We were recently asked to lift a 9-tonne mini demolition excavator, along with other materials, 23 metres onto the roof of the building it was being used to demolish. The client, a specialist demolition contractor, needed to take down a seven-storey structure in a confined London urban area while keeping disruption to a minimum.
Our Appointed Person carried out a detailed site survey to check access, ground conditions, and lifting requirements. These surveys are vital in planning as they confirm the right crane for the job, highlight potential risks, and ensure the lift can be carried out safely and efficiently.
For urban areas, getting a mobile crane to its final location can be challenging. Moving a crane to a worksite requires detailed route planning, and this route must then be agreed with all relevant highway authorities.
This is the first half of the challenge. The second, and occasionally bigger test of skill and expertise for inner-city jobs, is getting the crane into the best rigging position.
A good rigging position provides stability by allowing the operator to fully deploy the crane’s outriggers on firm, level ground, while also permitting the operator to extend, rotate (slew), and angle (luff) the main boom enough to lift and move the client’s load safely to its desired location. This is important because the length of the crane’s boom, the angle of rotation, and its luff angle all affect the crane’s maximum load capacity during the lift. This means selecting the best rigging location, where the mobile crane can operate safely, is critical. For this job, the crane needed to work at a 13 metre radius to place the excavator onto the roof. The only viable location was a very tight, confined space with no clear access capable of accommodating a large crane.
To overcome this, the client used their expertise to remove part of the lower-level ceiling, giving us access to the rigging area. This allowed our GMK 4100L to be positioned safely and set up for the lift. With Dave operating, Carl supervising, and Felipe handling the slinging, the team worked with precision to manoeuvre the crane into place and carry out the lift.
Within a few hours, the excavator and additional materials were on the roof ready for demolition. Once the works were complete, everything was brought back down in the same controlled way.
This was a technically demanding but rewarding project — a great example of how collaboration between client and crane team can solve access restrictions in busy urban environments.
Thanks to J Mould for allowing us to share their photos.
