Tag Archives: Koos Jordaan

Master Drilling’s Mobile Tunnel Borer heads to Anglo’s Mogalakwena mine

Master Drilling is readying its Mobile Tunnel Borer (MTB) technology for a contract at Anglo American Platinum’s Mogalakwena mine in South Africa.

The company, which revealed the news during its interim results presentation, said on-boarding for this project deployment was underway, with the start of “decline excavation” due by the end of the year.

Anglo American Platinum said in its own interim results recently that it was working on feasibility studies on the future of Mogalakwena, with completion of these studies expected at the end of 2021. Decisions on the pathway forward are expected shortly after this, however, one of the current key milestones at the asset includes progressing an underground exploration decline.

Master Drilling Executive Director, Koos Jordaan, said during the presentation that the contract with Anglo American Platinum is for a “turnkey operation” with Master Drilling providing capabilities in terms of construction, logistics and project management, in addition to its normal excavation services.

The MTB is a modular horizontal cutting machine equipped with full-face cutter head with disc cutters adapted from traditional tunnel boring machines. Unlike these traditional machines, it is designed to work both on inclines and declines, with the ability to navigate around corners and construct 5.5 m diameter decline access tunnels.

One MTB unit was previously scheduled to carry out a 1.4 km project at Northam Platinum’s Eland platinum group metals operation in South Africa, however this was cancelled in March 2020 due to the pandemic. This deployment followed testing of an MTB unit in soft rock at a quarry just outside of Rome, Italy, in 2018.

Alongside news of this latest MTB deployment, Master Drilling said in its results that it was studying the potential to deploy two of these MTB units in tandem for twin-decline access as part of the technology’s second-generation developments.

“We can already see the benefit of utilising two of these machines to do a twin-decline access to an orebody,” Jordaan said.

Looking to vertical developments, Master Drilling reported that it had received shareholder funding approval from the Industrial Development Corporation for the latest work on its Shaft Boring System (SBS), designed to sink 4.5 m diameter shafts in hard rock down to 1,500 m depths.

IM witnessed the main cutting mechanism of what was previously billed as being a 45-m long, 450-t machine at the back end of 2019.

The company has since said it will introduce a “smaller scope system” as part of its introduction to the industry.

While busy on the latest slimmed down design of the SBS, Master Drilling has signed a letter of intent with a prospective South Africa project that could see a machine start sinking activities in the first half of 2022, Jordaan said.

Outside of these developments, Master Drilling reported on several contract awards across the globe, including a three-year raiseboring extension with AngloGold Ashanti in Brazil, a joint venture agreement with Besalco Construction to work on Codelco’s Chuquicamata copper mine, an executed contract with Glencore’s Raglan mine in Canada, an agreement with Zimplats in Zimbabwe and a “long-term contract” on the Khoemacau copper-silver project in Botswana.

Master Drilling keeps advancing technology developments in face of market uncertainty

Having recorded a slight decrease in operating profit for the year ending December 31, 2019, Master Drilling pointed investors to several positive mining technology innovation developments within its latest financial results presentation.

In terms of financials, the main headlines were a 6.9% rise in revenue to $148.3 million and a slight decrease in operating profit of 5.1% to $22.4 million. The company put the latter down to “adverse global market conditions and an uncertain macro operating environment”.

Koos Jordaan, Master Drilling Executive Director, focused on the latest with the company’s Mobile Tunnel Borer (MTB), Shaft Boring System (SBS) and automation, remote operation and digitisation efforts when addressing investors on the financial results webcast.

Starting with the MTB, the company confirmed the Phase 1 project it carried out for Northam Platinum at its Eland platinum group metals operation in South Africa was executed in the second half of 2019. According to Northam, this was a “performance validation project” that involved tunnelling on the 5.5 m diameter footwall conveyor decline at Eland.

The MTB is a modular horizontal cutting machine equipped with full-face cutter head with disc cutters adapted from traditional tunnel boring machines. Unlike these traditional machines, it is designed to work both on inclines and declines, with the ability to navigate around corners.

