NBSIR 73-412

The Incidence of Hazardous Material

Accidents During Transportation and

Storage

W. A. Steele

D. Bowser

R. E. Chapman

Technical Analysis Division

National Bureau of Standards

Washington, D. C. 20234

November 1973

Final Report

Prepared for Center for Building Technology

National Bureau of Standards

Washington, D. C. 20234

NBSIR 73-412

THE INCIDENCE OF HAZARDOUS MATERIAL

ACCIDENTS DURING TRANSPORTATION AND

STORAGE

W. A. Steele D. Bowser

R. E. Chapman

Technical Analysis Division

National Bureau of Standards

Washington, D. C. 20234

November 1973

Final Report

Prepared for Center for Building Technology

National Bureau of Standards

Washington, D. C. 20234

U. S. DEPARTMENT OF COMMERCE, Frederick B. Dent. Secretary

NATIONAL BUREAU OF STANDARDS, Richard W. Roberts. Director

CONTENTS

1. INTRODUCTION 1

2. SCOPE OF PROJECT 3

3. PIPELINE TRANSPORTATION OF HAZARDOUS MATERIALS 10

4. WATER TRANSPORTATION OF HAZARDOUS MATERIALS 13

5. MOTOR VEHICLE TRANSPORTATION OF HAZARDOUS

MATERIALS 25

6. RAILROAD TRANSPORTATION OF HAZARDOUS MATERIALS 29

7. STORAGE OF HAZARDOUS MATERIALS 32

8. SUMI4ARY 34

9. LIST OF REFERENCES 36
I-
1. INTRODUCTION

There has been growing international concern that

buildings, particularly multistory residential buildings, may

be subjected to loading conditions not normally considered in

design — abnormal loadings. The concern was initiated in

1968 with the much-publicized collapse of the Ronan Point

apartments in London. In this 22-story building of precast

concrete panel construction, collapse was triggered by an

accidental explosion of gas (an abnormal loading) that leaked

from the 18th floor. As a result of the explosion, one corner

of the building collapsed.

In November 1971, the Department of Housing and Urban

Development requested the National Bureau of Standards to

make a study of all aspects of abnormal loading and the problem

of progressive collapse. A discussion of several sources of

abnormal loading is reported elsewhere [l]."*" Several of these

types of loading are considered to have a frequency of occurrence large enough to warrant particular attention.

This report is one of a series describing background

research concerning the incidence of abnormal loading; in this

case accidents resulting from the transport and storage of

of hazardous materials, including qualitative judgments

regarding prespective risks. The effect oh building of the

^Figures in brackets designate literature references listed

at the end of the report.

1
abnormal loading discussed herein, as well as others reported

in the series, will be contained in a future report on abnormal loading and building safety.

2
2. SCOPE OF PROJECT

Although there have been few cases of collapse of

buildings due to accidents with hazardous materials, there

is a basis for increasing concern since: (a) multistory

construction using new technology has grown over the past

decade, meaning more buildings may be susceptible to collapses

each year; (b) the quantities of hazardous material (particularly petroleum products and other chemicals) being produced

and transported have grown to keep pace with the expanding

U.S. economy; and (c) many types of chemicals now being transported are of a more volatile nature and their behavior is

often not well understood.

One would like to examine these three trends to determine the magnitude of each in creating potential progressive

collapse related explosions. Unfortunately, it has not been

possible to develop analytical predictions of these occurrences,

largely due to the scarcity of data and the diversity of

collection procedures.

This report outlines the major trends in hazardous material transport and storage. Where possible, bounds are placed

on the probabilities of accidents involving these materials.

The report is organized in terms of methods of hazardous

material transportation and storage. These methods-Pipeline,

Water, Motor Vehicle, and Railroad Transportation Systems -

are addressed in the next four sections, respectively, with

Storage Systems discussed in a fifth. The length of each

3
section is based on the amount of available data and not

necessarily on the risk involved in an accident. Section 8.

contains a summary of the results from these five sections.

A list of references compiled during the study is provided in

Section 9. •

Before describing the effects of changes in the operations

of each mode, consider the changes in the magnitude of the

problem at hand. Table 1 shows the increase since 1938 in

transportation of crude petroleum and its products [2] . The

table shows that the total goods transported has grown at an

annual rate of 5 percent since 1938. Of the 1970 total of

1.69 billion tons per annum, about 47 percent is carried

through pipelines, 24 percent by water carriers, 2 8 percent

by motor carriers, and 1 percent by railroads.

