Signalling infrastructure safety cases for Channel Tunnel services over British main lines

Construction of the Channel Tunnel resulted in the ordering of trains for International operations. At the same time, the then owners of much of the United Kingdom infrastructure, British Rail Network South East (since replaced by Railtrack), were developing a Safety Management System which would include assessment of safety cases before issuing Certificates to permit infrastructure changes or new types of train or operation. This anticipated the Railway (Safety Case) Regulations 1993 which became Law that year. The Safety Case is, in effect, a comprehensive document demonstrating that the proposed infrastructure changes or new trains are acceptably safe. The Signalling Infrastructure Safety Case, described in this paper, is just one of a number of documents supporting the overall safety case. The author discusses hazards analysis, track circuits and other signalling equipment