Although substantial progress has been made in the control of occupational health hazards, there's an unseen danger which, if not addressed, has the potential to cause long-term health issues for miners — noise pollution.
According to a report by the National Institute of Occupation Safety and Health (NIOSH) in the USA, coal miners suffer some of the highest rates of hearing impairment by profession, increasing from 70 to 90 per cent by the time they reach retirement age.
The report also found workers who were exposed daily to noise levels exceeding 90dB had higher rates of single and multiple workplace accidents. Noise was found to be a 'stressor', interfering with concentration levels, worsening absenteeism, reducing productivity and increasing insurance costs.
"I’m sure noise can have serious health connotations," Michael Lubbe, director of Cincinnati Mine, a mining engineering company, told IndustrySearch.
"Studies have found people who are subjected to continuous 'droning' and other occupational noises have been known to suffer from nervous and aggression problems ."
Industry can be faced with a challenge: how to create a safer environment for workers through the use of quieter machinery?
One possible solution lies in the use of low-noise conveyors and low-noise conveyor components such as the DA-350 dual sprocket conveyor chain from Cincinnati Mine.
"The DA-350 was basically designed with two things in mind: for OHS, or hearing, because it's a chain that brings down the noise levels by about three decibels; and durability, as all mining engineers want a product that lasts longer and has more wear life," he said.
The fundamental reason behind DA-350's quieter noise levels lies in the sprocket design.
"When the chain is being laid down on the deck, it's being laid down quieter because the transition is much smoother," Lubbe said.
"The combination of an even-pitched chain and dual sprockets provides for better chain-sprocket interactions and yields less noise. Because you've got more chain engaged at any one time it also lessens the impact between the sprocket and the chain when it's moving between the links.
"The materials it's manufactured from definitely increases its durability.
"Tests done on this chain in the US — where it was designed — have shown these conveyor chains are capable of transferring approximately 1.2 million tonnes of coal during its production life.
"That's a good performance for a conveyor chain which is a consumable item."
In terms of maintenance the DA-350 requires the operators to maintain the correct tension and machine maintenance for maximum durability, according to Lubbe.
"If your tension isn't correct, you're going to end up with accelerated sprocket and chain wear."
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