AlllOb T?^ao?

NBSIR 78-1421

Fire Hazard Evaluation of BART

Vehicles

Emil Braun

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D C. 20234

March 1978

Final Report

Prepared for Urban Mass Transportation Administration

Department of Transportation

Washington, D.C. 20590

1421

NBSIR 78-1421

FIRE HAZARD EVALUATION OF BART

VEHICLES

Emil Braun

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

March 1978

Final Report

Prepared for Urban Mass Transportation Administration

Department of Transportation

Washington, D.C. 20590

U S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Dr. Sidney Harman. Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director

CONTENTS

Page

LIST OF TABLES . . iv

LIST OF FIGURES iv

Abstract 1

1. INTRODUCTION 1

2. SUBWAY CAR DESIGN 2 2.1. Interior Car Design 2 2.2. Exterior Car Design 3

2.3. Communication System 3

2.3.1. Intra-Train Communications 3

2.3.2. Inter-System Communications 4

3. FIRE PERFORMANCE OF EXISTING BART MATERIALS 4

3.1. Test Methods 4

3.1.1. ASTM D 1692 4

3.1.2. ASTM D 635 5

3.1.3. FS 5906/ CCC-T-191 5 3.1.4. ASTM E-84 5 3.2. Small Scale Flame Exposure Tests-Discussion 5

4. FIRE PROTECTION SYSTEM 6

5. FIRE INCIDENTS ON BART 6

6. FIRE SCENARIOS IN BART CARS 7 6.1. Interior Ignitions 7 6.2. Exterior Fires . 8

7. SYSTEM IMPROVEMENTS 9

7.1. Furnishing Improvements 9

7.1.1. Wall and Ceiling Liners ..... 10

7.1.2. Carpeting 10

7.2. Floor Assembly 10

7.3. Fire Detection 10

8. RECOMMENDATIONS 11

9. REFERENCES 11

iii
LIST OF TABLES

Page

Table 1. List of Fire Tests for Synthetic Components Used

in BART 13

Table 2. Test Results of Seat Cushions and Upholstery Fabric

Tests Conducted by BART 14

Table 3. Acceptance Criteria for Test Methods Used in

Qualifying BART Materials 14

LIST OF FIGURES

Page

Figure 1. Exterior views of A-car and B-car configurations ... 15

Figure 2. Seat placements in A-car and B-car configurations . . 16

Figure 3. Seat assembly - cushions and frame 17

Figure 4. Comparison of ignition source characteristics and

minimum ignition energies for various seat assemblies 18

iv
FIRE HAZARD EVALUATION OF BART VEHICLES

Emil Braun

Abstract

A fire hazard evaluation of the subway cars used on the

San Francisco Bay Area Rapid Transit District was performed.

After analyzing the cars' interior and exterior design, five

recommendations were made that, if implemented, would improve

passenger safety by decreasing the probability of developing

a hazardous fire situation. Among these recommendations were

the upgrading of current upholstered urethane seat assemblies

and the need for the development of a fire detection system

appropriate for rapid rail transit vehicles. Those system

improvements would not only provide passengers a safer traveling environment but would also provide a modest level of

protection for the heavy investment in rail vehicles.

Key words: BART; fire accidents; fire hazards; fire safety;

fire scenarios; mass transportation; material fire performance;

rail vehicles; subway car design; UMTA.

1. INTRODUCTION

At the request of the Urban Mass Transit Administration (UMTA),

the National Bureau of Standards (NBS) conducted a limited fire hazard

analysis of the subway cars used on the San Francisco, California Bay

Area Rapid Transit District (BART). The purpose of this investigation

was to ascertain if any aspect of the design details or the material

specifications relating to the subway car could result in an environment

that has a high probability for developing into a hazardous fire situation. Throughout this analysis, primary consideration has been given

to passenger safety under various fire scenarios and only secondarily

to the protection of the rail vehicles. The analysis relies on material

evaluations supplied to NBS by BART, with the testing being done by

laboratories other than NBS.

