The BR High Speed Train, or Intercity 125 as it was marketed, is possibly our most successful class of passenger trains, having first entered service in 1976, and still beng used by four Train Operating Companies (EMT, East Coast, Arriva XC and FGW) and one open access operator, Grand Central. Over the years they've been extensively rebuilt, both mechanically and in terms of seating arrangements. Today the bulk of the fleet have been re-engined with MTU prime movers although the EMT allocated units are equipped with Paxman VP185s. They will continue in frontline service for a number of years yet, although electrification of the GW and Midland mainlines and the uncertain prospect of the Hitachi IEP may doom them by the end of the 2020s, by when they will have been in service, racing up and down the country for over 50 years.