New Converter Dolly to Hit the Road

new converter dolly to hit the road

Bob Woodward, Chief Engineer at the Australian Trucking Association tells about a new converter dolly to hit the road and explains what it’s all about.

Volvo Product Trainer and friend of the ATA Bill Manton has hit the road from Brisbane to Darwin, trialling the ATA Industry Technical Council’s exciting ‘proof-of-concept’ project – a new converter dolly design.

Led by the ATA Industry Technical Council and MaxiTrans, the project further developed a rigid drawbar converter dolly after issues were raised about the dynamic issues with hinged drawbar converter dollies, especially with brake reactivity and tyre wear.

With the support and provision of materials from MaxiTrans, Hendrickson, Alcoa Wheels, Bridgestone, Jost and Wabco, a prototype of the converter dolly was developed and put on display earlier this year at the Brisbane Truck Show, gaining an overwhelming amount of interest to trial the dolly. 

Bill Manton is the first to have trialled the dolly, taking it 7,000km on the return Brisbane to Darwin trip in a series of truck combinations including a Type 1 Roadtrain Class 2 combination, a Type 2 Roadtrain Class 2 ABB Quad and a BAB Quad.

While trialling the converter dolly, Billy was also taking Volvo’s new XXL Cab for a test run, to see how each would handle on the journey. Setting off from Volvo’s Wacol site, Bill had the truck set up as a B-double, towing the dolly through to Toowoomba. 

From Toowoomba, Bill had the combination set up as a Type 1 (A-double) unit to see how the dolly handled. He drove out to Dalby before getting someone else behind the wheel to assess how the co-driver was driving with the double road train combination.

During the rough areas along the Toowoomba to Roma route, Bill said the truck handled well and the dolly tracked as good as a B-double combination.

“The dolly was very stable over the rough sections,” Bill said. “There is noticeable reduced sideways movement and I was able to gain a tighter lateral tracking measurement whilst travelling over rough sections. It was also a great trip to get the feel for the Volvo XXL’s room and appreciate its refinements and large space in the bunk area.”

As manufacturers and suppliers are looking for safer designs, and operators are seeking improved productivity with safer outcomes, the converter dolly project and Bill’s trial have played an important role in enhancing industry safety and productivity. 

The needs of our industry are constantly changing, and the ITC is essential to ensuring operators and businesses stay up to date with best practice.

On the return journey from Darwin, Bill was joined by fellow Volvo Product Trainer Tim Sweeney.

“I’ve got to say, I have personally done this trip many times on 2-up express and I can honestly say this is the best truck ever,” Bill said. “I have been doing such a tough job in that environment, but the mattress is fantastic, sway and sideways movement is very limited and cabin noise is quiet. It’s comfort at its best.”

Coming through Mt Isa, Bill and Tim coupled the combination as a BAB-quad, moving the converter dolly further away from the truck. Bill and Tim noted a decrease in the handling stability, increased drag and increased fuel consumption, just by moving the dolly back in the combination. 

Bill estimated the increased sideways movement to be approximately 100-150mm sway on the fourth trailer though rough sections of the road. 


new converter dolly to hit the road


Since finalising the trial, Bill has provided the ATA’s Industry Technical Council with a detailed report analysing each aspect of the dolly’s performance. Bill’s report noted that compared to normal air suspension dollies, the converter dolly has much better handling in all areas.

“There is absolutely no kick-back felt in the cabin from the dolly over rough bumps which will contribute to a better freight ride over the dolly. It’s an amazing design and the best dolly I have ever towed,” said Bill.

MaxiTrans CEO and Managing Director,Dean Jenkins, says despite being an essential part of the trailer combination, the dolly is often neglected and overlooked, however due to the advent of A-Doubles, it has certainly become increasingly important.

“MaxiTrans, in conjunction with the ATA, have been working together on the concept for quite some time and although the rigid drawbar may not suit every combination, the recent feedback from initial trials demonstrate the safety benefits,” said Dean.

“In conjunction with the Volvo XXL demonstration journey from Brisbane to Darwin, the team found the combination to be very much more stable over rough sections, with reduced sideways movement, better towing in a straight line and absolutely better handling in all areas compared to a normal air suspension converter dolly with the normal hinged drawbar for on highway work.

“This is such a great initiative for MaxiTRANS to be involved in, assisting in making a real difference by delivering improved safety and handling for the wider transport community.” 

For more information or to get the Industry Technical Council membership kit, head to the ITC Website.


new converter dolly to hit the road