(Wed 25th Jun 2008)
Industrial Fire Journal / April 2008:
It is universally accepted that to fight a full surface storage tank fire successfully large amounts of water, foam concentrate and the hardware capable of projecting firefighting foam onto the burning surface area must be available simultaneously for a minimum of 60 minutes.
How this can be achieved must be addressed site by site, clearly highlighting the need for close liaison between petrochemical plant and the municipal fire and rescue services.
The wakeup call came in 1983 with the full surface fire of a 75-metre diameter floating roof tank containing crude oil in south Wales that presented many problems to the fire response crews over a prolonged period, culminating in the "boil-over" phenomenon.
As the Fire Chief at the Fawley Refinery ‚Äì and having attended this incident ‚Äì it became very clear to me how vulnerable the refinery was with respect to its then capability of fighting a full surface tank fire, with the knowledge that there was a major deficit in water supplies, foam concentrate storage and lack of large capacity foam monitors onsite or indeed tap into the major cooling water supply lines, ie 48" / 36" / 24" diameter above ground, salt water mains high volume low pressure, with the provision of 8" manifolds providing 6: (150mm) and 2.5" (70mm) outlets on each manifold strategically installed in selected areas around the site clearly identified for the use of emergency services only.
In addition, one mile of 6" (150mm) hose was purchased plus two purpose-designed hose trailers ‚Äì sufficient hose to provide fire water half a mile from each tank farm.
In Fawley's case, it was established that two miles of 6" hose would be required to provide sufficient volume of water to feed two large capacity foam monitors (24,000 lpm per monitor).
Over recent years there has been a change in philosophy for extinguishing full surface tank fires with minimum risk to firefighters, utilising high volume monitors that can be sited well away from the tank involved, thus avoiding the necessity of siting smaller capacity portable monitors inside the dike area, and exposing firefighters to unnecessary risk.
With this in mind, and to further improve tank firefighting capability, a major project was developed to purchase an additional mile of 6" (150mm) hose with associated ancillary equipment, two large volume foam cannons (Angus Colossus), although following extensive tests this was changed to two Williams Six Guns, and modification to two of the refinery foam trucks to provide one 6" (150mm) valved Storz delivery on each truck plus the purchase of one 6000 GPM (24,000 lpm) towable diesel fire pump providing flexibility for fire water availability.
With equipment now onsite and changes made, ongoing training continues being conducted both with refinery fire and response group and ‚Äì most importantly ‚Äì jointly with the municipal fire and rescue service. This culminated in November 2007 with a major tank fire exercise involving five counties, where crews from Hampshire, Dorset, Berkshire, Surrey and the Isle of Wight joined Fawley's fire and response group.
Without doubt Buncefield oil terminal incident focussed both petrochemical companies and municipal fire response groups alike, and with close liaison the incident was handled professionally by all involved.
The exercise was a massive logistical project with responding crews providing the required pumping capacity utilising their recently acquired HVPs (high volume pumps) under a new government scheme. These pumps are capable of delivering around 8,000 lpm connected into the 8" manifolds. In addition the two refinery 8,000 lpm fire trucks were utilised feeding one six gun, with the 24,000 lpm diesel pump supplying the second six gun.
With all the units operating and operational pressure of 9 bar achieved, foam concentrate was introduced to both monitors sited on the roadway adjacent to an empty 45 metre diameter FR tank with both foam streams meeting easily the trajectory required. For the first time an RAF (Royal Air Force) Chinook helicopter was used to transport one of the HVP units into the refinery, lowering it alongside a fresh water reservoir.
This was clearly a successful exercise, objectives achieved, demonstrating how critical it is for preplanning and to understand the logistics involved dealing with a storage tank full surface fire, underlining once more the importance of liaison between industry/municipal fire response crews.
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