Rear treat for heavy good vehicles

A purely mechanical solution is being used to steer the rear axles of heavy goods vehicles

Following the publication in February of our article, ‘Active steering corners with precision’, Yorkshire farmer George Mitchell got in touch to tell us about a mechanical trailer axle steering system which he has built himself and tested full size. It uses links and bell cranks, and includes a simple method of improving handling in reverse. Three semi-trailer axles are mounted on a turntable and, as the vehicle makes a turn, the tractor pulls the trailer round, causing the turntable to rotate relative to the trailer in the opposite sense. This acts on two link rods attached to bell cranks, which manoeuvre the front and rear sets of wheels into the turn, so eliminating tyre scrub and helping the trailer to follow the tractor, thus reducing any cutting in. More details of the technology appear in the April issue of Eureka.