As the alignment of the tunnel is not straight in the horizontal plane
or in the vertical plane, the lining had to be designed to follow the
curves. The Paper explains how it was possible to use only twelve pos
itions to align the segments. The laser and computer guidance method i
s described and the importance of mix design and placement of lining s
egment mortar emphasized. The methods used to solve problems raised by
interaction between tunnels, reinforcement of segments, nature of gas
kets and bolting are examined.