| Class DF50 | |
| Powertype: | Diesel-electric |
| Builddate: | 1957–1963 |
| Totalproduction: | 138 |
| Uicclass: | Bo'Bo'Bo' |
| Britishclass: | Bo-Bo-Bo |
| Wheeldiameter: | 800mm |
| Length: | 16400mm |
| Width: | 2932mm |
| Height: | 3987mm |
| Locoweight: | 85.1 t |
| Tractionmotors: | MT48 x 6 |
| Maxspeed: | 90abbr=onNaNabbr=on |
| Poweroutput: | 1,060 hp (DF50-0), 1,200 hp (DF50-500) |
| Firstrundate: | 1957 |
| Lastrundate: | 1983 |
| Preservedunits: | 3 |
The is a class of Bo-Bo-Bo wheel arrangement diesel-electric locomotives operated by Japanese National Railways (JNR) in Japan from 1957 until 1983.[1]
The first batch of 65 locomotives was built between 1957 and 1962 with Sulzer 8-cylinder 8LDA25A 1,060 hp diesel engines.[1] [2] Production was shared between Kisha Seizō, Mitsubishi, and Nippon Sharyō.[2]
A later batch of 73 locomotives was built between 1958 and 1963 with MAN V6-cylinder V22/30 1,200 hp diesel engines.[1] [2] Production was shared between Hitachi, Kawasaki, and Toshiba.[2]
Class DF50 locomotives were intended for use on both passenger and freight services, and included a steam generator for train heating.[3] They operated on the following lines, including use hauling "Blue Train" sleeping car services.[2]
In later years, operations were restricted to Kyushu and Shikoku, with the remaining locomotives withdrawn in 1983, except for DF50 1, which later passed into JR Shikoku ownership.[1]
The locomotives were initially painted in all-over maroon with stainless steel bands, but were subsequently repainted into the standard JNR diesel locomotive livery of vermillion and grey.[2]
Three Class DF50 locomotives were preserved.[3]
See main article: Japan Railways locomotive numbering and classification. The DF50 classification for this locomotive type is explained below.