Rubber tire drive although not a new idea for Railcar Movers worldwide is unique in the United States where all major manufacturers with the exception of the Shuttlewagon still manufacuture weight assisted steel wheel drive movers.

The main advantage of the rubber tire drive system is that it does not require additional weight to be borrowed from the attached railcar in order to provide enough traction to move the railcar. Since the coefficient of friction of steel to steel is approximately .25 to .33 verses .70 to .80 for rubber to steel, a rubber tire drive produces two to two and a half times the tractive effort for equal vehicle weights. A low coefficient of friction and axle load restrictions limit the pulling capacity for these older type steel wheel drive Railcar Movers. Additionally, if not enough weight is available in the attached railcar to provide the weight necessary to increase traction not enough pulling force can be gene ated to move the load. This can be problematic in situations involving moving empty railcars.

The Shuttlewagon's rubber tire drive system produces the same pulling power regardless of the attached weight. The other major advantage that rubber tire drive offers is the pneumatic support for the axles provided by the tires. With traditional steel wheel drives the steel drive wheels are bolted directly to the axle hubs with no su pension of any kind. Borrowing weight from the attached railcar simply increases dynamic loads on the axles and other drive train components, adversely impacting axle and drive train life. The cushioning effect of the rubber tires provided by a rubber tire dirve system protects the axles and drive train from shock loads generated by pulling heavy loads along steel rails, while the inclusion of aniti-slip traction control (standard equipment on all Shuttlewagon models) prevents accidental over rotation of the tires on start up when pulling heavy loads and greatly improves tire life, a significant benefit for users.