The usual methods involved imploding the tank and cutting sections out from above. This requires large cranes and is therefore time consuming. The solution also needed to be safer and be viable with the location’s restricted space. ALE produced an innovative plan that used climbing jacks to jack-up the tank, enabling the client to work at ground level to cut and remove a section. ALE then jacked-down the tank, ready to repeat the process.
The solution required a lot of advanced preparations. Holes were cut into the tank to install 20 climbing jacks, each with a capacity of 150t. They were positioned on top of concrete supports, at numerous points below the main steel construction pillars of the tank. Hydraulic hoses connected the jacks together, with a central contact point in the middle of the tank.
The jacking was carried out in stages of 1.6m at a time. ALE initially completed each stage in a day and a half, but this was reduced to one day. Once in a routine, the preparation carried out beforehand enabled ALE to work swiftly and complete the entire jack-down safely in approximately 11 weeks.