Abstract: Apparatus for moving railroad cars, barges or the like along tracks includes three double-acting hydraulic cylinder mechanisms operatively supported from trackside overhead framework structure. A first, push-pull hydraulic mechanism is extensible and retractable within a plane parallel to the railroad tracks and the same is disposed toward one side of the tracks. A second, clamping hydraulic mechanism is supported upon the free end of the push-pull mechanism. As a result of the disposition of the first mechanism toward one side of the tracks, the clamping mechanism is able to positively clamp the upper side wall portion and said rail portion of the railroad car. Movement of the car in either a forward or backward mode is attained under the influence of the first mechanism. Alternatively, the push-pull mechanism can retard movement of the car and safely retains the car in a predetermined position when the mechanism is not actuated.