Upgrading of existing train connection between London and Dover (entrance to Euro tunnel) to a high speed line with double transport capacity.
The 2 back-up installations of this project consist each of 10 waggons and of a California switch. Their length is 210 m. They contain the complete infrastructure necessary for the operation of the tunnel boring machine and for the finishing of the tunnel.
Originally designed for 8 segment rings per shift, the plant reached heading performances of 14 segments per shift, which proofed that the system designed and supplied by Rowa exceeded the requirements by far. Since the „Central Line“ remains operational during the whole con-struction period, no interference with the train service is allowed, and therefore settlements are tolerated only in the order of millimeters. In order to keep the settlements within the tolerances, not only the lining segments are back-filled, but also the shield.
In addition, the roadway of the lining segment transport crane with a load of up to 4.5 t is situated in this area as well. The loads of the mentioned components and the fact that this area has to be freely accessible are the reason why the back-up installation 2 has to be supported through a massive open frame construction on auxiliary rails. These auxiliary rails had to be dimensioned specifically for these extraordinary loads.