transported, then laid on site, and welded to a longer length (1.5 - 2.0 kin), replacing the existing jointed rails. Several welding methods (flash butt, gas pressure, enclosed are Almino-thermic) can be used for both options, and the most suitable method must be determined according to the scale, conditions on site and other factors.
3.2 Use of a New Track Structure
Numerous maintenance-free track structures have been proposed, tested and laid over the last several decades. Japan is the unique country to have extensively laid slab tracks, a type of ballastless track, over approximately 2,000 km.
The standard gauge Shinkansen accounts for most of these tracks, but slab tracks are aggressively being introduced when elevating or constructing new meter gauge conventional lines, etc. This is proof that Japanese railways keenly feel the need to reduce track maintenance labor.
In the case of the Shinkansen, track repair costs and construction cost for slab tracks have been reduced to about 40% and 140% respectively compared to those for ballast sections.
Comparing construction costs and annual maintenance expenses, slab tracks are quite economically feasible for tunnels and viaducts.
However, there are many difficulties with laying slab tracks on lines which are currently in service. Therefore, several types of new prototype track structures which use composite resins and asphalt and which allow work to be performed during short train intervals are being laid or under test (See Fig. 5.).
