Drawbar

The term drawbar has several meanings. It denotes the mechanical connection between a towed vehicle and the tractor, the electronic system with the identical task and an ancient tool. The first sense in particular is widely used, but they are all still in common use.

The drawbar as a mechanical connection between vehicle and tractor unit

In the past, the carriage and the draft animals had to be connected in a way that allowed a change of direction. After all, the horses or cattle had to be able to go left or right without dragging the carriage or overloading the material. With the invention of the internal combustion engine, this need continued. Agricultural trailers or camping vehicles, for example, need a connection in the form described. The drawbar follows the identical logic as it has for thousands of years:

• fixed connection with vehicles that have centrally arranged axles
• movable connection at the steering rim with trailers with several axles by means of a pivot steering
• in use with tractors usually made of metal
• with carriages possibly made of wood
• with carriages also used for braking

The electronic version

Electronic drawbars are controlled by a computer. There is no tactile connection between the individual vehicles. This means there is no physical connection. Nevertheless, the cars or trucks follow the tractor as if they were tethered. Sensors and specialised software ensure that the convoy drives safely and smoothly. The system is currently used practically exclusively in commercial vehicles on factory premises. The idea is to be able to move as many vehicles as possible with only one pilot, while using less fuel or electricity due to the low air resistance.

The tiller as an old-fashioned tool

The drawbar is a tool that used to be used for woodworking. It was suitable for removing large quantities of chips and for smoothing and finishing. In principle, it is a cross axe. For fine work, these drawbars are still used in shipbuilding, for example. It is unclear why the tools have the identical name as the connection between the vehicle and the towing animal or tractor. The shape of the tools suggests that they were used provisionally for the connection and that the name became naturalised in this way.