The Class 52 diesel hydraulic locomotive was introduced by BR Western Region in 1962 to provide The Class 52 diesel hydraulic locomotive was introduced by BR Western Region in 1962 to provide Warships. At this time the required power output was not achievable by a single power unit and the Westerns were fitted with two Maybach engines coupled with a Voith 3 speed hydraulic transmission. This had the added advantage that the locomotive could run, if necessary, on one engine which reduced the levels of breakdown and rescue previously experienced. The major drawback with the design however, was the high gear ratio experienced with the Voith hydraulic transmission.