PACCAR, in its development of trucks for Australia, is still primarily focused on heavy duty trucks and prime movers.
Electric may not prove as a viable path forward for this sector of the industry, with long haul and interstate travel the primary focus.
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“At least 80 per cent of road transport is done by heavy articulated vehicles, and that’s only increasing,” says Jonathan Crellin, Product Program Manager at PACCAR Australia.
“How are we going to keep building trucks that can suit the transport task in Australia? On average, a Kenworth K220 does 570km a day.
“Trying to convert those to an alternative fuel solution will be a very big challenge into the 2030s and 2040s.
“Using bigger combinations is one way our operators are trying to reduce their CO2 emissions.”
Head of Vehicle Homologation at Daimler Truck Australia Pacific Romesh Rodrigo says the manufacturer is focusing first and foremost on electric development.
He says they’re facing a ‘zero emission vehicle energy quandary’, with the current lack of infrastructure limiting how both OEMs and businesses can approach beginning their moves towards alternative power.
“Electric trucks are great in concept, until you need a charger,” Romesh says.
“Battery electric is what we have here now. The key thing that we want to hone in on is that our future is based on electric power.
“We’re going into a scenario where the energy form is up in the air. What we are looking at here is the power source we need to fuel trucks, whether that’s battery electric, hydrogen fuel cell or hydrogen combustion, we need electric power. Everything is aligning to single power source.
“The engagement level we have at the moment is with the Department of Transport. I want to present the argument that we need to be engaging with the Department of Climate Change and Energy. We have to start looking at how do we address our challenges.
“This isn’t limited to axle loads, but we’re talking about payloads with zero emissions. We need to look at how we support these vehicles with infrastructure.”
Study on coupling
While it was the host of the conference, the ARTSA Institute itself had its own major presentation to give, based on the findings of a study into dynamic loads on trailer couplings.
Conducted in association with the ATA, TIC and HVIA, it came about almost from necessity. Funding through the NHVR’s Heavy Vehicle Safety Initiative allowed ARTSA-I to conduct their first study in the area in 37 years.
As those who work with trailers would know, combinations have changed greatly since the late 80s, a time when B-doubles were a new venture.
ARTSA-I executive member and Chair of the working project group Martin Toomey released the findings ahead of the conference, with a number of key discoveries made.
The project involved the measurement of the coupling forces on quad-trailer 160 tonne road trains in situations that would mimic their daily routine over hundreds of kilometres in the NT.
An instrumented dolly was then used through different positions and combinations on the road train so the research team could measure the forces at different locations.
“Australia has always been a global leader in high productivity road freight,” Martin says.
“There was a lot of uncertainty about the engineering calculations needed to manage the forces of those extra combination vehicles.
“The previous study has never been revisited. We’ve now got vehicles operating in Australia that are much heavier. We put stress sensors on it and we could see what was happening under those new extreme forces.
“We could then validate those findings and come up with conclusions and calculations.”
Well-respected engineer Robert Smedley, the Managing Director of Smedley’s Engineers, was one of the leads on the project, responsible for one of the research streams.
They tested combinations including AB triple and AAB triple, and used the dolly to test the forces of the exact same load across different combinations. Most of the travel was done between Darwin and Katherine.
“We had a lot of different roads with lots of different surfaces and crossings to give some extreme test outcomes,” Robert says.
“In order to measure the forces accurately, we created arrays of load cells. Each one is calibrated, we designed them ourselves and road tested them. When you combine them in an array, you can get a load force path which operates in all six axles.
“You can get a very good picture of the force and the direction of it.”
With the movement of the dollies across the combination, the research team could get a strong idea of how force affects every trailer coupling along the truck.
They found that the forces throughout the coupling were similar no matter whether the dolly was underneath the second, third or fourth trailers. This was contrary to the conventional understanding that had been developed previously in current Australian Standards.
However, the peak forces that were experienced across the combination were in line with what was expected from the formulas provided in the Australian Standards.
One of the more interesting results from the experiment was that there was no evidence that maximum force would plateau as combinations got longer, with more trailers. Peak forces were proportional to the overall mass of the combination, meaning that it is dependent on weight, and not the amount of trailers.
Extremely high forces would most commonly occur when the vehicle was at very slow speed or coming to a stop. This included situations where the vehicle was braking, shunting or being manoeuvred.
The highest overall forces were measured while underway at low speed over floodways, which would be particularly relevant to rural operators.
