Dowding, Reynard and Associates Technical Services (DRATS), specialising in all areas of winder engineering, has developed a sound reputation, both locally and internationally, for rebuilding and modernising existing winders.

The company has established a foothold in Africa and early this year was awarded the contract to act as consultants and project managers for the refurbishment and upgrading of winders for the Mopani Copper Mines’ Mufulira and Nkana divisions near Kitwe in Zambia.

The contract at Mufulira involves partial refurbishment of four winders, and DRATS drew up the design specifications and is managing the project to final acceptance and hand-over tests. As part of the Mufulira contract, one of the surface man winders has just been completed and commissioned with new brakes and brake control system and new electrical equipment for the winder’s speed control.

DRATS was the main contractor for a turnkey project to upgrade the electrical control systems of seven winders at Nkana. The project, which involves design, manufacture, supply, installation and commissioning, was started early in 2003 and is almost complete. The main challenge was to carry out the installation and commissioning without adversely affecting the mine’s production schedules. All of the installation was undertaken while the winders were off-line for winder examination or for routine maintenance. DRATS had to work round the clock in some instances to manage this, but there was no loss of production as a result of the project work. Also at Nkana, DRATS has just completed a design study for upgrading a rock winder to substantially increase production capacity.

Phase 1 of the re-opening of Kalana Mine south of Bamako in Mali is almost complete. Here DRA Technical Services was involved in the total rebuild of two Russian winders that had first been commissioned in the late seventies. The winders had to be upgraded mechanically with new brake control systems and the electrical speed control systems, now obsolete, had to be replaced entirely. The headgears at each of the two shafts had to be modified for permanent production duty rather than for shaft sinking as originally installed. All the hardware was designed and manufactured in South Africa and shipped by container to Mali.

DRATS was established five years ago and is the only specialist winder consulting company in South Africa. The company has extensive experience in winder technology, with particular expertise in winder mechanical and electrical design, brake system and mechanical component design and stress calculations, training of winder maintenance staff, accident/failure investigations, technical audits and risk assessments, statutory winder testing and examinations, and winder automation. The company conducts work on a turnkey or EPCM basis.