HomeMy WebLinkAboutGasoline Tank Truck Rollover IncidentsTRAINING BULLETIN #4
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TRAINING BULLETIN NUMBER 4
GASOLINE TANK TRUCK /TRAILER ROLLOVER INCIDENTS
TABLE OF CONTENTS
I. INTRODUCTION
II. GASOLINE TANK TRUCK /TRAILERS
III. OVERTURN TANK TRUCK PROBLEMS
IV. VACUUM TRUCKS
V. TOWING WRECKERS
VI. OFF- LOADING OVERTURNED TANKERS
VII. CONCLUSION
VIII. GLOSSARY OF TERMS
IBC. INCIDENT COMMAND CHECKLIST
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I. INTRODUCTION
Approximately 25 million gallons of gasoline are produced by oil
refineries in and adjacent to the City of Los Angeles each day. This
gasoline is pumped underground to distribution terminals where it is
loaded into large tank trucks for delivery to the consumer by way of City
streets and freeways. Given the volume of traffic and the amount of
gasoline transported on our freeways and highways, the potential for a
gasoline tank truck rollover is great.
When a tank truck /trailer is involved in an accident and a tank rollover
occurs, it creates an incident that may take many hours to abate and many
different agencies to help reopen the roadways. A tank truck rollover
emergency will create major traffic congestion on freeways as well as
local surrounding streets. Thousands of people and hundreds of businesses
may be affected which will cause loss of revenue and productivity to the
community.
Tank trucks transport approximately 90% of all the ,fuels used by
vehicles. Truck transportation of these hazardous materials is strictly
regulated by the Department of Transportation through the National Highway
Traffic Safety Administration, Bureau of Motor Carrier Safety and the
Office of Hazardous Materials. The State of California also imposes
regulations on tank trucks which requires periodic CHP inspections. In
addition, Division 38 of the Fire Code regulates tank vehicles for
flammable and combustible liquids.
In spite of these requirements, accidents still occur and can present a
variety of problems to Firefighters. These problems are not limited to the
hazardous petroleum products. Tank trucks and their design present hazards
all their own. For instance, the operation of the internal and external
valves could result in the automatic opening of the vapor vents causing a
larger spill. To avoid these types of problems it is necessary to have an
understanding of tank truck design. This Training Bulletin will address
these and other concerns and will assist in the handling of problems that
can be encountered in 3,.:ank truckitrailer :railer a llove emergencies in a safe
and expedient manner.
II. GASOLINE TANK TRUCK /TRAILERS
A. Tank Trucks (MC306 - Three Basic Types)
1. Single tank truck with two axles (see Figure 1) or three axles (see
Figure 2). The capacity of the two axle truck is 3,000 gallons and
the three axle truck is 5,000 gallons.
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NO PICTURES ON THIS PAGE
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2. Truck tractor with a semi - trailer connected together by a fifth wheel,
have one tank that is approximately 40 feet long with a 9,000 gallon
capacity (see Figure 3).
Figure 3: Tank Tractor with Tank Semi - Trailer (NO PICTURE)
3. Tank truck pulling a two axle trailer: Each truck and trailer tank is
approximately 20 feet long. The, capacity of the truck tank is 4,200
gallons and the trailer tank is 4,800 gallons (see Figure 4).
Figure 4: Tank Truck and Two Axle Tank Trailer (NO PICTURE)
B. Tank Design and Construction
1. Most tanks are made of aluminum, maximum 3/16 inch thick at the
bottom of the tank. The tank is designed to be very light so it can
carry more product.
2. Tanks usually have two to four compartments, with single bulkheads
separating the compartments. Double bulkheads are required when
carrying flammable products with different flash points in the same
tank, e.g., diesel and gasoline. Baffles are installed in the
compartments for tank strength and do very little for reducing
surge of the product (see Figures 5 and 6).
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3. Vapor recovery /pressure vents and the combination spring- loaded fill
cover and pressure- actuated vents on top of tanks are protected by an
overturn rail that runs the length of the tank (see Figures 7 and 8).
