Abstract: The apparatus includes two somewhat convex shoes clampable along the adjacent sides of a pair of rails for engagement by the peripheries of wheel flanges so that the wheels are raised just clear of the rails, a load-sensing device at the highest portion of each shoe, and load-indicating means connected to the devices. The apparatus is sectional, the shoes being urged apart into rigidly clamped positions by two struts separable from the shoes to facilitate portability. Two spaced-apart support members are secured to each shoe to embrace its outer and lower faces, each support member being vertically adjustable relative to the shoe to suit different heights of rails. The shoes have replaceable wear-strips.