These products-crude oil, gasoline, liquid petroleum

gas (LPG) , kerosene, jet fuel, etc. - are volatile liquids

which have been transported on a mass scale for many years,

but they are not the only ones of interest. Hydrogen, liquid

natural gas (LNG) , ammonia, vinyl chloride, and cyclohexane

are a few others which are now being used on significantly

larger scales than ever before. Furthermore, according to

Strehlow [3] , much less is known of the properties of these

substances when released into ^the atmosphere.

4
TABLE 1

Total Crude Petroleum and Products in Domestic Transportation

in 10^ tons of 2,000 pounds per ton

Water Motor

Total Pipeline Carriers Vehicles Railroads

1938 360 140 140 20 60

1943 480 200 120 80 80

1948 690 260 240 120 70

1953 860 360 270 180 50

1958 1010 430 300 250 30

1963 1200 520 340 310 30

1968 1570 730 360 450 30

1970 1690 790 400 470 30

Source: [2]

5
The number of explosions caused by ignition of unconfined

vapor clouds (the admixture with air of volatile solvents and

combustible gases in the open air) over the last forty years

is shown in table 2. These figures are approximate because

reporting procedures were not well defined in earlier years

and some sample data seemed to include only the most spectacular explosions. However, several trends do appear to exist.

Unconfined vapor cloud explosions (which are only one component of all accidents) have dramatically increased from 0.4

accidents per year to a current rate of about 7.5 accidents

per year. At the same time, the average damage per accident

has also increased by an order of magnitude. Extrapolating

these trends would imply more accidents in the future ^ due to

unconfined vapor clouds, each of a more costly nature.

Although the two tables do not present a conclusive

picture that total hazardous material transportation presents

a serious risk to residential multistory dwellings, they do

show that: (a) more material is being moved and (b) that

accidents which occur today seem to be much more serious

than those of a few decades ago.

Ideally, one would like to know (at the very least) , the

total amounts of each dangerous material transported in the

vicinity of "damageable" buildings. Unfortunately, there is

a severe paucity of data and deficiencies in the nature in

which they are collected. The general difficulty of collecting relevant information, experienced by other researchers in

6
Table 2: Unconfined Vapor Clouds (U. S, and Europe)*

Average Loss/ Average Loss/

Explosions/ % involving Reported Expl. Year

Year LP or Butane ($ x 10^) ($ x 10^)

1930-39 0.4 100 0.25 .03

1940-49 1.2 50 1.50(0.9)** .7 (.4)**

1950-54 3.4 71 0.19 .4

1955-59 3.4 88 0.50 .9

1960-64 3.6 33 0.33 .8

1965-69 5.0 28 6.84(2.74)** 26 (10)**

1970-71 7.5 27 2.27 12.5

Figures were derived from Table 1 of [3]

**Average when single catastropic explosion of period is renoved.

7
the field, has (in fact) led the Office of the Secretary of

Transportation, DOT, to initiate research by the Technical

Analysis Dividion (TAD) of the National Bureau of Standards

in an effort to improve the situation.

As an example of the difficulties present in learning

about goods being transported, an excerpt from Motor Vehicle

Standards for Hazardous Material Transportation [16] is

quoted below.

Other [than DOT] sources of accident data were

trucking and safety associations, state agencies and

private companies. Different types of organizations

collect accident data for different reasons. The

result of this, of course, is that they universally

collect few facts of any value to the investigation

while the bulk of their information is aimed at

specialized needs. Some associations use selected

segments of Department of Transportation data either

as is or in a new format to express information

germane to their particular association.

A basic limitation of the available incident/

accident data is that the groups (federal, state,

insurance companies, truck owners) requiring the

information, have different reasons for collecting

the data. As a result, and because of associated

costs of collecting and storing data, most of the

data is sketchy and lacks uniformity. Although

insurance companies and fleet owners collect large

quantities of accident data that could be useful,

they are not made available because of litigation

problems or unwillingness to divulge private

company records.

The National Transportation Safety Board, which is in

charge of investigating "serious" accidents and making

recommendations for new Federal Standards, summed up its

own frustration in the 1971 Annual Report to Congress [5]

.

8
At this time, neither the modal administrations

nor the National Transportation Safety Board is

investigating properly an adequate number of surface

transportation accidents for the purpose of preventing

their recurrence. The problem, for the most part,

rests with insufficient resources. As a result,

adequate accident data are not available. Without

such data, the effectiveness of the Safety Board's

recommendations cannot be assured and agencies

responsible for transportation safety do not have

access to information needed to make safety program

decisions.

