JNR Class DD51
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 JR-Freight DD51 1166 at Shin-Fuji Freight Terminal |
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| Power type | Diesel-hydraulic |
|---|---|
| Builder | Hitachi, Kawasaki, Mitsubishi |
| Build date | 1962 - 1978 |
| UIC classification | B-2-B |
| Gauge | 1,067 mm |
| Wheel diameter | 860 mm |
| Length | 18,000 mm |
| Width | 2,971 mm |
| Height | 3,956 mm |
| Locomotive weight | 84 tons |
| Transmission | Hydraulic |
| Top speed | 95 km/h |
| Power output | 2,200 hp |
| Career | JNR, JR Hokkaido, JR East, JR Central, JR West, JR Freight |
| Number in class | 649 |
| Disposition | Operational |
The DD51 is a class of Japanese B-2-B wheel arrangement diesel-hydraulic locomotives. 649 locomotives were built between 1962 and 1978 by Kawasaki, Hitachi, and Mitsubishi. Despite this number, it is not quite the most numerous diesel type manufactured; that accolade goes to the DE10 class, with a total of 708 locos built for branch line and shunting use.
The class was designed for mainline passenger and freight use with more power than the D51 and a higher maximum speed than the C62 steam locomotive classes. This was achieved by installing two 1,100 hp engines in an 18 metre long centre-cab design, unusual for mainline operation. The V12 DML61 engines were developed from the 6-cylinder inline DMF31 engines used in the DD13 locomotives.
Locos numbered from DD51 501 to 799 and from 1001 to 1186 were equipped to operate in multiple, and locos numbered DD51 800 to 899 and 1801 to 1805 were built without steam generators for train heating.
All locomotives numbered from DD51 2 onwards were finished in the standard diesel livery of orange/red with grey upper surfaces separated by a white stripe. Re-engined locos operated by JR Freight in Hokkaidō sport a livery based on the DF200 colour scheme, with no white stripe, which lends them a more workman-like appearance. These locomotives are frequently used in pairs double-heading freight trains.
JR Hokkaidō locos are all finished in the stylish “Hokutosei” livery of blue with a gold stripe and shooting star logo. These are used in pairs for hauling sleeper trains (Hokutosei, Cassiopeia, and Twilight Express) between Hakodate and Sapporo. These trains must now represent the only opportunity to enjoy DD51 haulage on scheduled passenger trains.
DD51 592 (now withdrawn), and now DD51 791, was repainted in the “Euroliner” livery of pale blue with dark blue stripes for use with JR Central’s “Euroliner” Joyful Train set.
The celebrity of the class must however be number DD51 842, which is currently designated as the Imperial Train locomotive. Whereas regular members of the class have white handrails and edges to the running boards, they are polished stainless steel on this particular locomotive, as are the exhaust shrouds. Based at Takasaki Depot, it is also used for special excursion trains.
As of April 2003, there were 138 DD51s still in service, with the vast majority operated by JR Freight. Of these, many have recently undergone life extension refurbishment, which includes removal of steam generator equipment where still fitted. These locos are distinguished by a new livery of blue with grey upper surfaces separated by a white stripe, and cream end panels.
DD51 class locomotives also formed the basis for the DD17, DD18, and DD19 self-propelled snow plough units. The prototype, DD51 1, with its unique, more rounded appearance, is preserved at the Usui Pass Railway Heritage Centre in its original livery of brown with white lining.
[edit] References
- Kōichi Inoue, “Kokutetsu Kikansha Jiten” (JNR Locomotive Guide), Man To Man Books, 1999
- “2003 JR Zensharyō Handbook” (JR Rolling Stock Handbook), Neko Publishing, 2003
- “Tetsudō Zukan” (Railway Picture Book) JR & JNR Edition, Ikaros Publishing 1998
