Mining and professional engineering services provider UMS Group, which designs and constructs underground and surface works – as well as associated surface infrastructure such as process plants – for mining clients, has earned a reputation for being an innovator. In particular, the company has brought fresh thinking to the highly complex task of shaft sinking, as Robert Hull, Group Chief Operating Officer, and Murray Macnab, Group Technical Director, made clear when they spoke to Modern Mining recently.
With offices in many countries across the globe, UMS has a healthy order book for shaft work, with three major shaft-sinking contracts on three continents in its portfolio, as well as an important role on a major South African shaft-sinking contract project where it is a key member of the ‘owner’s team’. UMS is also engaged in a number of smaller contracts where it is performing shaft and headgear upgrade and optimisation work. In addition, it is busy with studies on shaft, underground, surface and process projects for a wide range of clients.
According to Hull, one of the main contributors to UMS’s success is the breadth of its service offering. “Not only are we contractors but we have a full design, engineering and procurement capability which allows us to offer clients a true seamless service – from initial concept right through to construction and commissioning,” he says. “Having this full suite of services means we can beat industry norms when it comes to delivering projects, particularly when clients engage with us at an early stage of project development.”
The value that UMS’s broad offering can bring to projects is well illustrated by the company’s current contract at the Ero Copper Caraíba Operations mine in Brazil to sink a 1 500 m deep, four-compartment, vertical shaft as part of a project to deepen the mine. The company will employ the slipe-and-line method to enlarge a raise bore hole.
“Our involvement started when we were asked by the client to review a feasibility study for the deepening project,” says Macnab. “This initial engagement led to us designing an appropriate shaft solution to meet the client’s objectives and then being appointed to implement it, a task which has seen us undertake the capital cost estimation, engineering design, project schedule and procurement. We’re now well into the execution phase and busy with the changeover from the pre-sink to the main sink, which will get underway towards the end of this year.”
He adds that UMS has also designed a full headgear that can rapidly swing over and facilitate a changeover to blind sinking should the hole block up. “We hope we never have to use it, but it is available and further de-risks the project,” he says.
The range of skills that UMS offers derives from its rich heritage. The Group is the inheritor of the expertise of Shaft Sinkers, which was established more than six decades ago. UMS acquired the Shaft Sinkers brand in South Africa in 2015.
Hull points out that as result of the acquisition UMS can claim a vast library of sinking knowledge and experience built up across 250 mining and shaft projects undertaken globally, 170 km of vertical shafts sunk and over 35 km of incline and decline shaft construction.
“Along with the acquisition, we also purchased a fleet of winders and other sinking equipment, which we’ve subsequently expanded significantly,” Macnab adds. “We now have more than 35 units in our fleet which can be deployed at short notice to projects. This gives us a distinct competitive advantage as procuring new winders can take between two and three years.”
UMS’s South African sinking operations are run by Takalani Randima (who is the first woman to run a shaft sinking company). The Professional Engineering services division is managed by Graham Roberts. Both have extensive operational underground mining experience.
“Deeply rooted in our culture of innovation at UMS is that we question the conventional wisdom,” says Macnab. “Having said this, we’re also prepared to go with traditional methodologies and equipment, suitably modified, when it is appropriate. In general, our philosophy is to embrace technology. In particular, we are great believers in mechanisation and we’re also starting to apply 4IR technologies to shaft sinking through our company UMS 1Worx, a recent acquisition, which is a specialist in this field.”
Macnab believes that one of the big challenges facing shaft-sinking organisations is to match the sinking rates that used to be achieved in the 1980s and earlier. “The problem was that these rates of vertical advance were achieved at a cost, which I can attest as I was a junior engineer back then working on a sub-vertical shaft sinking project for one of the gold mines,” he recalls. “Yes, our progress was good but – as was the case with all shafts being sunk at the time – the number of injuries incurred was unacceptably high.”
He says that starting in the 1990s, shaft sinking rates dropped as the focus on safety improved. “This occurred because the industry, for reasons of safety, started to move away from concurrent work, where you would have teams working one above the other,” he states. “It was the right thing to do and it achieved its aim of making shaft sinking safer but it was also taking much longer to sink shafts. At UMS, our approach has been to try to approach the productivity that was achieved back in the 1980s without in any way compromising safety. We’re of the view that working underground must be as safe as working in an office.”
As proof that this goal is attainable, Macnab points to one of UMS’s current shaft sinking contracts – a nearly 700 m deep ventilation shaft in New Mexico in the US.
“We recently achieved a sinking rate of 105 m over a month, which is truly exceptional, and yet we have an unblemished safety record,” he says. “Even more amazing is that we only have 54 people working on the shaft sinking, with only five or six below surface at any one time. I compare this with what I saw in my early days in the mining industry, when there would typically be around 60 working inside the shaft, about half on shaft bottom and the rest in the stage and working above each other. It was a nightmare. Today, it’s organised, safe and pleasant.”
Macnab says that a major contributor to the excellent sinking rates on the New Mexico contract is its use of a vertical shaft mucker (VSM). “The VSM has been used in South Africa with unsatisfactory results but we’ve modified both the machine and the manner in which it is employed and the results are exceptional. We’ve replaced the long operating levers with joysticks – this is less fatiguing for the operator, who can now lash and load while expending a quarter of the energy.”
He adds that the drill jumbos being used by UMS all have remote control capability, allowing the operator to stand in a safe position at all times.
On its Brazilian contact, UMS will be turning to the traditional cactus grab for lashing the blasted rock with kibble tipping in the headframe in the event of the raise bore hole becoming blocked. “Cactus grabs have largely fallen out of favour because of the safety issues they present,” says Macnab. “Nevertheless, they are extremely effective and can outload any other machines around. We’ve worked in close conjunction with our supplier in South Africa to address the safety concerns associated with this equipment and – to further promote safety – we will not have anyone working at shaft bottom during lashing.”
Aside from its US and Brazilian contracts, UMS’s third major shaft contract is for the sinking of the production and ventilation shafts for Lucara’s Underground Expansion Project (UGP) at its Karowe diamond mine in Botswana.
Hull says that UMS’s current shaft work will continue to keep it busy for at least two to three years to come. “Our contracts in Brazil and Botswana both have about 30 months to run but our New Mexico contract will be finishing next year so we will be working hard over the next few months to renew our order book. We already have some additional work at the Brazilian project and elsewhere in South America, as well as other locations in which we operate, so we’re very confident that we should be able to sustain and exceed the strong growth we’ve experienced over the past several years.”