Murray & Roberts Cementation has set a mining industry benchmark by establishing an innovative emergency egress system – from design to operation – in just 11 days at Petra Diamonds’ Finsch Mine, 160km northwest of Kimberley, South Africa.
Mine management needed to add a temporary personnel escape route from the mine’s underground operations while refurbishment work is being conducted on a decline which normally serves as the second escape route. This is required in terms of the Mine Health & Safety Act.
Refurbishing the decline will take several months and Murray & Roberts Cementation’s Neil Lane says Finsch Mine approached the company directly to assist with establishing a second egress system as quickly as possible.
"Following consultations with representatives from Finsch Mine and the DMR’s Mine Health and Safety Inspectorate, it was decided to utilise an existing 2.1m diameter raisebored ventilation pass that extends 280m to the mine’s 35 level, to create the required emergency evacuation facility," said Lane.
"The proposed system was reminiscent of that implemented to rescue the 33 miners who were trapped underground in the San Jose Mine in Northern Chile just over a year ago. The Cementation Mining Group participated in this rescue operation and we used the same design principle to set up the escape route at Finsch."
Murray & Roberts Cementation mobilised shaft and mining engineers at very short notice to develop the facility which comprises a small headgear, a winder system and a wheel-guided conveyance capable of transporting 12 people at one time to the surface in the event of an underground emergency.
"We containerised and pre-commissioned the entire winch system, so it was a case of ‘plug and play’ when the facility arrived on site at the mine," Lane added. "The mine cast a concrete slab in preparation, and when the winder arrived it didn’t take long to couple up the cables and get the system going."
The winch is electrically powered, with standby generators available, and travels at a speed of 0.5m/s.
Commissioning of the system components took place throughout the project. The winch and controls were tested at the point of manufacture and were commissioned as they were assembled. Several test runs were carried out by a joint Murray & Roberts Cementation and Mine team.