inspection if unsecured closures were found in transit.

RSPA and FRA believe that aligning the inspection requirements in

current Sec. 173.31(b) with the design and operations requirements in

Sec. 173.24 will clarify their full intent, foster compliance with

safety standards, and improve hazardous materials transportation

safety. Comments on the proposed Sec. 174.68 came from most of those

filing responses to the NPRM and they covered five aspects of the

proposal. First, several commenters argued that Sec. 174.68 was the

wrong place for pre-trip inspection requirements, that, as shipper

responsibilities, they belonged in Part 173. RSPA and FRA agree and the

final rule includes pre-trip inspection in Sec. 173.31.

Second, several commenters said that the proposal raised the duty

of care for pre-trip car preparation to an all but impossible level.

Current Sec. 173.31(b)(1) requires that ``the shipper must determine to

the extent practicable, that . . . fittings are in proper condition. .

. .'' [emphasis added] The origin of the phrase ``to the extent

practicable'' in Sec. 173.31(b) has its roots in the Interstate

Commerce Commission's (ICC) regulations prior to 1960. In those

[[Page 49065]]

regulations, the ICC required shippers, before loading the tank car, to

examine the tank and each appurtenance to see that the safety and

outlet valves, safety vents, the excess flow valves (if any), the

closures of all openings, and the protective covers of all

appurtenances were in proper condition.

In a letter dated July 10, 1959, to AAR, the Manufacturing

Chemists' Association (MCA) stated that the addition of the words ``to

the extent practicable'' in the tank car loading section was to clarify

the purpose of the regulations and to make the regulation more

realistic and to eliminate from the regulation items which were either

very difficult to inspect or very expensive to inspect such as a full

inspection of safety relief valves or excess flow valves. Read

literally, the regulation at that time would impose a duty on the

shipper to disassemble and inspect safety valves and excess flow valves

prior to each trip.

As a result of the MCA letter in 1959, AAR petitioned the ICC to

amend the current regulations by inserting the phrase ``to the extent

practicable'' in the tank car loading section. The ICC agreed and the

new phrase went into the regulations on March 23, 1960, under Order

Number 42. From the beginning, this phrase was meant to reflect the

practical impossibility of, for instance, taking the valves apart

before each trip; the additional language was not intended to excuse

poor pre-trip preparation. This final rule does not enlarge the ``to

the extent practicable'' standard.

Third, several commenters seemed to confuse the essential elements

of the loose closure violation by arguing that evidence of a leak (or

release of product) in transit does not necessarily prove the lack of a

pre-trip inspection. They mistakenly believed that the proposal focused

on releases of hazardous materials rather than the broader fault: loose

fittings and closures. FRA and RSPA agree that leaks can develop in

transit from sources other that insecure closures, the failure of a

rubber lining and the failure of a frangible disc are two possible

examples. This provision was developed from the requirement in the

current Sec. 173.31(b) that closures must be secured in place with an

appropriate tool, and the final rule makes no changes in that

requirement.

Fourth, many commenters argued that the condition of tank cars in

transit is the responsibility of the railroads, that it is their duty

to ensure that the closures are, and remain, tight. RSPA and FRA note

that current Sec. 173.31(b)(3) requires the shipper to make closures

``tool tight'' prior to shipping and that Sec. 173.24(b) and (f)

require closures to be designed, maintained, and closed so that ``under

conditions (including the effects of temperature and vibration)

normally incident to transportation'' they will remain secure.

Responsibility for tight closures must rest primarily with the offeror.

The railroads' duty to inspect a tank car is aimed at detecting obvious

leaks and defects in the running gear of the vehicle. FRA's pre-

departure inspection requirements--applicable to all trains whether or

not carrying hazardous materials--are found at 49 CFR 215.13. Appendix

D to Part 215 describes the inspection to be performed by a train crew,

``At each location where a freight car is placed in a train and

[designated inspectors] are not on duty. . . .'' Appendix D requires

the train crew to reject a placarded hazardous materials tank car from

which lading is leaking. As the National Industrial Transportation

League said in its comments, ``The key issue in determining the

regulatory responsibilities under the HMR should be to determine which

functions parties actually performed, or should have performed.'' This

final rule is not intended to, nor does it, change these essential

relationships.

