Ballast Tractor - Uses

Uses

The main use of ballast tractors is to move heavy and abnormal loads using an independent drawbar trailer, modular wheel-trailer units, or a dolly trailer. An advantage of using ballast tractors is that one can be used to push-steer a trailer around a corner. A girder trailer, for example, is double-articulated so the front tractor can pull the load around a corner whilst the rear tractor can push the rear end (at an angle) around the same corner. Therefore a push/pull combination can make an abnormal load more manoeuvrable than a rigid solution pulled by several tractors. Use of a following tractor can increase the control and brake force available when descending a hill.

Another specialized use for ballast tractors is in showman vehicles. The ballast tractor used in this case may be a typical tractor unit fitted with a ballast box used to tow one or more specialized trailers that contain fairground rides which may not fit onto a standard fifth wheel connecting trailer. The overall weight of showman's vehicles tends to be much less than those used for heavy haulage to comply with vehicle weight legislation, particularly axle loads. Sometimes, one or more generator sets for powering the rides could act as the ballast; a more economical solution than having dead-weight as ballast on a tractor and providing a separate vehicle for the generators. Modern generators tend to be smaller and can fit between the cab and the fifth wheel of a conventional tractor unit, reducing the need for fairground use of ballast tractors. A vehicle used for towing fairground rides may also be called a "showman's diesel road locomotive", reflecting back to the steam-powered showman's road locomotives that originally provided this function.

A ballast tractor is somewhat limited in its use in modern day road freight because tractor-trailer combinations are more flexible and practical to move normal heavy loads. A heavy duty tractor unit equipped with a temporary ballast box may also be used as a normal fifth wheel -based tractor-unit, but its kerb weight is often high thus reducing the payload of the entire vehicle, compared to a lighter-weight unit.