Regarded as leaders in achieving outstanding Performance-Based Standards (PBS) outcomes, Smedley’s Engineers, as the first recognised end-to-end PBS consultancy firm in Australia, boasts a highly qualified team from trucking businesses, truck manufacturers, trailer builders and OEM suppliers.
That makes it notable given most, if not all other PBS assessors, have narrow industry experience.
According to Smedley’s Engineers Managing Director, Robert Smedley the team has close to 100 years in combined vehicle experience.
“The dedicated team at Smedley’s Engineers have backgrounds from right across the industry, providing the experience and know-how required to identify and resolve issues for their clients,” he says. “We are in touch with industry and what makes a difference to them and their bottom line.”
As a result, Smedley’s Engineers can identify and resolve issues that others cannot.
“When a challenge comes up, we aren’t afraid to get our hands dirty to solve problems for our clients,” Robert says.
As a nationally based PBS consultancy, Smedley’s Engineers are on the ground and hands-on when needed. Jackson Heil, a mechanical engineer employed by Smedley’s Engineers, worked with Laurie Brothers, Ron Finemore Transport (RFT), Chief Fleet & Maintenance Officer, to help develop a quad-quad B-double curtainsider set capable of operating in the eastern states with a Gross Combination Mass (GCM) of 77.5 tonnes.
The first iteration of the combination, according to Jackson, had two steer axles on the lead trailer and one on the tag.
The design was subsequently refined to the point where a suitable swept path could be achieved with just one steer axle on each trailer, thus significantly reducing the cost of the finished product.
“Working with axle manufacturer Hendrickson, we got it to one steer axle at the rear of each axle group which saved a lot of money,” he says. “It was a matter of figuring out the best way to set it all up and it slowly evolved to completion.”
The new flat deck curtainsider combination can run with a GCM of 77.5 tonnes hauling palletised flour from central western NSW to Sydney, Brisbane and Melbourne.
Customarily, Jackson will speak with the customer about what is required to begin with and where it is they want to transport their freight.
From here it is decided which type of combination is best going to suit their needs while delivering the best outcome on road networks around the country.
Improvements to heavy vehicle route access, long sought after by operators working in the space, have subsequently followed ever since these high productivity freight vehicles have been accepted and fine-tuned.
“As the road networks slowly improve,” Jackson says, “we have started to see better access being granted which has opened up other lanes for the 30m A-double that couldn’t be done to begin with.”
With a background in heavy vehicle manufacturing, Jackson is also involved in PBS certification and access space. In sum, he liaises closely with the manufacturer, operator and the road manager to achieve the best on-road result for all three parties.
“Once we compile our recommendations, we discuss everything and move forward with the customer and manufacturer to deliver the PBS outcome they are after,” he says.
The trend of using wide-base super single tyres is a big part of this design process.
“Hendrickson had done significant testing on super singles on quad-quad and tri-tri B-doubles and they passed this information on to RFT to use when setting up their new PBS combinations,” Jackson says.
Validation of the super single testing yielded, however, some different results than was initially expected. Super singles performed worse in Low-Speed Swept-Path evaluation during a computer simulation.
To verify the modelling was correct, Smedley’s Engineers commenced field testing.
“Lots of PBS assessors in the past have ‘wrongly’ assumed that super singles got the same LSSP results as duals, but they don’t,” says Robert. “We were surprised ourselves when this was verified in the field tests. We are happy to say, though, that we’ve developed a solution in conjunction with Hendrickson and MaxiTRANS.”
Smedley’s Engineers PBS accessor Andrej Bucko, who has completed hundreds of PBS assessments in addition to having developed vehicle simulation models, explains the variation in LSSP can occur when super singles are matched with self-steer axles. “The steer axles don’t turn as well with singles as they do with duals.
So, swept path was an issue with the Ron Finemore combination but not Visy, as they did not have self-steer axles,” says Andrej. “Additionally, we expect that the amount of difference between duals and singles in swept path will be dependent on the make and model of self-steer axle so a solution will have to be calibrated individually to a specific self-steer axle model.”
At low speed, so goes a common presumption, tyre dynamics are inactive and different configurations will not have a significant impact on swept path outcomes.
This is wrong according to Dion Simms, an Automotive Engineer at Smedley’s Engineers.
“The kinematic geometry of the same self-steer axle fitted with duals or fitted with super singles does differ and those kinematics really matter when you’re pushing for the best outcome for a given level of road network,” he says. “After seeing the results vary in response to the parameters in our test schedule, I know I came away with a reinforced respect for the quality of the ADAMS modelling we’re producing, and I wasn’t alone. PBS is seen as simulation centric. It was valuable to close the loop and see those simulations reflected in real-world results.”
With a background in OEM passenger vehicle architecture and motorsport, Dion joined the project to coordinate the physical testing and to conduct the data logging and reality capture.
He managed the field testing to verify the issues identified to get super singles to pass PBS.
Even so, for the past two years, Smedley’s Engineers have worked on getting super singles broadly into PBS at higher masses.
Earlier this year, Truck Industry Council (TIC) and the Australian Road Research Board (ARRB) engaged in pavement wear testing on new ultra-wide tyres (super singles).
TIC said test results would provide scientific evidence required to develop a case for increasing mass limits for heavy trucks and trailer axles fitted with wide base single tyres.
Super single tyres through PBS at masses equivalent to dual tyres have changed the game according to Robert because it means higher payloads, better fuel efficiency as well as improved tyre life and lowered tyre costs.
It leads to better environmental outcomes, too.
“This is one of the single biggest things industry can do to reduce carbon emissions in a long haul country like Australia – short of moving to nuclear power and batteries,” he says. “I have been a supporter of this initiative and worked closely with Chris Loose in getting the funding proposal to happen.
“We provided data about the safety benefits that was used in the submission for the funding.”
One of the byproduct issues with quad-quad B-doubles running at Higher Mass Limits (HML) is ensuring the weight distribution is exact so that each axle group is neither over nor underloaded.
“This is a common challenge with these combinations but I think for the most part RFT is managing to load the new combination close to its maximum GCM every time,” Jackson says. “This ensures optimum productivity benefits and maximum return on investment.”
Since last year Visy Logistics has been moving away from its standard B-double curtainsider configuration by embarking on an ambitious high productivity vehicle program by commissioning some 50 30 metre A-doubles.
The reduced swept path dimensions are achieved through low-speed cornering.
These A-doubles have a higher centre of gravity given the unique payload of cylindrical tall paper bundles which makes it a difficult product for load restraint and cornering.
Moving to super singles allowed Smedley Engineers to significantly improve the performance of the A-doubles, given they typically get a much lower payload heights than B-doubles according to Andrej.
“The Visy vehicle carried indivisible loads which provided a unique challenge,” he says. “Typically, if a vehicle fails SRT or HSTO the solution is to lower payload height until a vehicle passes those standards.
However, as the load is indivisible this was not an option. Super single tyres combined with wide axle track width, wide suspension hanger track and high roll stiffness suspension allowed us to meet the required load height.”
Being able to access tyre data is sometimes an issue since not many manufacturers perform the tests necessary for assessors to model super single tyres so there is a lack of data especially compared to more common sizes like 11R22.5.
“However, the National Heavy Vehicle Regulator have announced that the PBS system will be moving to a standard or ‘generic’ tyre where a single dataset will be used for a specific tyre size,” Andrej says. “Therefore make/model restrictions for super singles could become irrelevant.”
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