97304 entered service with Network Rail in July 2008, having originally entered traffic in January 1964 as D6917 and then having been subsequently renumbered as 37217 under the TOPS scheme in April 1974. In November 2008 the locomotive was named 'John Tiley', honouring the former Network Rail Engineering Manager and worked on the European Rail Traffic Management System (ERTMS) Early Deployment Scheme over the Cambrian lines in Wales; the pilot project for Level 2 deployment on other parts of the UK network. European Train Control System (ETCS) equipment was fitted to two car Class 158 diesel passenger units, as well as three of Network Rail's Class 97 locomotives and the project ran between 2007 and 2013. When not required for ERTMS operations, 97304 was available for Network Rail Test Trains and the locomotive is currently based out of Network Rail's Shrewsbury depot on RHTT operations.