Tag Archives: Shaft sinking

GCR Mongolia JV hits shaft sinking milestone at Oyu Tolgoi

GCR Mongolia, a joint venture between Gobi Infrastructure Partners and RUC Mining, says it has reached a depth of 1,000 m on Shaft #4 at the Oyu Tolgoi mine in Mongolia.

On the achievement, RUC Mining said: ­“This achievement is a testament to the unwavering dedication and efforts of our exceptional shaft sinking project team.”

Back in 2018, GCR Mongolia was awarded a contract to design, construct and commission the sinking and lining of Shaft #3 and #4 and build the stage one material handling system at the copper-gold underground project.

The shaft sinking aspect for these ventilation shafts involves blind sinking and concrete lining of the two shafts, while the material handling system will require the installation of 9 km of conveyors able to transport ore to surface at 6,500 t/h. Shaft #4 was planned to be sunk to a depth of 1,200 m with a finished diameter of 11 m.

Oyu Tolgoi, in the southern Gobi Desert of Mongolia, is expected to produce the equivalent of 500,000 t/y of copper at its peak.

Murray & Roberts Cementation and Palabora Mining celebrate last blast at new vent shaft

Leading underground mining contractor Murray & Roberts Cementation and its client Palabora Mining Company (PMC) have celebrated the last blast at the new ventilation shaft, which took its depth to a final 1,200 m below surface on January 9, 2024.

The 8.5-m diameter upcast vent shaft – which holed through to an already-developed return air way at depth – is vital to PMC’s Lift II project. Lift II will develop access to ore resources sufficient to extend the life of this copper mine beyond 2040. Murray & Roberts Cementation Senior Project Manager, Fred Durand, says a key achievement was the project’s fatality-free record, earned over more than a million hours worked.

“The achievement of a million fatality free hours – reached in November 2023 – is more than just a number,” Durand says. “It reflects the deep-rooted safety culture that has permeated every aspect of the project.”

The innovative sinking methods, used for the first time in South Africa, were also carefully focused on achieving zero harm. Murray & Roberts Cementation employed its Canadian shaft sinking methodology, adapted to what became called ‘the PMC way’. This method included a solution to poor ground conditions, where the sidewall of the shaft was closed up within 48 hours by means of the shaft concrete lining after every three metres of advance.

“Among the improvements that this facilitated was the removal of the hazardous work by rock drill operators at the shaft bottom, who would traditionally have to install temporary support,” Durand explains. “We also decided not to conduct concurrent work in the shaft, so there was no risk of danger to anyone below when work was carried out from the stage.”

Durand emphasised the close collaboration between Murray & Roberts Cementation and PMC to ensure the success and safety of the shaft sinking. The project was significant insofar as there were many lessons learnt to be taken forward into future projects, he says, further improving the safety record of shaft sinking practice.

“We are already looking ahead to two more important shaft sinking projects within the South African mining sector, where there is potential for certain of these learnings to be applied,” Durand says.

A veteran of over 15 shaft sinking projects around Africa during his career, Durand admits finding aspects of the PMC way initially quite unusual when he joined the project in 2022.

“Ultimately, though, we all want to deliver safe projects, so there are many brilliant ideas that we have proven on this project,” he says. “These strategies have been combined with the company’s leading mining and engineering expertise, and made us very excited about the future of shaft sinking and contract mining.”

To facilitate streamlined programming on the project, the work ran on continuous operations with two 12-hour shifts. This, he notes, improves on the usual eight-hour shift system, which requires three shift changes – each change taking up valuable project time. The two-shift system requires only a morning and evening change.

The vent shaft will replace the two existing vent shafts from the Lift I project, which are likely to be affected as they are in the Lift I zone of influence. In the final stages of the project, Murray & Roberts Cementation will strip out its services from the shaft, lift out the stage and dismantle the headgear. Final demobilisation of the company’s infrastructure will be carried out during the March quarter of 2024, according to Durand.

Murray & Roberts Cementation continues to boost mining reputation in southern Africa

Murray & Roberts Cementation continues to add to its order book of business in southern Africa, with the company saying it is engaged in a number of projects in South Africa and having project prospects in nearby countries.

According to Graham Chamberlain, New Business Director at Murray & Roberts Cementation, the busy pipeline of projects demonstrates the mining sector’s faith in the company’s industry knowledge and depth of skills. In southern Africa, the main projects underway are at De Beers’ Venetia Mine, Ivanhoe Mines’ Platreef project and Palabora Mining Company.

