A Common Nonexotic Hazardous Material
ON HAZARDOUS MATERIALS
In last month’s column, I discussed the problems of handling truck incidents involving hazardous materials. Basically, these problems concerned the difficulties of identifying the chemicals, obtaining information about the hazards of specific chemicals, containing the incident, gaining access to the incident, water supply, and the potential for a running spill fire.
Unfortunately, the emphasis in many articles on hazardous materials in truck incidents focuses on the more exotic chemicals. Fire officers reading these articles tend to dismiss them as not being applicable to their jurisdiction because there is no such chemical in their area. Yet, one of the most hazardous of materials moves through every area without the fire service giving it much thought. It is a product so common, so frequently seen, that its great potential for destruction goes unrealized. This common product is gasoline.
In order to understand the potential for destruction from a truck load of gasoline, consider the Caldecott Tunnel collision near Oakland, Calif., in 1982. This accident involved a cargo tank truck (4500 gallons); a tank trailer (5400 gallons) carrying a total of 8000 gallons of gasoline; a 53-passenger bus that was empty and returning to the depot; and a passenger car.
As a result of this incident seven people were killed and two were seriously injured. All of the deaths and injuries were due to the resulting fire, except for the bus driver who was ejected from the bus during the accident.
A 1978 Honda Accord heading west with only the driver, entered the Caldecott Tunnel about 12:12 A.M. This car was followed by the tank truck and trailer combination and then by the bus. The car began to weave and bounced off of the walls of the tunnel several times. The driver of the car stopped in the left lane of the two-lane tunnel tube.
The tank truck driver drifted into the left lane and struck the car. At the same moment the bus also struck the car. The bus then struck the tunnel wall and bounced back into the right lane striking the gasoline trailer. The trailer came to rest on its right side in the right lane. The tank truck driver got the vehicle stopped in the right lane just past the accident scene.
The tunnel was now completely blocked. Traffic began to back up behind the accident scene. The motorists in the vehicles behind the accident have indicated that they had no concern about fire, but were worried about being struck from behind by other vehicles unaware of the accident. These motorists report that there was a fire near the tank truck “about the size of a barbeque fire.”
As the motorists waited for traffic to clear so they could back out, they observed thick black smoke coming up from the road and moving toward them. As they tried to escape, they reported two waves of smoke and heat. The first wave reached them as they were about 250 feet from the scene. The second wave happened several minutes later.
With the second wave came loud explosions and the lights went out.
Tunnel personnel were notified of a number of accidents in the tunnel. They therefore notified the California Highway Patrol (CHP) at 12:13 A.M. At 12:14 A.M., tunnel personnel met the gasoline truck driver leaving the western end of the tunnel (direction of travel) reporting that his gasoline truck was on fire. This tunnel employee reentered the control room, called the CHP, and asked them to notify the fire department.
Another tunnel employee took a tow truck into the west end of the tunnel. He was able to get within about 500 feet of the accident site. He observed that fire filled the tunnel and burning gasoline was flowing westward in the gutter in front of the tank truck. He then backed out of the tunnel and notified the control room of the extent of the fire.
At 12:20 A.M., the tunnel console operator again called the CHP and requested that the fire department be notified. The CHP dispatcher finally contacted the Oakland Fire Department at 12:21 A.M.
At 12:27 A.M., four units of the Oakland Fire Department arrived on the scene. They were at the westbound exit and established their command post about 100 feet from the exit.
The Orinda Fire Department was notified of the incident by the CHP at 12:26 A.M. This fire department arrived at the east entrance of the tunnel, but reported that the heat and smoke made it impossible for them to enter.
The flowing fuel was entering a storm sewer designed to carry water out of the tunnel. Because of the burning fuel, the fire department ordered the control valves closed to contain the runoff in the holding tank between the valves.
At about 1 A.M., it appeared that the danger of explosion was over. The Oakland Fire Department then ordered two fire fighters into the tunnel to search for possible survivors. There was none and the seven bodies were located at this time.
By 1:30 A.M., the eastern portion of the tunnel had been examined for structural damage and cleared for fire department entrance. The Orinda Fire Department then laid lines into the tunnel and began fighting the fires. The fires were declared under control at 2:54 A.M.
In addition to these problems, at 1:39 A.M., one of the fire officers reported a strong odor of gasoline in a lake west of the tunnel. Fortunately, a survey with a flammable gas detector indicated very low concentrations of gasoline vapors. The fire department estimated that less than 200 gallons had gotten into the lake and that none had entered the Oakland sewer system.
The lessons learned from this incident are:
- The need for fire departments to work with bridge and tunnel authorities to ensure prompt notification of incidents.
- The need for fire departments to develop specific response plans for incidents on bridges or in tunnels, particularly if different jurisdictions are responsible for each side.
- The need for monitoring capabilities and traffic signals at the entrance of the tunnels and bridges.
- The need for an internal communications system for immediate notification of a problem.
- The need for public education of the evacuation exits from tunnels, including the location of crossover points to the other tubes.
- The need for fire departments to be familiar with built-in fire protection devices such as ventilation fans and standpipes.
- The need to develop hazardous material transportation routes so that these types of trucks are required to avoid tunnels.
Products that we see every day can create major hazardous materials incidents. Fire service personnel cannot be lulled into a false sense of security by their familiarity with the product. They must preplan and be alert all the time.