"Modal administrations" are DOT units involved in establish

ing and enforcing rules and regulations regarding the trans

portation of commodities. These units are the USCG, the

FAA, the FRA and the FHA.

9
3. PIPELINE TRANSPORTATION OF HAZARDOUS MATERIALS

The setting of Federal pipeline standards and investigations of "major" system failures has been the responsibility

of the Office of Pipeline Safety (OPS) of the Department of

Transportation since late 1968. These investigative and

regulatory responsibilities have been separated on the basis

of lading, with natural gas pipelines and liquid pipelines

being the two categories.

The hazard associated with natural gas pipelines has

been analyzed by Burnett, Somes, and Leyendecker [6] . Therefore, the danger posed by natural gas pipelines is excluded

here.

The incidence of liquid pipeline accidents is probably

somewhat easier to measure. The nature of recorded liquid

pipeline incidents is such that accident records, and not

the hazard, appear to be the best component for analysis.

Table 3 shows accident data collected by the Office of Pipeline Safety and (before OPS ' s creation) by the Office of

Hazardous Materials of the Federal Railroad Administration

[7] . As can be seen, the overall trend in accident rates

is downward ; decreasing by almost 40 percent between 1968 and

1971.

Combined with this marked increase in safety is the

nature of these liquid pipelines: for the most part they

serve to transport crude materials between natural sources

and processing plants. By nature this leads them mainly

10
TABLE 3

Liquid Pipeline Accidents During Operations

by Commodity Involved

1968 1969 1970 1971

Crude Oil 332 246 216 172

Gasoline 79 62 63 51

LPG 43 48 24 39

Fuel Oil 29 23 15 21

Jet Fuel 9 6 9 4

Condensate 7 2 • - 5

Diesel Fuel 6 8 10 5

Kerosene 3 1 2 2

Lube Oil 1

Others 7 8 9

Total 499 403 347 308

11
through low density rural areas, particularly in the south

central states such as Texas, Oklahoma, Kansas, Louisiana

and Missouri. In fact, these five states (10 percent of the

union comprising 12 percent of the National Population in

1970) accounted for 56 percent of the liquid pipeline accidents

between 1968 and 1971.

The reported liquid pipeline accidents for 1971 [7]

,

included only 8 injuries and one death out of 308 accidents

from 19 different causes. It appears, therefore, that

although serious accidents caused by liquid pipeline explosions

have occurred, they are not likely to become a significant

hazard assuming current trends of a decreasing number of

accidents continue.

3 0

12
4. WATER TRANSPORTATION OF HAZARDOUS MATERIALS

According to statistics published by the American

Waterways Operators, Inc., [8], inland freight traffic for

all modes of transportation in the United States in 1970

totaled 3.5 billion tons. The Army Corps of Engineers

reports a total of 1.56 billion tons of waterborne commerce

for the U.S. in 1970. Of this amount, 710 million tons

were transported over inland waterways and the Great Lakes.

An additional 238 million tons of cargo were transported by

water in coastal and coast-wide traffic. Thus water commerce

represents a sizable fraction of the total of U.S. commercial

transportation.

In 1967, an estimated 414 million tons of hazardous

materials were shipped via water carriers. This constituted

approximately 2 3 percent of the total quantity of hazardous

materials shipped in the United States. By 198 0, this figure

is expected to be approximately 470 million tons, a 13.5

percent increase. Approximately 17 percent of all crude

petroleum products is shipped via water carriers. Petroleum

and petroleum products constitute approximately 84 percent

of all hazardous materials shipped via water carriers. [8]

Also see table 4

.

A breakdov/n of the major petroleum products shipped by

V7ater is shown in table 5. Although other waterborne cargoes

may present an explosive hazard to buildings, petroleum far

outstrips the others as the source of possible damage. The
potential for a major fire exists whenever combustible liquids

or gases (such as petroleum and LNG) are discharged overboard. In addition, marine casualties have occurred where the

petroleum cargo contributed to explosions. One example is the

collision involving the cargo vessel SS African Star and the

M/V (motor vesses) Midwest Cities and Tow barge in Mississippi

on March 16, 1969 [9]. Seventeen people were killed, four

missing and presumed dead and forty injured. Another example

is the Meljoy Transport Company tank barge MOS 106 that caught

fire and exploded at the Triangle Oil Refining Company

loading facility on the upper Mississippi River at La Grange,

Missouri, on Nov. 12, 1969 [10]. Tank barge MOS 104 and towboat M/V Martin were also moored at that facility and were

involved in the subsequent fire. Six persons were killed and

one was injured seriously.