At the Venetia Underground project near Musina, work has been ongoing since 2013 in one of the largest investments in South Africa’s diamond industry in decades. Transitioning from open-pit to underground mining will extend the mine’s life until 2046. Murray & Roberts Cementation has been engaged in sinking, lining and equipping of two shafts – the production and service shafts – to a depth of 1,080 m. The company also developed a decline tunnel and is completing associated surface and underground infrastructure, in a project whose scope included raiseboring work to establish ventilation infrastructure.

“In this maturing project, the mine is now getting into ore and starting to develop the infrastructure levels,” Chamberlain says. “At the shaft bottom, good progress continues to be made with the construction of workshops, pumping stations, silos and loading arrangements.”

Murray & Roberts Cementation is also conducting all the infrastructure development at Ivanhoe Mines’ Platreef project near Mokopane. This includes the sinking of a 5.1 m ventilation shaft to meet horizontal development at 950 m below surface. To achieve the high accuracy levels demanded by the project, the raiseboring equipment was guided by directional drilling technology.

“A unique aspect of this project is that the shaft will be hoisting ore at that same time as allowing upcast air to reach surface,” Chamberlain says.

Another vent shaft by Murray & Roberts Cementation – measuring 8.5 m in diameter and reaching a depth of 1,200 m – is nearing completion at Palabora Mining Company near Phalaborwa. Part of the mine’s Lift II expansion, the project has earned an impressive safety record – being fatality free and achieving 574 days without a Lost Time Injury since 2022. Ground conditions were among the reasons why a blind sink was chosen as the optimal method instead of raiseboring, as the side walls needed immediate support to prevent scaling.

“We also have a number of services projects underway related to raiseboring, grout plants and rehabilitation,” Chamberlain explains. “Much of our work in this field is focused on old infrastructure that requires maintenance, repairs or upgrades; we also conduct extensive vertical work in ore passes and silos.”

The company carries out vital rehabilitation in ore passes where ground conditions have deteriorated to prevent ore from moving smoothly – thereby risking production targets. Innovating safer techniques for this work, Murray & Roberts Cementation has developed the tube-and-fill method, first applied about seven years ago at an underground platinum mine in South Africa. These installations are also expected to outlast the lifespan of an ore pass rehabilitated with traditional shotcrete.

“On the engineering front, we continue conducting rebuilds of underground mining equipment at our Bentley Park facility near Carletonville,” Chamberlain says.

He highlights the work of the company’s design department, which remains extremely busy with feasibility studies associated with vertical work. With the renewed interest in commodity segments like copper, there is also previous work that customers are asking Murray & Roberts Cementation to review and update.

Training in underground mining and related skills at the company’s Training Academy on Carletonville continues to empower many thousands of learners each year, Chamberlain points out. This skills development is done on behalf of clients, as well as for the company’s own requirements.

“At any one time, we can host about 420 learners, and we are generally at full capacity,” he says. “We have just recently upgraded these facilities to further enhance training technologies that allows learning to take place safely but in a realistic environment.”

In compliance with many African countries’ localisation regulations, Murray & Roberts Cementation has registered companies in eight countries in the Southern African Development Community – most of which have seen the company active with raiseboring. Chamberlain notes that there are specific opportunities in Zambia that the company hopes to capitalise upon in the near future, and is encouraged by the mining sector’s progress in countries like Namibia and Botswana.

Platreef-Ivanhoe-Murray&Roberts

Murray & Roberts Cementation to accelerate ore hoisting at Ivanhoe Mines’ Platreef project

In a project innovation that will allow early hoisting of ore at Ivanhoe Mines’ Platreef project, in South Africa, Murray & Roberts Cementation will be repurposing its 3 Shaft – a ventilation shaft – to serve a dual function.

“This is a unique project in many respects, as the shaft will be hoisting ore at that same time as allowing upcast air to reach surface,” Graham Chamberlain, New Business Director at Murray & Roberts Cementation, says. “We were able to bring our well experienced experts into the planning process to develop a safe and effective solution.”

The project has followed the sinking of the vent shaft by Murray & Roberts Cementation, which had required very accurate drilling, using raiseboring equipment guided by directional drilling technology. The 5.1-m diameter shaft meets horizontal development at a depth of 950 m below surface.

