Tunnel boring machines successfully complete work on the Eurotunnel.
In July 1987, Kawasaki received an order for two tunnel boring machines (TBMs) with diameters of 8.17 meters for the underwater railroad for the Channel Tunnel linking Great Britain and the European continent. These machines were to excavate part of the two underwater tunnels from the coast of Sangatte in Northern France to the British coast. Due to the chalk strata on the French coast partly leaking with some faults, a sudden inflow of high-pressure water was expected during construction. In addition to these complex strata 40 meters under the sea and a high water pressure of a maximum 10 atmospheres, continual high-speed boring of 16 km at 500 m per month was also required. The difficulties become clearer when compared with the commonly accepted conditions for a TBM project: several km of boring at 200 – 300 m per month under a pressure of 1 – 2 atmospheres.
Furthermore, the leadtime from contract to design, manufacture and delivery was also set at only 13 months. However, because Kawasaki is a leading manufacturer of shield machines and TBMs, it aggressively surmounted these difficulties, supported by its expertise and track record for around 1,000 of these products. It was in June 1988 that the two machines were shipped from Kawasaki’s Harima Works with more than 10,000 parts and underwent test runs.