The potential for a major incident arises from the

growing level of traffic and volume of commerce on the waterways of the U.S., including greater tonnages of petroleum.

Figure 2 shows the growing level of waterborne commerce over

the last 2 3 years.. The upward trend is expected to continue.

Two other factors may affect the involvement of hazardous

materials in castastropic incidents. The National

Transportation Safety Board projects that, by 198 0, supertankers and LNG tank vessels will transport 50 percent of the

oil and natural gas needed in the United States. The largest

tanker now in use in the United States has a cargo capacity

14
Figure 1 : Principal Commodities Carried by Water

Calendar Year 1970, Total Commerce

in the United States

FOREIGN COMMERCE DOMESTIC COM^/ERCE

* Taken from [11]

.

1 "C

TABLE 4

Hazardous Materials Production

Produced & Handled* ' % Increase % Increase

Classification 1968-69 1979-80 1968-69 1979-80 Per Year

Flammable

materials 1 ,620.0 2,420.0 50 3.8

Compressed gases 508.0 1,067.0 110 7.0

Explosives 20.0 40.0 100 6.5

Corrosive

materials 45.1 95.9 112 7.1

OxidizincT aaents 7.8 19.4 149 8.6

Poisons 1.2 2.6 117 7.3

Etiologic materials 7.8

Cryogenic materials 36.0 92.0 156 8.9

Radioactive

materials 17.00 ** 163.0** 860 22.8

Molten materials 13.0 41.0 215 15.0

Total 2 ,258.9***3,778.1*** 67***

Millions of tons

Thousands of tons

*Computational errors in the original table have been corrected.

17
of 350,000 tons, and the largest tanker under construction

(to be completed in the summer of 1973) will have a capacity

of 460,000 tons. The technology now exists to construct a tanker

with the capacity to carry 1,000,000 tons [12] and such a

tanker may be a reality in the future. Should such a vessel

be involved in a casualty, its increased volume of cargo

could magnify any resulting damage. At the same time its

size could prevent it from navigating within a dangerous

distance of damageable buildings.

Casualty files for marine accidents are maintained by

the Office of Information and Analysis of the U.S. Coast

Guard. Casualties involving commercial vessels are

required to be reported to the Coast Guard whenever the

casualty results in the following:

(a) Actual physical damage to property in excess of

$1,500.

(b) Material damage affecting the seaworthiness of

efficiency of a vessel.

(c) Stranding or grounding.

(d) Loss of life.

(e) Injury causing any persons to remain incapacitated

for a period in excess of 72 hours; except injury

to harbor workers not resulting in death and not

resulting from vessel casualty or vessel

equipment casualty.

The form used by the Coast Guard for coding reports is shown

in Figure 3. Separate categories are co'ded for damage to the

18
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19
vessel, to the cargo, and to property. A computer listing

for the coded accident reports has been searched, and all

accidents occurring in 197 0 with property damage greater

than or equal to $1,000 were noted, A total of 207 were

found. It was thought that those casualties with property

damage greater than or equal to $100,000 (13 incidents) would

be the most likely to have involved buildings and hence

warranted further investigation. The uncoded reports were

obtained and examined, but none of them made mention of

damage to buildings. Lt. Commander Lauridsen, Head of

the Information and Analysis Office, does not recall any

incidents in past years where extensive damage to a building

has occurred. Although building damage may have occurred

in some of the 194 unexamined cases, it seems reasonable

to assume that any such damage was minor. Despite the probabl

minor damage, there are reported incidents which could have

caused building damage under slightly varied conditions.

In addition to the files just mentioned, the Office of

Information and Analysis compiles a statistical summary of

casualties [13]. For the fiscal year 1971, a total of 2,577

reported casualties involved 4,152 vessels. Of these

casualties, 176 (6.83 percent) were due to fire and/or explosion (and many of these could have involved hazardous material

Another 175 casualties (6.80 percent) were due to collisions

while anchored, docking, or undocking. This latter category

includes instances where buildings are most likely to be in

20
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21
the near vicinity. Should vessels involved in casualties in

either of these two categories be carrying hazardous material,

extensive building damage might ensue. Unfortunately, the

summary does not categorize accidents by type of cargo,

although some indication of cargo content may at times be

inferred from the category of vessel type. The following

is a partial summary of the listing of the types of vessels

involved. -

Total No. of Number of vessels involving Explosion

Type of vessels Collisions while anchored, and/or

Vessel (see [14 ] ) docking or undocking fire

Freight Not Known 59 27

Cargo

barge 1,8 90 66 4

Tankship Not Known 17 3

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To ferret out the uncoded reports for these incidents

for the purpose of discovering if hazardous materials were

partially or wholly the cargo and if building damage occurred

and was significant would be impractical from the standpoint

of time and expense.

