QUEBEC — IamGold Corporation of Toronto has awarded the $20-million contract for mine hoists for its Westwood gold mine near Val d'Or to DavyMarkham of Sheffield, U.K. The order includes the largest double-drum hoist for a North American mine in recent times. The production hoist will have a diameter of 5.4 metres, a drum width of 2.4 metres and a payload of 20,000 kg. The production shaft will be 2,652 metres deep.
DavyMarkham will also design and supply a 5.5-metre, double-drum service hoist plus associated clutch and brake systems. ABB has been sub-contracted to provide drive systems for both hoists including a digital control system and the hoist operator station.
Both double drum hoists are being manufactured in halves, for ease of transportation and assembly on site. The drum shells will be machined on modern CNC machinery to provide parallel grooving, with two anti-synchronous crossover sections, suitable for the specified diameter of hoist rope, while the drum side assembly will be bored and face machined for accurate location onto raised flanges on the drum shaft. Each drum shaft will be machined from a high quality, single forging and supported by a pair of self-aligning bearings, rated to give an L10 life of 200,000 hours. The drive motor for the production hoist will be an overhung rotor type and the drum shaft will have a removable, solid flange for connection to this motor, eliminating the need for additional bearing supports.
A particular feature of the DavyMarkham mine hoist design is the provision of a multi-channel hydraulic brake control system, which ensures full SABS compliance and maximum safety under fault conditions. This system has been specified on both Westwood hoists and will be interfaced with ABB’s digital hoist control equipment, so that if a fault occurs with one brake channel, only one cluster of brake units is affected and the remaining clusters provide correct brake application and controlled deceleration.
Delivery is scheduled for spring or early summer 2010.
Please see www.DavyMarkham.com.
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