Any transportation system presents both the occupants and operators

with a certain level of fire risk which depends in part on the fire

characteristics of the materials used in constructing and furnishing the

vehicle. In addition, since mass transportation systems confine large

numbers of people in small areas, evacuation may be difficult in a fire

situation. This is especially true in subway systems, which present

unique problems, such as the evacuation of passengers and personnel from

a car made untenable by fire and located not at a station, either above

or below the ground. The BART system is made up of approximately 73

miles of mainline track and 38 stations. About 25 percent of mainline

1
track is below ground while nearly 42 percent of the stations are underground. These underground stations represent unique evacuation

problems that must be recognized in any overall fire safety analysis,

but that will not be discussed here, since this paper is devoted to the

potential fire hazards in the rail vehicles.

2. SUBWAY CAR DESIGN

BART vehicles come in two configurations, an A-car and a B-car

(see figure 1) [1]1. Except for the attendant’s cab, which is mounted on

the front of an A-car, both configurations are identical. An operational

train is made by coupling up to eight B-cars between two A-cars. Since

A-cars contain all train controls, the smallest train that can operate on the BART system is two A-cars coupled back-to-back.

When the cars are mechanically coupled to each other, the cars are also automatically coupled electrically. The lead A-car automatically

receives traffic information from a central computer system that monitors

the overall system. The train computer system is completely interactive

to the extent that the train operator’s primary function is that of monitoring an annunciator panel in the attendant’s cab of the lead car. Also,

the train operator controls the door closure override to insure that all

patrons are clear of the doors before they close.

2.1. Interior Car Design

Figure 2 illustrates the seat placement in the A-car and B-car

configurations [2]. Each configuration provides sufficient seating for

72 passengers and a maximum "crush load" of an additional 216 standing

patrons. There are eight longitudinal seats located behind modesty

screens adjacent to each door. The remaining 28 seats are divided into

three sections separated by the side entrance doors.

Each seat assembly consists of a molded urethane foam bottom and

back encased in an upholstery fabric. The fabric is a combination vinyl/

nylon assembly (figure 3) [1]. The outer edges of both bottom and back

cushions are vinyl with the center section made of a nylon fabric. The

seat cushions snap into the seat frame which, in turn, is attached to the

sidewall

.

The sidewall and ceiling liners are made of molded, glass fiber

reinforced, polyester resin. The ceiling liner is riveted to the roof

panel and has recessed molded inserts for lighting and speakers. The

sidewall liner also forms the interior plenum for the heating and air

Numbers in brackets refer to the references listed at the end of this

paper.

2
conditioning system. The air handling system has outlets along the

bottom sill of each window, while the returns are located along the

bottom of the sidewall, below the seat assemblies.

The floor panels, throughout the passenger compartment, are covered

with a latex foam pad and wool carpet, except over the bolsters. In

these areas, the standard latex foam pad is replaced by a vinyl-covered

polyester urethane pad, Baryfol (TM) . This special pad is intended as a sound barrier against under-car noises emanating from the track areas.

2.2. Exterior Car Design

f The car exterior is made of extruded aluminum sheet stock. The

car is designed such that all train controls and machinery are located

below the car floor. The only exceptions are the electrical wires for

lighting and inter-car communications. While some of the subfloor wiring is confined to conduits, the majority of the wiring is strapped at

convenient intervals to the under-floor beams and completely exposed to

the under-car environment.

The under-car equipment, which is attached to floor beams and

bolster plates, includes:

a) the heating and air conditioning equipment,

b) the trucks subsystem motors and braking system (dynamic and

friction brakes)

,

c) the air suspension system,

d) the starting and braking resistors,

e) the third rail shoe (1000 VDC).

The floor that separates this equipment from the passenger compartment

is constructed of an aluminum ((6061-T6) .15 cm (.060 in)) sandwich with

a 2-inch core of polyurethane foam. This extends throughout the length

of the car.

2.3. Communication System [3]

There are two interrelated communication systems in each train.

One is for intra-train communications and the other is for communications

between the train operator and central control. Switching also exists

on the train operator’s console to permit public address announcements to

be made directly by central control to the passengers.

2.3.1. Intra-Train Communications

There are two types of intra-train communications. One is a general

public address system that allows the train operator to simultaneously

key on all of the speakers in each car. Under standard operating

3
conditions, this is used to announce station names. However, in the

event of an emergency, it is intended to be used to direct passenger

movement away from hazardous locations.

The other mode of intra-train communications is the passengerto-attendant intercom located at the ends of each car. The intercom is

activated by the passenger when he depresses a button located next to

the speaker/microphone.

