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Far from Frigid



Every industry has its own vernacular, ‘lingo’ and acronyms designed to prevent entry to the outsiders looking in. The earthmoving sector is no different with an array of perplexing if not amusing terms to describe equipment and mechanical issues; many deemed inappropriate for such a well-respected magazine as @ The Coal Face!

Which brings me to today’s topic of Articulated Dump Trucks or ADT’s otherwise affectionately known as ‘Artics’. Far from frigid, there is a lot to like about these versatile off-roaders that are as comfortable in land subdivisions as they are muddy construction sites, infrastructure projects and mine sites.

Conceived in the late 50’s, early 60’s these three axle machines are mechanically driven and generally range between 25 to 60t. Fast (think in excess of 50km/h) and manoeuvrable, there are an array of manufactures vying for business that include Volvo, Cat, Komatsu, Terex, Bell (also marketed under John Deere), Doosan and/or Moxy. 

Broken into two key sections, these machines comprise a main tow unit or tractor with a dump body aka trailer. Unlike conventional trucks, steering on these machines is completed by hydraulic cylinders that push and pull the tractor relative to the trailer allowing both sections to move at great angles and tight turning circles. 

With a trailer that rotates on a horizontal plane to the tractor unit and back axles that pivot relative to the trailer frame, these trucks are extremely rugged off roaders that can negotiate great inclines and slippery conditions with all wheels in contact with the ground; a design that allows them to move quickly and efficiently in areas that would otherwise compromise larger rigid vehicles.

While miners are known to enjoy the flexibility that these trucks offer, this category of off-road hauler has come under increased scrutiny regarding safety with a higher than average incidence of rollovers. 

To reduce these incidents, manufacturers have directed their efforts towards stability assist systems as well as the development of low centre of gravity water tanks and service modules to keep the weight of the truck’s load as low to the ground as possible. 

Available in a dazzling array of configurations, in the Valley you will likely see these trucks fitted with a standard ‘tub’, water tank or service module however, depending upon their application (and location) can be used as concrete mixers, container trucks, hook loaders, cranes as well as the odd rocket launcher

In context, many of you may remember the scenes following Hurricane Harvey in 2017 when Caterpillar ADT’s were used in Houston to aid rescue efforts within the local community. Looking more like amphibious army ducks, these machines were able to negotiate deep water crossings that normal civil machines would not contemplate. 

See this footage and more at


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Good. Better. Best.



Hitachi’s range of mining excavators is a dominant force in Australia. With six machines in their mining line up, they have a solution for every size and type of mine, from the versatile 120t EX1200-7 excavator through to their EX8000-6 weighing in at a whopping 837t.

Available in backhoe and face shovel configurations, these machines are highly regarded and operate globally. Instantly recognisable in their distinctive Hitachi orange, you’re most likely to find the EX2600, EX3600 and EX5600 backhoes working in the Valley.

Sitting in the sweet spot of Hitachi’s diggers is the EX3600. A stalwart of the Australian mining industry, Hitachi has deployed locally over 100 of these 370t excavators since launching the EX3600-5. Now in its third iteration, the Japanese manufactured EX3600-7 is Hitachi’s latest generation machine built upon industry feedback and the Company’s learnings in the field to produce more fuel efficient product for customers.

In a development immediately broadening the appeal of this excavator, miners now have an option of power plant with both the Cummins QSKTA60 or MTU 12V4000 on offer.

Combined with improvements in the machine’s hydraulic system, operators can reasonably expect reductions in fuel consumption between 4 – 7% compared with the previous model (the EX3600-6 with Cummins engine configuration). Further, intelligent management systems including main pump electric regulators on each individually controlled hydraulic pump as well as, a hydraulic regeneration circuit, permit this machine reduced pump demand, enhancing engine power, lowering fuel consumption and increasing productivity.

All too aware of the detrimental effects of dust and moisture ingress, Hitachi has introduced slit-less solid conduit harnesses and junction boxes. In the instance of damage, electrical harnesses between junction boxes can be replaced individually, ultimately reducing maintenance time and cost. Likewise, the cab riser now features a pressuriser system to minimise dust infiltration and extend the service life of electronic components within.

Improving upon a product that customers already like, the hydraulic hoses between the boom and main piping have been rearranged from an arch to underslung configuration removing the need for clamps, reducing deflection and increasing reliability. And I could go on, with features too numerous to contemplate in this article.

Find out more today by contacting your local Hitachi representative or go online at


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D11 Heaven



Next gen D11 dozers continue long history at Bengalla mine with more than 20 years and numerous additions and upgrades of the model.

In 1998, New Hope Coal’s Bengalla mine purchased its first four Cat® D11 dozers, marking the start of a long relationship with the machines.

Last month the mine took delivery of the first of four D11 Next Gen machines from leading Cat dealer WesTrac. The first two are upgrades for retiring dozers that have clocked up tens of thousands of operating hours, while another two are being purchased to replace hired machines.

Maintenance Capital and Projects Specialist Ben King has worked at the Bengalla mine for more than 15 years and is well acquainted with all the D11 models that have been put to work at the site.

“They’re a really good, reliable machine and very modular,” Ben said.

“The operators really like them – they’re a big 104-tonne machine that is suitable for ripping through hard rock seams and they’re really well supported by WesTrac.”

According to Ben, with the life of the mine now extended to 2039, the new Cat D11s will be put through their paces.

