The JNR Class DE10 is a diesel-hydraulic locomotive operated by the Japanese National Railways and its various successors since 1966.
History[]
Designed to promote JNR's campaign of a "smokeless railway" to eliminate steam locomotives on the Japanese National Railways as part of their Power Modernization Plan, the DE10s were developed as a versatile freight locomotive for use on the Japanese rail network. Largely replacing the older DD13 diesel-hydraulic locomotives, a total of 708 locomotives were manufactured from 1966 to 1978.
The locomotives were designed based on trial results obtained from testing the DD20 diesel locomotives; wheel slips were frequent due to insufficient adhesion coefficient and excessive axle load made the locomotives too heavy and as a result mass production was abandoned for those locomotives. With this in mind and the DD13's inability to enter certain branch lines due to its weight, the DE10 was designed to solve these issues.
When initially introduced, the locomotives were used to haul passenger trains such as the Akatsuki and Nihonkai, as well as switching duties; their versatility however meant that they were used for numerous other jobs as well, such as pulling long freight trains and charter trains. When the JNR was privatized and split in 1987, all seven of the newly-formed JR Group's constituent companies took ownership of DE10s, making this the only locomotive to be operated by all seven companies of the JR Group.
Despite their age, the DE10 remains a mainstay of the JR Freight fleet, and is a common sight pulling freight trains, special trains, switching and towing out-of-service trains. 186 locomotives remain in service, while nine locomotives have been preserved; three other locomotives were preserved in the past but have since been scrapped. Many DE10 locomotives withdrawn from service on the main JR network have been resold to other private companies; within the JR network, the DE10 locomotives are being replaced with DD200 locomotives.
Design[]
The DE10 features a steeplecab-like design, giving it an appearance similar to that of a switcher locomotive; this design was chosen to help the locomotive reduce its weight by reducing its axle load. Unlike the similar-looking DD51 and DD13 locomotives, the DE10 features a long hooded design due to it only having one engine as opposed to two. The driver's cab is notably off-center; it was designed as such to allow for switching and short turnaround operations.
Specifications[]
The DE10s are fitted with a single V12 prime mover, designated the DML61Z, based on the DMF31S prime mover used on the earlier DD13 locomotives; this engine features strengthened pistons and a differently mounted intercooler to increase power output. Total power output is about 2,200 PS (1,600 kW). The DE10 uses a DW6 hydraulic transmission; the transmission works similarly to a Voith turbo transmission and features three built-in torque converters and two speed switching valves to change the locomotive's running characteristics for different applications such as switching or pulling heavy freight or passenger trains. As a redundancy measure to prevent overheating, a mechanism is built into the locomotive which sprays water on the engine; five portholes are used to drain the water.
Preservation[]
The following Class DE10 locomotives have been preserved:
| Number | Manufacturer | Date manufactured | Date retired | Location | Notes |
|---|---|---|---|---|---|
| DE10 1 | Nippon Sharyo | 13 October 1966 | 7 February 1987 | The Railway History Park, Ehime, Shikoku, Japan | Prototype locomotive; displayed under shelter |
| DE10 30 | 28 June 1968 | 24 October 1986 | Poppo-no-oka, Chiba, Japan | Displayed outdoors, coupled to passenger cars ORoNe 24 2 and OHaNeFu 24 2; formerly displayed on Floating Pavilion Yotei Maru museum ship | |
| DE10 88 | Kisha Seizō | 9 April 1969 | 7 February 1987 | Kotsu Park, Miyagi, Japan | Displayed outdoors, coupled to caboose Yo 13797; cab open for public viewing |
| DE10 95 | Nippon Sharyo | 9 July 1969 | 3 February 1987 | Mōka Station, Tochigi, Japan | Stored on siding |
| DE10 503 | 16 July 1968 | 9 December 1986 | Otaru City General Museum, Otaru, Hokkaido, Japan | Displayed outdoors coupled to various freight cars | |
| DE10 1014 | 21 May 1970 | 30 November 1993 (JR Freight) Fall 2010 (KFS) |
SL Kyurokukan, Tochigi, Japan | Displayed outdoors, used as parts donor; painted in unique variation of the Kansai Freight Service paintscheme | |
| DE10 1511 | 6 November 1970 | 20 October 1993 | JR Freight Central Training Center, Tokyo, Japan | Painted in JR Freight paintscheme, used for training purposes; not open for public viewing | |
| DE10 1677 | 28 September 1974 | 31 March 1987 | Kotsu Park, Saroma, Hokkaido, Japan | Displayed outdoors | |
| DE10 1702 | Kawasaki Heavy Industries | 13 July 1974 | 5 February 1987 | Mikasa Railway Memorial Hall, Mikasa, Hokkaido, Japan | Displayed outdoors coupled to freight cars SeKi 6657 and WaMu 66172 |
The following Class DE10 locomotives were preserved in the past but have since been scrapped:
| Number | Manufacturer | Date manufactured | Date retired | Last location | Notes |
|---|---|---|---|---|---|
| DE10 11 | Kisha Seizō | 16 February 1968 | 31 March 1987 | Konosu Shiritsu Fukiage Elementary School, Saitama, Japan | Displayed outdoors; scrapped 2015 due to deterioration |
| DE10 26 | Nippon Sharyo | 19 March 1968 | Kurate Town History and Folklore Museum, Fukuoka, Kyushu, Japan | Displayed outdoors; scrapped 2003 due to deterioration | |
| DE10 1005 | 26 January 1970 | 31 March 1991 (JR Freight) 16 March 1996 (Kamioka) |
Former Okuhida-Onsenguchi Station, Gifu, Japan | Displayed outdoors as Kamioka Railway KMDE101; scrapped 2007 |