Placing explosives with an all terrain

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The 700t all terrain crane from the fleet of Bergheim-based crane contractor Wasel was positioned at the foot of the 250m chimney. It was responsible for hoisting the explosives crew together with their drilling gear and explosives up to a work platform on the flue at a height of around 140m.

Once there, they placed around 30kg of explosives in 140 boreholes. As a result of its enormous height, the giant chimney could not simply be demolished by placing explosives at its base, and instead it had to be demolished using a single-folding method.

From the same location, the all terrain crane with a total of 145t of slewing platform ballast, was able to also support the demolition work on the façade of the neighbouring building. Using its 91m luffing lattice jib, it was able to reach even the furthest points to help dismantle the façade.

A large platform which held a team of workers and the salvaged material was hoisted in full over the neighbouring 70m high building. The platform was then used on the other side of the building at radii of up to 80m. The safety cage, personnel and demolition material created a gross load case of around 8t. To manage this large radius, the radius of the slewing platform ballast was set to the maximum value of 8.4m. For working on the chimney with radii of around 45m, the ballast distance was reduced to 6.4m using the hydraulic slewing mechanism.

“A hydraulic unit was also on the site in the immediate vicinity of the crane in case of emergency. When working with safety cages and work platforms on the crane hook, a unit of this type is mandatory so that if the crane engine suffers a failure, the safety cage can be lowered safely at any time. However, it was not needed on the former power plant site. The crane, which, in fact, also has an integral emergency take down system of its own, functioned perfectly throughout the job which lasted several weeks,” said Liebherr.