The number of accidents in 1968 had increased 10.9 percent (annual growth rate of 2.7 percent) from 1964, while in

the same period (see table 6) accidents in which hazardous

materials were the cargo increased 117 percent (annual growth

rate of 21.5 percent). It is expected that , by 1980, marine
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casualties will have increased 57 percent (at an annual growth

rate of 4 percent) ; casualties involving hazardous materials

are projected to increase 330 percent (an an annual growth

rate of 14 percent [8]) . It may well be assumed that the

potential for building damage as a result of such an incident

rate is also increasing, although not at the same rate.

The Texas City disaster of April 14, 1947 is the only

documented instance of structural damage to buildings. However, no recent (within the last 25 years) instances of

structural building damage were discovered in the course of

this investigation, although the potential for such damage

exists in a small number of cases. The increasing amount of

water transportation of hazardous materials, particularly

petroleum, and the increasing rate of casualties in which

such materials are the cargo, will present a growing hazard

in the future. Factors contributing to this risk include

the location of fuel transfer terminals in densely populated

areas, and the use of super-tankers with increased cargo

capacities. With sufficient exposure, circumstances could

arise such that a major catastrophe would result.

24
5. MOTOR VEHICLE TRANSPORTATION OF HAZARDOUS MATERIALS

In 1969, the Factory Mutual Research Corporation performed

an analysis of all freely available accident statistics

concerning motor vehicles transporting hazardous materials

[4] . Although some accident information was not available

because it was not collected or not released, 3,887 accidents

were adequately documented. The report indicates that these

were probably representative of the total of 14,400 national

hazardous material accidents which are believed to have

occurred during the 30 month period between July 1966 and

December 1968.

The report [4] concluded that 6 9 percent of hazardous

material accidents involved vehicles transporting petroleum

products or other combustible or flammable liquids; 12 percent

involved corrosive liquids; 10 percent involved explosives;

and the remaining 9 percent involved miscellaneous poisons and

radioactive materials. Of the petroleum product accidents (i.e.,

most of the 69 percent), 0.8 percent were believed to have

led to explosions. No estimate was made of the explosions

resulting from accidents involving the other commodities.

Using these tank truck figures, one can calculate the

expected number of tank, truck explosions per annum to be

32, that is 0.8 percent of 69 percent of 12/30ths of 14,400.

A figure of 32 explosions is certainly not alarming when considering the portion of these accidents which are likely to

be significant and which also take place in the built up areas.

25
However, one must question both the applicability of a 1966-

1968 average figure in the mid-1970 's and also the possible

number of explosions resulting from non-tank truck explosions

To estimate the change in tank truck accidents with

time, the American Petroleum Institute figures on motor

vehicle accidents in their indistry were consulted. Table 7

shows the change in accidents and accident rates over the

ten year period 1961-1970. Although accident rates per mile

driven have decreased significantly, the increase in total

mileage has cancelled out the safety gain.

Tank truck accidents have increased at an annual rate of

about 2.4 percent. Assuming that all of the additional accidents involved loaded trucks (which is very unlikely) , then in

the last four years there would be an increase from 32 (based

on the 1966-1968 average) to about 37 explosions per year,

still not a large number.

The explosions resulting from hazardous materials other

than flammable liquids could not be easily analyzed. These

commodities are flammable solids, explosives, oxidizing

agents, acid anhydride, combustible compressed gasses,

corrosive liquids, poison gas and radioactive materials.

Since statistics are much less documented on these accidents,

it was assumed that the probability of their unpublicized

occurrence was negligible compared with tank truck accidents

reported. Although the assumption is far from satisfactory,

the paucity of data necessitates it.
TABLE 7

ten Years Comparison of Petroleum Industry

Tank Truck Accidents*

No. of

No. of Vehicle Miles Accidents/

Companies No. of Traveled No. Million

Year Reporting Trucks (Millions) Accidents** Miles

1961 26,264 485 4,738 9.87

1962 75 26,877 387 4,056 10.49

1963 51 19,803 379 3,736 9.85

1964 104 23,513 459 3,458 9.50

1965 152 27,390 546 4,588 8.41

1966 124 24,695 537 ' 4,452 8.30

1967 104 24,108 522 4.314 8.27

1968 93 22,697 530 4,421 8.35

1969 80 29,821 754 5,330 7.06

1970 76 29,442 757 5,567 7.35

Figures taken from [15].

