The Córas Iompair Éireann601 Classlocomotives were built in 1956-1957, by Motorenfabrik Deutz at Cologne, Germany. They were 3 small shunting locomotives (601, 602 & 603) of B wheel arrangement and were fitted with a Deutz V8 F8L 614 engine of 130 hp, with Voith hydraulic transmission and chain final drive. They weighed only 18 tons and had a maximum speed of 32 kilometres per hour (20 mph). These locomotives were never fitted with train brakes, so had limited usefulness compared to their successors, the G611 class. The G601 locomotives were withdrawn from service between 1965 and 1972.
One of these locomotives, number G601, has been preserved by the Irish Traction Group and is currently awaiting restoration at Carrick-on-Suir. In 2010 a secondhand engine was purchased to replace the seized engine currently fitted.