South African engineering consultancy TWP Projects has successfully completed the erection of the preassembled headgears of both the main shaft and the services shaft at Royal Bafokeng Platinum’s (RBPlat’s) Styldrift shaft complex.

TWP, the engineering, procurement and construction management contractor for the deep-level shaft on the Styldrift Merensky phase 1 project, which forms part of the Bafokeng Rasimone platinum mine, is a joint venture (JV) between Anglo Platinum and Royal Bafokeng Holdings.

The 50:50 JV was formed to exploit platinum-group metals (PGMs) in the Merensky and upper group two reefs on the Boschkoppie, Styldrift and Frischgewaagd farms, on the western limb of the Bushveld Complex.

Following a restructure of the JV in 2009, RBPlat was formed. The company holds a 67% majority interest in the JV.

The Styldrift Merensky phase 1 project entails a twin vertical shaft system: the main shaft, reaching a depth of 740 m, and the services shaft, reaching 705 m. Full production of phase 1 is expected to be achieved by 2017, which will increase the Bafokeng Rasimone platinum mine’s production to 430 000 t/m.

The main shaft and services shaft headgears were designed by the Anglo technical division and Mining & Engineering Technical Services (Mets) respectively, and were manufactured and preassembled on pads. The main shaft headgear was assembled in three sections, and the services shaft headgear in four sections. The erection of the headgear was undertaken by Louwill Engineering.

The total weight of the two headgears amounts to an estimated 1 200 t.

TWP project manager Pieter Louw reports that the headgear centre tower and A-frame sections were assembled on concrete pre-erection pads and frames, and placed into position using a 1 000 t lattice boom crawler rig-type crane from Sarens, one of the biggest cranes in South Africa.

“Assembly of the main shaft headgear, an A-frame steel tower structure reaching a height of 58,6 m, started a few months ago and the erection started on January 31, with the last lift taking place on February 18. “The services shaft, a 41,3-m-high steel prop tower, also took a few months to assemble and about one week to erect, with the final lift on February 12,” says Louw.

He adds that it was TWP’s responsibility, as the project manager, to ensure the smooth assembly of the headgears while slow deep-sinking activities were still in progress prior to the main deep-sinking-phase deadline. “With a current workforce of about 400 on site, this was by no means an easy undertaking, and was made possible with the cooperation of all the contractors,” explains Louw.

The original programme would have been to stop operations, build the headgear and then embark on sinking, which would have adversely affected the overall schedule and programme. The sinking of the shafts, undertaken by Shaft Sinkers, was able to begin in October last year.

TWP currently has 13 different shaft systems on its books, some in the design phase and others under construction.

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