Sub-surface Railway

London Underground is introducing new rolling stock and a new signalling system on the Sub-surface Railway. To accommodate the new trains which are longer than the current fleet it has been necessary to make changes to the track layout at several junctions and stations. This has also necessitated changes to the existing signalling system pending the completion of the new signalling system. Rails and Tunnels Limited were invited to provide engineering support to Balfour Beatty Rail Limited for the changes to the track layout and signalling on the Metropolitan Line and the track layout at Hammersmith Depot on the Hammersmith and City Line.