Lateral force has been reduced, allowing the locomotive to move freely to the side within the restrictions in force with the 3-axle structure, unusual in the world.
1.3 Renovation of DD51 Diesel Locomotives
The renovation of badly deteriorated DD51 diesel locomotives is currently underway. The work involves reinstalling a new SA12V17O engine and replacing the bogie and basic brake equipment parts, transmission and inverter parts, electrical wiring, corroded air pipes and part of the exterior of the car body.
2 New DF200 Diesel-Electric Locomotive
2.1 Development Concept
(1) Demand for DF200 diesel-electric locomotive
In Hokkaido, long-range freight trains are hauled by diesel locomotives because some parts of main lines are not yet electrified. In electrified urban areas, however, recently freight trains compete with passenger trains that have higher speeds and high-density operation. The most commonly used locomotive in Hokkaido is the Series DD51 diesel-hydraulic locomotive. The series was designed in 1962 and has maximum power of 1200 kW and a top speed of 95 km/h, insufficient to keep to the schedules of higher performance commuter trains. The multiple use of two DD51 locomotives has therefore been employed to increase acceleration and train power.
The main goals in developing the DF200 locomotive are as follows.
* Higher operating speed of 110 km/h
* Higher acceleration
* Higher performance, in particular, faster climbing speed in mountainous areas
* Faster speed on curves
* Reduced axle weight
* Easier operation, less maintenance
The balancing speeds on flat ground are as specified below.
* 110 km/h (container freight train, 800 ton load)
* 100 km/h (container freight trains 1000 ton load)
