Operators Are The Front Line In Drilling And Blasting Operations
Editorial Focus by Harold Hough

            The heart of drilling and blasting operations isn’t the explosive, but the heavy equipment operator – especially the drill operator.  Since many drilling and blasting bottlenecks are operator caused, a skilled operator can keep maintenance costs down, even if the training is expensive and his salary is high.  A skilled operator knows the equipment’s capabilities and won’t abuse it.  This is very important with drills, where even a small mistake can put too much torque on rotary parts.  The operator can also recognize a problem before it occurs and inform the maintenance people before something expensive breaks.  This avoids delays and keeps production costs down.
            Most mine and quarry operators are unaware that poorly trained operators have a major impact on the efficiency of drilling equipment.  If a blast hole drill is only operated by a fair operator (90 percent as good as an experienced one), than the mine is not only operating at 90% efficiency, it is  having an impact on maintenance because he is only getting 1,800 hours of work out of the drill between 2,000 hour overhauls.  That’s one to two percent of the initial cost of the equipment for every 2,000 hours of operation.  Therefore, if the drill costs $75,000, and runs 4,000 hours a year, the additional cost of using marginal drill operators will be $3,000 a year in additional maintenance alone.  This doesn’t include the economic costs of not using your equipment at full capacity or the risk of equipment damage due to operator abuse. 
            Compare that to a highly skilled professional operator who can get an extra 10% more out of the equipment than the skilled operator.  He is helping produce 10% more ore per rebuild cycle, which equates to 25 extra shifts of work per every 2,000 hours of operation.
            Another way to reduce maintenance costs is to choose the right drilling equipment in the first place.  Obviously, some of these choices include blast hole diameter, the depth of drilling, how much drilling is required, and if angle drilling is required.  One of the major decisions, however, is if a mine should purchase a electric drill, which costs less to operate and requires less maintenance, or a diesel drill, which isn’t restricted to a small area by cables leading back to a power source.
            Although the diesel drill is able to roam over the property at will, the trade-off is higher maintenance and operation costs.  A diesel drill requires rebuilding every 2,000 hours of operation.  Consequently, a mine that has two eight hour shifts a day and works five days a week will have to rebuild its drill once every six months.  Since rebuilding requires one or two weeks, the mine will have to slow operations or have a second drill to pick up the slack.
            A diesel drill will consume 10% to 12% of its initial cost in parts and labor during the first 2,000 hours of operation.  Each succeeding 2,000 hours, may see that cost rise to 15%.  If the mine is trying to cut maintenance costs, those costs will go higher.
            Another consideration is the heavy pounding a drilling machine undergoes.  A mine operator can initially save some money by buying a blast hole drill with a lighter frame.  Although this may be okay for a small mine with intermittent drilling requirements, as time goes by, a light structure will develop cracks as the pounding takes a toll on the metal.  In the long run, equipment with more metal is more cost efficient.
            Equipment should also be purchased with the operating schedule in mind.  If a mine operates on a continuous basis, more equipment must be purchased so individual pieces can be pulled out for scheduled maintenance.  If the mine stops work on weekends, extra equipment may not be necessary if maintenance takes place then.  If a mine doesn’t have a preventative maintenance program, the money should be spent on instituting one.
            Drilling equipment also requires some special attention.  Some drilling experts recommend that a mine focus on the power systems (the engine and hydraulics).  Others suggest paying a lot of attention to the pivot and bearing points with inspections and lubrication.
            Vendor support is also critical to keeping equipment running.  Some drills made in other countries are cheaper, but spare parts must be ordered from the factory and the delay may cost several weeks in down time.  A supply warehouse in the United States can limit the problem.
            However, the key factor remains the operator.  A good operator can maximize the performance from a marginal piece of equipment, get the most out of new equipment, and limit downtime for maintenance.  Good drilling and blasting practices needs to remain focused on people more than equipment.