Rail car mover
A railcar mover is a road-rail vehicle (capable of travelling on both roads and rail tracks) fitted with couplers for moving small numbers of railroad cars around in a rail siding or small yard. They are extensively used by railroad customers because they are cheaper than owning a switcher locomotive, more convenient and cheaper than paying the railroad operator to do the switching, easier and more productive than manual moving of cars, and in addition they are more versatile since they can travel on road wheels to the cars they need to move, instead of needing clear track.
Some have two drive systems and drive only on steel wheels on the rail, with their rubber tires lifted out of the way, while others have only one drive system and use steel rail wheels only to guide them and use their rubber tires on the rail, in a similar fashion to HiRail trucks. These systems have a higher tendency to derail while pulling loads and in curves.
Railcar movers are fairly lightweight, so in order to gain more traction some models transfer weight from the car they are hauling onto their own wheels to increase their effective weight. These models use steel wheels on steel rail, much like a locomotive, which provides a more consistent traction among wider variety of conditions. The steel wheels also last far longer than rubber tires and overall cost less to operate. Other models that employ the rubber tire drive while on the rail do not use weight-transfer from the railcar. In Europe, trucks (lorries) fitted with railway wheels and couplings are used as rail car movers (often called towing or shunting vehicles).
Numerous manufacturers produce railcar movers, in multiple countries. The first railcar mover was built by Whiting Corporation, now Trackmobile in 1948.
Well-known railcar mover brands in North America include Trackmobile, Rail King and Shuttlewagon.
Trackmobile is the most well-known railcar mover world-wide and began as an in-plant project at Whiting Corporation, Harvey, Illinois. In 1947 a young ex Navy fighter pilot and engineer named Marshall Hartelius was assigned to modify an old industrial locomotive Whiting had used for years inside their plant. Their locomotive was constantly being trapped on dead-end tracks, losing hours of productivity. Hartelius was charged to find a way to move it by road to avoid bottlenecks to railcar movements. He first designed a road wheel system to mount on the locomotive, but found it was cumbersome and complicated. Furthermore, in spite of the added utility of road-to-rail capability, the locomotive consumed a lot of fuel and oil and required constant repair. Marshall scrapped his first design and in its place submitted to his boss a concept for a vehicle specifically designed for in-plant rail movement. It had hard rubber tires to move by road and flanged steel wheels to work on rail.
The central problem was how to design a machine that was light enough for road movement and yet heavy enough to start and stop railcars. Hartelius' solution to this engineering dilemma: borrow weight from coupled railcars to increase the vehicle weight for traction. He designed a coupler head that could be operated from the driver's seat, and that would raise hydraulically to lift the railcar, transferring up to 49,000 lbs (22,680 kg) to the wheels of the vehicle.
A prototype was built in 1948, and designated the "Mule." It went to work in the Whiting plant and was an immediate success: railcar movement was accomplished in a fraction of the time the locomotive had required. It consumed little fuel, required little maintenance, and dramatically lowered operating costs compared to the locomotive. Hartelius had solved a difficult railcar switching problem for his company.
One day in 1950 Marshall wondered if other companies might be interested in a Mule.
He put one on a trailer and took it around the country, demonstrating the advantages of a mobile railcar mover.
Since that day, more than 10,000 Trackmobile units have been put into service in 54 countries.
In Ireland, Unilokomotive has been manufacturing the range of Unilok Road/Rail Wagon Movers since 1954. Diesel and Electric (battery powered)are available. The Unilok carries out shunting tasks that locomotives 4 to 5 times their weight would do, but with greater mobility and at a fraction of the cost.
In Italy Zephir produces rail-road shunters since 1977, both diesel and electric (battery powered).
In Belgium, the company UCA produces the UCA-TRAC, rail/road vehicles based on the chassis of a JCB Load-All (UCA-TRAC B) and JCB Fastrac (UCA-TRAC F). The UCA-TRAC provides traction through its rubber wheels.
AAR Type "E" coupler as may be serving on any rail car mover in North America. Pulling up on the link at the rear releases the knuckle allowing uncoupling.
Shunting vehicle (Unimog)