There is always a vapor space present for product expansion.
Figure 7: Top View of Tank With Vents (NO PICTURE)
Figure 8: Typical Cross - Section of Tank and Vent (NO PICTURE)
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4. The product is off - loaded from the bottom by gravity through the
internal valves. These internal valves are operated by either air,
mechanically or a combination of both and are referred to as emergency
valves (see Figure 9) .
Figure 9: External Plumbing and Internal Emergency Valves (NO PICTURE)
5. The external piping has shear sections which will break to prevent
internal damage to the tank and valves.
6. Products carried by tank truck /trailers include but are not limited
to gasoline, diesel and jet fuels. The large capacity trucks are
usually full or empty when traveling to and from their destinations.
Partial loads are carried by the smaller single tank trucks which make
small deliveries at various locations.
III. OVERTURN TANK TRUCK PROBLEMS
• A. Problems encountered when a two or three axle tank truck rolls over:
1. Trapping or injuring the driver.
2. Tank can have up to four compartments, with two or three different
products, such as diesel and two grades of gasoline. These may be
difficult to identify from a safe distance.
When 'carr ing two t f event. ` rot,ucts, the 'c•ompa r treats are r'equ rei
to haw. do;?- e bulkheads with a vo i d space in between. This void or
air space may be illegally plugged because of a leak in one or both
of the bulkheads. DO NOT REMOVE the plug because up to 200 gallons
of mixed product may be present in the void space.
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B. Problems encountered in a truck tractor and semi - trailer when rolled
over:
1. The tractor will probably rollover with the semi - trailer and could
trap or cause injury to the driver.
2. Greater risk of tanker failure due to the weight of the product and
size of the tank.
3. Total weight of the tank can be as much as 80,000 pounds.
C. Contributing factors and problems that can cause a tank truck and two
axle tank trailer to rollover:
1. The tank trailer may become unstable if the tank truck makes a high
speed turn or an erratic move which can cause the tank trailer to
rollover on its side or top.
2. The tank truck seldom rolls over in a tank trailer rollover incident
because of the anti - rollover device incorporated into the tow bar of
the trailer. If the tank truck is damaged due to the accident and
cannot be driven the product shall be off - loaded before the vehicle
is towed.
3. When the tow bar of the trailer becomes twisted it is very difficult
to disconnect because it is under tension. It should not be
disconnected until after the empty tank is uprighted or when safe to
do so.
D. The tank may develop leaks in several areas caused by the
accident /rollover. These leaks may not be able to be stopped. The
major areas vulnerable to leaks are:
1,
Vapor recovery /pressure vents on top of the tank.
2. Combination spring - loaded fill cover and pressure - actuated vent. on
Lip oi the tank_
3. Internal valves and external piping.
4. Ends of the tank and at all welded seams.
E. Tank integrity is hard to determine and is affected by the following:
1. The internal and external structural damage to the tank caused. by
the accident.
a. The external damage is often under the tank and can only be seen
when the tank is uprighted.
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b. The internal damage, which is of greatest concern, cannot be
verified until the product has been removed from the tank and
inspected from the inside.
2. The lightweight design and construction.
3. Age of the tank and metal fatigue which is from traveling empty.
F. NO ATTEMPT SHOULD BE MADE TO UPRIGHT ANY TANK TRUCK OR TANK TRAILER
BEFORE IT IS OFF- LOADED.
1. The weight of the product can make the tank six times heavier when
full.
2. The structural integrity of the tank is hard to determine.
3. The frame of the tank is designed to carry the tank and its load
only in the upright position.
4. The tank could fail without warning if uprighted full, resulting in
one large instantaneous spill.
IV. VACUUM TRUCKS
A. Capacity
1. Vacuum trucks of 2,500 and 5,000 gallon capacity are available from
most waste disposal companies for use in product off - loading or
spill cleanup (see Figures 10 and 11).
