Space spin-off for tunnel boring Machines

The picture shows Trude, the world´s largest tunnel boring machines (TBMs) with a diameter of 14.2m, excavating the new Elbe Tunnel in Hamburg, Germany. It took two years and five months for the German tunnelling company, Herrenknecht AG using Trude to drill the 2,561 metres underground tunnel. Trude is using a new transmitter produced by the German company Astro- und Feinwerktechnik Adlershof GmbH based upon know-how gained from their work for ESA on the Cassini-Huygens spacecraft. A number of these transmitters are mounted on Trude and provides a look into the ground in front of the TBM. Every second the transmitters send sound waves into the ground, microphones receive the reflecting signals which are data processed and visualizes important geologic changes up to 40 m in front of the rotary shear blade. Herrenknecht AG is now applying this new technique from ‘space’ in order to be able to drill tunnels even better and faster.