JNR Class DD15

The Class DD15 (DD15形) is a four-axle Bo-Bo wheel arrangement diesel-hydraulic locomotive type operated in Japan as a self-propelled snowplough unit since 1961 by the national railway company Japanese National Railways (JNR), and later by East Japan Railway Company (JR East) and West Japan Railway Company (JR West). A total of 50 locomotives were built between 1961 and 1966, and as of 1 April 2016, 6 locomotives remain in service. A total of 50 locomotives were built between 1961 and 1966, divided into the following sub-classes. The Class DD15 was developed from the Class DD13 locomotive design, with the addition of snowplough units at either end. The snowplough units could be detached, allowing the locomotives to be used for shunting and other duties outside the winter periods. However, with the snowplough units mounted, the locomotive axle load was nearly 16 t, restricting use on rural lines, and so the class was superseded by the later Class DE15 locomotives, which had separate snowplough units. As with the Class DD13 locomotives, the Class DD15 had two 500 hp (370 kW) DMF31SB diesel engines. 46 Class DD15-0 locomotives were built between 1961 and 1965 by Nippon Sharyo, with the first locomotive delivered in November 1961. As of 1 April 2016, six Class DD15-0 locomotives remain in service. Four Class DD15-300 locomotives were built in 1966 by Nippon Sharyo.