Irregularities in rail geometry can give rise to very high dynamic loads. These defects partly occur during manufacture of the rails and are known as rolling defects and during operation in the form of corrugations.
The only remedy for such defects is grinding. A typical Rail Grinding train consists of a series of vehicles equipped with grindstones, which form a grinding effect on the rails surface, thus producing smooth surfaces and eliminating rail irregularities on specific profiles. Rail profiling is done to keep larger contact bands at the wheel rails interface, reducing stress that causes shelling and corrugation. In addition, profiling can also provide steering effect through curves to reduce flange wear and noise from flanging and wheel screech. Large wheel rails are important for rail lubrication, to help reduce rail wear and screech.
Rail grinders are designed to grind away a thin layer of material from the rail surface before surface cracks can propagate. The accurate application of the rail grinding program enables transverse rail proﬁles to contribute to:
Significant reductions in wheel-flange and high rail-gauge - face wear
Reductions in rolling contact fatigue
Improved vehicle stability;
Reductions in the formation of corrugation; and
Reductions in wheel/rail noise.
Rail grinding is a practical and economical technique for removing the surface defects and also for maintaining suitable rail proﬁles. Appropriate rail grinding interval depends on rail metallurgy, track curvature, axle loads and fasteners. Recent researches indicate that a multi - prolonged approach, including the use of premium, high hardness rail, wheel/rail lubrication and rail profile grinding is effective for extending rail life.