Tunneling system for forcing tubular channel through banks of earth, uses cutting head on leading edge of sectional tube which is advanced through bank by reciprocating mechanism

摘要

The tunnel sleeve consists of three sections (20, 30, 40) which are forced through the earth as the cutting head (3) on the front of the first section (20) removes material. The head and first section are moved forward by jacking rods (21, 22), which are anchored to a support plate (41). The support plate is mounted on a stationary horizontal base (45, 46). After the front section has advanced by 20 cm, the other sections are moved up behind and the support is moved forward for the next cut.