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4 comments

Texas City Refinery Explosion

Posted August 01, 2012 10:00 AM by cheme_wordsmithy

The Texas City Oil Refinery is the second largest in the state of Texas, and the third biggest in the U.S. Up until early 2005, the 1200-acre facility processed up to 460,000 barrels of crude oil every day, and from a distance it seemed like the plant was in good order. Unfortunately, it wasn't until after the worst refinery explosion of the decade that the facility's major safety procedure and safety culture flaws were revealed.

Incident

On March 23, 2005, operators had started up the raffinate splitter tower (gasoline component separator) section of the ISOM unit used to increase the octane of gasoline, and began filling it with hydrocarbon fluid. Abnormal pressure built up in the tower due to an abundance of fluid, and relief valves opened to allow the components to escape to the "blowdown" drum. Shortly thereafter the filled drum ejected fluid and vapor in a "geyser-like" stream out the vent stack into the air. While workers alerted to the cloud rushed to shut-off all hot-running equipment, a contractor attempted to turn on his diesel pick-up truck. Operators ran to him in an attempt to stop him, but once the fuel content in the air had diluted to the UEL (Upper Explosion Limit), the engine provided an ignition source, resulting in a huge vapor cloud explosion. The fireball injured 100 people and killed 15, including some workers in a trailer parked near the process unit. They were in a meeting, and were unaware of the situation.

(Fire extinguishing operations after the explosion. -->)

Cause

The direct cause of the incident was the poor operation and condition of the raffinate splitter tower, and its flawed blowdown system. In 1997, the atmospheric blowdown was replaced with an identical one due to budget constraints, despite safety regulations prohibiting that type. Between 1994 and 2004, apparently eight similar cases of flammable emissions from the blowdown vent occurred, but no corrective action was taken. In addition, operators involved with the raffinate splitter tower did not follow standard (timely) procedures for discharging the fuel during the restart, and ignored the open maintenance orders on the tower's instrumentation. The alarm meant to warn workers of excess liquid in the unit was disabled.

Many other safety problems could be considered causes of failure. A number of other alarms and safety sensors were disabled, malfunctioning, or non-existent. Poorly trained control operators worsened the situation by opening the discharge valve, allowing hot discharge to flow through a heat exchanger and pre-warm the inlet fluid. Safety protocols for equipment and vehicle placement were also not being followed by some of the staff, including the guest contractors.

For a complete breakdown of the disaster and its causes, check out this video by CSB (the Chemical Safety Board).

Lessons Learned

On top of the casualties, BP (the owner of the refinery) had $1.5 billion in expenses and lawsuits to take away as a hard learned lesson on process safety. Among the refinery's most fatal flaws was its inadequate safety culture; disaster investigators concluded the facility nurtured an environment in which workers were neither well-informed of nor well-encouraged to speak up about safety issues. On top of this, leadership did not take control to properly train workers and operators on emergency procedures and situations. Replacing the actual blowdown system, as well as the numerous malfunctioning safety systems, alarms, and sensors were also not a high priority under a tight budget. The lack of alarms was the reason that some people remained unaware of the emergency that was taking place until after the explosion.

This horrible accident is just another example of how important it is to keep safety a priority in the workplace. Establishing and following standard work safety practices, doing routine tests and maintenance of safety systems, and encouraging open communication among workers are all important aspects of a safe work culture. Furthermore, investment into work safety should be considered synonymous with investments towards quality work and quality product. As we have seen in numerous case studies, the bottom line is a very thin line to walk alone; companies with a misplaced emphasis on it are setting themselves up for a dangerous fall.

References

Texas City Refinery Explosion - Wikipedia

What Went Wrong: Oil Refinery Disaster - Popular Mechanics

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Guru

Join Date: Jan 2008
Posts: 1756
Good Answers: 59
#1

Re: Texas City Refinery Explosion

08/02/2012 1:31 AM

Time and again, it is misplaced priorities, and human laxness are the real cause of the failures. And, without fail it was not single failure, but a sequence of errors not arrested successfully, that led to the ultimate failure.

The refinery, and some freight derailments are fairly simple examples.

On the other hand, the failure investigation of the space shuttle exposes the same human wishful thinking guided selfdelusion. And that is, at the top of our technological and management expertise. Still, sloppy and wishful thinking permeated the program. I still recall the phone conversation between the booster's engineers and NASA. The engineers obiected strenously to a launch in the out of spec cold temperatures. NASA wanting badly (for political, budget reasons) the launch, asked the same people to put on their "management hats". They did, and they approved!?!