**The total accident figures in 66-68 disagree with the average

figure of [ 5 ] because of alternative definitions of accident.

27
The National Transportation Safety Board (NTSB) , has

shown considerable concern over the fact that construction

above and below expressways has shown a marked increase in

recent years. In the report, A Study of Safety Considerations

in the Utilization of Airspace Over and Under Federally Aided

Highways [16] , the NTSB has described a number of alarming

examples where the airspace above expressways is used for the

construction of large multi-story buildings. The increased

danger in locating structures above, rather than alongside,

roadways is difficult to assess whithout examining the dynamics

of hypothetical explosions. However, the obvious increase in

fire hazard should be kept in mind. The Board is awaiting

actions from the Department of Transportation on recommendations

made in the above-named report [16]

28
6. RAILROAD TRANSPORTATION OF HAZARDOUS MATERIALS

Over the six-year period, 1965-1970, 3,858 railroad

tank cars were involved in 2,321 accidents in the United

States and Canada (see reference [17]). Of thesQ 625 cars,

lost lading due to mechanical damage. This represents

approximately 3.9 mechanically damaged tank cars per thousand

tank cars per year. (Average number of cars in service 1965-

1970 was 164,730.) A large proportion of these were limited

to minor leaks with partial lading loss as the only consequence.

Only 3 accidents involved explosions which caused

structural damage to neighboring properties. These three

(Dunreith, Indiana, January 1, 1968; Laurel, Mississippi,

January 25, 1969; Crescent City, Illinois, June 21, 1970)

contributed $10.6 million damage, of which approximately $3.2

million was due to the explosions, with the remainder attributed

to fire damage before and after the explosions. This represents a tremendous part of the total estimated damage over the

six years, which was $23.3 million.

The presence of a study on railroad tank car safety

(i.e., [18]), combined with others, demonstrates the Federal

Railroad Administration's (FRA) determination to limit these

incidents and their catastrophic damage. The effects of FRA

pressure, however, will be difficult to assess if traffic

levels of dangerous materials continue to increase. (In this

regard, the Office of Hazardous Materials of the Department

of Transportation is currently strengthening its effort

29
to acquire more meaningful data on this general subject)

.

Assuming that the two phenomena have opposite and

somewhat equal effects, damage can be expected to remain

on the order of that of 1965-70. It has been suggested in

a report by the Association of American Railroads [18] that

this period is, in fact, not at all representative, with 1969

alone contributing over 5 time s the average annual number of

major ruptures. The six years of data imply:

1. An explosion of a ruptured tank car causes

structural damage on an average of once every

two years; and

2. An average damage of $3.5 million from each of

these explosions, where $1.05 million is due to

the explosion itself.

The accident statistics of 1971-72 confirm the first

result, with exactly one explosion damaging residences in

East St. Louis, Illinois. The extent of damage, however, was

somewhat larger than the average figure of $3.5 million.

An analysis has been made of costs and benefits derived

from adding safety devices to existing tank cars in [17]

.

Design improvements considered were head shields, shell shield

bottom fitting shields, top fitting shields, coupler shields,

and rocketing shields (rocketing is defined as the propulsion

of large segments of tank cars caused by explosions) . It is

estimated that had rocketing shields been applied to all the

cars of the types involved in previous explosions, a savings

30
of over $4 00 per car in rocketing costs alone would have been

realized over the 30 year lifetime of the car. This is not

necessarily the only alternative, for applying thermal shields

to the same cars would eliminate rocketing caused by fire

damage and additional non-rocketing damage caused by fire.

It is estimated that a rocketing shield and a thermal

sheel shield would yield a total savings of over $1,200 per

car. The best combination can not be determined, however,

until ^he engineering costs of installing the shields is

estimated.

Tank car safety devices are only one aspect currently

under investigation by the FRA. Additional studies have

considered the advantages of limiting tank size and relocating

tank cars in train make ups to name a few. One would hope

that the Federal Railroad Safety Act of 1970 has had an effect

on accident rates which has not yet been reflected in the data

of [17].

