The Córas Iompair Éireann 101 Class locomotives, numbered B101-B112, were built in 1956 by the Birmingham Railway Carriage and Wagon Company.

They were fitted with Sulzer 6LDA28 engines of 960 hp (720 kW), with four Metropolitan-Vickers MV137 traction motors.

With their design, size and axle loading, they were intended for mixed traffic duties, hauling both freight and passenger trains.

However, during the 1960s many of the secondary lines that they were used on were closed and following the arrival of the 181 Class, the 101s were relegated to goods, permanent way and pilot duties.

103 survived and has been preserved by the Irish Traction Group, and is currently in storage at Carrick-on-Suir railway station.