Øyvind Haave demonstrates how on
a curve, just a light touch on the
brakes is enough to start a trailer
skidding past the truck pulling it.
Photo: Rune Petter Ness

Stopping dangerous trailer skids

A Norwegian invention may reduce the number of fatal accidents between trailer trucks and cars.

Slippery winter roads make it easy for trailers trucks to skid. Roads with deep grooves or curves, evasive maneuvers, and sudden braking all raise the risk of a trailer skid.
Willy Marthinussen from Malm in North Trøndelag has invented a mechanism that stops trailer skids and straightens out the vehicle. The technological prototype for the mechanism has been developed in cooperation with NTNU.


The anti-skid mechanism consists of an intelligent control box that detects incipient skids and activates a mechanism that then counteracts the uncontrolled movement. A car with a trailer has one spot that allows for rotation: the trailer hook. A four-wheel trailer attached to a truck also has front wheels that turn. Hence, there are two weak points where a trailer on a large truck may skid. The control box continuously registers the speed and movements of the trailer. If a trailer starts to skid, the control box activates the counteracting mechanism immediately.


Two years ago, Marthinussen presented a sketch of the antiskid mechanism to the Department of Energy and Process Engineering. “We recognized the quality and potential of the idea right away – and we were eager to help develop it,” says PhD student Øyvind Haave and consultant Gunnar Kvernland. Practical solutions were discussed with hydraulics experts at the department. Marthinussen was aided in checking for possible patents of similar mechanisms, setting up a business plan and applying for funds to develop the product. The Norwegian Industrial and Regional Development Fund (SND) granted the inventor some money for first phase research. To document what happens when a large trailer skids on a slippery surface, the scientists and the inventor cooperated with a driver training school in the Trondheim area. A video recording was made as an experienced truck driver caused his rig to skid by nudging the brake a bit. “That was all it took for the trailer to almost skid ahead of the truck,” explains Haave. The video proved that you need a lot of room to accommodate a skidding trailer.



One fatal accident costs society more than 20 million kroner. In 2002, police registered 282 accidents involving trailer trucks on Norwegian roads. This is an increase of 6% from the year before. Thirty-one people were killed, and 387 were injured in 2002, all in accidents involving large trucks with trailers.

The next step was to involve the Department of Engineering Cybernetics in creating a mathematical model of the anti-skid mechanism. Once installed in a simulation program, the model provided scientists with the opportunity to study a variety of scenarios. The simulations illustrated how the mechanism reduced an uncontrollable skid on snow from a 90-degree to a 10-degree rotation without any help from the driver. With a normal reaction from the driver, the skid could be reduced to as little as a 2-degree oscillation. The mechanism also causes the trailer to stabilize the truck if it starts to skid.


The next phase of the project will be to test the anti-skid mechanism on a trailer truck; the group is looking for investors to help build a prototype. Eventually, the group hopes to establish a company together with GründerParken AS. This company, which will be called Wimasafe, will be in charge of commercializing the anti-skid mechanism.