JNR Class D51

The Class D51 is a 2-8-2 steam freight locomotive designed by Hideo Shima, chief mechanical engineer of the Japanese Government Railways, and built from 1936 to 1945 for that system and then for Japanese National Railways. It was a development of the earlier Class D50 and kept that engine's parallel boiler and wheel arrangement, but was made shorter so that it fitted the standard branch line turntables, and it used electric welding in place of riveting to cut weight and axle load. Production was shared among several builders, among them Kawasaki, Kisha Seizo, Hitachi, Nippon Sharyo and Mitsubishi, and it is regarded as the most heavily produced locomotive of any power type in Japanese railway history. The engines came in early, standard and wartime forms, and a few have been kept running on heritage services.