Fifth, several commenters argued that the proposed rebuttable

presumption will be impossible to meet. The proposed rule states

examples (derailment and vandalism) that will rebut the presumption,

but they are not intended to be exclusive. In FRA's experience in

discussing alleged violations with shippers over the past few years,

the following circumstances have led to either termination or a penalty

amount significantly reduced from that originally proposed, depending

on the facts and circumstances of each case:

Delivery to a mistaken destination and subsequent

rerouting to the original destination,

Erroneous spotting at a repair facility,

Actual delivery to the consignee prior to inspection,

Abnormally rough handling by a railroad,

Gaskets, otherwise secure at the start of the trip,

deteriorating enroute in a manner the offeror could not have foreseen.

One commenter cited case law on irrebuttable presumptions. RSPA and

FRA agree with the commenter that a presumption impossible to rebut

would not be proper; for the reasons given, RSPA and FRA do not view

the presumption in the regulation published today as impossible to

rebut.

In some cases, FRA has seen pre-trip inspection check lists that

were at obvious odds with the conditions discovered on the car. The

rebuttable presumption stated today is not designed to make enforcement

``easier,'' it is designed to make responsibility more certain. For

most shippers of hazardous materials, today's rule will not mean a

change in the regulator/regulated relationship.

When FRA issues a Notice of Proposed Violation for an alleged

violation of the HMR, the respondent (railroad, shipper, or

manufacturer) is afforded the opportunity to investigate the charges

and to collect factual evidence to mitigate or dismiss the case.

Respondent has the opportunity for a hearing. FRA, or an Administrative

Law Judge, considers respondent's submissions, together with the

factors in 49 U.S.C. Sec. 5123(c), before reaching a decision. The

standard in this final rule does not change the process by which FRA

enforces railroad related hazardous materials violations. FRA expects

that, by clarifying the responsibility of the shipper, there will be

fewer loose closures on tank cars and fewer injured railroad employees.

Several commenters mentioned mishandling, even abusive handling, by

the railroads. FRA's own studies have demonstrated that overspeed

impacts in railroad switching operations are far from a rarity, but FRA

is not aware that overspeed impacts will loosen the threaded fasteners

securing lading retention fittings on a tank car. Overspeed impacts can

cause severe structural damage, lessen the service life of the car, and

cause frangible safety vent discs to rupture. In such cases,

enforcement actions against the railroads are appropriate, and FRA

pursues them. One shipper, PPG Industries, Inc., put impact recorders

on a test fleet of 50 tank cars operated out of its Lake Charles,

Louisiana plant. The impacts in excess of 6G's (about 8 miles per hour)

between July 1992 and December 1993 are documented in PPG's comments in

this docket. Because they are limited in geographic scope, RSPA and FRA

cannot say that this data presents a typical picture, nation-wide, but

PPG's charts are graphic evidence, arranged by railroad and by

terminal, that railroad tank cars are subject to stresses well above

their optimum operating environment.

In the final rule, RSPA is articulating a rebuttable presumption

standard aimed specifically at loose closures on tank cars. The

statement of this presumption in Sec. 173.31(d)(2) does not mean,

however, that there is a different standard for railroad tank cars than

for

[[Page 49066]]

other packagings used to transport hazardous materials. The ``secure

and leakproof'' standard established in Sec. 173.24(f) applies to

closures on all packagings used for transportation. If a hazardous

materials package is discovered with loose closures, either the

closures were not designed properly or they were not tightened

properly. Neither RSPA nor FRA are aware of hazardous materials

packagings designs that allow closures to loosen in transit. Hence the

presumption that, when an inspector discovers a loose closure, it was

not tightened properly. RSPA has made the presumption explicit for

railroad transportation because FRA's enforcement experience, discussed

earlier, proves the need to focus responsibility on those who prepare

hazardous materials for transportation.

The following table lists the adopted paragraphs or sections and,

where applicable, the corresponding paragraph or section contained in

the current HMR. In some cases, the cross-references are to provisions

which are similar to, but not identical with current provisions.

------------------------------------------------------------------------

New section Old section

------------------------------------------------------------------------

173.31(a)(2)............. 173.31(a)(4) [except 4th and 5th sentence].

