Lifting a tunnel boring machine from 35 metres under London’s streets
King lifting was contracted to remove a tunnel boring machine (TBM) from a National Grid London power tunnel shaft at its Wimbledon site in August 2022.
In Spring 2020 the National Grid and Hochtief-Murphy Joint Venture (HMJV) embarked upon a seven-year, £1 billion project, to rewire South London via deep underground tunnels, to keep Londoners connected to safe and reliable electricity supplies – due to be complete and fully operational in 2027.
Using TBMs, 32.5km of 3m diameter tunnels are being constructed deep below the ground, to carry high voltage electricity cables between Wimbledon and Crayford.
Intermediate shafts are required at key points along the route of the tunnel, which will be linked by TBMs as work progresses along the planned route.
To carry out the excavation of these tunnels, specialist equipment is required to lift and lower the TBMs to and from the intermediate shafts.
King Lifting removed a TBM from the shaft at the Wimbledon site and positioned onto transport for its onward journey.
The Liebherr LTM 1650-8.1 with its 700t capacity and 155.0t of counterweight was used for this project. The 8-axle crane is designed to deliver maximum performance. The easily interchanged boom enables operators to choose between a 54 or 80 metre telescopic boom, which delivers fantastic flexibility. A view of our LTM 1650 on site can be seen here.
The TBM was split into two parts with the heaviest being 45t and both were successfully removed from the bottom of the shaft, approximately 35m below ground level. Access to the shaft was restricted, however King Lifting is well equipped to deal with situations where space is limited, and all complexities were overcome.
All works were completed to plan and on time following rigorous health & safety protocols, resulting in another successful heavy lifting engineered solution from King Lifting.
Tunnel Boring Machine (TBM)