Three track railway tunnel relining system - canopy is erected over central track, allowing this to remain in use

摘要

The invention is designed for the replacement of linings in three track railway tunnels whilst keeping the central track in service. This is achieved by erecting a canopy over the central track. This canopy totally encloses the track and runs on rollers on rails. The relining units consist of a number of portal frames which are supported on the two outer tracks. The first unit (A) loosens the old lining (v) and is followed by a unit to support the lining (B). A third unit (C) carries a working platform and pneumatic drills to break out the old lining. It also supports the soil behind the linings. A subsequent unit erects new linings.