Opinion: Converter dolly hits the road

By: Bob Woodward

A recent trial has yielded impressive results

Opinion: Converter dolly hits the road
The concept was originally on display at this year's Brisbane Truck Show


Volvo product trainer and friend of the Australian Trucking Association (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.

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, Manton 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, he had the truck set up as a B-double, towing the dolly through to Toowoomba. 

From Toowoomba, Manton has 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. 

Converter dolly.JPG

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

"The dolly was very stable over the rough sections," Manton says.

"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," he said.

As manufacturers and suppliers are looking for safer designs, and operators are seeking improved productivity with safer outcomes, the converter dolly project and Manton’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, Manton was joined by fellow Volvo product trainer Tim Sweeney.

 "I’ve got to say, I have personally done this trip many times on two-up express and I can honestly say this is the best truck ever," Manton says.

"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, Manton and Sweeney coupled the combination as a BAB quad, moving the converter dolly further away from the truck. They noted a decrease in the handling stability, increased drag and increased fuel consumption, just by moving the dolly back in the combination.

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

Read down to Steve Brooks' views and experience of the trolly, here

Since finalising the trial, Manton has provided the ATA’s Industry Technical Council with a detailed report analysing each aspect of the dolly’s performance.

His 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," Manton says.

"It’s an amazing design and the best dolly I have ever towed."

MaxiTrans CEO and MD Dean Jenkins says that 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," Jenkins says.

"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 www.truck.net.au/ITC

Bob Woodward (pictured) is chief engineer of the Australian Trucking Association

Bob Woodward.JPG

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