In Northam’s most recent annual report, it said the MTB trial would allow the company “to test and optimise both the efficacy of the machine as well as service functions that support the machine’s operation”.

At the end of February, Northam said: “The MTB trial was completed, yielding positive results, and will be applied to develop the Kukama belt decline barrel.”

This latest contract at Eland, termed the Phase 2 contract by Master Drilling, started up this quarter and will see a 1.5 km decline constructed in around 18 months, the raiseboring specialist said.

Jordaan said during the webcast that the company had experienced some delays in the start-up phase of this project, but recently it had obtained and “realised a steady build up”.

“Apart from this project, there is a lot of interest out of industry,” Jordaan said of the MTB, adding that the company was working on upfront engineering estimations for two other projects.

In addition to carrying out estimates for these projects Jordaan said an “alternative contractual business model” was under review for future MTB projects. This model is focused on the “capital nature” of employing the MTB and, Jordaan said, could “make a big difference as to the way we provide this service”.

Looking to the company’s vertical developments, Jordaan reviewed progress on the company’s SBS project.

In the second half of 2019, Master Drilling carried out an “experimental project” just outside of Fochville, in South Africa, to cut a 10 m test shaft of 4 m diameter. IM witnessed this in October, where the main cutting mechanism of what could eventually be its 45-m long, 450-t SBS was tested out in 300 Mpa rock.

When IM visited just over a week into these daily demonstrations, the machine was around 4.6 m below surface, no cutters had been replaced and Jordaan was satisfied with the machine’s performance.

In the webcast, Jordaan confirmed that the testing had seen the machine get up to “just short of a 1 m/hr instantaneous penetration”.

Such advance numbers could add considerable value to shaft sinking projects “if you consider the current complexities, safety-related issues, cost and productivity” associated with conventional sinking, he said.

Master Drilling, in order to mitigate the risks associated with bringing this mechanised technology to a largely conventional sinking industry, has split the development of the SBS into five phases.

Phase one – the testing that took place just outside Fochville – was concluded in the December quarter, while phase two to four – covering the assembly, manufacturing and commissioning of a machine and proving it to be commercially ready – had funding in place from Master Drilling’s partner, the Industrial Development Corporation.

Lastly, on the automation, remote operation and digitisation efforts, the company said it had completed several milestones during 2019.

One of these was displaying the ability to operate a raiseboring machine situated 3.5 km underground from a room on surface at the AngloGold Ashanti-owned Mponeng gold mine, in South Africa.

Jordaan said just over 20% of production was able to be completed by remote control during this project. “This helps you a lot if you have operations with high re-entry times,” Jordaan said, adding that it aids utilisation.

The company was looking to roll out this remote operation functionality across another four rigs in South America, North America, Scandinavia and India, according to Jordaan.

Looking at automation, Master Drilling has the capacity to employ semi-autonomous control on 42 rigs in its fleet. Jordaan said this has already shown to optimise the cutting cycle and provide a 20-50% productivity benefit at certain sites.

“We have also developed full autonomous control – the engineering side of it – and are waiting for the ideal project to apply and introduce it to industry,” Jordaan said.

When it comes to digitalisation, Jordaan was able to report that Master Drilling’s real-time operational reporting facility was continuing to be rolled out across all its operations. He also said additional modules were being developed around this hardware and system, which would provide even more benefits to users.

Master Drilling brings excitement to the shaft boring sector

What Master Drilling is demonstrating on a patch of land some 15 minutes’ drive outside of its Fochville, South Africa, headquarters has the potential to change the hard-rock shaft sinking industry.

That is not an exaggeration.

Interested parties – major mining companies included – are being shown how the main cutting mechanism of what could eventually be its 45-m long, 450-t Shaft Boring System (SBS) can cut through hard rock.

The 15 in patented cutter heads are progressing through 320 MPa dolorite. Started up on cue over a three-week period that began on October 14, the machine is cutting around 40-50 mm a day.

When IM visited just over a week into these daily demonstrations, the machine was around 4.6 m below surface, no cutters had been replaced and Koos Jordaan, Executive Director of Master Drilling, was satisfied with the machine’s performance.

