Ballast tractor

Extra-heavy-duty chassis versions of mass-production tractor units are fitted with drawbar hitches and a separate ballast box as an alternative.

[citation needed] With a semi-trailer, ballast is added in the form of the weight of the attached trailer pressing down upon the tractor's fifth wheel.

Additionally, ballast tractors are often fitted with heavy-duty hub reduction axles, a combination resulting in exceptionally low maximum speeds.

[citation needed] A strong chassis is required to both support the extra ballast weight and pulling forces transmitted by the drawbar.

Other designs also included sleeping cabins in the ballast for the drivers and the crew for longer journeys and harsh weather conditions,[5] This made the height of the tractors increase significantly, these units are still used today in the gulf area due to extreme heat.

Earlier coupling consisted of in house made metal hitch which had loops to lock drawbar eyes with a pin.

Most high-volume manufacturers offer heavy-duty chassis versions of certain tractor units, which enable a ballast box to be fitted.

In Europe, manufacturers tend to send some of their products to another company (owned by the parent) to be converted into a special heavy-duty version.

Countries where modernization is taking place, such as regions of the Middle East and South Africa and Asia, operate larger number of ballast tractors due to the greater frequency of heavy loads (such as power station components) and infrastructure projects.

Apart from being used by fairgrounds as a direct replacement for the steam-powered showman's engine, specialist moving and haulage companies use ballast tractors.