Weight of Rail per Meter means total weight of rail in one meter. 52kg/m (really 51.89kg/m, 105lb/yd) rail is also used extensively. And is denoted by w. Weight of Rail per Meter is usually measured using the Kilogram per Meter for Linear Mass Density. Note that the value of Weight of Rail per Meter is always positive. Typically, the value of Weight of Rail per Meter is greater than 0.