Tunnelling machines.

摘要

A tunnelling machine has a tunnel lining stage 10 including a pick-up device 34 for picking up concrete lining segments 12 from the floor of the tunnel and placing them in position radially around the tunnel. In order not to damage the segments when picking them up and in order to enable the pick-up device 34 place the segments directly in position butted up against already placed segments, the pick-up device comprises at least one suction pad (40) adapted to engage the segments and means for evacuating the suction pad to hold the segment against the segment.