“During this process, Ivanhoe looked at bringing forward some of their ore generation activities, and this required adding hoisting capacity,” Chamberlain explains. “The timeline for their main shaft meant that it would not be able to contribute to this capacity, so a team was established to consider how to retrofit the vent shaft into an early hoisting shaft.”

As an integral part of that multidisciplinary team, Murray & Roberts Cementation conducted a feasibility study on the options, allowing for the selection of the most suitable methodology. The company also carried out the necessary designs, including winders and headgear as well as hoisting and tipping arrangements. In September 2023, the project was awarded to Murray & Roberts Cementation to implement, and is scheduled to take about two years.

“This project stands out in terms of innovation, adaptability, teamwork and design,” Chamberlain says. “With our many decades in the sector, we were able to draw on hundreds of years of experience in mining – and leverage this in our design team.”

Among the range of technical challenges is the need to work within the vent shaft while it is performing its function of channelling an upcast current of air to surface. Any blockage of the air current in the shaft would affect the development operation of the mine, so this is critical to avoid.

“There needs to be periods during which we can reduce the ventilation, but we will have to ensure that air flow is always adequate,” Chamberlain says. Another vent shaft is planned to add ventilation capacity for the future.

Chamberlain points out that it will be necessary to deal with the slight deviations in the shaft; while accurately drilled, vent shafts are not designed to the same tolerances as hoist shafts. An important aspect of the design was the steelwork required to accommodate those deviations.

“The work will be conducted by a relatively small team of our highly skilled people,” he says. “This will include the installation of a compact headgear using refurbished winders from our strategic stockholding.”

The infrastructure will employ technology that will allow man-less operation to enhance safety, using automated processes in loading and measuring functions, for instance. The project will require specialised subcontractors on much of the equipment employed, but the more day-to-day consumables are procured locally to support local businesses.

“In the absence of a supplier, we would then develop their capability through our procurement system and enterprise development commitment,” Chamberlain says. “In this way, we foster small businesses and help to nurture them until they are self-sustaining.”

Redpath Deilmann, Thyssen Schachtbau to backfill Gorleben mine as part of closure plans

BGE, Germany’s federal agency for waste disposal, has taken what it says is the first important step towards the closure of the Gorleben mine in Lower Saxony with the award of contracts to backfill the mine using the salt originally excavated as part of plans for a nuclear storage project.

A consortium consisting of Redpath Deilmann GmbH and Thyssen Schachtbau GmbH Germany have been awarded with the work, with the pair expected to commence operations once mining permits have been obtained – currently estimated for mid-2024. The backfilling work is expected to take three years.

Redpath Deilmann sunk two exploration shafts at Gorleben to investigate its potential as a final disposal for nuclear waste using the ground freezing technique. These two shafts, sunk from 1986-1999, were 7.5 m in diameter and went down to depths of 933 m (Shaft 1) and 843 m (Shaft 2).

In September 2020, the Gorleben salt dome was withdrawn from the list of potential sites for a nuclear repository due to geological reasons based on an interim report by BGE. Following this, the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection commissioned BGE to close the mine.

The original shaft sinking saw salt transported to the surface, which has since been stored in the immediate vicinity of the mine. Around 400,000 t of rock salt is currently stored there on a salt heap, which is now to be used to backfill the mine.

Dr Thomas Lautsch, Technical Managing Director of BGE, said: “By signing the contract, we are taking the first big step towards closing the mine in Gorleben. The striking salt heap will now gradually disappear and the exploration mine will be filled step by step.”

The Gorleben mine will be closed in phases. After the mine has been backfilled, the two shafts will be backfilled via another construction contract (phase 2) yet to be tendered. In a final order, the site will be made usable again (phase 3).

Murray & Roberts Cementation hits 1,000 m shaft sinking milestone at Palabora’s Lift II expansion project

Leading underground mining contracting company, Murray & Roberts Cementation has achieved what it says is a remarkable milestone at the end of July 2023, successfully reaching the 1,000 metre mark on its contract to sink the 1,200 metre ventilation shaft at Palabora Mining Company’s Lift II expansion, in South Africa.

This significant feat stands as a testament to the company’s exceptional capabilities and dedication to safety, it says.

The Palabora Mining Company Lift II expansion project is a crucial endeavour for PMC, aimed at enhancing the efficiency and capacity of its operations. The 8.5-m-diameter ventilation shaft will serve the Lift II block cave and plays a pivotal role in the overall mining infrastructure.

