Conditions That Led To The Buncefield Explosion And Fire Exist At Many More Facilities Both In The U.S. And Abroad
Vol. 21 No. 1
Hemel Hempstead, U.K., is now one of those places that maps in history books denote with a tiny icon of flame. On December 11, a massive explosion measuring 2.4 on the Richter Scale shattered the Buncefield oil depot an surrounding area north of London, only three miles from the Hemel Hempstead fire station. Fires that swept the depot blackened the English horizon for the next three days.
The U.K.'s Health & Safety Executive (HSE) is leading an investigation into the explosion. Still, pending the result of that investigation, many things that went wrong at Buncefield are readily apparent.
Buncefield was built in 1968 primarily to provide aviation fuel for Heathrow airport. It was expanded in the 1980s and the 1990s by the addition of pipelines bringing fuel in from the Humber and Merseyside and taking it to Heathrow and Gatwick airports.
The layout of the terminal complex contributed to the intensity of the fire. The fuel tank spacing is an issue. Tanks were grouped three and four to a dike, known as a bund in the U.K. These containment areas are intended to prevent spillages from spreading.
Storage tanks are like drunks at a Christmas party. The best idea is to keep them far apart, not seated next to each other at the dinner table. Pioneers in the petroleum and petrochemical business recognized that their entire inventory could go up in a flash. Accordingly, the early storage tanks were spaced two-to-four tank diameters apart and sat in their own personal dike instead of sharing with neighboring tanks.
Of course, that was the good old days when land was cheap, tanks were relatively small and there was no hope of extinguishing even the smallest one. Throughout the years that valuable safety buffer between tanks has grown less and less as some fire protection guidelines took advantage of improvements in the fire protection, computerized plant operation and better equipped fire brigades. Management took advantage of the good changes but ignored many of the bad changes such as much larger tanks, the skyrocketing value of the product, minimum staffing and even some unattended operations such as the driver operated truck loading racks. Today jumbo tanks are squeezed into acreage originally set aside for far fewer gallons of storage. One oil company even briefly adopted the idea that individual dikes be replaced by having the entire tank farm be one dike, the floor tapered toward an impounding zone. This sounds good but years later when more tanks have been added, together with poor ground maintenance, all of the tanks may be subject to one dike fire.
Economic pressures have heavily subdued fire protection specialists. Likewise, insurance companies, the firefighter's chief ally, have fallen from their position of strength. In the 1970s, the Oil Insurance Association issued their own requirements for tank spacing and many other engineering points. Since OIA issued property insurance at most U.S. refineries as well as refineries abroad, their word was their bond.
Things change. Today there is no real dominant insurance leader in the refining and petrochemical business. A fire insurance policy written for an oil company may involve 20 or 30 insurance companies acting together. At most, a single insurance company may carry about 10 percent of the larger risk. That seriously waters down the influence that an insurance company has when it comes to engineering issues. Instead of issuing their own real world engineering guidelines, insurance companies fall back on the industry standards long compromised by committees who legislate guidelines, and we all know how strict legislated items are not.
Tank spacing is not the only invitation to disaster waiting for an RSVP. For example, instead of tank farm product piping being underground where sanity dictates, for total protection from a dike fire, it is openly exposed to any fires thanks to governmental pollution control standards.
Companies have added more and more personnel to their safety and environmental departments to deal with government mandated OSHA and other personnel safety issues. Because of these heavily mandated requirements little interest is seen in hiring qualified people to improve guidelines on fire protection and spacing issues. Most of the corporate fire protection personnel responsible for internal standards are always under pressure to compromise and compromise. Standards, after all, cost money. Meanwhile, insurance companies have not shown real interest in hiring fire protection people to pre-plan new installations because they are just following the lead underwriter. Most have engineers that make brief plant inspections to see how things are going and that is about all they have time for.
As far as the fire itself, flashback with me to what seems like another century when large fires were apparently handled better. On Christmas Eve, 1989, a vapor cloud release led to a massive explosion that ripped through a Baton Rouge refinery tank farm, killing two men. Sixteen storage tanks ranging from 60 foot to 135 foot in diameter were set ablaze. Water in the above ground mains was frozen and therefore useless. The situation was analyzed and prompt action taken. Large diameter hose was laid to an alternate water supply. Small 1,000-to-1,500 municipal pumpers were brought in for water supply relay operations. Outside contractors from Williams Fire & Hazard Control brought the biggest fire fighting nozzle available -- barely 2,000 gpm. Add to this arsenal some 500 and 1,000 gpm self-educting nozzles. AFFF /AR served as the ammunition.
Within 12 hours the tanks and millions of gallons of burning fuel on the ground were extinguished.
That was 1980s technology. Today the technology available makes the equipment used at Baton Rouge look like a hand pumped steamer. Now it is common for facilities to have equipment such as large gpm pumpers, portable pumps, very large gpm foam educting nozzles up to 15,000 gpm and large foam supplies readily available. Unfortunately, firefighters at Buncefield found their hands tied by bureaucratic issues that should have been resolved in advance as part of an emergency pre-plan. The fire established a hold that even the considerable resources of local and industrial brigades united could not quickly defeat.
Facilities like Buncefield are allowed to evolve using weakened fire protection standards. The lesson that Buncefield teaches is that crowded tank farms using common dikes are dangerously vulnerable. However, the skills and technology to deal with these colossal fires exist. The only thing missing seems to be the will to call upon those resources.
David White also works as an industrial fire protection consultant.