Buncefield Fire Accident - Essay Example

BUNCEFIELD INCIDENT al Affiliation) Key words: Buncefield incident, Fire Introduction Buncefield fire incident occurred in the morning of Sunday, 11 December 2005 at an oil terminal in Hertfordshire England. The terminal is called Hertfordshire oil storage terminal. The terminal was owned by Total UK limited and was the fifth biggest in United Kingdom with a capacity of 60 million gallons. The fire was caused by a series of explosions with the first explosion originating near tank 912. This led to further explosions that consumed over 20 oil tanks. The fire destroyed a large part of the Buncefield oil storage and transfer depot and in the process injured 43 people. There was no death reported (Mannan 2006). The first explosion occurred at 6 a.m., which led to more explosions that were heard over 200 km away. These explosions overwhelmed 30 storage tanks in total. The explosion was caused by overfilling of the large petrol tank 912 on the previous day; Saturday 10 December 20005.This was due to failure of control gauges that allowed employees to monitor the filling process of petrol in the tanks. The gauges were to automatically stop the filling process when the tanks were full. This failure led to escape of vapour petrol that floated off west of the site towards Mayland Industrial estate. The petrol vapour mixed with air forming a flammable cloud as seen on CCTV cameras. This cloud was then ignited violently and caused the first explosion. The fire was completely contained after five days. The two levels of controls were a gauge that failed to operate and an independent high-level switch (IHLS) which was not operational. The gauge was previously maintained in august of that year when it stuck but maintenance people could not explained why it had failed again. The independent high-level switch was not operational due to lack of a lever that was to maintain it in operational state. This was however not reported by the maintenance crew, which led to all the confusion (Mannan 2006). When these two controls had failed to control the flow of petrol from the tank, reliance shifted to a bund of wall surrounding the tanks, which are a secondary containment and system drainages and catchment areas, which were tertiary containment. These two containments were to retain the petrol from flowing into the offsite environment but these containments failed. There were pollutants from fuel and fire fighting liquids that leaked through these containments and flowed into underground water. This shows that the containments were not properly designed and maintained. The initial explosions were due to proper maintenance and management of the two controls. The designers of these two controls did not emphasize on the criticality of the gauge and the padlock to be used in the independent high-level switch to the people using them. The installation and maintenance of these controls were not carried out with the seriousness it deserved. The failure could have been eradicated if the design and installation was rigorous and up to the required standards. Clear guidance and instruction should have been passed to the installers on the importance of the importance of availability of the padlock on the switch at all times. The contract of ordering and installation at that time had been given to a company called Motherwell control systems. This company did not carry out their tasks properly. The secondary and tertiary containments were not designed and maintained to the required standards, which led to the aftermath leaking of petrol and liquid pollutants through them into the offsite environment and underground water. The emergency response of the escalating flow of liquid was not properly designed. If channels were available to confine the flow of fuel and pollutant after the secondary and tertiary containment had fail, then this flow of liquid could have been reduced (Mannan 2006). Apart from these inadequacy in design and maintenance, other key are were ignored. The level of petrol was control by the gauge and switch. In additions to these controls, an alarm depended on the proper working of these controls. If this alarm had been designed in a manner that it worked independently from the other controls, then it could have sounded and the incident could have been prevented. This alarm was not frequently checked and the Motherwell control system company did not test if it was working while it was installed. The filling process of several tanks was monitored by only one screen. This meant that the staff monitoring this process only views one tank at a time. This inadequate of screens prevented simultaneous monitor of the tank, which could have alerted the staff of overfilling of tank 912. The occurrence of filling event on the eve of Buncefield incident was somehow confusing. Control of rate of filling the tanks were not clearly considered there was an increase in fuel that was supposed to be taken into these tanks since one depot was not operating. The systems worked at rate higher than the recommended. This might have caused faster filling of the tank as was anticipated by the staff. With the controls not working, the events occurred faster due to faster rate of flow of petrol in this system (Fujimoto 2007). Several organizations undertook research over most part of southern England including London and parts of northern France to access the impact of Buncefield incident on air quality. The combustion of fuel produced smoke that was visible hundreds of kilometres from the site. This affected air and road traffic and that day and several days after the incident due to poor visibility. Flights were cancelled in some airports and some major businesses were interrupted. Air pollution was eminent but not on a large scale. The smoke slightly affected the quality of air in areas surrounding this site (Gant 2010). Surface water was also sampled along river near this site, namely, river Ver. Samples were taken both upstream and downstream for two weeks to test for presence of potential fuel and pollutants from fire fighting chemicals. Traces of these pollutants were discovered in samples taken from both upstream and downstream of river Ver but of low quantity. Zinc concentration in these waters was a little high. This pollutant concentration decreased after few day of sampling. Ground water is found 45 metres underground. Samples of soils around Buncefield site have been taken. They show presence of clay with flint, which is relatively not permeable. This can prevent pollutants from sipping down to the ground water. Ground water is a source of drinking water and other uses. Samples of water from boreholes surrounding the site have been taken to find out if pollutants have penetrated to ground water. Very small percentage of these sample show minimal pollutants in them (Gant 2010). The nearest source of drinking water around this site is 3kilometres away. Water companies have ensure that drinking water within a radius of 5 kilometres from the site is constantly checked and treated before distribution to avoid contamination of any kind. Land investigations have also been carried out. Trial pits were dug and samples of soil analysed in the laboratory. Results have shown that soil 30 centimetres from the ground have traces of fuel and pollutants from fire fighting chemicals. Fire fighting water has also been disposed, as it might have been contaminated. In general, the incident did majorly affect the environment, as most aspects of the environmental pollution were minimal (Gant 2010). The explosions that occurred in Buncefield incident had a larger magnitude than it was predicted. This is because, just before the water pump to fight fire had been started, over 250 thousand litres of had spilled from the tanks. The start of water pump might be the possible igniter of the fire becasuse immediately it was started, there was the first explosion. From scientific theories, explosions occur in a confined area. Pressure builds in this confined area until the area confining this matter fails thus an explosion occurs. In the Buncefield case, the cloud of petrol was not confined thus a clear understanding of the explosion could be that it originated from the cloud and blew the 912 tank that contained over 60 million gallons of liquid petrol. This explosion if a large tank containing 60 million gallons of petrol could be very devastating. In conclusion, Buncefield fire incident occurred in the morning of Sunday, 11 December 2005 at an oil terminal in England. The first explosion occurred at 6 a.m., which led to more explosions that were heard over 200 km away. These explosions overwhelmed 30 storage tanks in total. The explosion was caused by overfilling of the large petrol tank 912 on the previous day; Saturday 10 December 20005.This was due to failure of control gauges that allowed employees to monitor the filling. When these two controls had failed to control the flow of petrol from the tank, reliance shifted to a bund of wall surrounding the tanks, which are a secondary containment and system drainages and catchment areas, which were tertiary containment. References 1. Mannan, M. 2006. The Buncefield explosion and fire-lessons learned. Process Safety Progress, 138-142. 2. Gant, S., & Atkinson, G. 2010 Dispersion of the vapour cloud in the Buncefield Incident. Process Safety and Environmental Protection, 391-403. 3. Fujimoto, Y. 2007 The Buncefield Oil Depot Explosion and Fire. Journal of Occupational Safety and Health, 53-58. Read More