2.3.2. Inter-System Communications

Two-way communications, via the train radio system, exist between

central control, trains and maintenance vehicles. In addition, a system

of telephone lines is installed along mainline tracks. There are two

types of telephone lines, maintenance telephone lines and emergency

telephone lines. Maintenance telephone lines are brought out as plugin jacks at each maintainable piece of equipment. Portable phone handsets

can be plugged in and communications can be established with the Central

Communications Controller.

The emergency telephone lines are an independent system that provides

emergency call boxes within line of sight of not more than 1,000 feet

apart in all tunnel and subway sections. It is possible to remove power

from the third rail by a trip button located in these telephone boxes.

3. FIRE PERFORMANCE OF EXISTING BART MATERIALS

Table 1 is a list of the flame exposure tests that were required to

be performed on the synthetic components in the BART vehicle. Table 2 is a summary of the results of tests performed on the seat cushions and

upholstery fabric according to the records on file by BART [4]. The

test results for the other materials were not in BART files, however,

upper flammability limits were specified in the original specifications

and BART personnel stated that all of the materials used in BART vehicles

met or exceeded these limits. These limits are listed in table 3. All

of the specified test methods except for ASTM E-84 utilize a small and

localized ignition source.

3.1. Test Methods

3.1.1. ASTM D 1692

This test determines the rate of burning or extent of burning of

cellular plastics using a horizontal screen to support a 15 x 5 x 1.3 cm

(6 x 2 x .5 in) specimen. A propane bunsen burner with a flame spreader

attached is the ignition source. It is applied to one end of the specimen

for 60 seconds.

4
BART requires that materials tested by this test method "selfextinguish." This term, which was used prior to the 1973 revision but is no longer considered meaningful, was used to classify materials which

did not propagate a flame under these test conditions.

3.1.2.

ASTM D 635

This test is intended for the measurement of the rate of burning or extent of burning of self-supporting plastics. A 12.7 cm x 1.3 cm (5 x

.5 in) specimen in its end-use thickness is clamped with its long dimension in the horizontal direction. A bunsen burner flame, fueled with

"laboratory gas," is applied to the unclamped end of the specimen for 30

seconds. All materials tested by this method must "self-extinguish"

(that is, the specimen must not propagate a flame under these test

conditions) in order to meet BART acceptance criteria. However, as in

ASTM D 1692, this term is no longer considered meaningful. 3.1.3.

FS 5906/ CCC-T-191

This test method is intended to determine the horizontal burn rate

of various materials. Like the previous test methods, this one also

applies a bunsen burner flame to the lower surface of a 33.0 cm x 11.4

cm (13 x 4.5 in) specimen. Upholstery fabrics tested by this method

must not have a flame spread rate in excess of 12.2 cm/min.

3.1.4.

ASTM E-84

The purpose of this test is to determine the surface burning characteristics of various materials. A specimen 51 cm wide by 7.3 m long

(20 in x 25 ft) is mounted and supported on the ceiling of a long test

chamber. Two gas burners pointing up at one end of the chamber impinge

flame on the exposed surface of the specimen. The test evaluates a material's flame spread, fuel contribution, and smoke development.

BART's primary concern is with flame spread and, therefore, the acceptance criteria for flame spread is 75 on a scale where red oak is 100

and asbestos-cement board is 0.

3.2. Small Scale Flame Exposure Tests-Discussion

Small scale flame exposure tests are designed to measure a particular

physical characteristic of a material in a given environment. The degree

to which this evaluation is related to real world performance depends

on the scenario that was used to develop the test method and the degree

to which the test exposure simulates a real world fire situation. With

the exception of ASTM E-84, all of the test methods used to evaluate

component materials in the BART vehicle assume that the material will be

exposed to a small ignition source and that it will be the first item to

5
ignite. The ASTM E-84 test was designed to evaluate mainly wood-base

interior finish building materials under more severe fire conditions than

a small bunsen burner. This test was used to evaluate BART floor coverings. The carpeting, therefore, i9 tested under flame exposure conditions

that are significantly more severe than used on the other components.

There is a question as to whether the ASTM E-84 test is meaningful for

testing floor coverings such as carpeting [5].

