Downtime reduced
September 1st 2005

The Storage Tank Division of MB Engineering Services has completed an intricate tank jacking procedure for BP Grangemouth that has reduced maintenance downtime during remedial work in the tank foundation and eliminated the need to replace the tank bottom.

The foundation for the 36m diameter, 11m high Tank 339 had suffered major settlement problems, with the tank bottom settling 400 to 450mm below the tank edge. To allow access for operatives and equipment under the tank to carry out repairs, the entire tank had to be jacked up by 2.5m.

The jacking system had

to support a jacking weight, including the roof, tank floor and snow loading, of 300t. It also had to resist wind loading. A Byggwik jacking system was modified to allow jacking from outside the tank. The system was braced to cater for all loads imposed during jacking.

MB Engineering Services devised a system where both the centre deck and tank bottom plate could be supported. This allowed the tank to be jacked and allowed the tank bottom to be lowered safely onto a new foundation. The system is suitable for roof tanks to 45m in diameter.