Figure 10: 2500 Gallon Capacity Vacuum Truck (NO PICTURE)
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Figure 11: 5000 Gallon Capacity Vacuum Truck (NO PICTURE)
2. These vacuum trucks require a vapor_space and their actual capacity
is approximately 400 to 500 gallons less than the rated capacity.
The actual capacity is always less because of the vapor space and
the specific gravity (weight) of the product.
B. Vapor Recovery
1. Vacuum trucks do not have a vapor recovery system, so a hose must
be extended from the truck when it is loading so the vapor in the
truck can be expelled as the liquid is being vacuumed up.
2. The total length of the vapor hose from the vacuum truck should be
a minimum of 50 feet down wind from any ignition source and
downhill because gasoline vapor is three to four times heavier than
air.
C. Vacuum Truck Classification
1. Vacuum trucks are classified by three tank cleanliness standards:
a. Dirty - Tank is empty of product, but it has not been cleaned.
Clean - Tank i s empty of product an has .been washed with
water, but there is a possible trace of water and product from
the previous load.
c. Super Clean - Tank has been chemically cleaned and is free of
product.
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2. Clean vacuum trucks should be requested to prevent any reaction of
the product in the vacuum truck tank. The contamination of the
product is not a major concern, however, the overriding concern
should be the availability of the vacuum truck within a reasonable
time
D. Vacuum Truck Equipment
1. Additional equipment is often needed by the disposal company to
help clean up the site.
a. Additional vacuum /vapor hose and related fittings, i.e., 2
sections each of 4 ", 3" and 1 1/2" hose. Sections of vacuum
hose are 25 feet in length.
b. Drums for contaminated sand, dirt or absorbents used to contain
the spilled product.
c. Extra personnel to assist in the clean up.
2. The disposal company must be given the following information:
a. They are responding to an overturned tank truck /trailer.
b. The type of material spilled, or to be off - loaded.
c. The amount of material to be removed, the number and capacity
of trucks needed.
d. Bring additional sections of hose.
3. The proper amount and type of equipment requested from the disposal
company needs to be verified by Fire Department personnel, (0CD or
Incident Commander) .
4. Have the vacuum trucks meet the CHP or LAPD at a designated area to
be escorted to the incident from the proper direction..
There may be a problem in .eterf ninq how many vacuum trucks wi.l€ he
needed at an incident. This is because the tank truck /trailer together can
hold 9,000 gallons or more. A vacuum truck rated at 5,000 gallons really
only holds approximately 4,600 gallons due to product weight and required
vapor space. At an incident where a full trailer tank is overturned which
can hold 4,800 gallons, the off - loading will almost always require two
vacuum trucks. You should request two vacuum trucks with a capacity of
5,000 gallons each. The first 5,000 - gallon truck will be used to off -load
the overturned tank and the second vacuum truck will be used to pick up
any on -scene spills and /or any remaining product that is in the overturned
tank. If the tank truck needs to be off - loaded, it is necessary to request
a third 5,000 gallon capacity vacuum truck.
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V. LARGE TOWING WRECKERS
When the overturned tank is empty, two 20 -ton commercial towing wreckers
are required to upright the tank. Usually, you cannot determine the
mechanical status of the tank truck until you have off - loaded and
uprighted the trailer tank. If it is obvious that the tank truck is
damaged and needs to be towed, it shall be off - loaded before being moved.
VI. OFFLOADING OVERTURNED TANKERS
As of May 1988, the Shell Oil Company discontinued providing the service
of their Response Action Team (RAT Team) for off - loading overturned
gasoline tank trucks, except for those that are owned and operated by
Shell Oil Company.
The Shell Oil Company has provided a "Tank Truck Rollover Emergency
Manual" to all three Hazardous Materials Task Forces and the Research
Unit. Their manual provides technical information and guidelines on how to
handle overturned tank truck emergencies-.