173.31(a)(3).............

173.31(a)(4)............. 173.31(a)(7) [1st sentence after ``Effective

July 1, 1991...'' and preceding ``..., as in

effect on November 16, 1990''].

173.31(a)(5)

173.31(a)(6)............. 173.31(a)(3) [1st sentence].

173.31(a)(3)(i).

173.31(b)(1)............. 173.31(a)(5) [except last sentence].

173.31(b)(2)............. 173.31(a)(12).

173.31(a)(15) [1st sentence preceding

``...nonreclosing pressure relief

devices.''] [2nd preceding ``...provided

that the liquid...''] [3rd sentence

preceding ``...breather holes are not...''].

173.31(b)(3)

173.31(b)(4)

173.31(b)(5) .............................................

173.31(b)(6)

173.31(c)................ 173.31(a)(14) [1st sentence preceding

``...equal to or greater than...''].

173.31(a)(14)(i) [1st sentence preceding

``...ullage space or dome of tank.''].

173.31(a)(14)(ii).

173.31(a)(14)(iii).

173.31(d)(1)

173.31(e)(1)............. 173.31(a)(17).

173.31(e)(2)

173.31(f)

173.314(c), Note 2....... 173.314(c), Note 25.

173.314(c), Note 3....... 173.314(c), Note 21.

173.314(c), Note 4....... 173.314(c), Note 20.

173.314(c), Note 6....... 173.314(c), Note 12 [except 1st and last

sentence].

173.314(c), Note 7....... 173.314(c), Note 18 [1st sentence preceding

``...g, when offered for transportation.''].

173.314(c), Note 8....... 173.314(c), Note 19 [1st sentence preceding

``...g, when offered for transportation.''].

179.7

179.16................... 179.100-5.

179.18................... 179.100-4.

179.20

179.22................... 179.100-21.

179.105-8.

179.200-25.

179.203-3.

Appendix A to Part 179... 179.105-5 (b) and (c).

Appendix B to Part 179... 179.105-4 (d) and (e).

Subpart F to Part 180

180.501

180.503

180.505

180.507

180.509

180.511

180.513

180.515

180.517

180.519

------------------------------------------------------------------------

IV. Review by Section Summary

Part 171

Section 171.7(a)(3). The 49 CFR reference sections for the

Association of American Railroads standards and for a Compressed Gas

Association standard are added, revised or removed, as appropriate, to

reflect the changes in this rulemaking.

Part 172

Section 172.101. In the HMT, three special provisions are removed.

Special Provision ``B41,'' appearing in column (7) of the entries for

benzyl chloride, fluorosulfonic acid, and titanium tetrachloride is no

longer necessary due to the new inspection and test intervals adopted

in this final rule. Special Provision ``B43,'' appearing in column (7)

of the entries for carbon dioxide, refrigerated liquid, hydrogen

chloride, refrigerated liquid, and vinyl fluoride,

[[Page 49067]]

inhibited, also is no longer necessary because of the new inspection

and test requirements. For the Division 2.1 (flammable gas) entries

ethyl chloride and ethyl methyl ether, Special Provision ``B63'' is

removed, thus prohibiting the use of tank cars without head protection

or thermal protection.

Section 172.102. As discussed above, Special Provisions ``B41'' and

``B43'' are removed. The inspection and test intervals (i.e., 5-3-1)

specified in Special Provision ``B41'' and the nondestructive test

requirements specified in Special Provision ``B43'' are incorporated

into Subpart F of Part 180. Special Provision ``B63'' appears only in

the entries ethyl chloride and ethyl methyl ether and, therefore, in

paragraph (c), is removed. Special Provision ``B64'' is amended by

changing the head-protection section reference ``Sec. 179.105-5'' to

read ``Sec. 179.16,'' and Special Provision ``B79'' is amended by

changing the head- and thermal-protection section references

``Secs. 179.105-4 and 179.105-5'' to read ``Sec. 179.16 and 179.18''.

Part 173

Section 173.31. The section heading is revised to read ``Use of

Tank Cars.'' This section also is completely revised and reorganized

for clarity.