4. FIRE PROTECTION SYSTEM

No active fire detection and suppression system exists on the BART

system. Fire suppression takes two forms. For interior car fires, one

fire extinguisher is located at each end of every car. In A-cars, one fire extinguisher is behind the attendant's seat, while the other is in

a compartment behind seat number 1 (figure 2). In the B-car, the fire

extinguishers are behind seats 1 and 36 (figure 2).

Fire suppression for under-car fires is accomplished by a series of

sprinkler heads located between tracks at grade level at all underground

stations. The line to the sprinklers is dry and must be activated from

the platform. The sprinklers are capped with plastic shields that are ejected at 15 psi water pressure. In addition, there are dry standpipes

at each station to facilitate fire fighting.

5. FIRE INCIDENTS ON BART [6]

From March 1975 until November 1976, there have been 27 fire or smoke incidents on subway cars of the BART system. All but three of

these incidents occurred below the car floor and did not penetrate into

the passenger compartment. The remaining three cases involved interior

car fires that produced only minor damage, primarily because the fires

were detected at an early stage of development and quickly extinguished.

Two involved smoldering or burning trash that was extinguished by BART

personnel. The third was an aborted arson attempt to ignite a seat

cushion with a pile of matches.

In addition to these incidents, there have been two serious fires

involving BART transit vehicles: one in November 1974 and the most

recent in November 1976. In the former incident (car 618) the fire

originated in the under-car areas and, before it could be contained,

penetrated into the passenger compartment. The cause of the fire was a locked brake.

The 1976 incident (car 120) originated in the passenger compartment

of the last car in a nine car train. The fire began in the center of

the car, at seat number 21, and caused varying degrees of damage throughout the car. The cause of the fire has been attributed to an "external

agent" [6].

6
6. FIRE SCENARIOS IN BART CARS

Based on BART's fire accident records and from a knowledge of fire

experience in other transit systems, one can develop a series of fire

scenarios that are applicable to BART. These scenarios are a description

of the system's response to a given thermal input. An analysis of the

probable sequence of events contained in the scenarios should point out

those areas that must be protected or altered in order to reduce the

risk to life safety.

6.1. Interior Ignitions

If we assume that we are dealing with a transit vehicle in mainline

service and which is fitted and furnished in the same manner as current

BART vehicles, there are two primary parameters that need to be defined

to permit a determination of the effect of an interior ignition fire:

1) a description of the ignition source (the rate of energy release

and the total amount released, and

2) the location of the ignition source.

In a rapid transit vehicle, except for electrical fires, there are three probable locations for an interior ignition source. They are:

1) on the floor - in the aisle

2) on the floor - beneath a seat

3) on a seat.

The ignition sequence assumes that the first item ignited will be

either the wall, ceiling, or seat cushions. In order for the ceiling to

be the first item ignited, the ignition source, located in the aisle,

would have to produce flame heights approximately equal to the floor to

ceiling distance of the car (2.06 m) . This would require an inordinately

large amount of fuel. It is, therefore, highly unlikely that this has a high probability of occurrence. No consideration will be given to this

specific scenario.

For the remaining two ignition locations, probable flame spread

patterns can be postulated. Consider the case of a floor ignition

source. If the ignition source is below the aisle seat, there are two

possible modes of flame spread. One is along the carpet and the other is

along the seat cushions. Flame spread initially along the carpet (of

the type in current use) is not probable based on carpet compartment

tests, full-scale tests in mass transit vehicles, and an actual fire

incident (car 120). This would be true even if the ignition source were

reasonably large (e.g., 0.5 - 1.0 kg of newsprint). Based on the specified flammability characteristics of the seat cushions (section 3),

ignition of the seat cushion is the most likely path for fire growth.

At this point, the fire would probably grow in intensity until the back

of the seat, the ceiling, and the wall liners were ignited. Without

actual testing, it is not possible to determine if adjacent seat assem- blies would ignite prior to the ignition of the wall and ceiling liners.

7
For floor ignition sources near the wall, primary fire growth would

still be due to the seat cushions. However, the wall liner would ignite

at a much earlier stage of fire development and contribute to the total

evolution of heat and smoke.

