Trackaxle dollies can serve two separate and important functions while linking trailers. The rear steer dolly improves swept path and reduces tyre wear while the front steer dolly improves high speed stability and reduces tyre wear.
Trackaxle has developed a dolly which reduces the high speed off tracking of combinations such as road trains, A-doubles and Truck and dog combinations. While it makes a combination much more stable (hence safer) at high speed, it also reduces stress on tyres and suspension in a low speed turn. We have carried out testing with an A-double loaded with coal to 85 tonnes GVM. There is a test for high speed off tracking where the vehicle carries out a "lane change" manoeuvre at 80km/hr, shifting laterally through 1.76m over 61 m of travel. We had cameras mounted on the steer of the prime mover and the rear axle of the tag trailer, with line markings for reference. The footage from these, combined with the video from a camera behind the vehicle, reveals how stable the vehicle is through this quite drastic manoeuvre. Check the testing video in our videos section,