The maximum test speed in the narrow-gauge (existing line) in Japan is 179.5 km/h recorded by the 381 series railcar in 1985 in the case of an electric train and 153.5 km/h recorded by the 183 series railcar in 1988 in the case of a diesel rail car. In the case of commercial operation, commercial operation is performed at the maximum speed of 130 km/h in the case of most main trunk lines and commercial speed also exceeds 100 km/h.
In Japan, the braking stop distance is specified as 600 m or less by the ordinance of the Ministry of Transport and the maximum operation speed is limited to 130 km/h at present because of the above limitation. However, it is estimated that the maximum operation speed of approx. 200 km/h can be realized from the viewpoint of the car performance even by the present technique. Therefore, the study of 250 km/h operation is progressed at present mainly by Railway Technical Research Institute.
An electric train has been unrivaled in the high speed car. However, a diesel rail car having a performance equal to the electric train has recently appeared and demonstrated its power in the non-electrification zones because a high performance engine and a high speed bogie have been developed and car weight has been reduced. Figure 4.2-1 shows Japanese typical high performance diesel rail cars and table 4.2-2 shows its main specifications.
These high performance diesel rail cars have the motive power performances of a maximum speed of 130 km/h and a 25 ‰ gradient balancing speed of 95 km/h or more and moreover, their sharp curve passing speed is improved by 20 to 30 km/h compared to the conventional speed and thus, they achieve a great speedup.
4.2.2 Car speedup technology
(1) Motive power system
For speedup, it is necessary to improve the maximum speed, curve passing speed, turnout passing speed, and acceleration and deceleration speed of a train.
