Marthinusen & Coutts (M&C) recently successfully met an extremely tight deadline it had been set as a contract condition for the repair of a 94t 4736kW DC mine winder motor that had failed at Northam Platinum’s Zondereinde mine near Thabazimbi in Limpopo Province in July this year.
The motor had driven the man-winder hoist serving the mine’s No.1 shaft.
M&C was given just five days to perform all the necessary repairs after taking delivery of the motor at its Cleveland, Johannesburg, workshop.
“The clock started ticking when we took delivery of it on July 24, with the repairs having to be completed and the motor fully reassembled by July 29, when it was due to be collected and returned to site for re-installation,” said Owen Kilian, M&C’s Projects & Field Service Manager.
One of the motor’s field coils that was found to be damaged had to be rewound and the insulation, which had deteriorated over time, was replaced. “We also chemically washed all the parts in our Power Generation workshop in Benoni and dried out the halves in our dedicated drying-out ovens,” Owen said.
The contract also incorporated M&C having to provide a field service team to assist mine personnel in transferring an identical motor driving the rock-winder hoist at No.1 shaft to replace the other to keep the man-winder hoist working so as to minimise the disruption of underground operations while the failed motor was being repaired.
“The plan was to install the repaired motor to drive the rock-winder upon its return, which our field service team was also assigned to assist in installing as part of our contract,” Owen explained, adding that an additional five days was allowed by Northam under the repair contract for the on-site work undertaken by M&C’s field service team. Some repair procedures were also done on site, including refurbishing the armature of the repaired winder motor.
“We worked 24 hours a day over the 10 days we spent on the total project for the two winders. Without the excellent teamwork we were fortunate enough to share with the expert mine personnel and their rigging subcontractors we wouldn’t have completed the job in the very limited time we were given,” Owen commented.
“ACTOM Industry, representing the OEM for the winder motors, proved invaluable in ensuring that everything was done in accordance with the OEM’s quality standards,” he added.