Rail grinding is the most effective way to maintain steel rail. Known from the railway track working principle, railway actually provides a continuous and elastic foundation for train operation. As the main part of railway track system, steel rail directly attach wheel bear a lot load from train. A part of load is absorbed by steel rail itself, and rest of load produce the rail wears like surface fatigue, crack, scratch, deformation and etc. Rail wears can result in reducing steel rail service life, more maintenance work, more maintenance cost and damaging railway running. So that rail grinding becomes a vital processing to the railway track.
Steel rail grinding is applied widely because of its high efficiency in the world. Generally, rail grinding is realized by rail grinding wagon. There are 4 strategies for different rail wears, such as corrective grinding, transitional grinding, preventive grinding and particular grinding.
Corrective grinding is mainly used to eliminate or reduce the shorts of online rail. In general, it adopts positive grinding processing, set the grinding amount in advance (0.5-6mm). And then, interval of working is relatively long, which depends on the severity of shorts.
Corrective grinding is not an economical method, because it requires removing amount of metal on steel rail, and reducing the working life by costing too much grinding processing. But, for ensuring steel rail have more longer useful life, corrective grinding is very necessary, especially in the time of tough budge. Besides, steel rail with corrective grinding will lead to speed limit of railway.
Transitional grinding is a long term strategy (3-6 years) for steel rail. Its main function is transform corrective grinding to preventive grinding. This kind of grinding should go through several times grinding cycle, especially for nonstandard steel rail maintenance. However, from the view of preventive grinding cost, transitional grinding is a better choice for rational utilization of limited resources. Compared to corrective grinding, transitional grinding require less metal remove. For example, grinding amount is between 0.3mm to 1.0mm; grinding amount of each grinding cycle decrease regularly.
Functions of transitional grinding as following:
The main surface defect of steel rail is correct by corrective grinding and transitional grinding. Next step is preventive grinding, also called periodic grinding. It is used to clear or control the surface defect of steel rail, keep good performance and appearance of steel rail. Preventive grinding usually require little metal (0.2-0.3 mm), and grinding processing is more frequent or controllable.
Particular grinding is a method for special purpose beside three types of grinding we mentioned above.
In conclusion, rail grinding reduces the defect of steel rail. It is a great way to protect steel rail and whole railroad track system. In addition to, there is many other railroad fasteners bear the load from train and have relative defect like steel rail, including railway sleeper, rail clip, railroad spike, railway switch, rail pad and so on. How to maintain these kinds of rail components? More details at How to maintain rail clips? How to install and maintain railway switch? How to protect railroad spike from corrosion?