During the three years it took to tunnel under the Channel, the 1575-tonne tunnelling machines, guided by laser beams, cut through nearly a kilometre of chalk marl a month, almost 50 metres below the seabed.

• 在挖掘海底隧道花费的3年时间里，1575吨重的隧道掘进机通过激光引导在海底下面大约50米处每月挖通将近一公里的白垩泥灰土。