The weight of a railroad track is measured over a particular length. It is described as pounds per yard or kilograms per meter. The pounds-per-yard figure is almost exactly double the kilograms-per-metre figure. (i.e. 115RE rail is 115 lb/yd which is 57kg/m). The weight of track is an important factor that reflects the strength of that track. Generally speaking, the more rail weights, the more strength a rail has. As the axle loads get heavier and the train speeds get faster, more railroad track is designed and manufactured with heavier weight. At present, the heaviest railroad track is 77.5kg/m.
Factors that determine railroad track weight
- The weight of the rail should match the axle weight of the trains, and the axle ratio of 2.75 or more is reasonable.
- At a certain travelling speed, the vibration acceleration of each track component caused by the power of the train is inversely proportional to the rail quality. Therefore, to increase the travelling speed and ensure the line quality, the rail weight must be increased.
- The weight of the matched rail must be reasonably selected according to the total annual weight density.
How much does railroad track weigh?
Railroad tracks are produced or “rolled” into different sizes according to the rail standards of different regions or countries. Correspondingly, the railroad track weight varies.
|Country/ Region||Railroad Rail Weight|
|USA||AREA Rail 115(57kg/m), 119(60kg/m), 132(65kg/m), 133(66kg/m) 136(68kg/m), 147(73kg/m)|
|Russia||50kg/m, 65kg/m, 75kg/m|
|Australia||31kg/m, 41kg/m, 47kg/m, 50kg/m, 60kg/m, 66kg/m, 68kg/m, 73kg/m, 86kg/m, 89kg/m|
|China||9kg/m, 12kg/m, 15kg/m, 18kg/m, 22kg/m, 30kg/m,43kg/m, 50kg/m, 60kg/m,75kg/m|
|Japan||30kg/m, 37 kg/m, 40 kg/m, 50 kg/m, 60 kg/m|
At present, countries around the world use railroad rails for heavy-duty high-speed railways and ordinary-speed railways. For example, heavy-haul railways in Russia use R75 rails; the United States uses 136RE (65kg/m) and 140RE (70kg/m) rails; China’s main railway lines use CHIN60 rails. High-speed railways in the world use 60kg/m or heavier rails. For example, the rails used by the Japanese Shinkansen, French TGV and German ICE high-speed railways are all 60kg/m.
Length of railway track
Railroad rails are rolled in sections of fixed length. Lengths of rails produced are traditionally bolted together on each side with rail joints(joint bars or fish plate). This type of “jointed rail” brings large noise when the train passing by the jointed part. Also, it is a weak point on the railroad where needs much cost of maintenance. As the improving process of manufacturing, rail lengths have increased and is likely to increase more. This is for decreasing the joints between rails. After all, the joints are weak points for a railroad where a lot of maintenance work needs to be done.
The common length of railroad track across the world
|Country/ Region||Railroad Rail Length|
|USA||39ft (12m), 78ft (24m), 82ft (25m)|
|China||12.5m, 25m, 50m, 100m|
In China, the standard length of 43kg/m rail is 12.5m and 25m. Length of 50kg/m rail or above is 25m, 50m, 100m. The standard and most commonly seen lengths are 12.5m and 25m. With the progress of manufacturing technology, especially the supporting use of furnace refining, vacuum degassing and bloom continuous casting technology, it is possible to cancel the slow cooling of steel rails and create preconditions for production of the long-length steel rails. China now has the capability of producing long-length railroad track of 100m.
In other countries, long-length rail is also the trend of manufacture. To meet the development requirements of railways, many steel mills have carried out technical transformations for the production of long-length steel rails. The delivery length of rails in Japan is generally 25m and 50m; France is 36m and 80m; Voestalpine and Germany are 36m and 120m.
Compared with standard length rail lines, long-length rails have the following advantages:
2. Less damage to track components.
3. Reduce train swings, improve passenger comfort.
4. Reduce vibration and noise.
5. It is more suitable for the use of the multi-pick tamping machine.
Whether it is welded rail or jointed rail, the joints of two rails are always weak links of the railway. According to statistics, 80% of rail failures occur at the joints. For jointed rails, wheels will hit the rails at the joints. For welded rails, the impact of high-speed trains at the welds will cause tiny bumps on the rail treads, which will cause damage to the train wheels and rails, and cause train vibrations. Increasing the length of the rail and reducing the number of joints can reduce train vibration and improve passenger comfort. It not only reduces the rail-laying cost of the railway but also reduces the energy consumption of the locomotive and prolongs the service life of the rail.