Reaching a depth of 1,000 metres in the ventilation shaft is a major accomplishment, highlighting the expertise and commitment of Murray & Roberts Cementation in tackling complex mining projects, it says.

Fred Durand, Murray & Roberts Cementation’s Senior Project Manager, says one of the most remarkable aspects of this project is the unwavering focus on safety.

“Despite the immense challenges involved in underground mining and especially blind sinking, we have maintained an impeccable safety record throughout the Lift II expansion project,” he says. “The team’s relentless dedication to safety protocols and best practices resulted in an impressive milestone earlier this year of 574 consecutive days without a Lost Time Injury (LTI).”

He says that the achievement of this safety milestone showcases the company’s commitment to ensuring the wellbeing and safety of its workforce.

Durand concluded: “As the ventilation shaft project enters its final stages, the excitement and anticipation among all stakeholders, including PMC and Murray & Roberts Cementation, are palpable. The successful completion of this project will not only mark a significant engineering feat but will also have a profound impact on PMC’s mining capabilities.”

Murray & Roberts Cementation has aligned with the owner’s team to display technical excellence, professional management and passionate safety leadership from the day site establishment commenced in October 2019, according to Aidan Schoonbee, Senior Manager for PMC’s Lift II Construction, Concentrator and Vent Shaft.

Rajant teams up with Crossover Distribution to widen North America Kinetic Mesh footprint

Rajant Corporation, the pioneer of Kinetic Mesh® wireless networks, has entered a strategic distribution agreement with Crossover Distribution.

Crossover is, according to Rajant, a leading wireless solutions provider skilled in design and engineering expertise to support North America. It has provided solutions to both Vale and Nutrien in Canada.

The agreement represents Rajant’s further global investment to introduce its Kinetic Mesh solution to Crossover’s customers within industries such as mining, indoor automation, smart cities, public safety and rural broadband, the company said.

Crossover Executive Vice President, Darin Gibbons, says: “Rajant is a complement to other technologies in the Crossover portfolio. For example, the use of Sonim phones for industrial-hardened communications in underground mines with all the functionality of a cell phone on the surface is made possible by Rajant’s wireless networking. A Rajant BreadCrumb radio on mobile equipment is a practical way to have voice coverage at the mine’s working face.”

With Rajant, a NORCAT deployment allowed Crossover to test its UHF/VHF to VoIP phone crossbanding solution that seamlessly allows the worker to use either a phone or a radio and communicate on a legacy and Kinetic Mesh system, according to Gibbons.

“Further, we’ve achieved successful testing of add-on technologies, like fan controls, gas monitoring, geotechnical sensors, seismic sensors, post-blast reentry, hazard alerts, tracking, traffic control, underground fleet management, and more – all made possible by Rajant.”

Darrell Gillis, Rajant Sales Director – Canada, said: “Crossover’s primary Rajant Kinetic Mesh customer base of mines and ports, along with its business strategy to expand into other industrial and municipal markets, is specifically focused on wireless communication solutions. With Rajant Kinetic Mesh networking, Crossover now offers its clients a solution with total mobility, autonomous adaptability and mission-critical reliability.

“As a fifth-generation mining sales and service specialist, I’ve witnessed first hand the transformational nature of Rajant’s technology when it comes to mines. Of note is the exceptional work we are already doing in underground, which includes shaft sinking, shaft inspection and maintenance. Rajant Kinetic Mesh does not break the connection. Instead, the data is always transmitting and receiving even with the high speeds of the conveyances and the numerous shaft signal obstructions in a shaft. And, unlike leaky feeder systems, the shaft with Rajant has complete coverage with no dead spots that lose connection.”

Murray & Roberts Cementation shaft sinking alternative takes safety to a new level at PMC Lift 2

The sinking of a 1,200 m ventilation shaft as part of the Palabora Mining Company (PMC) Lift 2 expansion in South Africa is proving to be a partnership success story, based on an unshakeable commitment to safety, according to Murray & Roberts Cementation.

PMC commissioned this new ventilation shaft – which measures 8.5 m in diameter – to service its Lift 2 block cave, awarding the project to Murray & Roberts Cementation in February 2019. Now in its final phases, the project has earned an impressive safety record; it has been fatality-free, and, last year, achieved 574 days without a Lost Time Injury (LTI), the contractor reports.

The Lift 2 project will extend mine life by more than 15 years. Originally an open-pit mine, the Palabora mine transitioned to underground block cave operations in the early 2000s when Lift 1 was commissioned. Back in February, Murray & Roberts Cementation outlined that it had recently celebrated the achievement of a major milestone – reaching the 800 m mark – at the project.

