ABSTRACT
Herrenknecht has developed a special system that allows tunnel boring machines (TBMs) to turn 180 degrees in tight spaces – a major innovation for projects requiring a TBM transfer. The Herrenknecht TURN system (TBM Uplift and Relocation with Nitrogen) is the answer to the challenges of maneuvering massive TBM shields, whose single shields can weigh up to 2,500 tonnes or more, in confined environments. Each project presents unique conditions requiring intensive consultation and technical solutions developed in close collaboration with contractors and specialized partners. With the method developed by Herrenknecht, the TBM shield, including the cutting wheel, is placed on a custom-made steel cradle. This steel cradle is equipped with cushions filled with compressed nitrogen that lift the TBM shield so the machine can slide on steel plates with a low friction factor (0.01). Using simple tools (e.g. pneumatic chain hoists), the TBM is then manipulated and precisely positioned. This method allows the machine to be moved and set up for the next tunnelling phase with remarkable precision and time efficiency. In a meticulously planned operation, the Herrenknecht specialists used this newly developed system for the first time at the Filder Tunnel project in Germany to turn a 1,400-tonne TBM shield 180 degrees and transfer it into a parallel tube. With the system, the machine was moved little by little, ensuring stability and precision. Successful operations in Paris and London followed. In the summer of 2024, the system was used for the first time in the U.S. and a TBM shield with a diameter of 14 m and a shield weight of approx. 2,500 tonnes was turned and transferred to the parallel tube. Herrenknecht’s innovative system is an example of advanced service engineering solutions tailored to the unique requirements of each tunnel project, ensuring minimal disruption, maximum safety and maximum efficiency in the construction of complex underground infrastructure.
