The Class C51 (C51形) is a type of 4-6-2 steam locomotive built by Kisha SeizoMitsubishi and Japanese National Railways (JNR) Hamamatsu Works . The C classification indicates three sets of driving wheels. The C51 introduced 1.75 m (5 ft 9 in) diameter driving wheels to Japan. C51s raised the average speed on the Tōkaidō Main Line from 47.3 km/h (29.4 mph) to 55.3 km/h (34.4 mph). In 1930, a C51 hauled the first Tsubame (swallow) express, reducing travel time between Tokyo and Kōbe to 9 hours.[1]
^ abNaotaka Hirota Steam Locomotives of Japan (1972) Kodansha International Ltd. pp.57&96 ISBN0-87011-185-X