MINE RESCUE & SAFETY
Industry-first shaft rescue system
In late July , an industry-first Shaft Rescue System ( SRS ) was commissioned at Anglo American ’ s Aquila coal mine in Queensland , Australia .
The system is designed to lower cages into mine shafts to rescue trapped miners . It is equipped with a world-first intrinsically safe directional Wi-Fi communications system that can be used safely underground , according to the Queensland Mines Rescue Service , which commissioned the machine in partnership with Anglo American who funded the equipment for use by the industry .
QMRS says the SRS has interchangeable cage options and over 1,200 m of rope on the drum for use in deep shafts . It is engineered with multiple fail-safe braking systems and hydraulically powered from the Volvo FMX 10 * 4 truck engine , which also has a back-up power system .
IM spoke to two of the SRS ’ major suppliers to find out more about the system .
The SRS concept has been developed over the last eight years by Australia-based MCA Engineering , Paul Barwick , Director of MCA , says , leveraging MCA ’ s shaft construction experience to engineer this world-first mobile truck-mounted emergency platform .
MCA has a track record of transporting heavy loads up to 1,650 t from surface to significant depths underground , including the likes of ore bins and skips . It has achieved this through several transport mechanisms and , in the process , managed to cut the installation time of such heavy underground infrastructure from an industry average of three months to around 25 days , according to Barwick .
As part of a vertical development project for Newmont Mining ’ s Tanami Expansion 2 project in the Northern Territory , MCA will design , supply and install three underground ore silos . Barwick explained : “ At Tanami , one of the bins weighs 330 t and will be lowered in one piece in an underground chamber at the crusher station . One of these bins is 8-m diameter , by 55- m long ; another is 8-m diameter , by 20-m long ; and the third is 3.3-m diameter , by 67-m long .
“ MCA pioneered this type of method in Australia some 13 years ago with the capability of installing 1,600-t loads in an underground environment .”
The loads to be placed on the SRS do not come with such tonnages , but it still represented a new challenge for the company . Designed to operate down to depths of 1,200 m with a centreline of rope reach of 4 m from the rear outriggers , the SRS boom extends to a full height of 11 m from the ground ( from centreline of the headsheave ). The structure and its accompanying cylinders were also designed to withstand rope break and 120 % loads .
It has two cages – one able to accommodate six people for open shaft rescues and the other for one-person borehole rescue missions .
Barwick said the Volvo FMX 10 * 4 truck was selected as the base vehicle due to the availability of a rear engine power take off option that could drive the hydraulics . The mine winder for the 1,200 m of rope , meanwhile , was built to the MDG 33 Guideline for design , commissioning and maintenance of drum winders as stipulated for coal mines by the New South Wales Department of Primary Industries . While the SRS is to remain in Queensland for the foreseeable future , continue testing at Aquila and be on hand for any incidents in the state , Barwick saw potential applications for the SRS across several mining regions .
In late July , an industry-first Shaft Rescue System featuring an intrinsically safe directional Wi-Fi communications system that can be used safely underground at coal mines was commissioned at Anglo American ’ s Aquila coal mine in Queensland , Australia
“ We built this machine to go down to depths of 1,200 m , so we clearly see potential for it in hard-rock applications ,” Barwick said . “ We also have a leasing option in place to help further the rollout of the technology across the sector .”
The Wi-Fi and communications input for the SRS came from Becker Mining Systems ’ Australia-based subsidiary , which equipped the two cages with intrinsically safe communication systems that were certified for use in coal mines . It also supplied four-way gas detectors able to monitor O 2 , CO , CO 2 and CH 4 gases underground .
David Pitkin , Managing Director of Becker Mining Systems Australia , explained : “ When the customer ( Anglo American ) first approached us , we looked at what we did in the hard-rock shaft space and how we could adapt it for coal . It just so happened that we have an intrinsically safe range of communications equipment .”
The company ended up supplying a radio system that works in peer-topeer mode and a PC-based PLC system – the Mining Master Smart ( MMS ) – to translate the data back and forth over the Wi-Fi backbone . This data included real-time video and information from those gas monitoring systems .
“ There are a few players out in Australia that have a similar offering , but Becker is really the only one that offers a conventional digital radio network deemed to be intrinsically safe ,” Pitkin said . “ That is the value we brought to the table .”
Becker Mining Systems is used to supplying mine shaft communication systems all over the globe – in Australia , it is busy with a rope attachment and communications deployment at the new Wira Shaft at OZ Minerals ’ Prominent Hill mine – but the SRS came with different , more compact requirements .
“ We had to create a couple of smaller Wi-Fi modules to save on space for the SRS – there is very little space in that single-man cage , especially ,” Pitkin said . “ But this doesn ’ t hinder any of the communication infrastructure .”
The unmanned SRS has already been tested out to a depth of 75 m at Aquila with forward-and-back communication and without incident , according to Pitkin .
“ DEZEGA managed to combine the requests of the consumers and normative requirements and , as a result , create the best self-rescuer on the market ,” it says .
“ CARBO 60 is a new generation ergonomic device that is suitable for both shoulder and belt wearing , as well as for carrying in a pouch . This is a light and compact device that provides the miner with oxygen for at least 60 minutes during active evacuation .”
CARBO 60 , according to DEZEGA , has several advantages over other solutions on the market
including a balanced weight distribution , low breathing resistance , low temperature inhaled gas , optimal placement of breathing bag , a quick-release buckle for change-over , and an automatic starter that activates after the lid is removed .
26 International Mining | OCTOBER 2022