PROBLEM TO BE SOLVED: To provide a creep force measuring apparatus and a method, which can simply and easily measure the creep force between an actual rail and railroad wheels.
SOLUTION: A creep force calculating section 80 calculates the creep force as follows. A step 1 calculates a peripheral speed Vw=rω of the measuring roller 30 from a radius r of a measuring roller 30 and a detected value of an encoder 81 (a rotational angular speed ω of the measuring roller 30); a step 2 calculates the slippage rate s=(Vt-Vw)/Vt of the measuring roller 30 to the rail R from the peripheral speed Vw=rω of the measuring roller 30 and a detected value of an encoder 82 (driving speed Vt of a roller block 20). A step 3 calculates the equivalent friction coefficient μe=f/N from a detected value of a load cell 83 (tangential force f of the measuring roller 30 with respect to the rail R, based on a moment applying mechanism 70) and a detected value of a load cell 84 (normal force N of the measuring roller 30 to the rail R set by a pressure setting mechanism 40). In a step 4 the creep force is calculated, based on the slippage rate s and the equivalent friction coefficient μe.