Robert Moore learned the importance of planning early in his fire fighting career. In 1990, he was the assistant chief of the Channelview (TX) Volunteer Fire Department when an explosion and fire killed 17 people at an industrial chemical complex on the Houston Ship Channel.
To make matters worse for Moore, he also happened to be the safety supervisor for the chemical complex.
“I have the dubious distinction of being one of the fire chiefs at a chemical plant that had a major explosion with a massive loss of life,” Moore told responders attending the Xtreme Industrial Fire and Hazard Training in April in Beaumont, TX.
The explosion and fire affecting an area of the complex comparable to a city block originated in a 900,000-gallon chemical waste tank. Unbeknownst to plant personnel, a chemical reaction in the tank’s contents began to generate a pyrophoric fuel/oxygen atmosphere.
At 11:21 p.m. on July 5, 1990, the tank exploded, hurling its 24-ton roof into a parking lot 600 feet away. All the fatalities resulted from the initial blast with no other casualties reported.
“How many of you would ever think that a waste water tank is going to blow up?” Moore said. “What does waste water from a chemical plant have in it? It’s got hydrocarbons. Also it had peroxide, which is an oxidizer.”
Information released by the company states that the tank was taken out of service to repair a vent gas compressor. Normally, a nitrogen purge kept the vapor space inert and an off-gas compressor drew away the hydrocarbon vapors.
Workers reduced the nitrogen purge to a minimum during the maintenance. Unfortunately, a sensor to detect any dangerous oxygen buildup was badly placed in an area where the air remained stagnant.
Flammable atmosphere filled the tank’s headspace and the piping to the compressor. Attempts to restart the compressor ignited the vapor, triggering the explosion.
Not enough emergency response teams put sufficient thought and effort into pre-planning, Moore said. Since the wastewater tank was considered relatively safe, no pre-plan existed. As for training, some experiences are so overwhelming that the best firefighters find themselves staggered.
“I had the best fire brigade there could be,” Moore said. “But they had never dealt with anything like fatalities, especially fatalities that were their friends.”
Moore got on the scene to find his ERT in disarray. As soon as mutual aid arrived Moore ordered his brigade back to their primary jobs as process operators. Flames threatened the source of instrument air needed to operate remote valves.
“When we lost instrument air, all the valves returned to their default settings,” Moore said. “All the deluge and sprinkler systems tripped.”
Safely shutting down the process unit depended on reestablishing instrument air. It became doubly urgent because workers were still struggling to “crash” the neighboring facility, a propylene oxide plant, he said.
“The right place for ERT members was not out there fighting the fire,” Moore said. “They had the knowledge to shut down the process unit safely.”
Worse, the explosion demolished a fire protection monitor, compromising the fire water system. By the time the damage could be isolated, only two feet of water remained in the 4.5 million gallon fire water pond.
“We had to wait on the fire boats to come in and hook up to the system from the barge dock to rebuild pressure and get the fire water system back up,” Moore said.
Accounting for personnel under such extreme conditions is difficult, he said.
“I had them fighting fire in ditches down by the outfall,” Moore said. “I didn’t know where they were.”
For mutual aid, Moore depended on Channel Industries Mutual Aid (CIMA), a non-profit organization combining firefighting, rescue, hazardous material handling and emergency medical capabilities of the refining and petrochemical industry in the greater Houston metropolitan area. Moore served eight years as a CIMA specialist.
“I always told my guards, ‘If I need CIMA, I’m going to call you,’” Moore said. “’You will use the radio to request a zone one call.’ When they did, I had 108 companies responding to me.”
Such a large number of responders can be both comforting and demanding, he said. Resources must be managed correctly.
“We always start defensively until you figure out what you have,” Moore said. “When you know what you have, you can begin to act offensively and take care of it.”
In lieu of adequate pre-planning, the best move a fire chief can make is to locate an ERT member who has actual experience as an operator of the unit ablaze.
“Use that person as a resource,” Moore said. “They know more about that unit than you do. Utilize the people who know.”
Storage tank fires can be fairly predictable, Moore said. Process unit fires are not.
“I’m not saying that storage tank fires are easy to deal with,” he said. “They’re resource intensive at the best of times. But you know where the fire is. It’s going to stay in that tank.”
Drainage of runoff quickly becomes a critical issue, he said.
“Back in the days of surround and drown, that created a lot of problems,” Moore said. “If you put that much water out there you will have to deal with it at some point. Know where the ditches go. Know where everything drains to. If you’ve got a burning liquid that floats on water, the fire is going to travel too.”
If that burning liquid is drawn into the sewer system, flames can pop up anywhere and greatly extend the fire, he said.
Under certain conditions, it might be better to tell the operators to increase flow to the maximum rather than isolate the unit, he said. It helps take away the heat.
“Say you’ve got a fire burning in a pipe rack and you tell operations to isolate it remotely,” Moore said. “You may have just created a bomb. When it starts heating up and pressure builds, the pipe is going to come apart, creating more problems.” Æ
Expect spill fire when dealing with any burning process unit.“Where is it going to go if a pipe opens up?” he said. “To the ground and into the sewer system. You are going to have a three-dimensional fire. Making those isolations might create a BLEVE risk. You may have a pressure vessel involved.”
Flame impingement might even lead to structural collapse.
“I was actually at a fire on the ship channel where a distillation column started leaning over,” Moore said. “Remember the rule – the collapse zone is generally 1½ times the height of the structure. You need to be outside that zone.”
Losing instrument air was only one of the major problems at Channelview. Drawing air into a system that requires a vacuum can be just as hazardous.
“If you have a fire nearby, it can start sucking flames into the system,” Moore said. “Also, the noise from several thousand pounds of rushing air is enough to kill all communications. You can’t hear.”
Watching the operators closely when communications is impossible can be a good indicator of the severity of the situation.
“If you see those operators running around, you know there is a problem,” Moore said. “I can say that because I was an operator at one time. We didn’t move too quick unless there was a problem.”
The process underway may represent a wide variety of temperatures, everything from cryogenic to exothermic.
“It might involve multiple feed stocks with different boiling points, different flash points and even different vapor pressures.”
Decisions made during an on-site emergency can also have wide ranging impact off site, he said.
“Most plants have a community around them,” Moore said. “It might not have been there when the plant was built but it’s there now. Cities get bigger and start to encroach on your safe zone. You have to think about hospitals and schools that may be around.”
The threat to the surrounding community might be the deciding factor in whether the fire should be extinguished at all, he said.
“Think about what’s burning,” Moore said. “Is it vapor? Under pressure? It might be safer to just let it keep cooking and burning off. Don’t get too zealous and say, ‘Look, we can put this out,’ because you might have to deal with a flammable vapor cloud looking for an ignition source.”
Testing responders even further, the 1990 Channelview emergency included a fire on a cooling tower. The solution involved placing a fire truck with a deck gun next to the tower and drafting from the fire water system basin.
“Don’t try to fight the fire on a cooling tower,” Moore said. “I mean the specific fire itself. Get some water, throw it on top and stop it that way. If you try to fight the fire where it is at, you’re going to lose that cooling tower.”
Channelview was only one of a series of industrial disasters during that period. Only eight months earlier an explosion and fire at another chemical complex on the Houston Ship Channel killed 23 people and injured more than 300.
Dealing with the aftermath of the explosion and fire at Channelview became a career changer for Moore.
“It’s one reason why I’m at Texas A&M today,” Moore said. “I dealt with that situation for the next five years. When it was over I cried ‘Uncle’ and went to A&M to teach about it instead.”