As of February 1989, Hazardous Materials Task Force 4 received equipment
an training on what is considered the safest an quickest method of
off - loading an overturned tanker. This method is accomplished by drilling
a three inch hole in the ALUMINUM tank with an air drill. Once this hole
is drilled, a metal tube or "stinger" is inserted into the fuel
compartments. The hose from the vacuum truck is connected to the stinger
and the entire product is then pumped out so the tanker can be uprighted
safely.
NOTE: Each compartment in a multi - compartment tank must be drilled and
pumped out individually.
Incident Commander's Request for Vacuum Trucks
In a tank truck /trailer rollover incident, the early ordering and arrival
of the correct number and capacity of vacuum trucks are important fa: t'ors
i n the abatement of the hazard. This will also expedite the cleanup and
the reopening of state highways /freeways and City streets.
The owner of the vehicle involved in the truck /trailer rollover is legally
responsible for product removal and cleanup of any spill on state
highways /freeways or City streets. However; when a hazardous waste hauler
company is contacted, they will not respond unless there is a "responsible
party" who has approved and is prepared to accept financial responsibility
for the waste hauler's services.
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In emergency operations, the Fire Department initiates the Incident
Command System which provides for multi- agency representation. On
incidents that occur on state highways /freeways, the CHP is the on -scene
manager, Los Angeles Fire Department is the Incident Commander. Cal Trans
is responsible for cleanup of state highways /freeways, and has the
authority to order and pay for vacuum trucks when:
1. An immediate fire /life hazard exists.
2. The truck driver does not know if the owner will accept the
responsibility.
3. The owner cannot be contacted.
4. The owner cannot or will not pay.
If the Incident Commander on State Highways /Freeways has determined that
the owner is not available or capable of providing the required resources,
the Incident Commander may request the vacuum trucks through OCD. If the
CHP or Cal Trans is on the scene, this action should be discussed at the
command post.
On Los Angeles City streets, the Incident Commander shall always attempt
to have the owner or responsible party accept the responsibility for
ordering the vacuum trucks, but if this is not possible, the Incident
Commander can order the number and capacity of vacuum trucks needed
through OCD. When OCD orders the vacuum trucks directly from a hazardous
waste hauling company, the Fire Department becomes the agency responsible
for payment for the hazardous waste hauling and disposal. This request
requires approval of the Deputy Department Commander. Refer to 2/1- 49.47:
SPECIAL PROCEDURES - REMOVAL OF HAZARDOUS WASTE. The required EPA
Identification number for the Hazardous Waste Manifest will be obtained
from the on -call Chief of the Bureau of Fire Prevention and Public Safety,
VII.. CONCLUSION
AL a rollover incident, the tank truck usually remains s . t;: qht while the
trailer tank has overturned. Time is always an important consideration
when a tank truck or tank trailer is overturned. The abatement of the
hazard of an overturned tank should be accomplished as quickly and safely
as possible.
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VIII. GLOSSARY OF TERMS
BAFFLE: A transverse partition in a cargo tank which is not
liquid tight. Main purpose is for tank strength.
CAPACITY: The maximum volume of any tank in United States
gallons or pounds.
CARGO TANK: Any atmospheric tank, low pressure tank, pressure
vessel or special vessel designed or used for the
transportation of liquid or gaseous hazardous
materials.
COMPARTMENT: A separate product carrying space of a tank motor
vehicle. One tank may have one or more such spaces.
CROSSOVER LINE: A line installed in the tank piping system to allow
unloading from either side of the tank.
GLADHANDS:
HEAD AND
BULKHEAD:
Fittings for connection of air brake lines between
vehicles /trailers.
A liquid -tight transverse closure at the end of a
cargo tank or between compartments of a cargo tank.
INTERNAL VALVE: A valve designed and installed in such a manner as
to remain in an operable condition when the exterior
parts are damaged or sheared off. It will prevent
the unintentional escape of the contents of the tank.
LOW PRESSURE
TANK: Any tank designed to operate at pressures above 0.5
psig, but not more than IS psig.
