British Rail Class 170 – The Turbostar Workhorse Introduced from the late 1990s, the Class 170 Turbostar became one of the most successful modern diesel multiple units on Britain’s railways. Built by Bombardier, these trains were designed to replace ageing first-generation DMUs and bring faster, quieter, and more reliable journeys to regional routes across the UK. Capable of up to 100 mph, the Class 170 is equally at home on long inter-urban runs and busy commuter services. With air-conditioned