Nonprofit organisation Mines Rescue Services (MRS) on January 21 carried out test work on a new mobile rescue winder at Gold Fields’ South Deep mine, in Gauteng.

The mobile rescue winder, a world-first technology, will allow proto teams to access shafts and carry out rescue operations at depths of 3 000 m if required. It can carry up to six people at a time, as well as equipment and medical supplies. Previously, rescue winders could reach depths of 1 200 m.

This is vital for South Africa, which has some of the deepest gold mines in the world.

Tech Edge Group's Winches and Winders had manufactured the mobile mines rescue winder (MMRW), in collaboration with MRS, Minerals Council South Africa members, the Department of Mineral Resources and Energy (DMRE) and labour.

Gold Fields executive VP Martin Preece states that MRS volunteers are the unsung heroes of the mining industry. “They are highly skilled and trained mining employees from all over the country who carry out rescue operations when it is required.”

The testing involved lowering and raising the conveyance at a speed of 1.5 m a second, with a simulated load of six people, to a maximum depth of 3 km.

“Eight out of the ten deepest mines in the world are located in South Africa. Once the mobile rescue winder has been fully licenced by the DMRE, we will be able to access employees located at depths of up to 3 000 m faster than we were able to before in the event of an emergency," MRS CEO Mannas Fourie explains.

Winches and Winders chairperson Russell Moore tells Mining Weekly that the catalyst for the design of this innovative equipment was the 2010 mining accident at the San Jose gold mine, in Chile.

South Africa was one of the countries to contribute to the relief efforts, including airlifting a Winches and Winders’ standard winder to San Jose to act as standby to the efforts of the Chilean authorities. This incident brought together some of the best global mining safety experience from South Africa, Latin America, Australia, the US and Canada, but also highlighted critical issues in the technology available to speedily mobilise and implement relief efforts. 

"This prompted us to design a mobile, go-anywhere, self-contained rescue winder specifically designed to address the need for rapid response, deployment and resolution of underground mining emergencies; the MMRW.

"We offered the concept to MRS, who contracted Winches & Winders to bring our MMRW design to fruition," Moore explains.

The design of the MMRW, which is the culmination of nine years' worth of design and development, was specifically engineered to improve mobilisation and efficacy of rescue efforts, including its rough terrain capability for off-road and rural access and for it to be self-contained system, including with power supply and sheave wheel deployment.

Winches and Winders took care to manufacture a normal height vehicle so no additional road permits are required, while it had all normal statutory requirements for man-riding mining conveyances.

Moore points out that the winder drive and control systems are considerably more complex and sophisticated than existing rescue winders. Rope dynamics - the movement, tension, and material properties - at extreme depths necessitated extremely sophisticated control and feedback systems. This means that the rescue team on the surface can operate confidently. 

He adds that the developed specifications were, at times, difficult to resolve in one design. "Our aim was to design a solution that will give rescuers an advanced, efficient, widely applicable solution. This meant developing ideas that balanced engineering invention and solid pragmatism.

"One of the most exciting elements of the MMRW is the sheave wheel deployment system, which is so novel that we have patented it. The self-contained sheave wheel means that no additional headgear or on-site rigging is required at the rescue site, saving valuable hours in rescue operations."

The MMRW needed to be deployable in most terrains, including normal roads, so it needed a non-permit vehicle.

"This was a challenge as there is some serious equipment mounted on the truck, but our engineers managed it through careful truck selection, balanced loads, and persistent design evolution. 

"Also included in the design are the one- or six-man conveyance, which is the cage that attaches to the end of the rope. This means rescuers can select their conveyance depending on the size of the rescue shaft, and can begin rescue efforts with the much narrower conveyance before the rescue shaft is widened. Again, this saves valuable time when retrieving people trapped underground, or delivering essential supplies and equipment during rescue operations," Moore concludes.