Electric motor repair service provider Marthinusen & Coutts has performed its ninth on site gearless mill drive winding project for copper miner First Quantum Minerals’ (FQM’s) Cobre copper mine in the district of Donoso, in Panama, Central America.

Marthinusen & Coutts, during October and November 2022, carried out the winding and subassembly of an 18 MW gearless mill drive for a new ball mill at the Cobre mine as part of the expansion of the mine’s processing plant to cater for increased ore output.

Marthinusen & Coutts was contracted for the latest project by Cobre mine’s owners and operators Minera Panama, the Panamanian subsidiary of FQM.

Marthinusen & Coutts’ seven-person on site team, led by divisional CEO Richard Botton, performed the work in 40 days.

“We already knew from previous experience that the working conditions at the mine are extremely tough, owing to frequent heavy rain, high humidity and excessive heat, but our familiarity with the procedures involved helping to ensure that the project went according to plan and was completed on time,” Botton says.

He adds that owing to the project’s complexity, the winding and subassembly had to be done on site.

Additionally, Botton points out that preparation for a rewind like this is extensive and starts about six months prior to site establishment.

The machine is transported to site from the original-equipment manufacturer (OEM) in Europe in four quadrants, each of which weighs 85 t.

“We are responsible for the connecting and continuity between the four segments, which have been pre-wound by the OEM,” he explains.

“About half of the tools we use for the on site work are purchased and supplied by the mine itself, while we have to supply and bring with us the remaining, more specialised tools, along with the test equipment that’s needed,” he says.

Further, Marthinusen & Coutts has also executed four on site winding and subassembly projects on gearless mill drives for FQM’s Sentinel copper mine in Zambia in recent years.