Published in March 2008 Australian Longwall Magazine

Safety and comfort, as well and increased flexibility of design, also translates to increased production efficiencies, which in turn translate to full order books for those manufacturers at the cutting edge – so to speak – of the underground diesel equipment game.

Much of the recent development of underground diesel equipment design has centred around the operator’s cabin, with dashboards inspired by the automotive industry and a wide range of adjustability both within the cabin, and of the whole cabin position itself.

Last year, Vought Engineering launched its Highlander Car, an underground coal hauler with an innovative driver’s cab design it calls the Ergo Pod. While the car itself is electric, the driver’s pod can also be retrofitted to other machines.

“In the past, there have been shuttle cars available with north-south seating arrangements, meaning two seats – so the driver gets out of one seat and sits in the other seat when he wants to go forwards or backwards,” Vought managing director Graham Vought told Australian Longwall.

“A variant was brought out by another OEM, where they sit side on to the machine. On bumpy roads, that side saddle arrangement isn’t ideal because your head and neck are turned to face the direction of travel, so ergonomically, it has its ill effects,” Vought said.

“So what we’ve come up with and patented is a seat combined with a console and steering wheel, dashboard and pedals which basically allows the driver to face his direction travel,” Vought told AL. “The big benefit of this is that when the driver turns the steering wheel left, the machine will go left and when he turns it right, it’ll go right.

“That applies to which ever direction he’s travelling, and that isn’t achieved on the side saddle or the north-south seating arrangements. This combined with suspension in the seat and the ability to rotate the seat hydraulically using the steering wheel means the driver has superior vision and comfort. It also saves him undoing a seat belt and changing over to another seat.”

Two Ergo Pods are currently in use at Xstrata Coal’s Oakey Creek mine in the lower Bowen Basin. While Vought said the Pods are able to be retrofitted to existing shuttle cars, the ones at Oakey Creek are mounted on Vought’s Highlander Coal Car.

“The operator’s still coming to grips with the different style [of controlling the machine], but it looks like they’re going to go for that as their preferred method of control,” Vought said. “Now, we’ve just had a tender sent to us by BMA [BHP Billiton Mitsubishi Alliance] for a quote on a rebuild of a shuttle car, and they’ve specified an Ergo Pod on the rebuild.

“We’ve had a high level of interest from South Africa, and we plan to exhibit the Ergo Pod in Las Vegas this September,” Vought said.

There are of course several other underground coal vehicles with their own unique features.

Bucyrus’ Compact Loader is operated via control stick steering and has a dashboard that has been inspired by those of the motor industry.

“This is a unique feature within our product range and is the first machine designed and manufactured by Bucyrus Underground not to utilise a steering wheel,” said Steven Brownsell, of Bucyrus’ market development arm. “By not employing a steering wheel, the operator is given additional leg-room and makes the operator’s cab more comfortable during long operating periods.”

Brownsell said modularity was a key design criterion to ensure great flexibility in underground applications.

“The engine compartment is modular, using a bolt-on design which allows the selection of alternative engine and exhaust configurations depending on the mine’s duty and ventilation requirements. These include 107kW 4-cylinder and 132kW 6-cylinder engines using wet scrubber (particulate filter) or optional dry scrubber systems.”

He told AL that another unique feature of the machine was the location of the posi-stop brakes inboard, which allowed the machine frame to be wider, giving increased stability to the operator and pedestrians. Brownsell said this also allowed a variety of tyre options and inflation media, enhancing carrying capacity and safety.

Hydraulic and fuel tanks are mounted separate from the vehicle frame and are located within a pod-mounting arrangement system giving the benefit that optional mounting positions and capacities are available for the mine to select.

Bucyrus said that the Compact Loader was designed with a fully enclosed operator’s compartment and selectable cab heights for ease of access. The operator’s compartment can also be located in various positions on either the left or right hand side.

Like all Bucyrus diesel powered equipment, the Compact Loader has dual independent cooling systems, one cooling system for the engine and another for exhaust gas. Each system has its own water pump, radiator, header tank and pipe work.

Brownsell said Bucyrus Underground equipment is unique in that the radiators within all its diesel machines are horizontally located.

“The market response to the Compact Loader has been very positive,” he said. “We are in discussion with various Australian and overseas mines about the Compact Loader and other Bucyrus equipment.”

He said the electronic control technology used in the Compact Loader has been operating successfully in the heavy lift machines working in non-flameproof and soft-rock mining applications in Europe.

“It was the success and positive feedback from these various mines and operators of this technology that we decided that the utilisation of this technology would be of benefit within the underground coal mining sector,” he said.

Brownsell said it was these heavy lift capabilities that are becoming an ongoing trend in the sector, as well as overall increases in size and the ability to fulfil a variety of tasks required by mines and contractors.

“Bucyrus Underground engineered the Compact Loader to access low seam operations that to date have been difficult to access with the diesel machines that are available on the market today. Our intention was to design a machine that would exceed the expectations of customers and set the future standard for design and capability in the sub-10-tonne market.”

And he said the future for underground diesel machines – as opposed to electric ones – is still bright.

“Due to the duty cycles required in underground mining diesel machines do have a place within a mine and contractor’s inventory list,” Brownsell told AL. “Future equipment direction would move towards the use of integrated electronic control systems between operator and machine along with stricter emissions control technology that would require full DPM [diesel particulate matter] traps.”

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