including those described below, and this policy has been continued to the present day even after privatization.
(1) Restoration of the deteriorated conditions 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
(6) Reinforcement and replacement of deteriorated structures
1.2 Increased Transport Capacity
Increased transport capacity is called for when transport demand rises over railway sections, and the means to achieve it are diverse.
Typical methods include increasing the number of trains, lengthening train make-up and enlarging cars, each of which critically affects track and structures.
Increasing the number of trains will increase track maintenance work. Moreover, maintenance work is carried out during the interval between trains, so reductions in track maintenance time due to increase of train number must also be taken into account.
We must also consider that once the number of trains exceeds prescribed limits, relief tracks must be built at the stations. Depending on the increased number of trains double tracking may be necessary. Relief tracks may need to be extended if train make-up is lengthened.
Enlarging size of cars has a more significant effect. It will increase the axle weight of cars. This problem cannot be covered by maintenance work only. It will lead to the strengthening of track structure and other structures. Especially bridges must be reviewed in detail, and reinforced and replaced as necessary.
1.3 Higher Speeds
Higher speeds are the eternal pursuit of mankind, and a key element in the competition with other means of transport. We are now in an age where a speed of 300 knVh on standard gauge lines is a reality, and the race is on for 350 km/h. Furthermore, magnetic levitated linear motored train capable of running at 500 km/h are undergoing service tests. Even on meter gauge lines, speed is being increased by and by. Level crossings with roads present a greater obstacle than gauge against speed up.