What did change there in physical reality? Not a thing. A shuttle still went up in smoke, with consequences.

Recently, I saw an excellent presentation on airline safety in the same vein. It was heavy on human laxity, caused mainly by the excellent functioning of the automated functions. When those fail, things happen. A Korean (?) airline automatically strays, and soviet air defense mistakenly shoots it down. An Airbus from brazil to europa gets into turbulence, both pitot tubes freeze up. The computers lose their mind, the pilots are undertrained, and / or unable to wrest control from the computers. The plane goes into the drink.

In the present time, the failure rate from the horse and buggy, sailing ships, baby death rates, etc. are in the past. But the thinking is not adiusted to the present, low, still not acceptable error rate.

Something got to give. Muddled thinking first, IMHO.

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Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 5537
Good Answers: 503
#2

Re: Texas City Refinery Explosion

08/02/2012 5:27 PM

No matter what happens you will never out do the idiocy of the management.

Some years ago I worked for Praxair which is a a large industrial and welding gas manufaturing and supply chain. For many years they had all of their specialty gases made at a number of different plants around the country until one had a major accident and blew up.

After that the upper management decided it would be safest to put ALL the gas manufacturing in ONE location.

Apparently having 1 out of a a dozen or more facilities/eggs go up in flames wasn't good enough. Now all their eggs come from one basket so if one goes up everything goes.

Seems better on paper that way I guess.

__________________
"Bah Humbug and a merry buggering off to all. Now get out of my yard or I'll get the hose." tcmtech.
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Guru

Join Date: Jan 2008
Posts: 1756
Good Answers: 59
#3

Re: Texas City Refinery Explosion

08/02/2012 8:37 PM

I left out one category. The politician and buerocrats too smart by half, and hero in their own mind.

A few years ago Canada decided to go all metric inside the airline industry. Imagined progress, I guess. Now, the airline industry is a classical case of a Closed User Group. They get their fuel by lbs, fly by knots and sea miles, calibrate their altimeters by Hgmm, etc. Nobody cares, because nobody interfaces with them from the public on that operational level. On the other hand, inside everybody speaks the same language. Unambigouos even in shorthand.

So, outsider simply needed to sow confusion. They ordered canadians to take fuel in metric ( 0,43kg = 1 lbs). Some airlines got fueled up in the wrong system, and some crews did not catch it. A few near misses, then a fiery crash, as the airplane did run out of fuel, ad had to land at an unsuitable airfield.

Did anybody got hung for the transgression? Not that I know of. The blooming stupidity got quietly scrapped, and swept under the carpet.

That is what you get for being at cross purposes. And feel free to substitute your favorite actors into this tale.

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Guru

Join Date: Jan 2008
Posts: 1756
Good Answers: 59
#4

Re: Texas City Refinery Explosion

08/02/2012 9:33 PM

Then there is one more for plain and simple management hubris and arrogance. Until recently transport airplanes training and handling was based on the Boeing system. Fighter, aerobatic, small planes are in different categories.

Then came Aerobus, intending to compete. Innovating the use of composites. So far so good.

Then a fully loaded Airbus did take off New York's Kennedy airport, gets into the wake turbulence of an airplane (nothing unusual), pancakes into a residential area, and kills plenty. First thought is terrorism. Well, not so, but something much more mundane.

Aerobus decided to design differently, and require different airplane handling. Its vertical stabilizers (rudders) are fastened with limited strenght screws. The hydraulic actuators are strong enough to do damage to the plane itself. To show plainly, that the management was aware of that problematic area, the pilot training explicitly forbidden max. application of rudder force by the pilot. A figleaf, if I ever saw one.

The pilot, in a tough spot, applied his early Boeing style training, and countered the wake turbulence with vigorous countering on the rudder. It did shear off. And the uncontrollable airplane pancaked in.

Was that the fault of the pilot? Only a lawyer covering asses can think that way. In real life, in a tight spot training honed to an instinct takes over, and it better be right every time. Management hubris, with a lawyerish figleaf created an unnecessary contradiction for the pilot, that brought him (or her) into a conflict in a crisis.

Did I say, that setting limits on airplanes is wrong? NO!!. Airplanes are the most mechanically and aerodynamically limited structures I know of. But you deviate from a standard at your peril.

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