All pre-Shinkansen railroads in Japan were narrow gauge segmented tracks measuring only 3 feet 6 inches wide because of the country's mountainous terrain. These were deemed unsuitable for high speed use, so standard gauge tracks measuring 4 feet 8 1/2 inches between the rails were laid for the Tokaido Shinkansen. The track segments of the Shinkansen were welded together to form a continuous surface for greater high speed performance and safety, instead of individual track segments laid end-to-end with seams between each segment.
Curves on the Tokaido Shinkansen route are constructed to a relaxed minimum radius of 8,202 feet. The steepest allowed gradient ratio is 1/50. The entire length of the Shinkansen is grade-separated, with no road crossings over the tracks to interrupt passage of the train. Instead, the train descends through cuts beneath road crossings and passed through viaducts in urban areas.
The original Tokaido Shinkanzen consisted of 12 "0 Series" cars per train when it was introduced in 1964. This number was upped to 16 cars in 1969. Each 0 Series car was 81.5 feet long and 11 feet wide. The last of the 0 Series cars was retired from service on December 1, 2008.
All bullet trains are electric. The Tokaido Shinkansen is powered by 25 kilovolt, 60 Hz alternating current supplied on overhead power lines. The top speed of the O Series Tokaido Shinkanzen bullet train was 130 mph. The conventional narrow-gauge Limited Express train covered the 325-mile route from Tokyo to Osaka in six hours and 40 minutes. The maiden runs of the Tokaido Shinkansen cut that time to just four hours and by 1965 the bullet train had reduced it further to 3 hours 10 minutes. In less than three years, total passenger volume on the Tokaido Shinkansen reached 100 million and today it is the busiest high-speed rail route in the world.