For fires originating on a seat, critical fire stages would be

reached sooner in comparison to floor fires. There would be nearly

simultaneous involvement of back and seat cushions. At a given stage of

fire growth, sufficient feedback energy would exist to permit the lateral

spread of the fire to an adjacent seat cushion in the same seat assembly.

From this point on, the growth and spread of the fire would resemble a floor ignition.

So far, we have postulated fire growth patterns assuming an ignition,

but have not considered the characteristics of the ignition source and

the minimum energy necessary to cause ignition. Probable ignition

sources range from smoldering cigarettes to flammable liquids. They

differ only in the rate of energy release and the total energy released.

The total energy in turn depends on the mass of combustible material in

the ignition source. Figure 4 shows the relationship of energy release

rate for various ignition sources to the total heat released for a given mass of material [7]. Based on previous experimental work [8,9], ignition

levels for various seating materials are indicated. These minimum values

were arrived at empirically in a series of experiments conducted on subway and bus seat assemblies currently in use. Strictly speaking, these

results pertain to the physical constraints present and the materials em- ployed at the time of these tests. Nevertheless, it can be inferred that

a significant improvement in ignition resistance can be realized by

changes in the materials used in constructing the seat assemblies.

6.2. Exterior Fires

Since a majority of the fire incidents occurring on the BART system

have originated below the floor, consideration must also be given to the

probable results of sub-floor ignitions. In addition, sub-floor fires are

the most difficult to handle because detection usually comes late in the

development of the fire. Sub-floor fires may be caused by a variety of

sub-system failures. The brake failure in car 618, described in section

5, is but one example of the consequences that may follow a mechanical

or electrical failure. One of the reasons this incident ended with no injuries to passengers and crew can be attributed to the above ground

location of the train at the time of the failure. Above ground failures

that stall a train do not represent the same degree of risk to passengers

that similar below ground failures do. For example, if this train had

been in the Trans-bay tube, passengers would have had a more difficult

time evacuating the train and fire fighting personnel would have also

encountered special difficulties in suppressing the fire. The greatest

hazard of such an incident would occur if the train were located between

stations. Simple scenarios can be described for sub-floor failures and

their consequences. The critical parameters that enter into the

description are:

8
1) the location of the train at the time of detection,

2) the condition of the train as a result of the failure (i.e.,

is the train moveable)

,

3) the intensity of the fire.

While the first two items determine the nature of the response that BART

must initiate, the third determines the effective time available for evac- uation and suppression. The fire penetration resistance of the floor

assembly becomes critical. If, at the time of detection, a sub-floor fire

has spread over all appreciable areas of the floor assembly, the floor

will fail sooner than if a fire is detected at a much earlier stage of

development

7 . SYSTEM IMPROVEMENTS

There are several areas that can be upgraded to reduce the level of

risk to life safety in the BART vehicles. While several different

improvements will be suggested, some may represent technological and

economic hardships that will effectively rule them out as viable. Since

it is virtually impossible to completely harden a system against the

occurrence and subsequent spread of a fire, two types of improvements

will be discussed; those that inhibit the growth of a fire (i.e., changes

in vehicle furnishings) and those that provide early detection of a fire.

7.1. Furnishing Improvements

Based on the scenarios postulated in section 6.1, initial fire

growth from an interior fire source can be inhibited by improving the

fire resistance of the seat assemblies. As currently designed, the seat

cushions represent the largest contribution to the hazard level of the

vehicle. There are several options available for upgrading the seat

cushions. If we set aside, for the moment, the added problem of vandalism, the replacement of the nylon fabric in the upholstery design with a more fire resistant material would go a long way towards lowering the

hazard from small incidental fires (i.e., a trash bag). An example of

such a replacement is the use of a complete vinyl covering over the

urethane cushions. If, however, one is concerned with vandalism, which

may be the case in any subway system, or is concerned with larger ignition sources (i.e., newspaper), serious consideration must be given to

replacing the existing cushions. It has been found that a fire-retarded

neoprene cushion upholstered with a vinyl fabric is quite resistant to

fire growth from larger ignition sources [9]. As a seat assembly, it

has the added advantage of retaining fire retardant properties when the cover fabric is penetrated.

9
7.1.1.