New paragraph (a)(1) corresponds to the language in the HMR for

cargo tanks and portable tanks (see Secs. 173.32c(a) and 173.33(a)).

The section also includes reference to certain ``AAR'' specification

tank cars that are authorized for hazardous materials service in the

HMR (see Secs. 173.241 and 173.242). When these tank cars are used for

the transportation of hazardous materials, the tank cars must meet the

minimum specification for new construction as required by AAR.

New paragraph (a)(2) is essentially current Sec. 173.31(a)(4). The

first, second, and third sentences are revised to clarify the use of

the term ``authorized.'' Prior to December 19, 1957 (ICC Order No. 33),

the regulations stated that:

[T]ank cars and appurtenances may be used for the transportation

of any commodity for which they are authorized, as indicated on the

certificate of construction. When a car is to be used for the

transportation of a commodity other than those approved on the

certificate of construction, it must be approved for such loading by

the A.A.R. Tank Car Committee. Changes in fittings or commodity

stencilling required to transfer a car from one service to another

as authorized on the certificate of construction, may be made only

be the owner or owner's authorized agent * * *.

As evidenced by the language above, the term ``authorized'' means

those commodities designated on the certificate of construction and

approved by the AAR Tank Car Committee. Order No. 33 changed the

regulation by removing the phrase ``as indicated on the certificate of

construction'' because many car owners did not have a certificate for

older Class ARA-II (built prior to 1917), ARA-III (built prior to

1927), and some ICC-103 (built after 1927) tank cars. Because this

final rule requires that the original and subsequent tank car

certificates must be maintained for the life of the car and transferred

with ownership, RSPA is clarifying the purpose of this paragraph by

inserting the phrase ``in this part and specified on its certificate of

construction'' at the end of the first sentence. See Sec. 180.517. The

second and third sentences are modified accordingly. Provisions

contained in the fourth and fifth sentences of current

Sec. 173.31(a)(4), stating that DOT 105A-W, 109A-W, 111A100W4, 112A-W,

and 114A-W tank cars may be used for any commodity for which it is

approved and may be stencilled accordingly, and that a tank car

stencilled to indicate that it is authorized for one commodity may not

be used for any other service, are removed. The stencilling requirement

for these cars is optional and, therefore, not enforceable.

New paragraph (a)(3) provides that no person may fill a tank car

with a hazardous material when the tank car is overdue for periodic

inspection and test. This provision allows the movement of tank cars

containing hazardous material residue to a tank car facility for

inspection and testing.

New paragraph (a)(4) is current Sec. 173.31(a)(7). It removes

reference to a compliance date, now past, and establishes that air

brake equipment support attachments must be welded to pads instead of

directly to the tank shell in conformance with Secs. 179.100-16 and

179.200-19.

New paragraph (a)(5) prohibits the use of an internal self-

energized manway that is located below the liquid level of the lading

on a tank car, beginning on the effective date of this final rule.

After the effective date of this final rule, an exemption would be

required in order to continue to operate such a tank car. This

provision was proposed paragraph (a)(22) in HM-175A.

New paragraph (a)(6) is current Sec. 173.31(a)(3). It removes

specific ``DOT'' class references and explains that any tank car of the

same class with a higher tank test pressure than the tank car

authorized in the HMR may be used. The paragraph is also simplified by

specifying the hierarchy of the letters in the specification marking

that describe special protective systems (e.g., ``J'' for thermally

protected, jacketed cars; ``T'' for thermally protected, non-jacketed

cars; ``S'' for cars with head shields but without thermal protection;

and ``A'' for cars without protective systems).

New paragraph (b)(1), concerning the use of coupler vertical

restraint systems, is current Sec. 173.31(a)(5). It is revised to

require all DOT specification tank cars and any other tank car used to

transport hazardous material to be equipped with a coupler vertical

restraint system. This revision also removes reference to a compliance

date, now past, excepting DOT specification tank cars in nonhazardous

materials service from being equipped with a coupler vertical restraint

system.

New paragraph (b)(2), concerning pressure relief devices, is

current Secs. 173.31(a)(12) and 173.31(a)(15). This revision is

simplified by using the term ``poisonous by inhalation'' (see

Sec. 171.8) in place of the defining criteria.