“Feasibility studies indicated that a blind sink was the optimal method, despite its higher cost and longer time frame,” Jas Malherbe, Murray & Roberts Cementation’s Project Manager, explained. “Ground conditions were among the reasons why raiseboring was not an option, as the side walls needed immediate support to prevent scaling.”

Traditionally, the shaft would be lined to within 12-18 m of the shaft bottom, with the sidewalls being temporarily supported with split sets and mesh. However, the difficult ground conditions led to high levels of scaling that made this practice unviable.

“With ground conditions being such a key challenge on the project, we responded in an innovative way by taking the shaft lining right down to the blasted face,” Malherbe says. “The shaft sinking methodology in this project is, therefore, based on the Canadian shaft sinking method pioneered by Murray & Roberts Cementation – but has been adapted to ‘the PMC way’. This has involved lining the shaft to within 1.5 m of the shaft bottom, after mucking out the waste.”

Murray & Roberts Cementation uses a specialised concrete mix for rapid setting and early strength which hardens to 3 MPa within four hours – and this would be in place for at least eight hours before blasting. This solution requires that the blast is conducted while the shutters are still in place – so the shutters are strengthened and a toe added that would better handle the blast. The exposed concrete above the shutter is able to withstand the blast, as it has already cured for 48 hours.

Malherbe explains that drilling is undertaken by two twin-boom electro-hydraulic jumbo drill rigs. These are slung down the shaft from surface and nested in the four-deck stage for drilling the shaft bottom, a procedure which is repeated for each 48 hour blast-to-blast cycle. Waste rock is lashed using an excavator with a 0.36 cu.m bucket, which is lowered from surface through the stage to shaft bottom.

After blasting, an excavator is used for loading rock from the shaft bottom, which is safer than the conventional cactus grab, according to Murray & Roberts Cementation. Ground conditions lend themselves to the generation of large rocks during blasting, which can be difficult to handle. These are broken up using an hydraulic breaker, which can be coupled to the excavator. An 11-t kibble transports the waste rock to surface.

The Lift 2 project will extend mine life by more than 15 years

“Lashing a shaft with an excavator is not a new idea, but it is usually a back-up method to the cactus grab,” Malherbe says. “In this project, we decided that the excavator would be the primary lashing method, to further enhance safety on site.”

Steps have also been taken towards automating the headgear, to avoid the safety hazards of manually hooking the kibble to tip out the waste rock. This includes the winding engine driver being able to use a camera to check for correct hooking.

“We also opted to use electric actuators in this project, rather than the traditional pneumatic and hydraulic cylinders on equipment such as the bank doors, swing chutes and tipping chutes,” Malherbe continues. “This has allowed us to mitigate the risks such as hearing loss from the noise of certain actuators, and contamination from oil leaks.”

According to Sechaba Letaba, PMC’s Package Manager on the project, PMC took a deliberate decision to prioritise safety in the sinking of this ventilation shaft.

“By taking the PMC way, we have accepted that the pace of sinking would have to be compromised,” Letaba says. “This has proved to be a positive approach, as we have an outstanding safety record on the project. This is in stark contrast to the history of shaft sinking, which would often claim lives and cause injuries. We are therefore very proud of what we have achieved to date.”

He highlights the pivotal roles played by Sam Ngidi, PMC Senior Manager Operation & Lift 2 Project, and Aidan Schoonbee, Senior Project Manager Construction – in driving the project and ensuring its success.

Fred Durand, Murray & Roberts Cementation’s Senior Project Manager, points out that unexpected challenges tend to have an impact on scheduling, so the strong relationship of trust with PMC was vital to solving any issues as they arose.

“Our approach has always been to work closely with customers on solutions, and to ensure they are regularly updated on progress,” Durand says. “As a team, for instance, we decided that the rock breaker was the right solution for the issue of oversized rocks, and it was accepted that this would have an impact on the cycle times.”

Similarly, encountering more challenging ground conditions than expected required a significant mindset change about how the team approached the project.

“With the supportive relationship between PMC and Murray & Roberts Cementation, we were able to agree on the necessary remedies and adjust the timeframe to suit our priority – which was safety,” he says.

Malherbe concludes that, for Murray & Roberts Cementation, the lessons learnt on this project have shown the industry a viable alternative method of shaft sinking that takes safety to a new level.

