Safety Cases for Electromagnetic Compatibility of T121 Track Circuits and Eurostar Trains

This paper describes the approach taken by the authors to demonstrate the safety of continued operation of the T121 track circuits on Network Rail (NR) infrastructure that are potentially affected by the Eurostar trains which operate on the Channel Tunnel Rail Link (CTRL). The approach taken by the team from RLE, TRE and CSE was novel in that it has used a qualitative approach to demonstrate freedom from WSF, with a quantitative (analytical) approach based on a detailed electrical model constructed in a software-based network modelling package to demonstrate freedom from RSF. This was supplemented by detailed analysis of the operation of the track circuit receiver and the characteristics of the electrical noise produced by the trains.