日本国铁为配合提高既有线路列车速度计划,于1984年5月下旬,在中央东线高尾——松本间进行了提高曲线通过速度的试验。国铁列车的通过速度,在运转管理规程中本有规定,但对高性能的优等列车,可在规定之外再提高5km/h的速度运行。因此,在半径1400m的曲线处为120km/h,半径 In response to the plan to increase the speed of existing line trains, Japan’s National Railways conducted a test to increase the speed of curve passing through the high tail-Matsumoto line in the eastern part of central China in late May 1984. The passing speed of the national railway is stipulated in the operation management regulations, but for high-performance superior trains, it can be operated at a speed of 5 km / h beyond the stipulation. Therefore, a radius of 120 km / h at a curve of radius 1400 m