Used Equipment Test: Doosan DA40 dump truck
Never one to shy away from climbing behind the wheel of any type of truck, Matt Wood heads off the roads he knows so well to take a look at the Doosan DA40 articulated dump truck
The opportunity arose recently for me to trade my logbook and bad highway attitude for some dirt road desert hauling and have a closer look at life behind the wheel on the other side of the chain link fence.
So I headed to Kalgoorlie and spent some time in a gold mine with a six-wheel drive Doosan DA40 dump truck. As you can see from the pics, it’s not a brand-spanker – this example is a part of ADT’s WA hire fleet. ADT is the West Australian agent for Doosan artics, so as a result they sell, hire and service these off-road bangers.
The DA40 has been updated a little since this truck hit the hire fleet. Driveline ratios have been revised, resulting in taller gearing for saving fuel.
The truck you see here is doing 1821rpm at 50km/h. The updated truck drops that down to 1572rpm. Also, the new DA40s also get a gradient meter on the digital display to help drivers keep an eye on stability when tipping.
I quickly learnt that out here there are no log books, no speed cameras and no driver-facing cameras. There are, however, rules, plenty of rules and inductions – and a breathalyser.
As I went through the induction, I realised I looked a bit silly wearing my crisp new hi-vis and shiny white hard hat. My boots lacked the red dirt stain of a local and my face lacked the thousandyard squint of someone who spends hours driving under the hard desert sun.
I was advised that many in the earthmoving industry call this type of truck a Moxy, which is a throwback to a brand bought by Doosan in the noughties. The trucks might be Komatsus, Caterpillars or other brand of articulated dump trucks, but ‘Moxies’ they remain.
Under the bonnet of the DA40 is a 500hp, 13-litre Scania which puts out a pretty hefty 2370Nm of torque. All that grunt is fed into an 8-speed (eight forward and four reverse) ZF torque converter automatic which then powers all six wheels.
The front diff is a ZF planetary drive while the rear uses one centrally mounted diff that powers both rear axles.
The rear end of the DA40 is a similar setup to a grader, with one diff driving all the wheels through a set of outboard gear wheels. It’s like hub reduction writ large.
Payload is 40 tonnes while the machine itself weighs in at about 30 tonnes. In gross weight
terms, this truck grosses about the same as a road-going PBS B-double, but only on six wheels.
To help with steering in the muck, the big unit has a rear-drive torque bias so it won’t pull itself off the road in slippery conditions.
A basic digital screen read-out displays all the vital information that a driver needs once the key is flicked. The DA40 uses hydraulic rather than pneumatic brakes and the park brake is an electric switch on the console. In fact, surprisingly, the Doosan doesn’t have any air systems at all.
On the day of our test, the truck was employed on a job building a wall for the gold mine’s tailings dam.
The boss was on the digger loading up the dump trucks as they filed along the dam wall. The loaded trucks then progressed along the top of the dam wall to where a D8 dozer was waiting to flatten the fill into the top of the wall. It was a round trip of only 3km or so.
I did a couple of familiarisation laps with a Kiwi fella by the name of Don, who’s been living and working in Kal for the last 10 years.
“It’s all about working hard and saving a dollar,” he says. “Hopefully in a few years I’ll have enough together to build a place back home and live the quiet life.”
The initial striking characteristic of the DA40 on the haul road was comfort. While Don was seated on a suspension seat, my butt was planted on a flip-down jump seat with little padding.
The Doosan was pretty darned comfortable.
The front suspension uses nitrogen-charged shock absorbers which do a great job of soaking up the bumps.
As I said, there’s no particular speed limit on this site, it’s pretty much down to common sense and comfort. You don’t want to spill your coffee after all.
We rolled to a stop on the dam wall and wait as the digger dropped excess fill from the wall into the bucket.
Once loaded, we proceeded at a modest pace down the road to dump. I’ve got to say that this thing was pretty darned quiet as well.
ON THE JOB
Then it was my turn to go for a spin, and I climbed up into the cab looking every bit like the seventh member of the Village People. Thunder rumbled ominously in the distance, echoing over the top of the scraggy eucalypts.
Then the heavens opened up, which in this part of the world means the day’s work can be cut short at any time. The red West Australian dirt quickly became greasy red clay mud. I’d already grown a couple of inches while walking towards the truck.
Driving heavy machinery in these conditions can quickly get treacherous but I found that, as an offroad machine, the DA40 does a pretty good job of keeping all its feet on the ground.
Unlike other artic machines, the Doosan’s oscillation point is in front of the articulation point. This distributes load across the front wheels a lot more evenly when turning in the muck. Without wanting to resort to wanky sports car language, it results in flatter cornering.
With about 32 tonnes of dirt in the tipper body, the truck feels stable enough. The chassis has a 7-degree slope up from the articulation point, which gives the big orange beast a pretty low centre of gravity when loaded.
The rear-axle group pivots up and down on a central axis, which also makes for some pretty gnarly off-road ability. The rear-axle group alone has a 15-degree approach angle and a 25-degree departure angle. And the front suspension has 16 degrees of wheel travel.
This was the first time I’d driven a vehicle with an off-highway-spec Scania engine. And I loved it.
Apart from having a reputation for being pretty tough and fuel efficient in industrial applications, the 13-litre donk has plenty of grunt on tap – it performs like a loud, hairy-chested cousin of its more subdued on-highway stablemates.
There’s even a bit of cheeky turbo whistle.
As I rolled through the site, the rain kept on coming and really started to make things greasy under the wheels. There was a bit of sideways action in places as all six wheels attempted to regain their purchase.
Tipping off was a piece of cake. Just pull back a lever to raise the body, and roll forward when empty; no tailgate switch and no air bags to dump. I could get used to this!
After a bit it was clear that the weather was going to bring the day to an early halt. Every vehicle on site soon ground to a halt before someone slid off the wall or the haul road.
But that was ok … I’d had my fun.
THE BOTTOM LINE
There’s a lot to like about the Doosan DA40 articulated dump truck, and most of that can be appreciated from the driver’s seat.
It’s a comfortable and almost cosseting beast. In fact, it rides better than quite a few road-going trucks I’ve driven. It’s also quite sure-footed off the haul road and in the muck.
Hauling dirt and ore appeals to the big kid in me. Big machines, roaring engines, mud and dust. But it’s just a little too far from an espresso machine.
I mean where am I going to get a piccolo latte out here? And can you even get single origin beans this far from civilisation? Maybe I’ll have to stick to the blacktop.
1. Hauling dirt in the desert made for a change of scene for reviewer
2. As you may have guessed, the 40 in DA-40 refers to the truck’s 40-tonne payload
3. The Doosan DA40 articulated dump truck is pretty awesome off road 2
The cab is simple but effective