Wall and Ceiling Liners

The wall and ceiling liners present the most difficult problems in

terms of improving their fire characteristics without sacrificing other

material properties. Since the expense of replacing the installed

liners is prohibitive, one must seek acceptable alternatives. The use

of a special surface coating for the wall covering, such as an intumescent paint, may be a quite acceptable form of fire protection. However,

any proposed product must first be tested before specific recommendations

can be made. This testing should include an examination of properties

other than fire, e.g., permanency. In addition, careful thought should

be given to its maintenance and how its wear life affects the flammability

characteristics

.

7.1.2.

Carpeting

Based on past experience and accident data, it appears that commercial floor coverings do not greatly affect the growth of a fire in a compartment, except during flashover conditions.

7.2.

Floor Assembly

Not only does the floor assembly support passengers in a car, but

it also acts as a barrier between passengers and any hostile environment

that may develop beneath the car. The actual fire penetration resistance

of the BART floor assembly described in section 2.2 is not known, but a ply-metal floor assembly (plywood-aluminum sandwich) has been estimated

to have a 10-minute endurance under a given fire load [9]. It can be

anticipated that the BART car floor assembly (aluminum-polyurethane

sandwich) would have an appreciably shorter endurance time under the same fire load conditions. However, a retrofit at this time does not

seem possible nor do any practical means appear to exist to harden the

floor assembly against sub-floor fires. It may be possible to partially

protect the floor assembly by shielding critical floor areas. However,

the nature of the shielding material cannot really be described without

an analysis of sub-floor fires.

7.3.

Fire Detection

Because of the problems encountered in dealing with the wall and

ceiling liners, serious consideration was given to the installation of

fire detectors. With the upgrading of the seat cushions, fire detectors

should provide the means necessary to detect a fire in its early stages

of development and permit BART personnel to initiate appropriate fire

suppression procedures. Two problems, however, are encountered in the use of fire detectors:

1) what type to use,

2) where to install them.

10
The type of detector to be installed is dictated by the environment

in which it will be used and its tolerance for false alarms. The location of the detectors in the vehicle also poses some problems. An

investigation of flow patterns in a vehicle that is in use must be made

in order to properly determine correct placement of the detectors. In

addition, care must be exercised to insure that communication lines

between detectors, train operators and central control are compatible

with existing or new hardware. This is beyond the scope of this study,

but such an investigation must be performed to insure effective utilization of the detectors.

8 . RECOMMENDATIONS

Based upon a review of the design and materials used in the BART

subway cars, and analysis of potential fire situations, it is recommended

that

:

1. BART upgrade the flame resistance of the seat assemblies, e.g.

,

by introducing all vinyl upholstery. In order to further increase evacuation time, serious consideration should be given to

incorporating neoprene cushions with the vinyl upholstery.

2. BART investigate the technological and economic feasibilities

of using an intumescent coating on the wall and ceiling liner.

3. BART develop a means for hardening the floor assembly against

sub-car fire penetration at least in those areas most vulnerable

to fire exposure.

4. BART, after additional study of detector types and locations,

install a fire detection system to indicate the presence of a fire on board a train.

5. BART, in the interim, provide walk-through inspection after

passing the terminal stations and/or prior to entering storage

facilities

.

9 . REFERENCES

[1] BART Operations and Maintenance Manual, Car Body and Interior

Components Manual, Vol. 12 (December 1974).

[2] BART Operations and Maintenance Manual, Transit Vehicle Manual,

Vol. 1 (March 1972).

[3] BART Operations, Rules and Procedures Manual.

[4] BART Train Safety File (Flammable Materials).

11
[5] Cellular Plastics Products - Disclosure of Combustion Characteristics

and Certification, 40 FR 30842, Federal Trade Commission.

[6] Personal Communications - BART Personnel

[7] Personal Communications - Philip Oglesby, Nat. Bur. Standards.

[8] Braun, E. , Report of Fire Test on an AM General Metro Bus, Nat. Bur.

Standards (U.S.), NBSIR 75-718 (June 1975).

[9] Braun, E., A Fire Hazard Evaluation of the Interior of WMATA Metrorail Cars, Nat. Bur. Standards (U.S.), NBSIR 75-971 (December 1975).

