The 7TM’s hydraulic jacking coupler moves horizontally, as well as vertically, to facilitate coupling on curves. The coupler lifts the rail car to transfer weight to the 7TM, giving it a tractive effort of 20,000 lbs on rail. The 7TM is powered by a 6 cylinder gasoline engine or a 4 or 6 cylinder diesel engine. A torque converter and a four speed transmission transfer smooth constant power to the railwheels.