The Eurotunnel Class 0031 are a fleet of twelve 0-4-0diesel locomotives used for maintenance duties in the Channel Tunnel. They were originally built to 900 mm (2 ft 11+7⁄16 in) gauge by the Hunslet Engine Company between 1989 and 1990 for construction work in the tunnel, and were subsequently rebuilt by Schöma to 1,435 mm (4 ft 8+1⁄2 in) standard gauge between 1993 and 1994.[1]