Contractors digging a new generation of super tunnels under the busy streets of London recently required a safe, efficient and cost-effective method of removing the new generation of tunnel boring machines (TBMs) from Canada and Germany. To facilitate the installation of 400KV transmission cables needed to meet the demands for electricity for London for the next 50 years, up to 30Km of new tunnels are being bored using the latest in boring technology. This is the largest project undertaken by National Grid since building the super grid in the 1960s.

While TBMs do a great job of moving forward and boring the tunnels, they are not so good at retracing their steps to reverse out of the tunnel they have just dug. project engineers from Rotrex Winches were appointed to develop a method for the extraction of Cleopatra, a name given by local schoolchildren, after it had completed a new 13km tunnel. This involved installing an HB40 base-mounted hydraulic winch at the bottom of the shaft next to the tunnel entrance from where it could carefully pull Cleopatra back along the new tunnel. The winch was hired to the contractor by Rotrex Winches along with a hazardous area electric power pack, bespoke control stand and all hoses.

There were many technical hurdles to overcome, however over a period of two weeks the project was completed successfully. This is another project where Rotrex Winches was able to rise up and meet the challenging demands of an ever-changing and complex construction industry. Rotrex Winches is not just a winch hirer but a genuine winch specialist with unsurpassed capability and knowledge.