The fact that Master Drilling is showing off this cutting innovation now should not be a surprise.

The company first discussed what was previously called the Blind Shaft Boring System concept at the 2016 Mining Indaba, in Cape Town, South Africa. At this point, the company pitched the machine as being able to add significant value to projects given the shorter time frame it would take to reach new underground mine development levels.

The machine would be able to cut and muck, as shaft reinforcement, lining and other protective measures occurred. It would be work through hard rock from 200-400 MPa and sink shafts up to 1,500 m deep.

This aim has not changed in the more than three-and-a-half years since the premiere, but the name and the design has altered somewhat

Jordaan and Nicol Goodwin, Mechanical Engineer for Master Drilling, admit they went through seven designs before settling on what they are now presenting. Past iterations may have been more radical, but today’s blueprint, which has around 95% of detailed design complete, strikes a balance “between energy, complexity and sophistication”, Jordaan explained.

Design

Peter van Dorssen, Mining Advisor for Master Drilling, said some attendees – before seeing the machine in action – compared the concept with the V-Mole technology that is used on Herrenknecht’s Shaft Boring Enlarger (SBE).

Acting like a vertically-oriented modern hard-rock tunnel boring machine (TBM), shaft sinking with the SBE occurs in three phases – pilot hole, enlargement to pilot borehole diameter with a reamer and enlargement to final diameter of 7.5-9.5 m. The SBE was previously used to sink the Primsmulde shaft at the Endsdorf colliery in southern Germany.

While this technology reportedly performed well in the coal mine, achieving an average sinking rate of 7-7.5 m/d, it has not been tested in hard-rock conditions and, perhaps more importantly, the system cannot carry out concurrent mucking.

This means an access drift, as well as equipment, is required at the lowest part of the shaft to transport the muck to surface.

With Master Drilling’s SBS able to carry out cutting, mucking and shaft reinforcement concurrently, the comparisons tend to end there.

According to van Dorssen, Master Drilling’s newest machine can advance three times quicker than conventional sinking via drill and blast. It requires three-to-five people to operate the machine, none of which are exposed to the face. The safety considerations also extend to the changing of the disc cutters, which can be removed and replaced from behind the face.

Like the Mobile Tunnel Borer (MTB) for horizontal development (currently working at Northam Platinum’s Eland PGM mine in the North West province of South Africa), the SBS will be commissioned off a launchpad. This will be constructed with minimal civils work and alleviate the need for a timely and expensive pre-sink phase.

The front end of the machine (as it descends the shaft) is made up of the pilot cutting head – in a W-shape configuration – and gearbox. The pilot cutter head accounts for some 15%of the entire rock cutting, with the wider diameter reamer section that follows accounting for the remaining 85%.

This first section can independently progress by 1.5 m when cutting is taking place in three separate 500 mm phases.

The rest of the 45-m long machine catches up following this initial cutting, which is automated by a series of lasers that ensure the machine is on the correct course and using optimal force.

This cutting station is followed by two shaft gripping stations for machine support within the shaft. Following this is an enlargement station – also equipped with cutters – that widens the pilot hole carried out by the pilot cutter head to the desired diameter, with Master Drilling saying this will range from 7.5–11.5 m.

Behind this is a main stage made up of eight separate levels. Here, personnel will be able to carry out the rock bolting, lining and other reinforcement measures required. Personnel will also be able to probe drill for geotechnical measurements off one of these levels, enabling them to anticipate the fracturability and hardness of rock, in addition to any potential water inflows, ahead of actual cutting. Personnel operating on this main stage are protected by a series of finger shields that, while guarding them from potential rockfalls, still allow for a 360° access to the shaft for services.

A series of kibbles lowered by winches and transported on a conveyance on one of the levels of this stage bring the required shotcrete and materials to allow these concurrent tasks to take place.

Kibbles will also help with the mucking process, with two 16-t capacity buckets transporting the muck from the cut section to surface through a 2.1 m opening that present in all of the machine’s stations. Master Drilling is relying on gravity to recover 85% of the volume of muck at the enlargement section, with the remaining 15% recovered using a vacuum and/or slurry system.