J1I 'c

31
nesd ©VBff £7. STORAGE OF HAZARDOUS MATERIALS

Hazardous material storage facilities provide a somewhat

different risk to their environment, since their location is

fixed and generally well known. Railroad or motor transportation of hazardous materials is not as often considered a

problem when selecting a location for construction. This

might be the reason that fewer cases of destruction of

buildings by explosions at storage facilities are recorded.

Storage facilities are known to exist at every petroleum

refining plant, at distributing facilites where water carriers

supply railroads or railroad carriers supply motor vehicle

carriers, and where large-scale users deem it more economical.

Storage tanks are now located in many densely populated areas

including Providence, Boston, Philadelphia, and Staten Island

[19] . The latter city was involved in an explosion in early

1972 killing several workmen who were cleaning the tank from

inside

Although little research has been uncovered on the likelihood of storage facility explosions, a novel approach to

evaluating the risk of storing various quantities of material

at various distances from residential areas has been made in

reference [20] , where Siccama has analyzed the hazard posed by

the release of toxic gases into the storage facility's

environment. Based on the probability of such an event (which

can be reasonable estimated from past experience) , the dispersion rate of the gases (which can be calculated as a function

32
of weather conditions and other factors such as terrain contour, building configuration, etc.), the toxic effect of the

gases, and the distance between the storage facility and the

residential area, one can determine the maximum allowable

storage quantity which will maintain a desired level of safety.

The analysis should be directly applicable to problems

of explosions. One must, however, be able to calculate the

analogous infonnation required as input. The information

relating distance to expected forces is not well known for

most chemical explosions (as indicated in reference [3]), and

the force required to do significant structural damage also

needs to be estimated more accurately.

Siccama feels that this information can be obtained

through close international cooperation. He also suggests

that the technique could also be used for transportation

analyses as well as for storage facilities.

33
8 . SUMMARY

The five preceding sections have examined five different

handling procedures for hazardous materials. It has been

emphasized throughout this report that the scarcity of data

makes meaningful quantitative conclusions difficult. The

following conclusions are considered to be justified by data,

but not completely substantiated. They are presented for

discussion purposes and consideration rather than firm

decision-making.

Pipelines - There are basically two problems-natural

gas pipelines and liquid pipelines. Natural gas accidents

have been analyzed elsewhere [6] . There were 3 08 liquid

pipeline accidents in 1971, down about 4 0 percent from 1968.

The location of these pipelines in low density rural areas,

combined with an increasing safety record, seems to indicate

that this type of accident is not a serious risk at this

time.

Water Carriers - In terms of past accidents, the risk

to buildings seems to be negligible. The rapid increases in

volumes handled and sizes of vessels could significantly

alter the situation.

Motor Vehicles - On the average, 3 0-4 0 combustible

liquid explosions can be expected per annum (nationwide) . The

number of these which might occasion significant damage to

buildings cannot reasonably be estimated. Although accidents

involving other dangerous commodities are documented, their

34
frequency of occurrence in unknown. The increasing use of

airspace over highways for buildings could increase the risk

of this type of accident in the future.

Railroads - Some of the most serious accidents experienced to date have been associated with rail transport.

In addition, railroad accidents, both actual and potential,

have been subjected to the most extensive investigation.

The knowledge required to improve the safety record seems

to exist, along with a desire to use it. Without changes

in procedures, we can probably expect serious accidents to

continue at the rate of one every two years, with explosion

damage to structures of about $1.05 million per accident.

Storage - This area has received relatively little

emphasis in the past, likely due to a good safety record.

Documented accidents seem to have been caused by failures

in processing facilities which, for obvious reasons, are

located on the same sites as storage facilities. This

problem appears to be the most conducive for further analytical examination.

35
- : 9. LIST OF REFERENCES

1. Somes, N. F. , "Abnormal Loading on Buildings and Progressive Collapse", NBSIR 73-221, National Bureau of

Standards, Washington, D.C., 20234, May 1973.

2. Durand, J. D., Association of Oil Pipelines, Press

Release , Washington, D.C., April 25, 1972.

3. Strehlow, R. A., "Unconfined Vapor Cloud Explosions - An

Overview", Report AAE TR 72-1, UILU-ENG. 72 0501,

Aeronautical and Astronautical Engineering Department,

University of Illinois, Urbana, Illinois, February 1972.

4. Krasner, L. M. , Motor Vehicle Standards for Hazardous

Material Transporation , prepared by Factory Mutual

Research Corporation for DOT Contract #FH-ll-6897,

Report available from NBS Clearinghouse, Springfield,

Va., Document #PB192 167.

