Abstract: The invention is concerned with a method of constructing a lined tunnel using a tunnelling shield having a tall skin and in which the tunnel lining is of the expanded type comprising a number of ring sections 4 fitted together end to end and in which each ring section 4 is formed from a number of arcuate segments 5 which are fitted together circumferentially and which are expanded radially into contact with the surrounding ground 1. The expansion may be effected by means of one or more wedges which are driven between pairs of the segments, or by jacks which are expanded between segments.