10 Mining Constru C tion 1 2013 At the Marback stone quarry in Sweden the newly arrived T WiZ drilling system is helping V oglers AB to boost productivity A steep and nar ro w track r uns along the ridge of the Marback stone quar r y in souther n Sw eden leading to the highest point o v erlooking a cr ushing f acility an agg re g ate plant and forests and lak es in the f ar distance P erched on fractured rock just before the edge of an 80 meter drop a Smar tR OC D7C is perfor ming tophammer bench drilling equipped with the latest rock drilling tools with T thread technolo gy from Atlas Copco Secoroc that is helping to drill b last holes as deep as 285 m Huge savings Launched at the end of 2011 T W iZ has set a ne w benchmark for perfor mance in sur f ace and under g round mining operations The system consists of drill rods and shank adapters that of fer g reater stability and up to 30 per cent longer ser vice life w hich means that fe w er rod changes are required The longer life span of the T W iZ rods con v er ts into huge sa vings on time materi als and ef for t sa ys F rederick W inroth of Sw edish drill and b last contractor V o glers AB w ho w as among the frst drillers to tr y out the ne w T W iZ system The Marback quar r y site some 4 km south of the to wn of Ulricehamn pro vided an ideal en vironment for demonstrating the patented T W iZ drill system Since 1994 w hen the site opened Marback has been producing hard g re y gneiss agg re g ate to be used for concrete ballast in road constr uc tion applications I frst got the ne w T W iZ rods w hile w orking at sites in the Gothenb ur g re gion before the shank adapters w ere e v en a v ail ab le sa ys W inroth When I had the full system it all w ork ed perfectl y and the ben efts w ere impressi v e Ha ving k ept a close track on the per for mance of T W iZ and comparing with pre vious equipment W inroth sho ws the documented data using dif ferent drill bits w here he notes an a v erage penetration rate of 15 mmin He e xplained Nor mall y it tak es at least 30 minutes to back a w a y from the b last hole set up the rod collector and change drill rods So minimizing the number of rod replacements mak es a big dif ference to bottomline production Pre viousl y I w ould also count on ha ving to str uggle to uncouple the drill rods No w y ou just press the release b utton and the T W iZ rods break a w a y easil y n o margin for error When MC visited the site a frst section of 76 mm diameter b last holes had just been completed using the T W iZ system It w as a challenge said W inroth and pointed out the sloping ter rain and diffcult rock for ma tions T o position the drill rig he used an anchor and winch At these depths there is no mar gin for er ror Y ou ha v e to achie v e as close as pos sib le to 100 per cent straightness so that the e xplosi v es match the hole Getting it right mak es all the dif ference betw een giant boul ders or g ra v el w hen b lasting he said When each hole is completed it is sealed with a cone plug to pre v ent rain sno w and dir t from entering T o minimize do wntime a backup set of T W iZ drill rods are stored at the site as w ell as e xtension rods that can be used for an additional 3 4 m of drilling During drilling the majority of w ear and tear is placed on the drill rod and although the operation is monitored through the rig s Measure While Drilling system MWD W inroth w as rel ying on his e xperience to manuall y inspect the equipment and the se v en drill rods in the rod handling mag azine Blue smok e or percussion with a hollo w sound are typical signs of drill rod f aults as a result of loose joints o v erheating or both W ith T W iZ I ha v en t noticed an y of that he said This batch of T W iZ equipment has completed about 7 8 000 drillmeters and is still perfor ming w ell Cutting do wntime and boosting pro ducti vity is w hat T W iZ w as designed for and with automatic rod changing and less manual w ork in v olv ed W inroth w as conf dent that the ne xt three ro ws of b last holes w ould be completed within three w eeks Thanks to the long lifespan of T W iZ 300 drillmeters per da y i s not a prob lem he added Do wntime has also been mini mized w hich means that the compan y achie v es more holes in less time and that s also positi v e for me New benc hmark The T WiZ drilling system gi ves up to 30 per cent longer service life in the Marbac k quar ry All round impro vement L ess wear on the threads easy uncoupling of the rods and fewer rod c hanges mak es the job simple and effcient tHE MA gi C of t WiZ T WiZ is a tough and patented T thread drilling system offering X Up to 30 longer service life X Greater stability easy breakout X More holes per shift and drill rig X Three dimensions T WiZ 38 T WiZ 45 T WiZ 51 X Reduced total drilling cost