Modernization and Maintenance of Track and Structure
Introduction
The modemization of railways has taken place by predetermining the various goals required to improve existing railway conditions. The former Japanese National Railways have been upgraded following a number of techniques, after deciding on the goals, methods and time frame for each railway division.
In some cases, tracks and structures were not at all involved, but in most instances, they were the main concern. The simple reason is that tracks and structures act as supports for railway transportation. Tracks, in particular, directly support trains, and so are heavily involved.
In Japan, since the Tokaido Shinkansen was built in 1964, construction of standard gauge Shinkansen has continued and 220 - 275 km/h operation has been introduced on 2,000 km of railway sections. My lecture will make no mention of Shinkansen except for notable examples.
1 Goals of Railway Modernization
As a general rule, upgrading of the railways has taken place for one or more of the following goals. I would like to examine both the specific methods employed in order to achieve these objectives and Japanese experiences concerning track and structure requirements and their effects.
1.1 Prevention of Accidents
The prevention of accidents is a critical requirement which lies at the heart of railway operation. Holding back on investment in this area endangers the lives and assets with which the railway has been entrusted. The very survival of railways ruined by delays in providing the required maintenance and investment is in doubt.
Investment in the prevention of accidents should be a top priority. The former Japanese National Railways implemented timely measures including those described below, and this policy has been continued to the present day even after privatization.
(1) Restoration of the ruins left by World War II
(2) Countermeasures for the derailment of 2-axle freight cars
(3) Disaster prevention against heavy rainfall and earthquakes
(4) Installation of ATS as a measure to prevent train collision accidents in dense traffic
(5) Measures for level crossings arising from increasing motorization
