Abstract: A method of constructing a lined or relined tunnel utilizes four lining segments, three of which (1, 2, 3) have a longer arcuate length than the fourth (4). The tunnel is constructed within a shield (20) having a tubular member (21) and a curved build plate (22) having a minimum internal dimension at least the same as the outside radius of the lining. The shield also has a circular skirt (25) the upper part of which is extended rearwardly to form a hood (26). In the method a length of tunnel is excavated and the shield positioned therein, a first segment (1) is positioned on the build plate and the segments (2, 3) then located upon the first segment (1). The ends of the second and third segments (2, 3) remote from the segment (1) are pivoted outwardly to locate the fourth segment (4).