’WE NOW have a defined and funded project’, SRA’s Executive Director, Technical, David Waboso declared on May 18. He was referring to the UK’s trial site for ERTMS on the Cambrian lines from Shrewsbury to Aberystwyth and Pwllheli, which was selected last year after the decision was made not to install it on the West Coast Main Line.

Waboso was presenting the annual report for 2003-04 of the National ERTMS Programme Team (NEPT), formed a year ago by merging the separate activities of three organisations. He explained that the Cambrian Early Development Scheme (EDS) had become the principal focus of efforts to demonstrate that the standardised product being developed as a joint effort by several European countries could be deployed successfully in Britain.

This means adapting signalling principles and operating rules to suit ERTMS standards, not trying to create a UK version of the technology. For example, it has been decided that the Cambrian will have speed limits displayed in km/h from 2007, with in-cab displays changing automatically from mile/h as a train moves onto the line at Sutton Bridge Junction in Shrewsbury.

The Cambrian line is single track throughout its 218 route-km. It is worked by Radio Electronic Token Block with unlocked sprung points at passing loops, except for 6 km between Machynlleth and Dovey Junction which has track-circuit block and will be controlled from a new computer-based interlocking at Machynlleth. A captive fleet of 11 Class 158 DMUs and four Class 37 diesel locos will get train-borne equipment. ERTMS will be thoroughly tested in shadow mode during 2007, and the existing RETB and signalling will be dismantled at the end of that year when ERTMS assumes full control of trains. The EDS project is due to be completed by the end of 2008, when decisions on its future deployment will be taken.

NEPT also has to demonstrate by then that a sound business case exists for deploying ERTMS across the network. With TPWS coverage still being expanded to reduce collision risk on 160 to 200 km/h lines, any attempt to justify ERTMS on safety grounds ’just wouldn’t work’, Waboso insists. It could only be used to replace lineside signalling that is life-expired.

But Waboso stressed that the European railways are at one in saying ’the business case for ERTMS is about much lower costs’. Equipping the trains is estimated to cost £253000 per loco or multiple-unit, of which there are currently 4832 in service in the UK. This adds up to £1·22bn, which is 24 times the cost of installing TPWS on the same fleet since 2001. Waboso believes the cost has to come down by 50%.