Ainscough had to remove and replace two water storage silos, which were housed inside a 15.5m tall building. In order to provide the necessary access and space, a section of the building’s roof covering and a number of supporting roof purlins had to be removed first.
Using a Liebherr LTM 1055-3.2 all-terrain crane to lift a man-basket, the contractor was able to access the roof and its purlins. Once removed, the roof section was lifted off and set aside to provide the required clearance to remove the silos.
With access arranged, the two existing 7.75t silos, which were 10m tall and 4.3m wide, were individually lifted vertically out of the building using a Liebherr LTM 1100-5.2 configured on full-rig.
With the silo carefully lowered to the ground in the vertical position, a tail line from the 55t crane working on half rig to allow the transport to get into site, was attached to turn the silo through 90°, resting it horizontally on the ground.
The 100t crane was then re-slung to lift the silo horizontally onto the waiting loader for removal from the site. The process was repeated for both silos.
Ainscough then lifted the replacement silos into the building using the same crane configuration as for the extraction following the same process but in reverse. The team then reinstalled the purlins followed by the roof section for its re-fixing ensuring a weatherproof seal.
The job’s complexity required the input of no fewer than 45 separate lift operations to complete the lifts efficiently and safely.
With two drivers, a supervisor and a slinger in attendance, Ainscough was able to complete the lifts in a swift and safe manner, as contract lift manager, Stuart Vintin, explained.
Vartin said: “Topping and tailing any load is always a complicated procedure that requires extra care, particularly in such a tight area but it’s something that we do day in day out. The lift involved a number of hazards, as we had to avoid drainage. One of the cranes was also half rigged due to the lack of room, and because of this planning was crucial. Our team worked well together and the job was completed successfully.”