Development of the Tokaido Shinkansen railway-axles in 1950s-1960s and risk management

Abstract

The Shinkansen Line has experienced no serious car-accidents since its operation start in 1964. Why has the Shinkansen Line been able to keep such a good safety performance? This paper intends to clarify the background and the reasons why those miracles became possible - when, what kinds of risks and what kinds of actions the staff of the Japanese National Railways took in, who participated in the development of the Tokaido Shinkansen railway-axles in 1950s-1960s as a designer, an investigator, a maintenance engineer, an inspector, or a top executive in technology. I discovered all the staff had been dedicated to their duties and their actions were prudent enough in general. As a result their behaviors have reduced the riskiness of their works objectively. But the most of the staff were not so much sensitive to risk itself as a few technical top executives of JNR. For example when the inspectors first found unexpected micro cracks on the 20% running axles in 1965, the top executives adapted a new management system in 1966 based on those inspections, which contained a systematic long-range R&D plan of high-quality railway-axles as well as an effective risk management for micro cracks.