Jordaan remarked: “The whole idea of this mucking system is to handle material once and handle it in a simple way.”

This mucking mechanism will shift the normal shaft sinking constraint dynamic from mucking capacity to shaft lining speed, van Dorssen said.

The headgear to support these operations from surface will likely be around 35 m tall – small in comparison with other mechanised sinking setups – while the total power requirement comes in at around 10 MW, according to Goodwin.

KPIs

While the demonstration in Fochville was a massive sign of intent from Master Drilling on the mechanised shaft sinking front, the company is formalising this testing process by setting itself key performance indicators.

One: it wants to hit or exceed an advance rate of 500 mm/hr – replicating an 8 m/d target that includes an envisaged two eight-hour production shifts and one eight-hour maintenance shift.

Two: it wants to test the machine’s cutting ability on both wet and dry material.

Three: it wants to push the penetration rate another 25-40% higher, alongside boosting the revolutions per minute from the 8-9 rpm it is currently operating at, to 10 rpm.

The company wants to put the machine through its paces before it moves onto another stage of its development.

Jordaan said he was hopeful of completing this testing – which constituted phase one of the SBS development – in around two months.

From there, if the reception is positive and no unforeseen complications arise, Master Drilling would look to manufacture the parts for the full 45-m long machine. In this task, the company is being helped along the way by three local engineering companies.

Phase three involves assembling and commissioning the whole machine and committing to a small excavation to test it out, while phase four is an ideal point to carry out mine site test. Phase five would see a full SBS deployment to its first major project.

Master Drilling was rightly wary of giving timelines on completing all these phases, knowing it would be reliant on securing funds for the machine build from its partner, South Africa’s Industrial Development Corp, and may need to make small changes to the machine design dependent on miner feedback from initial testing.

Yet, the company has opened the number of possible mine site testing options by designing the machine for shaft enlargement. This could see mining companies in need of extra shaft capacity sign up Master Drilling as a contractor to carry out an enlargement project, first, ahead of a much riskier blind sinking operation at a new underground mine later.

In terms of machine configuration, all that needs to change to carry out an enlargement is the cutter head, according to Goodwin.

This could prove decisive in terms of industry acceptance, allowing Master Drilling to obtain a mining customer reference much quicker than it would have if the only potential avenue was a blind sink.

Competition

When asked how the machine is likely to perform in terms of cost per metre, Jordaan said it would be competitive with drill and blast, but the real value proposition came in the form of reaching the development level and, therefore, the orebody that much quicker than the conventional method.

If, as van Dorssen said, the SBS can achieve a sink three times quicker than typical shaft sinking, miners could also be in line to receive cash flow that much faster.

In a cyclical market like mining that is an incredibly powerful value proposition.

It could reduce the risk associated with commodity prices potentially going the wrong way during development and allow a company to start paying back the capital sooner than expected.

Other companies already claim their mechanised machines can achieve such shaft advances, but these have either not yet been proven in hard-rock applications – being trialled only in potash or other softer rock – or require bottom shaft access to realise these rates.

It’s worth acknowledging that the SBS could also be used in softer rock with the expected increase in drilling speed countered by the need for further rock reinforcement.

And, whereas other OEMs will manufacture one machine per project, Master Drilling has longer-term plans for each SBS unit it manufactures. This could allow the company to charge a reduced rate to mining clients as it writes off its investment over multiple contracts.

So, once again, Master Drilling appears to be pushing the envelope on boring technologies.

In addition to the MTB, which is designed to work on 9° inclines/declines and have a 30 m turning radius – not typical tunnel boring machine traits – it has also carried out a number of firsts in the raiseboring market, with the company behind some of the widest diameter and deepest raises in the world.

With resources and expertise from across the globe to call on, it can innovate at a pace and cost many of its peers cannot compete with.

For those reasons, Master Drilling and the SBS are worth keeping an eye on.