“Originally, we ran the D11s for about 5,000 hours a year and expected to get a total 50,000 hours out of them,” he said.

“With the later models we’re achieving about 6,500 hours per machine each year and do a mid-life rebuild around 7,500 hours and a full engine replacement at 15,000 hours before starting the cycle again.

“We expect to see even further increases in operational hours with the Next Gen D11s.”

“The other thing we have to consider is that because the mine is so close to town, we’ve always had to be mindful of noise so these Next Gen D11s come factory fitted with sound suppression kits.”

“From an economic point of view, they provide greater efficiency, improved productivity and a higher level of safety than their predecessors so there was no question that when we were ready for an upgrade, these were our number one choice.”

“Even with coal prices reducing, our goal is to make money on every shipment and the new D11s are helping us achieve that.”

According to Ben, the high-precision onboard Cat MineStar™ system, which incorporates a range of optional tools including Terrain for grading and Command for dozing, means operators could have their daily tasks pre-determined based on research and technical data.

“Our technical teams can upload data and instruct the operators on the most optimum ways to work for every shift,” he said.

“It provides some real productivity gains to ensure we continue to keep the cost per tonne down.”

While on holiday in the USA last year, Ben toured the Caterpillar® factory where the dozers are built and was able to see some of the machines destined for Bengalla moving through the production line.

“I’ve been involved with the D11s since I started at Bengalla 15 years ago and was closely involved in getting up the business case for the purchase of the latest machines, so I feel like they’re my babies,” he said.

“Having the opportunity to see them being manufactured was something quite special.”

WesTrac NSW and ACT Executive Officer Greg Graham and General Manager Mining Jody Scott were on site at Bengalla for delivery of the first Next Gen D11.

Greg said input from longstanding clients such as New Hope Coal had been instrumental in helping WesTrac work closely with Caterpillar to incorporate a range of previous aftermarket additions as factory fitted options.

“New South Wales has some of the most stringent safety compliance requirements of any mining jurisdiction in the world,” Greg said.

“For that reason, WesTrac and our clients have worked closely with Caterpillar to see a number of features being incorporated into the equipment design rather than added later.”

Jody said some of those options included fire suppression systems and the ground-level electrical centre. “Fire is one of the biggest safety issues on NSW mine sites and those in other states,” he said.

“Incorporating these systems with OEM input is a significant advantage when it comes to robust performance and rapid response in the event of an incident.”

“Likewise, if clients can opt for ground-level electrical controls to be factory fitted to new equipment, there’s a greater level of convenience and assurance than if they are fitted later.”

IMG: Adam Freeman (Bengalla – Mobile Maintenance Superintendent), Simon Allan (WesTrac NSW – Mining Support Manager), Warwick Gloster (Bengalla – Maintenance Manager), Greg Graham (WesTrac NSW/ ACT – CEO), Cam Halfpenny (Bengalla – General Manager), Jody Scott (WesTrac NSW / ACT- Mining General Manager), Gary Rayner (WesTrac NSW- Mining Business Manager), Ben King (Bengalla – Maintenance Capital and Projects Specialist) at the delivery of a new Cat D11 Next Gen dozer

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Belly Dumper



Sounding more like a dig my wife might have at me, the ‘belly dumper’ otherwise known as a bottom dumper is a type of off-road haul truck that unloads its material through a dump gate at the bottom of the trailer.

Differing from the standard rigid off-highway rear dump truck, they are located across many mine sites globally, however, are most commonly found in the United States. In Australia, they are used in specific coal, and bauxite applications in Queensland though are increasingly being decommissioned with age.

Available in articulated or rigid configurations, they are most suited to lighter and finer materials that include coal, bauxite and salt. In their articulated ‘config’, these machines have three axels incorporating a tow tractor and dump trailer with two two steer tyres in the front and four tyres at the rear of the truck and a further four tyres at the back of the trailer. Their rigid sibling is a stranger looking beast and as the name suggests, present as one integral unit fitted with two axels front and rear and the belly located in the middle.

The choice for the size and type of dump trucks at any mine depends upon a lot of variables, such as the type of mine, size of mine, minerals being mined, capital and loading machinery available. Belly dumpers are no different and are best suited to large-scale sites with ramp gradients of 5% or less.

Generally used in strip coal mines, they are particularly suited to applications with long cycles that require high average speed. Offering a higher payload for the same engine horsepower, these trucks provide high payload to weight ratios with the added advantages of weight balance, stability, long haul tyre performance and higher speeds on flat hauls.

Highly manoeuvrable, these trucks offer up to 85 degree steering angles in both artic and rigid formats and are highly mobile in moving around working areas. Fitted with clamshell dump gates in the floor of the dump trailer, operators can control the discharge rates of the hauled material by the degree of the gate opening.

Despite their success, the off-road belly dumper is not for everyone. These trucks often require dump stations with a bin designed to allow the coal to fall from below the truck into a hopper/crusher.

While offering the prospect of high transport speeds over longer hauls they require well-maintained haul roads, that are of course not universally available at mine sites around the world.While not household brands, the manufacturers of these machines are held in high regard and include Kress, Mega and Rimpull in the United States as well as our very own Kador Engineering in Australia that still build these weird and wonderful machines with capacities in excess of 240 tonnes. If you’ve not seen one in action, take a look at


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