JNR Class DF40

The JNR Class DF40 was a diesel-electric locomotive operated by the Japanese National Railways from April 1956 to February 1975.
==History==
The DF40 was a prototype diesel-electric locomotive used by the JNR, with a single locomotive prototyped while the company developed its own locomotives for domestic sales as well as potentially for export. A total of ten locomotives were prototyped; these were Hitachi's DF90, DF91 and DF93, Kawasaki's DF40, Kisha Seizō's DF41, Nippon Sharyo's DD42 and DD93, Shin-Mitsubishi's DD40 and DD91 and Toshiba's DD41.
One locomotive was built in December 1955 by Kawasaki with a serial number of 14; at the time the locomotive was unnumbered. The locomotive was purchased by the Japanese National Railways in 1956 for a trial period and numbered DF40 1; immediately after assuming ownership of the locomotive the JNR performed modifications to the locomotive and deployed it to Takamatsu Rolling Stock Depot in April 1956, where it was used on tests on the Dosan Line before being returned to Kawasaki for modification works. Kawasaki returned the locomotive to JNR in October 1956, where it was placed again at Takamatsu and assigned to pull the Minamikaze express service and freight trains.
DF40 1 was sent back to Kawasaki in March 1957 where it got upgrades; during this time, Kawasaki and Toshiba were producing the DF50 diesel-electric locomotives. DF40 1 was returned to JNR in June 1957 and was transferred to Kōchi Depot in March 1958. In August 1958, JNR purchased the locomotive from Kawasaki and used it together with the DF50s, painting it in the same color scheme as well; the fact the DF40 used the same prime mover as the DF50-500 locomotives meant it was easy to procure spare parts. In October 1961, DF40 1 was reclassified DF91 1 with the introduction of naming regulations (not to be confused with the DF91 locomotive built by Hitachi in 1959), and was used until 28 February 1975 when it was withdrawn, it having the longest service life of the ten prototype locomotives the JNR used; the locomotive was stored at Tadotsu Works and scrapped some time later.
==Design==
The DF40 features a semi-streamlined design in what is known as the "Shōnan style".
==Specifications==
The DF40 was fitted with a MAN V6V 22/30 mA V12 prime mover manufactured under license by Kawasaki and a Kawasaki K4-730A electric transmission. The prime mover produced 1,200 PS (883 kW).
==Gallery==
DF40 1 1956.png|DF40 1 when newly manufactured
Category:JR Group trains
Category:C-C locomotives
Category:Diesel locomotives
Category:Diesel-electric locomotives
Category:Kawasaki locomotives
Category:Japanese locomotives
Category:Prototype locomotives
Category:Scrapped locomotives
Category:Scrapped diesel locomotives
Category:Built in 1955