Master Drilling aims for new status as mining TBM specialist

Master Drilling, through subsidiary Master Tunnelling, is not trying to re-invent the wheel with its mobile tunnel borer (MTB) concept, but that doesn’t mean to say the application of such technology will not have a big impact on the underground mining space.

The company, up until recently thought of as a raiseboring specialist, is up against stiff competition in the horizontal mechanised cutting sector. It has Epiroc and its Mobile Miner, Sandvik and the MX650, Caterpillar and the RH55 and Komatsu (Joy) and its DynaMiner to contend with, all of which have been trialled in underground mines.

But, the South Africa-based company is hoping its contracting model, tunnelling partner, modular design and operational flexibility will put its MTB in the lead.

Mining companies on a global basis have been looking for a mechanised, continuous alternative to the labour intensive drill and blast batch process for decades.

Several companies have tried to cater to this need, but no one technology has provided the ‘silver bullet’ as of yet.

Still, the drive to get personnel out from harm’s way, the need to improve tunnelling quality with an increasing number of block cave developments and decrease the payback period for what can sometimes be multi-billion dollar investments has resulted in the latest slate of horizontal cutting machines.

Master Tunnelling has partnered with Italy-based tunnelling expert Seli Technologies to launch its new product and IM recently visited a quarry site just outside of Rome where the first MTB is being assembled and tested.

On site, Koos Jordaan, Executive Director of Master Drilling, talked IM and a host of other interested visitors from mining companies through the machine specifics.

“To reduce risk, we stuck to proven cutting technology,” Jordaan said, pointing to the cutter head design in a schematic within one of the quarry’s temporary offices. “The concept is not so radical, it is more incremental based on tunnel boring.”

The full-face cutter head is made up of 17” disc cutters, which are conventional from a TBM perspective, but are made up of five separate segments. This cutter head, like the majority of the 240-300 t MTB, is designed to be broken down for transport.

The MTB is made up of four track-mounted units containing various parts – the cutter head and bolting section is up front, followed by the transformer and 300 m capacity water and electrical reels on the third unit, and a 14 m3 capacity storage bunker and discharge system on the fourth unit.

The units are also equipped with conveyors that transport the mucked material along the machine.

These can be individually broken down and potentially shipped in 10-12 20-foot containers, according to Jordaan.

This modularity should enable Master Tunnelling to access existing mines with decline infrastructure and to start tunnelling from an underground location, as well as to work on such infrastructure from the surface.

The full-face cutter head is capable of a 1 m advance stroke and can cut rock in excess of 300 MPa compressive strength. It can also be remotely controlled by an operator, reducing exposure to the face.

The MTB comes with 5.5 m diameter cutter head or 4.5 m diameter cutter head. The former is for declines, portals, haulages, inclines, ramps, ring roads, etc, with the latter allowing for excavation of drives and contact tunnels.

Master Tunnelling is aiming for an advance rate of 6-9 m/d in 200-250 MPa rock, but is not discounting the possibility of a higher rate should the additional mucking transport systems behind the 23 m (4.5 m diameter MTB) or 31 m (5.5 diameter MTB) machines be able to keep up.

Jordaan admits going past the 300 MPa threshold was likely to lead to advance rates dropping off by as much as a third, but is adamant the machine has the capability to cut through such rock.

All of this cutting takes substantial amounts of power, which the four hydraulic motors have in abundance. The MTB has 1,300 kW of installed power and a 1,600 kVA on-board transformer that more than covers the machine’s requirements.

Behind the cutter head, hydraulically-powered side grippers ensure the machine can thrust forward and start cutting, while there is a finger shield that both protects workers and allows for a support drill to install cable bolts for ground support.

Master Tunnelling envisages at least three personnel being required for full continuous operation in most setups.

Driving on a flat roadway

As Master Tunnelling points out, “a round profile tunnel is not ideally suited for vehicles that require a flat driving surface, such as most trackless mining equipment.”

This is where a articulating tail conveyor at the end of the fourth tracked unit – containing the 14 m3 storage bunker – evenly distributes 3-5% of the cut material. This should provide the sort of flat driving surface trucks will need to come in and pick up the material.

