North Queensland carrier, Oakdare Holdings, has introduced three new Kenworth T659s into its operations.
The trucks are powered by a 550 horsepower Cummins X15 which has been matched with an Eaton 22 series Ultrashift plus transmission — the first automated gearboxes in the fleet.
The sidetipper roadtrains, rated to 165 tonnes, couple two trailers with a converter dolly and cart coal at a mine site in Collinsville in the Northern Bowen Basin.
Working in the upper thresholds of mass loading, the new trucks, which arrived in a daycab configuration back in January, are operating on private mine roads, with a permit for a public road crossing.
The new additions were originally ordered through Brown & Hurley in Townsville as part of a fleet replacement program.
The Kenworths they are replacing have, however, been retained and are now deployed in other, less demanding operations after a four-year service life.
The contract with the mining organisation requires the vehicles to run 24 hours daily, seven days a week.
As there are not too many more demanding applications for heavy vehicles, Oakdare has opted for a full heavy duty Dana driveline with a D2000F front axle, 52-190 rear axles and SD350 driveline on a 25-tonne-rated 6-rod rear suspension.
Of the 27 trucks in the fleet approximately 75 per cent of these are equipped with a full heavy duty Dana driveline according to Wes Connolly, Oakdare Holdings Managing Director.
“The heavy-duty driveline has given us minimal trouble,” said Connolly. “They’re a proven driveline. It’s robust. It’s strong. It’s reliable.”
“We went for the heaviest one available for a bit of extra comfort and security.”
According to Connolly, the Kenworth T650 to T659 models Oakdare operates, are a proven workhorse up in the area the fleet commonly frequents in northern and central Queensland.
“They’re a tough truck,” he said. “They work in pretty trying conditions giving you good service and reliability. That’s what it boils down to.”
The circuit the new Kenworth T659s travel on is 9.5 kilometres one way.
But in a 24-hour period an average number of loads can be as high as 30.
That requires the trucks to cycle around anywhere between 13 to 15 times a shift.
“It’s not a distance that gets us but the hours that the trucks do,” said Connolly.
The trucks that have been replaced had amassed 20,000 hours during their four years of service.
The fleet runs everything from B-doubles, which is their smallest combination to quad roadtrain combinations that cart quarry products to northern road works projects and mineral concentrate to Townsville Port.
“Probably half of our income is derived from the mining sector whether it be coal or metalliferous transport,” said Connolly.
The other half is derived from general roadworks predominantly supplying cartage for some local quarries to TMR projects.
Predominantly sidetipper focused in its operations, Oakdare is supplied its AZMEB units by MaxiTrans.
Until now, Oakdare has had, as a blanket rule, an 18-speed manual gearbox company.
“We chose the Eaton 22 series Ultrashift plus transmission just for the number of gear shifts that’s required on that job on the short cycle and to reduce driver fatigue,” said Connolly.
“It gives us more options to employ people that are only familiar with automatics. It opens our range up a bit more in the current employment climate where it’s hard to find people. We need to accommodate everyone for that sort of work.”
Eaton DM clutches offer the durability and performance necessary to withstand the high actuation conditions associated with automated transmission systems.
“We chose them just for the number of gear shifts that’s required on that job on the short cycle and I suppose to accommodate the various abilities of driver which we’re seeing coming through these days,” said Connolly.
“It gives us more options to employ people that are only familiar with automatics. So it opens our range up a bit more in the current employment climate where it’s hard to find people,” he said.
“We need to accommodate everyone for that sort of work.”
Although it’s too early to tell if the gearboxes have endured less stress given the move to automatics, Connolly is hopeful that they will help extend the clutch life.
“That’s one of the big things we’re focused on, trying to get better with automatic boxes,” he noted.
“The gearbox is programmed to start in first gear at every stop and we stop about seven times each way on each trip,” said Connolly.
“So clutch life is a critical concern for us going forward and it’s easier on the driveline by taking out a bit of human error which can crop up from time to time.”