SURFACE DRILLING only for a limited time – limited by the battery size and power capacity . Scenarios for drilling on battery alone could include a peripheral part of the quarry or mine without power infrastructure ; where it isn ’ t possible to reach the machine with the cable or where you want to drill in a position away from the main drill pattern such as one bench up or down to deal with some large boulders or similar , but don ’ t want to have to set up the cabling . You can just tram on battery to that location , drill the boulders on battery power and then return to the main drill area to reattach to the grid .”
Already the machine at Skanska has been moved from one side of the quarry to the other on battery tramming , which was about 25 minutes . “ Of course one day we want to be able to have an all battery drill only , but today to run a full shift like this would require a huge amount of battery power and density – battery capacity has to catch up first to allow for this . Every extra kWh we get into the battery is a step forward . It has happened in the automotive industry to some extent in terms of ever increasing range and it will happen in mining and quarrying too , especially with the pressure to deliver workable battery solutions for large mining trucks .”
Comments and feedback from mining companies so far on the machine and the concept ? While this machine was clearly a result of the push in construction and quarrying for green machines , the miners of course are watching closely for the potential to move a similar setup into larger blasthole drills . This unit has a maximum hole diameter of 115 mm , or 127 mm with the SmartROC T40 , which is still firmly in quarrying and smaller mines or presplit work . Noteworthy is that several of the large Epiroc mining drills up to the largest rotary Pit Viper 351 models are already available as cable electric machines – these can drill 406 mm holes .”
So what aspects of the new rig are new in terms of design and innovation ? “ Its certainly the customer ’ s ability to choose between cable electric or battery and the flexibility that it brings . If I only have the option of cable electric , then you always have to use the cable with a genset – whether to move tram it to a new quarry area , or even from the quarry to the workshop for maintenance .”
The battery is charged by the power cable – from completely empty to full charge takes about two hours . In terms of the battery capability in use – it will currently last a maximum of about one hour if just tramming and will be able to carry out about 45 minutes of drilling under battery , varying in terms of the amount of compressed air being used .
Regarding further commercialisation , in addition to the Skanska partnership , Epiroc in October 2022 signed a Letter of Intent with
Rental Group – plant hire specialists covering the Nordic region – to manufacture and supply 15 brand-new battery-electric surface drill rigs . Rental Group already have an extensive fleet of heavy construction machinery , tower cranes and special equipment , including 17 Epiroc drill rigs and a recent order for an additional 13 dieselhydraulic units .
Building blocks of autonomy
Caterpillar has progressed its autonomy roadmap in its blasthole drills significantly in recent years , particularly applied to its popular and proven MD6310 ( 203-311 mm ) and MD6250 ( 152-250 mm ) models . A recent project working with Thiess at a coal site in New South Wales , Australia saw three drill rigs being remotely operated by a single operator , with the project working towards rigs completing entire drill patterns across multiple rows in fully autonomous mode . Also in Australia , a large iron ore mine has a fleet of autonomous Cat ® MD6310 drills . Caterpillar is also working closely with a mine in Canada to progressively implement a remote-controlled , semi – autonomous and fully autonomous Cat electric drilling fleet , utilising the technologies engineered , designed , and / or integrated by Caterpillar . These are just a few examples .
The global OEM looks at applying autonomy in drilling like a series of building blocks . IM had an in-depth discussion with Caterpillar Drill Application Specialist , Greg Scott and Mason Biernat , Caterpillar Autonomous Drilling Application Specialist , about the phased approach and what is involved . “ You start with onboard Drill Assist automated functionality – which we break down into three major machine functions : auto level , auto mast and auto drill . Auto level you can think of as helping the machine understand how to level itself and then monitor conditions to make sure that it can adjust or lock out if something goes wrong , for example if the ground gives way below one of the jacks . Auto mast involves the machine independently raising the mast to a desired angle and locking ; as well as unlocking and lowering . Before any function or movement , the machine goes through a series of self-checks to confirm that components are in the right place and to help ensure safer operation for the machine and operator .”
Scott says that auto drill then takes on a greater level of complexity . “ If all mine sites were running one type of cutting tool and if they all had similar rock or ground conditions , it would be simple . You would just tell the machine to apply a particular feed force , maintain a set rotary torque and RPM , and turn on the bailing air to move cuttings or broken material out of the way of the bit .”
But the reality is that there are significant variations in those cutting tools and ground conditions . At the basic level for rotary drills , it could be down-the-hole ( DTH ) or rotary tricone . Tool selection will be based on the hole diameter and depth - what ’ s optimal for the ground conditions and operating environment ( like elevation ) to get the linear production needed in a timely manner , within the customer ’ s acceptable cost . It also comes down to customer preferences and strategic considerations based on local service and stocking points plus supplier alignments in particular regions .
Scott adds : “ When we talk about the building blocks of autonomy , we are talking about a machine that can easily adapt to new technology added later , such as auto drill controls . All of Caterpillar ’ s new generation drills , meaning those built since the end of 2018 , are equipped
Thiess last year deployed remotely-operated Caterpillar drill rigs at a coal mine
APRIL 2023 | International Mining