5. National Transportation Safety Board, Annual Report

to the Congress of the United States - 1971, Available

from U.S. Government Printing Office, Washington, D.C.,

Stock #5000-0053.

6. Burnett, E. F. P., Somes, N. F., and Leyendecker, E.V.,

"Residential Buildings and Gas-Related Explosions",

NBSIR 73-208, National Bureau of Standards, Washington,

D.C., 20234, June 1973.

7. Office of Pipeline Safety, Summary of Liquid Pipeline

Accidents Reported on DOT Form 700-1 , Annual Reports for

years 1968-71.

8. "Analysis of the Safety of Transportation of Hazardous

Materials on the Navigable Waters of the United States."

Report Number: NTSB-MSS-72-2 . National Transportation

Safety Board. Washington, D.C., March 15, 1972.

9. Marine Casualty Report: Collision Involving SS African

Star and M/V Mid-West Cities and a two in Mississippi

River on March 16, 1968." Department of Transportation,

Washington, D.C., Nov. 10, 1970.

10. Marine Casualty Report: Collision Involving SS Union

Faith and M/V Warren J. Doucet and Tow in Mississippi

River on April 6, 1969. Department of Transportation,

Washington, D.C., Nov. 10, 1970.

36
11. Waterborne Commerce of the United States: Calendar Year

1970. Part 5, Department of the Army, Corps of Engineers,

Vicksburg, Mississippi. Also conversations with the

following individuals and organizations:

12. Society of Navel Architects, New York, N.Y.

13. Proceedings of the Marine Safety Council, Vol. 28, No. 12

United States Coast Guard, Washington, D.C., Dec. 1971.

14. 1970 Inland Waterborne Commerce Statistics, American

Waterways Operators, Inc., Washington, D.C., Nov. 1971.

15. Summary of Motor Vehicle Accidents in the Petroleum

Industry for 1970 , American Petroleum Institute, Division

of Statistics and Economics, May 1971.

16. National Transportation Safety Board, A Study of Safety

Considerations in the Utilization of Airspace Over and

Under Federally Aided Highways , Report #SB60-34, April

6, 1969.

17. Railroad Tank Car Safety Research and Test Project: Final

Phase 2 Report on Accident Review , Association of American

Railroads, Report #RA-02-2-18, Chicago, August 1972.

18. Railroad Tank Car Safety Research and Test Project : Summary of Ruptured Tank Cars Involved in Past Accidents , Association of American Railroads Report #RA-01-2-7,

Chicago, July 1971.

19. Lt. Commander Danahy. Hazardous Materials Division, U.S.

Coast Guard, Washington, D.C.

20. Siccama, E. H., "The Environmental Risk Arising from the

Bulk Storage of Dangerous Chemicals", from Proceedings

Conference on Hazard Evaluation and Risk Analysis , Houston, August 1971, Sponsored by National Academy of

Sciences, Washington, D.C.

37

NBS-n4A (REV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. in:Hi.l( A 1 ION OR KI I'OK 1 NO,

IR 73-412

2. Cu) V '[ Ac r (. s s u>n No.3. Rt cipicni's Accession N(j.

4. Til LI-: AND SUIVl-l'I Ll- The Incidence of Hazardous Material Accidents

During Transportation and Storage

5. Publication Date

6. Performing Organization (ode

7. AUTHOR(S)

W. A. Steele, D. Bowser, and R. E. Chapman

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4314426

11. Contract/Grant No.

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

Center for Building Technology

National Bureau of Standards

Washington, D. C. 20234

13. Type of Report & Period Covered

Final Report

14. Sponsoring Agency Godc15. SUPPLEMENTARY NO! ES

16. ABSTRACT (A 200-word or less factual summary of most si^ificant information. If document includes a significant

bibliography or literature survey, mention it here.)

This report is one of a series describing background research

concerning the incidence of abnormal loading. The report is organized

in terms of modes of hazardous material transportation and storage.

These modes - pipeline, water, motor vehicle, and railroad transportation systems - are addressed in four sections with Storage Systems discussed in a fifth. The sections depend on the amount of

available data, rather than the risk involved in an accident. A

summary of the results is presented in the last section. On the whole,

there is little empirical evidence to substantiate a threat to

buildings from hazardous materials transport. However, trends in

volumes shipped in proximity to structures of interest raises the

prospect of future incidents.

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

)

Accidents; hazardous material; storage of hazardous material;

transportation of hazardous material.

18. AVAILABILITY Unlimited 19. SECURITY CLASS

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