A new approach to shotcrete
HIGH PROFILE
Underground mining shotcrete sprayers are evolving – Paul Moore recently caught up with Rick Kraft , Getman Product Manager , Concrete Products , about its new ProShot™ Concrete Sprayer that he has helped develop from the ground up with a focus on both performance & servicebility
Getman Corporation ’ s new ProShot™ Concrete Sprayers are designed to apply a consistent , quality layer of sprayed concrete in all underground mines and tunnels . The innovative design features an unparalleled boom coverage area , extending the spray reach in standard drifting situations . Optimal boom positioning minimises material waste , improving coverage when shooting blind corners and bulkheads . The ProShot Concrete Sprayer also features an accelerator dosing system that automatically synchronises to the concrete pump output without requiring further operator input .
The company says the unit ’ s design advances reflect Getman ’ s 68 years of service to the mining industry , meeting the challenge of maintaining a balance between a manoeuvrable chassis size and a layout that facilitates safe and easy daily maintenance . Well known in the shotcrete industry after working with mechanised shotcrete delivery equipment for over 30 years , Kraft joined Getman in 2018 . The company approached him to help develop an all-new shotcrete sprayer design , different from anything available to date .
He told IM : “ I knew the drawbacks of existing competitor machines on the market , most of which were based on standard designs dating back to the 1980s and beyond . At the time , those machines were ‘ state of the art ,’ and for years the ideas remained unchanged and there were very few choices available . Fortunately , technology has moved forward , and additionally a more thorough understanding of the needs of shotcrete nozzlemen and mine technicians .”
Kraft said Getman wanted to design a machine that was easy to work on and maintain , based on customer feedback . With this feedback , the unit was created from the ground up ; from scratch instead of just fitting the same components on the same frame . “ We took an innovative approach to product development with the ProShot , where every design decision made was not only based on product performance but also considering the technicians ’ and mechanics ' point of view . The time investment on the development side helped us deliver a fit-for-purpose dedicated mining sprayer .”
This intentional design included everything from adjustable and accessible hydraulic cartridges to an easy-to-reach water box and hydraulic components , avoiding the need to get underneath the machine or step over other major machine elements to get to major service points . “ Having personally serviced sprayers with thousands of hours in underground mines , it ’ s a dirty and hazardous job , especially if machines break down in the drift . Why not try to make this as easy as possible ? Something customers could look at and see the potential for enhanced safety and serviceability .” As an example , mechanics can easily access the hydraulic manifolds via removable covers , as opposed to buried in the machine as on other models in today ’ s market .
The ProShot prototype was extensively trialled in 2021 at a western US mine . “ The customer is appreciative of how we positioned components for accessibility ,” notes Kraft . They were so happy with the machine ’ s performance that they purchased it and will replace two other older machines with ProShot as well .” This mine is developing a new panel production level , where they will need to utilise three sprayers and a fleet of remixers .
Getman also moved the sprayer cab toward the centre of the machine and positioned it higher up
on top of the frame for better visibility , especially
when backing up . “ Moving the cab away from the nose of the machine also removes rebound exposure when spraying , and we took the boom and moved it to the centre front to make it easier
Canadian underground mining dealer Amalgamated Mining & Tunnelling was one of the first ProShot™ buyers - the machine is now in use with a mining customer
to park the machine in the centre of the drift . You cannot do this if the boom is offset to one side ,” says Kraft .
The ProShot has an entirely new boom design , which is not a high up type of crane where you have a pedestal with vertical access and a telescopic arm which has kinematic limitations . “ We wanted a boom with both a knuckle and an extension , to make it possible to spray around corners ,” Kraft comments . “ Caving mine production levels must do multiple rehabs around the corners of draw points – you can ’ t do that with a basic crane-style boom . Some drawpoint rehabs may consume several shotcrete trucks per draw and that doesn ’ t give you an option to manually handle a nozzle . Even if you could , you would have to slow the pump way down and it would take an exceptionally long time – perhaps several shifts . With the ProShot , we can spray two 4.6 cubic metre trucks out within an hour – each one at 20 minutes , plus backup time .”
ProShot also has a face-scanning capability based on OptiME 3D Shotcrete Optimizer technology , from Australia ’ s Murray Engineering . “ ProShot allows the operator to park the machine before spraying , move the boom down , then take a pre-spray scan and after spraying , a post-spray scan . The software overlaps those two scans and provides a graphic representation of the relative thickness of the shotcrete layer .”
OptiME allows automatic identification of over / under-spray areas using high-resolution precision measurements with Eye-Safe laser scanning . The mounted scanner is at the base of the boom and easily retrofittable to any sprayer , operating with 24-volt power . The scanner works via an in-cab operator tablet and connects through its own WiFi . The scans work like an audit – helping ground support engineers understand the spray output . This is a notable feature for mining and development contractors , as it can help operators validate what they say they have sprayed . IM
APRIL 2022 | International Mining 39