Driving underground presents unique problems that you just don't encounter on the surface.
Although for both the air is hot, heavy and humid, and filled with dust, when you add these to the cramped and hot conditions as well as the ever present problem of diesel particulate matter in the air it makes driving and working underground more difficult.
Sandvik is countering some of these diesel particulate challenges and working towards a better underground environment.
It has now introduced two new underground mining trucks with low emission engines, which according to the company makes them the cleanest underground trucks on the market.
The company has released the new 50 tonne capacity TH550 and the 40 tonne capacity TH450, which both come with energy efficient, low emission engines built to comply with EPA Tier 4i/Euro Stage IIIB emissions standard for better breathing on site.
In addition to a cleaner drive, the vehicles also have the smallest envelope size in their payload class and are designed to operate fully loaded on long spiral gradients of up to 20 per cent at high speeds, Sandvik says.
It goes on to state that these vehicles with the optional Tier 4i/IIIB Volvo engines consume less fuel, produce fewer emissions, and have better torque characteristics than the previous generation – the T50 and T40.
Sandvik Mining's product line manager for underground hard rock mining, Scott Rowe, explained the TH550 and TH540 are the only trucks available with this clean engine option.
"These trucks can provide a healthier environment for all personnel working underground," Rowe said.
"For example if these engines were running in the centre of a large city then the exhaust fumes coming out of the engines would actually be cleaner than the air they were taking in." Rowe added that in designing and developing its new underground truck range, the company paid attention to environmental, health, and safety issues, as well as the inevitable productivity and reliability factors.
"As well as our low emission engine option, both trucks incorporate ROPS and FOPS certified operator compartments, easy three point access into the cabin and to the top of the machine, improved visibility, ground level daily maintenance points, and safety rails along the top of the machine.
"Improved ergonomics – which will mean reduced fatigue levels over long shifts – include rubber mounted and isolated cabs, improved sound attenuation and heat isolation, more efficient air conditioning, and seats with low frequency suspension as standard," Rowe stated.
Making machinery maintenance easier has also been a consideration in the design of the TH550 and TH540.
"All checking points for hydraulic and engine oils, coolant levels, and air filters are at ground level; we have quick fill couplings for fluid and the belly plate opens by swinging it out to the side," Rowe explained.
"The engine cooler is easy to clean, and both trucks offer automatic central lubrication system," he added.
Sandvik has also planned for eventual truck problems by including a built in Vehicle Control and Management (VCM) diagnostics/troubleshooting alarm and log system which allows the vehicle operator to easily identify the source and cause of the issue.
The vehicle's full operating log can be downloaded to a standard laptop.
"Sandvik's VCM system also increases machine usability and efficiency through features such as automatic shifting, selecting the correct gear and speed depending on the payload, ground conditions and gradient, while at the same time increasing (vehicle) availability as there are fewer failures and reduced downtimes when troubleshooting," Rowe said.
"Additionally, the system ensures each TH550 and TH540 is automation ready, and able to be used with systems such the AutoMine underground mining solution."
According to the company the trucks' Dana axles have slack-adjustable Posi-stop brakes as standard, Posi-Torq springs in the front axles for between 69 and 85 per cent torque transfer to the higher traction wheel, and No-Spin diffs in the rear axles which provide 100 per cent torque transfer to the higher traction wheels.
"The benefits of this are reduced wheel spin, longer tyre life, and better traction in uphill hauling."
The TH540 has a payload capacity of 40 tonnes with a maximum speed of 33 kilometres per hour.
The TH550 has a capacity of 50 tonnes and a maximum speed of 30 kilometres per hour.