New paragraph (b)(3) requires head protection for all tank cars

transporting Class 2 materials and tank cars constructed from aluminum

or nickel plate. Tank cars currently equipped with half-head protection

are excluded. The compliance period is 10 years from the effective date

of this rule, except for class DOT 105 tank cars with less than 70 kl

(18,500 gallon) capacity when used to transport a Division 2.1

material, which have a compliance period of 5 years. This provision was

proposed paragraph (a)(19) in HM-175A.

New paragraph (b)(4) requires tank cars transporting Class 2

materials to have thermal protection. Exceptions from the thermal

protection standard are granted for ``chlorine,'' ``carbon dioxide,

refrigerated liquid,'' and ``nitrous oxide, refrigerated liquid,'' and

for tank car tank classes DOT 106, 107A, 110, and 113. This provision

was proposed paragraph (a)(20) in HM-175A. In the NPRM, RSPA did not

propose thermal protection for the commodities identified above (see

proposed Sec. 173.314(k) and (o)). The compliance period is 10 years

from the effective date of this final rule.

New paragraph (b)(5) requires bottom-discontinuity protection for

all existing tank cars transporting a hazardous material. The new

protection requirements conform to paragraphs E9.00 and E10.00 of the

AAR Specifications for Tank Cars, M-1002. Existing tank cars that

conform to Appendix Y of the AAR Specifications for Tank Cars, M-1002,

may continue in use. The compliance period is 10 years from the

effective date of this final rule.

[[Page 49068]]

This provision was proposed paragraph (a)(23) in HM-175A.

New paragraph (b)(6) is added to require tank car owners to

implement measures to ensure the phased-in completion of the

modifications on each tank car subject to this final rule. As discussed

earlier in this preamble, RSPA and FRA have several programs in place

to improve the tank car fleet. Owners, therefore, should develop

careful plans, procedures, and schedules to assure completion of the

modifications before the regulatory compliance date. Paragraph (b)(6)

also requires submission of a yearly progress report to FRA that shows

the reporting mark of each tank car requiring modification, the type of

modification required for each tank car during the previous year, and

the total number of tank cars modified the previous year.

New paragraph (c) was proposed as paragraph (d) in HM-201. This

final rule revises the terms ``un-insulated'' to ``non-insulated,''

``ullage space or dome'' to ``vacant,'' and clarifies that this

provision applies to cars in hazardous materials service only. A new

provision is added in paragraph (c)(3) to require all tank cars

transporting a PIH material to have a tank test pressure of at least

20.7 Bar (300 psi). This provision is consistent with other regulations

adopted under Docket HM-181 for PIH liquids.\19\ Also, several shipping

names appearing in the opening paragraph are revised for consistency

with the proper shipping name as shown in the Sec. 172.101 table.

\19\For further information see Performance-Oriented Packaging,

Docket HM-181, 55 FR 52402 (December 21, 1990). In general, liquid

materials PIH in Hazard Zone A are assigned Special Provision B72

and those in Hazard Zone B are assigned Special Provision B74. These

two special provisions require the use of a 105S, 112J, or a 114J

tank car having a tank test pressure greater than 18 Bar (300 psi).

---------------------------------------------------------------------------

New paragraph (d) reinforces the inspection requirements that must

be fulfilled before a tank car of hazardous materials is offered for

transportation. These provisions were proposed paragraph (a)(4) and

Sec. 174.68 in HM-201. These proposed requirements were revised and

combined based on suggestions made by the commenters.

In new paragraph (e), to clarify that the paragraph applies to

materials that are poisonous by inhalation, the paragraph heading is

revised to read ``Special requirements for materials poisonous by

inhalation.''

New paragraph (e)(1) concerns the use of heater coils. This

provision is essentially current paragraph Sec. 173.31(a)(17). This

provision was proposed paragraph (e) in HM-201.

New paragraph (e)(2) requires that tank cars used for materials

poisonous by inhalation must conform to at least a DOT 105S300W,

105S300ALW, 112J340W, or 114J340W. This provision was proposed

paragraph (a)(21) in HM-175A. It is made consistent with Special

Provision B74 for liquid PIH materials in Zone B. The compliance period

is 10 years from the effective date of this final rule.

