Trend of Rolling Stock Technology in Japan


    This reports gives an overview of the development of rolling stock technology in Japan after the Second World War and technological development required in the future. During the period from the second half of 1950s to the first half of 1960s, researches were promoted on high-performance and high-speed rolling stock. The research results were summarized to commercialize Shinkansen in 1964 that symbolizes a peak of technological development in the railway industry. After that, the Shinkansen networks were expanded and series 381 tilting express EMU trains were put into service on conventional lines. Except those innovative events in limited cases, however, technological development stagnated as a whole affected by the perennial deficit of the defunct Japanese National Railways (JNR). In European countries on the other hand, technological development for high-speed operation was triggered by the success of Shinkansen in Japan. As a result, TGV in France, ICE in Germany and other high-speed trains made their debut one after another to run at 250 - 300 km/h in the 1980s and 1990s. To compete with road and air transport that acquired a strong position after the improvement of expressways and airports, Shinkansen raised the maximum speed to 220 - 240 km/h on part of its network in the second half of the 1980s. During the transient period to JNR's privatization and division in 1987, a series of developmental activities were energetically promoted to raise the speed of Shinkansen trains on such themes as the developments of lightweight bolster-less trucks that feature high-speed running / curve-negotiating performance and improved ride comfort, lightweight aluminum alloy car body, three-phase AC induction motor drive system of the VVVF inverter control type, low-noise pantograph, and compact and streamlined roof-top and under-floor equipments that reduce the wayside noise level etc.. These efforts for technological development led to the debut of series 300 Shinkansen EMUs that run at the maximum speed of 270 km/h in 1992 March. This further advanced the Shinkansen rolling stock technology. Series 300X Shinkansen test cars ran at 443 km/h in 1996 July, which is the highest record in the domestic iron wheel / rail transport system. In addition, series 500 Shinkansen cars started revenue service at the maximum speed of 300 km/h in 1997 March for the first time in the country. To improve the ride comfort and curve running performance of narrow-gauge express EMUs of the natural tilt type, a controlled tilt truck was developed in the first half of the 1980s and put into use in 1989 just after the privatization and division of JNR. This truck, which controls the inclination of car body with pneumatic cylinders and improves the steering performance of wheel-set on curves, has been adopted for all express EMUs that have a tilting system in the country to cut the operation time on major narrow-gauge lines. As explained above, the Shinkansen and narrow-gauge rolling stock technology made great strides in the two-decade period in and after the 1980s to record the second peak in technological development. To attract more passengers by maintaining a superior position to that of airplanes, automobiles and other transport facilities, however, railway operators shall concentrate their efforts on technological development from now on to establish a railway system represented by such key words as (1) high level safety, (2) improved rapidity, comfort and convenience, (3) environment-friendliness and energy and saving, (4) maintenance-less system and (5) low costs etc.