South32 and Redpath kick off shaft sinking works at Hermosa

South32 has now broken ground on one of two exploration shafts at the Hermosa project in southern Arizona, USA, in a sign of major progress at the base and battery metal project.

This milestone achievement commemorates the initial surface excavation that will be continued by Redpath USA to a planned depth of 900 m, the contractor stated in a LinkedIn post. Redpath and South32 signed a “limited notice to proceed” for shaft engineering and design at Hermosa last year.

Redpath said in this latest post: “The shafts will enable underground access for continued exploration of a world-class deposit containing the US critical mineral zinc as well as lead and silver – minerals needed for supporting electrification and renewable energy.”

In South32’s March quarter results, the company said it invested $176 million over the last nine months as it continued critical path activity and study work for the Taylor zinc-lead-silver deposit and the Clark battery-grade manganese-zinc-silver deposit. It also directed $12 million to capitalised exploration in the nine months ended March 2023 as it continued exploration programs at Taylor and Clark and the copper-lead-zinc-silver Peake prospect 8.

Just last month, the Hermosa project was confirmed by the United States Federal Permitting Improvement Steering Council, an independent federal agency, as the first mining project added to the FAST-41 process, which is focused on supporting informed decision-making while reducing and eliminating unnecessary and costly delays associated with projects.

Anglo American increases Woodsmith polyhalite scale as shaft sinking progresses

Anglo American is upping the ante at its Woodsmith polyhalite project in the UK, increasing its planned spend while expanding its production scope following detailed design reviews and non-critical path studies.

In the company’s 2022 results release today, it said these reviews and studies had led to a number of areas being modified to align with Anglo American’s standards and its aim to optimise value for the long term.

The outcome is an enhanced project configuration to ensure the company delivers maximum commercial returns from Woodsmith over the expected multi-decade asset life, Anglo said. Included within this is an increase in the capacity of the shafts and other infrastructure to accommodate higher production volumes and more efficient and scalable mining methods over time.

More specifically, this has seen the company plan for a circa-13 Mt/y operation instead of the previous 10 Mt/y operation it had endorsed, subject to studies and approval.

“In light of these changes, Anglo now expects first product to market in 2027, with an annual capital investment of around $1 billion,” the company said.

Spending of $800 million is approved for 2023, with the bulk of initial spend on the shaft sinking and tunnel boring activities. As usual in developing underground mines, the schedule will largely be determined by the ground conditions encountered as sinking activities progress.

The Woodsmith project is located on the North Yorkshire coast, just south of Whitby, where polyhalite ore will be extracted via 1.6-km-deep mine shafts and transported to Teesside via an underground conveyor belt in a 37 km tunnel, thereby minimising any environmental impact on the surface. It will then be granulated at a materials handling facility to produce a low carbon fertiliser – known as POLY4 – that will then be exported from its port facility, where it has priority access, to a network of customers around the world.

During 2022, as part of the mentioned construction review, contracts were awarded for the shaft sinking operations, program management services and construction management to ensure the project can be executed in line with Anglo American’s stringent requirements. These contracts were awarded to Redpath (shaft sinking) and Worley (program management services and construction management).

With the award of these contracts and other infrastructure improvements, activities at the deep shafts have progressed. The service shaft is now more than 360 m deep, while shaft sinking began 120 m below the surface for the production shaft in January 2023, as planned. Both of these shafts are being sunk using Herrenknecht’s Shaft Boring Roadheader technology.

Three intermediate shafts will provide both ventilation and additional access to the mineral transport system (MTS) tunnel. The Lockwood Beck intermediate access shaft was successfully completed in 2022 and is fully lined and connected to the tunnel. Work on the MTS shaft at the mine head progressed through 2022 and is 85% complete, and the excavation at the final intermediate access shaft at the Ladycross site commenced in early 2023.

Following a planned maintenance pause in mid-2022 to refurbish the tunnel boring machine and allow the connection with the Lockwood Beck shaft, the MTS tunnel is now past the 21-km point and is more than 56% complete, progressing at rates not seen since the start of the tunnelling activities, Anglo said.

Anglo American concluded: “We believe that the changes we have made to the project have had a materially positive impact on the project’s long-term attractiveness and prospects. However, for accounting purposes at this early stage of the project’s development, we have recognised an impairment of $1.7 billion to the carrying value of the asset within special items and remeasurements, reflecting the extension of the development schedule and capital budget.”