12
Table 1. List of Fire Tests for Synthetic

Components Used in BART [4]*

Application Material Specified Test

Side Wall and Ceiling

Liner

Glass Fiber

Reinforced Plastic ASTM D635-63

Floor Sound Barrier

and Insulation

Baryfol 10M ASTM E84-61

Windscreen Panel Micarta (TM) Laminated

Melamine

ASTM D635-63

Seat Cushions Molded Polyurethane ASTM D1692-59T

Seat Arm Rest Supports Vinyl ASTM D635-63

Seat Trim Acrylic /Polyvinyl

Chloride

ASTM D635-63

Side Wall and Door

Insulation

Polyurethane ASTM D1692-68

Seat Upholstery Nylon /Vinyl FS 5906-53 of Fed

Spec CCC-T-191

Carpet Wool ASTM E84-61

Carpet Pad Latex Foam ASTM E84-68

*More specific information on physical characteristics of these materials

was not available.

13
Table 2. Test Results of Seat Cushions and Upholstery

Fabric Tests Conducted by BART [4]

Material Test Method Burn Length

(cm)

Burn Rate

(cm/min)

Polyurethane

Foam

ASTM D-1692 11.2 3.23

Upholstery

Fabric - Warp

- Fill

MVSS 302**

24.1*

22.9*

2.64

3.45

*

1 out of 4 burned

**Similar to Method

this length, the

5906 of Federal

others self-extinguished

Specification CCC-T-191

Table 3. Acceptance Criteria for Test Methods

Used in Qualifying BART Materials

Test Method Acceptance Criteria

ASTM D-1692 Self-extinguishing*

ASTM D-635 Self-extinguishing*

FS 5906 Max 12.2 cm/min - flame spread

rate

ASTM E-84 Max 75 flame spread index

* Since the 1973 ASTM revisions, this term is no longer used for any fire

tests

.

14
S.OOOR £ DOOR

COUPLER

A - CAR

B - CAR

Figure 1. Exterior views of A-car and B-car configurations

15
16

Figure

2.

Seat

placements

in

A-car

and

B-car

configurations
r)

17

Figure

3.

Seat

assembly

-

cushions

and

frame
-VINYL/NEOPRENE

(8)

63

UO

OS to

bU SB G3*S>ZZ ac
^

ot^bu

u ^ oo axes

oo

I

I

I

I

I

</»

i

i

i

I

l

i

6

3

CM 5C

3E

C3

I —

N>

uLbJ oo

^ oo

«V

*

<?

o* a

oo

C9

<n _cSi

GO

GO

(Q

(SllVMl 3SV333U A3U3N3 JO 31V0

18

Figure

4.

Comparison

of

ignition

source

characteristics

and

minimum

ignition

energies

for

various

seat

assemblies
NBS-1 14A.IRE V. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 78-1421

4. TITLE AND SUBTITLE

Fire Hazard Evaluation of BART Vehicles

2. Gov’t Accession

No.

3. Recipient’s Accession No.

5. Publication Date March 1978

6. Performing Organization Code

7. AUTHOR(S)

Emil Braun

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

I®. Project/Task/Work Unit No. 4927375

11. Contract/Grant No. DOT-AT-70007

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Urban Mass Transportation Administration

Department of Transportation

Washington, D.C.

13. Type of Report & Period Covered

Final Report

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less (actual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.)

A fire hazard evaluation of the subway cars used on the San Francisco

Bay Area Rapid Transit District was performed. After analyzing the cars*

interior and exterior design, five recommendations were made that, if

implemented, would improve passenger safety by decreasing the probability

of developing a hazardous fire situation. Among these recommendations were the upgrading of current upholstered urethane seat assemblies and

the need for the development of a fire detection system appropriate for

rapid rail transit vehicles. Those system improvements would not only

provide passengers a safer traveling environment but would also provide

a modest level of protection for the heavy investment in rail vehicles.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only die first letter of the first key word unless a proper name; separated by semicolons)

BART; fire accidents; fire hazards; fire safety; fire scenarios; mass transportation

material fire performance; rail vehicles; subway car design; UMTA.

18. AVAILABILITY Unlimited

|

1 For Official Distribution. Do Not Release to NTIS

|

1 Order From Sup. of Doc., U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. Cl

I 1 Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151

19. SECURITY CLASS

(THIS REPORT)

UNCL ASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF PAGES

22. Price

U9COMM.DC 29042-P74
'

.

)