Rail is weighed by the yard...( a yard is 3 feet or 36 inches)
If you look at the rail and it says 154 on it then it is "154 pound
rail". The lighter 138 pound rail is not as heavy duty as the 154
pound rail. There are many different rail weights.
In order to "weigh" the rail you would have to see what pound
rail you have then measure that by 3 feet then times that by how
long the railroad track is that you are trying to weigh.