The Córas Iompair Éireann 301 Class locomotives were the first diesel locomotives used on the CIÉ network, this class of 5 being built between 1947 and 1948 by the company for shunting use, particularly in the railway yards on Dublin's North Wall. They were a six coupled (0-6-0 wheel arrangement) locomotive, fitted with a Mirrlees TLDT6 engine of 487 horsepower (363 kW) with diesel-electric transmission via two Brush traction motors.