Murray & Roberts Cementation, an underground mining contractor, and its client Palabora Mining Company (PMC) have completed the last blast at a new ventilation shaft, vital to PMC’s Lift II project
Lift II will develop access to ore resources to extend the life of the copper mine beyond 2040. The latest work at the site has taken the depth of the ventilation shaft to 1,200 m below the surface, an impressive achievement especially with the innovative project being completed with an excellent safety record.
Murray & Roberts Cementation senior project manager, Fred Durand, explained that the project boasted a fatality-free record and earned more than a million hours worked. “The achievement of a million fatality-free hours – reached in November 2023 – is more than just a number,” he said. “It reflects the deep-rooted safety culture that has permeated every aspect of the project.”
The delivery of the project involved innovative sinking methods that were used for the first time in South Africa. Murray & Roberts Cementation employed its Canadian shaft sinking methodology which was adapted to what became called ‘the PMC way’. This utilised an innovative solution to poor ground conditions, where the sidewall of the shaft was closed up within 48 hours through the shaft concrete lining 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 commented. “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.”
In carrying out the project, Durand noted there were many lessons learnt which would be taken into future projects, and already the company is looking to two more important shaft sinking projects within the South African mining sector.
To facilitate streamlined programming on the project, the work ran on continuous operations with two 12-hour shifts. This improved on the usual 8-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 Q1 2024, Durand concluded.
