JNR Class DD50

The JNR Class DD50 was a diesel-electric locomotive operated by the Japanese National Railways from 1953 to March 1975.
==History==
The DD50 was an early type of diesel locomotive used in Japan, and is notable as being Japan's first diesel locomotive intended for main line use. The vast majority of diesel locomotives operated in Japan were switcher locomotives, but with the progress of Japan's dieselization and development of a "smokeless" railway the DD50 was conceived.
Six locomotives were constructed by Shin-Mitsubishi Jukōgyō from 1953 to 1954. Designed with mass-production in mind, the increased cost of producing multiple units of diesels, excessive axle load and a lack of a heating system meant that no further DD50s were produced. When introduced, the locomotives were deployed to Tsuruga Rolling Stock Depot and used on the Hokuriku Main Line; they were used to pull express trains such as the Nihonkai and Hokuriku and some freight trains. When the Hokuriku Main Line was electrified the DD50s were moved to Tōyama; when that region was electrified as well the locomotives were moved to Maibara, where they ran shuttle services to ferry passengers between trains due to differing current.
The locomotives were withdrawn from service on 10 March 1975 with the introduction of the revised timetable, after which the locomotives were stored at Maibara Rolling Stock Depot and could be seen from passing trains on the Tōkaidō Shinkansen. The locomotives were struck from the register on 26 December 1977. No DD50s have been preserved.
==Design==
The DD50 featured a semi-streamlined design, nicknamed the "Shōnan style".
==Specifications==
The DD50s are fitted with a Sulzer 8LDA25 prime mover fitted with a supercharger; this prime mover is manufactured under license by Shin-Mitsubishi. The locomotive uses a Shin-Mitsubishi DF50 electric transmission. The prime mover has a power output of 1,050 PS (772 kW).
Two locomotives were typically connected back-to-back and were usually not seen running alone.
Category:JR Group trains
Category:B-B locomotives
Category:Diesel locomotives
Category:Diesel-electric locomotives
Category:Mitsubishi locomotives
Category:Japanese locomotives
Category:Scrapped diesel locomotives