MANIFEST BOX: A moisture proof container used for storage of important
papers or records relating to the cargo being carried.
This box is carried in the cab area of the truck.
MANIFOLD:
MC306:
Used to join a number of pipelines to a common inlet.
or outlet.
The code of Federal 'egulations for Motor Carrie =r of
flammable and combustible liquids for low pressure
tanks.
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TANK TRAILER:
(FULL TRAILER AS CALLED IN INDUSTRY)
Any vehicle without motive power, equipped with a
tank mounted thereon and constructed so that it can
be drawn by a motor vehicle. No part of its own
weight rests upon or is carried by the towing motor
vehicle.
TANK TRUCK: Any motor vehicle equipped with a cargo tank mounted
thereon.
TRUCK TRACTOR: A powered motor vehicle designed primarily for drawing
semi- trailers and so constructed as to carry part of the
trailer weight and load.
SEMI - TRAILER: A vehicle with no motive power, equipped with a tank
mounted thereon. It is constructed so that part of its
weight is carried by the truck tractor.
SHEAR SECTION: A machined groove which reduces the wall thickness of an
outlet valve or adjacent piping by at least 20 percent so
that strain on piping will not affect the product
retention capability of the outlet valve.
VACUUM TRUCK: A truck with the ability to vacuum up chemical
sills or remove hazardous materials /waste by using
a pump on the truck.
VAPOR RECOVERY
LINE: A line which connects the vapor recovery hood to a
convenient location for attachment to a vapor
recovery hose.
VENTS:
Devices which control or limit tank pressure. Some
types are:
- Pressure Relief Vent
- Vacuum Relief Vevn,.
- Fusible Vent
- Frangible Vent
VOID: An enclosed space inside a tank or vessel between
the individual compartments.
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IX INCIDENT COMMAND CONSIDERATIONS
A. Size -Up Considerations - NO FIRE -
1. Overturned and a Spill - Where is it going; amount leaked and rate
of release
2. Overturned Tank Leaking - Where, amount leaked and rate of release
3. ID the Product - Placards, shipping papers and driver
4. Containment - Storm drains
S. Control Ignition Sources - Traffic, sump pumps, etc.
6. Rescue Problems
7. Evacuation - Immediate area /downstream
8. Access and Water Problems
9. Direct Incoming Companies - Upwind and uphill
10. Name and Location of Command Post
11. Detain Truck Driver at Command Post
12. Tanker Rollovers are to be Regarded as a HAZARDOUS MATERIALS
INCIDENTS
B. Los Angeles Fire Department Resources
1. Nearest Engines and Task Forces - Foam and foam nozzle
2. Hazardous Materials Task Force 4 (HMTF -4)
4.
OCD - Vacuum n cks
a State Highways, Freeways
b. City Streets
5. Rescue Ambulances /EMS Supervisor
6. Emergency Air and Light Utility
7. Hazardous Materials Response Unit (Mobile Lab)
8. Command Support Staff
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9. Fire Station 88 - Sand /crushed asphalt
10. Supply and Maintenance - ATF Foam
11. Helicopter With Airborne Engine Company
C. Other Resources and Agencies
1. CHP - Scene Manager on State Highways and Freeways
2. Cal Trans
a. Authorizes Disposal Company on State Highways and Freeways
b. Shutting off sump pump stations on freeways
c. Sand
d. Portable toilets
3. Department of Public Works (Los Angeles City) for City Streets
a. Storm drain contamination
b. Sand
4. Los Angeles Police Department
5. Department of Transportation - For traffic control on City Streets
6. Los Angeles County Health
7. Office of Emergency Services
8. Environmental Protection Agency
L.A.
9. ti County
LS; u �o County �r i Control)
10. Wrecker /Tow Trucks
11. Owner /Operator of Transport Company
12. Disposal Company (vacuum trucks)
13. United States Coast Guard
14. Fish and Game
15. Red Cross (food)