Modern Quarrying Q3 2018

CLOSE CLIENT-CONTRACTOR RELATIONSHIP FOR MUTUAL GAINS

For a contractor to provide a mining/quarrying customer with the most cost-effective load and haul solution while remaining commercially sustainable means optimising cycle times and applying the basic principles of earthmoving. It also requires close collaboration with the customer throughout the project, for mutual gains.

THOUGHT LEADERSHIP – CONTRACT MINING

A ccording to Graeme Campbell, commercial and operations manager at Raubex Group company, SPH Kundalila, it is often difficult for mines to choose from a range of contractors as pricing is usually competitive, most track records are sound, equipment is of a good quality and they all have strong mechanical and operational experience. “Thanks to software programmes that help contractors to price their projects accurately, the market is becoming increasingly competitive,” says Campbell. “For mining compa- nies this makes it difficult to discern which contractor to trust, and for contractors it’s a real challenge to stand out in a crowd.” Cycle times One important way of distinguishing the contractor with the best offering, however, is to compare cycle times, he says. “Cycle times are among the most important aspects of costings to calculate accurately, as the risks are numerous,” he says. “For a contractor, over-estimating the cycle times can lead to a quote becoming uncompeti- tive, while under-estimation can mean many hours of work for which they are not reimbursed.”

and customer. The results can be seen in reduced bottom line costs. “Using the example of moving waste rock on a gold mine, a few calcula- tions can demonstrate the financial benefit of quicker cycle times,” he says. “The principles apply to other materials and applications too.” Cost estimates Taking a project that requires 178 000 tonnes of material to be loaded and hauled monthly – working 26 days a month and 18 hours a day – two con- tractors could arrive at quite different cost estimates for the same job. If contractor A bases its calculations on the basic principles of earthmoving, continuous feedback and improvement throughout the project, they would arrive at a cycle time of 11 minutes and 6 seconds. Using four 25-tonne dump trucks, based on a working time of 468 hours a month, the rate per ton would amount to R8.00. Contractor B, on the other hand, does not incorporate additional infor- mation into the process, and relies simply on best practice and feedback only when deemed necessary. With a longer cycle time of 13 minutes and 50 seconds, they would need five 25-tonne dumpers working for 455 hours a month – leading to a higher rate per ton of R9,58. “The major difference is that

He notes that there are basic prin- ciples of earthmoving that influence cycle times and highlights the impor- tance of having ideal conditions both on-site and off-site. “When it comes to ensuring good on-site conditions, the loading area should be level and stable underfoot, while the haul road needs to be well-maintained and quality surface with as few stops as possible,” says Campbell. “Also, the off-load area should be easy to access, facilitating a quick turn- around time.” The right off-site conditions include the accurate recording of activities, timeous information on tonnes handled and hours worked per shift, daily application of earthmoving’s basic principles, and good feedback on health, safety and the mechanical status of equipment. “When these conditions are optimal – and maintained – the result is two-fold,” he says. “Firstly, the shortest cycle time possible is achieved, making for efficient work; and secondly, a safe environment is created, which benefits both the contractor and the customer.” He maintains it is possible to keep cycle times shorter than most contractors calculate, if proper planning is applied with continual revision of the process, and proactive engagement between the contractor

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MODERN QUARRYING QUARTER 3 - 2018