New paragraph (f) requires the use of a DOT 105S200W; a DOT

112S200W with an 11-gauge steel jacket conforming to Sec. 179.100-4; a

DOT 112S340W; or a DOT 112S200W tank car constructed from AAR steel

specification TC-128, normalized, for the transportation of certain

listed hazardous substances in Sec. 173.31(f) that pose a potential

threat to human health and the environment. This provision was proposed

paragraph (a)(24) in HM-175A.

Section 173.314. In the table in paragraph (c), the entries are

amended by removing references to the individual tank car

specifications and adding references to the authorized tank car

classes. This change ensures that Sec. 173.314 does not authorize a

tank car having a tank test pressure below the regulatory minimum in

Sec. 173.31(c). The current notes following the table are amended by

redesignating, revising, or removing all tank car ``design

requirements'' as follows (notes that apply to filling limits are

retained):

Note 1, no change.

Note 2 is restated without substantial change and moved to

Sec. 173.314(n).

Note 3 and Note 4 are restated without substantial change and moved

to Sec. 173.314(j), which is applicable to all materials having a

primary or secondary Division 2.1 (flammable gas) hazard.

Note 5 is restated without substantial change for clarity.

Note 6 is restated without substantial change and moved to

Sec. 173.314(o).

Note 7, which restricts the transportation of multi-unit tank cars

tanks (ton containers) to rail and highway only, is removed. RSPA

believes no valid reason exists to restrict the transport of these

units by water. A provision restricting the transport of multi-unit

tank car tanks by air is unnecessary because all multi-unit tank car

tanks exceed the maximum quantity limitations allowed by air.

Note 8 is restated without substantial change and moved to

Sec. 173.314(l).

Note 9 is moved to Sec. 173.314(j) and made applicable to all

materials with a primary or secondary Division 2.1 (flammable gas)

hazard.

Note 10 is restated without substantial change and moved to

Sec. 173.314(m).

Note 11 is restated without substantial change and included in

Sec. 173.314(m).

Note 12 is restated without substantial change. The filling density

requirements are moved to Note 6, and the design requirements are moved

to Sec. 173.314(k).

Note 13 is removed to eliminate duplication of the marking

requirements prescribed in Special Provision B12, Secs. 173.314(a)(5)

and 172.330(a)(1)(i).

Note 14 is removed because it is not referenced in the table.

Note 15 is removed since it is included with the other design

requirements applicable to tank cars used for materials having a

primary or secondary Division 2.1 (flammable gas) hazard in

Sec. 173.314(j).

Note 16, which is currently reserved, is removed.

Note 17, which references Sec. 173.314(g) is removed.

Note 18 is restated without substantial change and moved to Note 7.

Note 19 is restated without substantial change and moved to Note 8.

Note 20 is restated without substantial change and moved to Note 4.

Note 21 is restated without substantial change and moved to Note 3.

Note 22, referencing the requirements in Sec. 173.245, is

incorporated into the table under the entry ``Division 2.3, Zone A

materials.''

Note 23 and Note 24 are removed based on other changes in this

final rule concerning the elimination of grandfather provisions.

Note 25 is restated without substantial change and moved to Note 2.

Note 29 and Note 30 are removed based on other changes in this

final rule concerning the elimination of grandfather provisions.

In addition, the table in Sec. 173.314(c) will reflect the tank car

classes and not the specifications.

Section 173.319. Paragraph (a)(4)(iii) is revised by removing a

parenthetical reference to current Sec. 173.31(c)(13). A requirement

contained in Sec. 173.31(c)(13) prescribing special retest requirements

for class DOT-113 tank cars is revised and moved to new paragraph

Sec. 173.319(e).

Section 173.323. Paragraph (c)(1) is revised to require a tank test

pressure of at least 20.7 Bar (300 psi) for ethylene oxide no later

then 10 years after the effective date of this final rule.

Authorization for the use of a DOT 111A100W4 and 111J100W4 tank car is

removed.

Part 179

Section 179.1. In paragraph (c), the section reference

``Sec. 173.31'' is revised to read ``Sec. 180.507''.

[[Page 49069]]

Section 179.2. This section is amended by adding a definition for

``Tank car facility.''

