The ATA’s Industry Technical Council and Toll Group have conducted a formal trial of the converter dolly to evaluate its performance and acquire measurable data.
Since the converter dolly was first revealed, it’s been gaining a lot of interest. Not too long ago, Big Rigs spoke to several transport operators who had been involved in informal on-road trials – and the feedback was very positive. You can read this story by clicking here.
The operators we spoke to had trialled the dolly under a range of different operating conditions, with various types of larger trailer combinations and in diverse terrain.
The latest trial quantifies the gains possible through the dolly’s design by providing data using Inertial Measurement Units (IMUs), strain gauges and GPS.
Led by the ATA’s Industry Technical Council (ITC), with technical and component support from MaxiTRANS, Hendrickson, Alcoa Wheels, Bridgestone, JOST and WABCO; the ‘Converter Dolly Project’ uses a rigid drawbar rather than the typical hinged drawbar to address issues relating to brake reactivity and tyre wear.
The innovative new dolly removes the pivot point of a hinged drawbar, making a dramatic difference in the brake system control.
According to the ATA, the trial of the converter dolly prototype has showcased industry innovation, demonstrating superior capabilities when compared to other units.
ITC Member and Managing Director of Smedley’s Engineers, Rob Smedley said, “We were looking to complete back-to-back testing of the rigid drawbar dolly and a standard hinged drawbar dolly when used in an A-double combination, comparing the lateral force accelerations seen in each of the vehicle units to determine which is better.”
The IMUs were placed above the axle group in the lead trailer, the converter dolly and the trailing trailer to measure roll, pitch and yaw, and lateral, longitudinal and vertical acceleration. Strain gauges were fitted on the converter dolly fifth wheel pedestals and towing eyes to measure correlation of forces and comparative stresses, while GPS recorded positioning and speed.
“Initial observations left me really surprised at how severely the hinge drawbar pitched and danced around on the road in comparison to the rigid drawbar. It will be very interesting to examine the final data of the difference in performances between the two,” Smedley said.
Toll Group National Equipment Manager Ian Lipplegoes said improving safety for all road users is a very high priority for Toll and the company was proud to support the trial.
“The trial has been valuable and early outcomes are encouraging. We eagerly await the final results which will help demonstrate the safety benefits of making the dollies accessible to all,” Lipplegoes said.
With the data gathered during the trial now being evaluated, MaxiTRANS Engineering Support Manager Greg Brown said the project was about building a safer, better performing dolly than those already on the market.
“With the support of the project partners, we have seen this project evolve from concept to reality, and based on the success of the prototype, MaxiTRANS have since manufactured and sold a number of these dollies,” Brown said.
“It performs and handles better than other dollies and this trial has proven it, providing a direct comparison between the rigid drawbar and a hinged drawbar dolly to see the performance differences on the same route.”
ITC Chair and Managing Director of Kel Baxter Transport, Kel Baxter, has had the opportunity to trial the dolly as it made its way around the country. “I was immediately sold on the idea and have since had a dolly manufactured with another one on the way,” he said.
“Our drivers have been very impressed as the whole setup makes the combination feel like a single unit, with no pitching. This dolly has better handling than both airbag and spring hinged drawbar dollies.”
ATA Chief Engineer Bob Woodward said the difference in the vehicle’s stability when using the converter dolly during the trial was incredible.
“Visually, the trial demonstrated how much more settled the combination with the rigid drawbar converter dolly was on the road, tracking and in corners,” Woodward said.
“It’s amazing to see what can be achieved in our industry when the talent and expertise can be brought together to deliver real outcomes. The team is excited to see what the data produces.”
The prototype dolly will be trialled by one final operator in South Australia for further analysis before being sold.