Converter Dolly trial

Second stage of Great Northern Highway upgrades underway

The second stage of upgrades to the Great Northern Highway, north of Ord River are now underway.

Deputy Prime Minister and Minister for Infrastructure, Transport and Regional Development Michael McCormack said, "Upgrading the Ord River section of Great Northern Highway between Halls Creek and the Victoria Highway turn-off is vital as it is a key part of WA’s highwide-load corridor and provides access to mining and pastoral leases and the Port of Wyndham.

Federal Member for Durack Melissa Price said previous network assessments carried out in the Kimberley region identified this section of the Great Northern Highway as substandard, given its narrow road width and excessive edge wear. "The current road condition meant opposing traffic needed to pass with minimal separation, forcing vehicles onto the unsealed road shoulder when passing," Ms Price said. "The road upgrades will further improve safety and efficiency for road users and continue to provide employment for local people and businesses.

Phase two of the Great Northern Highway Upgrade – Ord River North Project includes the realignment of 11 kilometres of highway and will be delivered by WBHO Infrastructure Pty Ltd.

Phase one works, which included reconstructing eight kilometres of Great Northern Highway between the Ord River and Tickalara Creek, were completed last year.

The $43.5 million phase two project is jointly funded, with the Australian Government committing $34.6 million and Western Australian Government $8.9 million.

CONVERTER DOLLY TRIAL

Atrial to measure the performance of an industry converter dolly prototype has showcased industry innovation, demonstrating superior capabilities when compared to other units.

The prototype was developed following concerns raised regarding dynamic issues with hinged drawbar converter dollies, in particular brake reactivity and tyre wear. The innovative new unit removed the pivot point of a hinged drawbar, making a dramatic difference in the brake system control.

The Australian Trucking Association’s rigid drawbar converter dolly was developed 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,” Mr Smedley 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

It performs and handles better than other dollies and this trial has proven it

in partnership with industry suppliers and manufacturers MaxiTRANS, Bridgestone, Hendrickson, JOST, Wabco and Alcoa, and has since undergone informal trials with operators across the country.

Delivered by members of the ATA’s Industry Technical Council and Toll Group, a formal trial has taken place to evaluate the converter dolly’s performance and acquire measurable data using Inertial Measurement Units (IMUs), strain gauges and GPS.

“We were looking to complete back-toback 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,” ITC Member and Managing Director of Smedley’s Engineers, Rob Smedley, said.

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 concept to reality, and based on the success of the prototype, MaxiTRANS have since manufactured and sold a number of these dollies,” Mr 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,” he said.

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, and said he was immediately convinced it was a superior piece of equipment.

“I was immediately sold on the idea and have since had a dolly manufactured with another one on the way,” Mr Baxter 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,” he said.

The prototype dolly will be trialled by one final operator in South Australia for further analysis before being sold.

To watch the trial video visit www. youtube.com/watch?v=tpDTwSN39WQ.