Master Tunnelling has some form here, too. Its Master Drilling parent company carried out a horizontal raisebore drive of 180 m length and 4.5 m diameter in a kimberlite pipe at Petra Diamonds’ Cullinan mine in South Africa recently. A flat driving surface was created by using a similar solution to the one the company has devised for the MTB.

There are also a few other features worth flagging.

The MTB is able to operate on a 12° incline/decline, has a 30 m turning radius and can be dismantled and brought back to surface after a project is complete.

The latter is different from the bulk of conventional TBMs where, after use, they are buried underground never to be used again.

Master Tunnelling is also taking safety seriously with the MTB. Not only is it shielding bolting operators from potentially hazardous situations above their heads all the way from the cutting face, it is also installing gas detection, proximity detection and fire suppression systems on the units. An operational monitoring system, meanwhile, ensures the full-face cutter head is advancing as planned and the accompanying units are tracking as they should be.

Master Tunnelling anticipates a four-hour maintenance period for the MTBs every 24 hours based on a three, eight-hour shift pattern. During this time, the disc cutters can be replaced and the dust suppression and collection system can be checked.

The company also envisages this time being used for drilling a 30-50 m probe hole in advance of the MTB. This would be drilled through an opening in the cutter head and provide integral information about the water and gas levels of the approaching rock.

The MTB doesn’t do away with drilling and blasting altogether. To initiate cutting, the machine requires a rounded profile side wall to grip and thrust to take it forward. This requires a starter frame to be installed in advance of the drive, which can be put in position with a 15 t capacity wheel loader with appropriate manipulator attachment.

The frame requires a starting chamber 6.5 m high, 8 m wide and 12 m deep excavated by conventional drilling, blasting and scaling.

In an undercut level for block caving, this preliminary batch phase would only form a “small part of the excavation required”, Master Tunnelling says.

In addition to considering the setup requirements for the MTB to start operation, it is also worthwhile to look at what will follow the machine in terms of loading and hauling the excavated material.

This is where the bunker backup unit positioned at the end of the four tracked units proves useful, acting as a storage facility to allow truck changeover to take place behind the MTB when one truck is fully loaded and another truck comes in. This allows for continuous operation of the MTB incorporating a batch haulage system.

On long, straight advances there is also the possibility of using mobile conveyors for haulage, however the company thinks there will be less of these applications given the MTB’s major strengths are developing tunnels with a curvature or on a decline/incline.

Contractor advantages

In the battle for a market leading, horizontal, mechanised cutting technology, Master Tunnelling has a few advantages over its much bigger rivals in the mining space.

One: it is a contractor, meaning it is not asking customers to invest in this capital-intensive equipment. Instead, it will be contracted by the client to provide the MTB and associated equipment required for logistics and material handling.

Two: It has a partner in Seli Technologies that has carried out more than 1,000 km of tunnelling excavations and has been involved in mining work before (it excavated an 8 km long, 4.2 m diameter tunnel for Anglo American at Los Bronces, in Chile, back in 2009).

Three: It is offering something that is modular, can be broken down and assembled underground, and can be relocated from one project to the next.

Also, Master Tunnelling is offering the ability to turn around corners and keep tunnelling with the MTB, which could be particularly useful when tracking complex, or faulting mineralisation. It could also come in handy should the MTB encounter particularly hard to bore rock.

The concept phase of the MTB only started in April 2017 and only one MTB has so far been manufactured. So, for the right partner, there is the chance to get in early and to advise on their customised requirements.

Master Tunnelling is clearly thinking to the future in this regard, with the bulk of the MTB hardware being ‘automation-ready’.

Even though the set up at the quarry in Italy is to test basic functionality – cutting 10-20 MPa rock for 50 m and carrying out a 30 m turn – it has provided interested parties a chance to consider what the machine could do for their own operations.

Once it has optimised the setup time and demonstrated what it can do in some fairly competent rock underground, the wider mining community may start to further appreciate the MTB and what Master Tunnelling is offering.