Section 179.7. This section requires tank car facilities to have a

Quality Assurance Program (QAP). Paragraph (a) sets forth performance

standard for the program. Paragraphs (b)(1) through (b)(13) require

that the QAP have certain minimum requirements. The term ``Enhanced

visual imagery'' in paragraph (b)(10) is changed to read ``Optically-

aided visual inspection'' to correctly identify that the visual

inspection method is ``optically aided.'' Optically-aided visual

methods include the use of magnifiers, borescopes, fiberscopes, and

machine vision technology (e.g., a video digitizer that converts images

into digital form, and through image enhancement, image segmentation,

and feature extraction, the computer classifies objects within the

image). Paragraph (c) requires tank car facilities to ensure that only

personnel qualified to perform a particular nondestructive inspection

and test perform that operation. Paragraph (d) requires each tank car

facility to have written procedures, covering inspection, fabrication,

and repair operations as appropriate, for their employees. Paragraph

(e) cross-references the training requirements in Subpart H of Part

172. (Section 172.702 requires that a hazmat employer train each of its

hazmat employees.) Paragraph (f) specifies the compliance date by which

tank car facilities must have a QAP and written procedures in effect.

Section 179.16. This new section contains the tank-head puncture-

resistance requirements found in current Secs. 179.100-23 and 179.105-

5.

Section 179.18. This new section contains the thermal protection

requirements found in current Sec. 179.105-4(a), (b), and (c). A

requirement that the exterior of the tank car must be painted white in

proposed Sec. 179.18(d) is moved to Sec. 179.101-1, Note 4 in this

final rule. Editorial revisions are made to these requirements for

clarity and for consistency with other changes in this final rule.

Section 179.20. This new section contains bottom-discontinuity

protection requirements. For new tank cars, bottom-discontinuity

protection must conform to paragraphs E9.00 and E10.00 of the AAR

Specifications for Tank Cars, M-1002.

Section 179.22. New section 179.22 consolidates the marking

requirements contained in current Secs. 179.100-21, 179.105-8, 179.200-

25, and 179.203-3. Based on this consolidation, Secs. 179.100-21,

179.105-8, 179.200-25, and 179.203-3 are removed.

Section 179.100-4. This section is amended by removing the phrase

``except that a protective coating is not required when foam-in-place

insulation that adheres to the tank or jacket is applied'' at the end

of the first paragraph. This change is based on an AAR petition (P-

1050) to require protective coatings on the outside surface of the tank

shell and the inside surface of the jacket.

Section 179.100-21. The marking requirements contained in this

section are consolidated with other marking requirements in new

Sec. 179.22 and, as discussed earlier, Sec. 179.100-21 is removed.

Section 179.100-23. The head protection requirements contained in

this section are moved to Sec. 179.16(b), and, as discussed earlier,

Sec. 179.100-23 is removed.

Section 179.101-1. Certain editorial changes are made in

Sec. 179.101-1, Note 4, for clarity and consistency with other changes

made in this final rule. In the first sentence in Note 4, the section

reference ``Sec. 179.100-4,'' which addresses insulated tank cars, is

removed because Note 4 applies to non-insulated cars only. Note 4 is

revised to clarify that there is no need to paint the tank white when a

``thermal protection'' system is applied (consistent with current

Sec. 179.105-4(g) and proposed Sec. 179.16 (d)), and to remove a

requirement that tank cars in hydrogen fluoride service need to have a

dark colored band in the top platform and fitting area because hydrogen

fluoride is not a Class 2 (compressed gas) material. The last sentence

is also removed because it is not a mandatory requirement.

Section 179.103-1. Current paragraph (c), providing that a manway

may be located other than at the top of the tank is no longer valid

and, therefore, is removed and reserved.

Section 179.103-2. Current paragraph (a) containing manway cover

plate requirements is revised by removing the phrase ``may be of the

self-energizing type and''. This change would prohibit the construction

of tank cars with a self-energized manway located below the liquid

level of the lading.

Section 179.103-5. In current paragraph (a)(1), the first two

sentences authorizing the location of a self-energizing manway below

the liquid level of the tank is no longer valid and, therefore are

rem

This text is long and has been trimmed here. Open the source document for the complete record.