C [Weight per metre length] Explanation: The rail section is designated by its weight in 1b/yard or in kg/m. The standard rail sections in use on Indian Railways are 60 kg/m, 52 kg/m and 9OR for BG and 90R, 75R and 60R for MG and 50R for NG. In India, the standard rails are either of medium manganese or carbon steels.