OVERLOADED haul trucks can jeopardise the safety of mining systems while eating away at a company’s profitability. If a truck is habitually carrying oversized payloads, frames and structures are placed under unnecessary stress, truck bodies and tyres wear out pre-emptively and component life can also be shortened, increasing the risk of premature failure and unplanned downtime.
An overloaded haul truck can also unduly damage haul road surfaces, increasing site maintenance costs and reducing the overall efficiency of a mining operation. Because of this, more companies are turning to technology to prevent overloading. Mine production monitoring systems capture real-time payload data for mining trucks so managers can identify when and where overloading is taking place, and take action to prevent it. Managing payload is an important facet of running a safe, efficient and profitable operation; good payload management practices and accurate onboard weighing systems are now integral to profitable operations across a range of industries. The benefits of payload management vary from application to application, but the most important factor is that, through the use of appropriate technology, ‘right first time’ loading can be achieved.
Additional benefits include optimised loading cycles, improved safety due to less on-site movement and reduced wear and tear on plant, machinery and haul roads.
In the 2010 study Payload Variance Effects on Truck Bunching, data was collected from payload management systems at a number of surface mining operations. Because heavily-loaded trucks travelled more slowly up ramps than lightly loaded trucks, the faster trucks were impeded by the presence of slower trucks, resulting in ‘bunching’ and production losses.
In another 2010 study, The Application of Payload Monitoring Systems to Mining Operations, author James Davison carried out a case study at Xstrata Coal’s Liddell open cut mine in the Hunter Valley, monitoring the use of Caterpillar’s Vital Information Management System on the Cat 789B trucks at the mine.
Results established that most trucks were overloaded at least some of the time – the maximum was 40 per cent of the time – with some trucks exceeding their tonne kilometres per hour tyre rating by up to 28 per cent. The study concluded that the cost savings received through the use of payload monitoring systems were substantial, and integral to a company’s successful operation in Australia’s competitive mining environment.