As much as miners would like to operate on an even surface, the simple nature of the site rarely allows it.
Contours and slopes build an undulating and uneven surface for miners to work on.
This means that during mine construction and operation these contours and slopes need to be developed and blasted.
However this comes with potential dangers.
The ammonium nitrate fuel oil (ANFO) needed for blasting is delivered to the hole by the way of MPU either traversing less than optimum slopes to auger directly into the hole or via a large crew of personnel carrying the ANFO in buckets to complete the process.
Historically one of the major risks associated with mine development for drill and blast contractors has been working safely on these contours, according to Action Drill & Blast.
"Whilst issues surrounding drilling on contours had been addressed there remained a significant manual handling hazard to personnel due to the requirement for shot crew to physically walk the contours to prime, load, stem, and tie-in the shot," the contractor explained.
"The manual handling issues associated with these exercises can be enormous and presents one of the most frequent hazards for causing injury of any activity on a mine site."
In recognising this ever present danger on site Action Drill & Blast examined a number of questions, namely: How can we best protect our shot crew in carrying out their day to day duties; how can we deliver bulk explosives to the hole safely and efficiency; how can we eliminate, as far as is practical, the use of 20 litre buckets to carry ammonium nitrate fuel oil onto contours; and how can we record charge weight per hole throughout this process to better comply with increasingly onerous legislative requirements.
Contractors can limit the loads the crews carry to reduce the weight factor, but in doing so they increase the number of foot trips across the site, in turn increasing the potential for injury.
While pumping bulk explosives can be delivered by a 40 metre hose, resolving some of the issues, the hose length and availability preclude its use in many situations.
To overcome these inherent issues the company, in conjunction with International Explosives Equipment and the WA Department of Minerals and Petroleum, has developed a hopper to carry bulk ANFO onto contours.
It created two models, one up to 1.8 tonnes, which have an IT hitch and quick release couplings to allow discharge capacity on either side of the loader for differing slope conditions, a dual control capacity from the cab of the IT and the discharge point on the ground, and a variable delivery speed of up to 100 kilograms per minute.
In doing so Action Drill & Blast says it has reduced the risk of the physical labour of manually loading ANFO as well as the risk of injury.
It has also allowed it to reduce the number of shot crew required.
Additionally, an inbuilt discharge meter enables more accurate recording of explosives used on a hole by hole basis.