Sheffield heavy engineering concern, DavyMarkham has been awarded a massive $20 million order for the supply of mining hoists and associated electrical drives and controls, by top mid-tier gold producer IAMGOLD Corporation of Toronto, Canada.
The contract includes the largest double drum hoist supplied to North America in recent times, with a diameter of 21ft (6.4m), a drum width of 8ft (2.4m) and a payload capacity of 44,000lbs (20,000kg). It will serve as the main production hoist, operating at depths down to 8,700ft (2,652 metres), at IAMGOLD’s exciting new Westwood exploration programme.
“This is a very important contract gain for DavyMarkham and it is testimony to the cutting-edge design engineering technology we are applying to this key market sector and the extreme precision of our heavy engineering,” says Managing Director, Kevin Parkin. “The IAMGOLD Corporation is a major new customer for us and we are delighted to have won this major order in international competitive tender.”
Over recent years, DavyMarkham has been developing world-leading mine winder technology and has made particular inroads into the flourishing Canadian minerals market, supplying more than a dozen new hoists for gold and nickel mining projects; it was also the first supplier to the North American market to comply with the internationally-recognised South African SABS codes of practice, for deep shaft exploration. DavyMarkham has worked closely with ABB Montreal on the provision of electrical plant for these projects and gained a thorough understanding of how its drive and control systems operate, ensuring the highest levels of safety, reliability and performance for mine hoisting installations.
For the Westwood project, DavyMarkham will design, manufacture and supply a 21ft diameter production hoist and an 18ft (5.5m) double drum service hoist, together with associated clutch assemblies and multi-channel hydraulic brake control system. ABB has been sub-contracted to provide drive systems for both hoists, including high voltage motors, industrial drive units, digital hoist control system and a hoist operator station. Delivery is scheduled for late Spring, early Summer 2010, presently on a supply to mine site basis, although there may be the option of providing installation and commissioning services at a later stage.
With eight different mining operations in North America, South America and Africa, IAMGOLD is a leading global gold producer and additionally owns four mineral development projects that provide a strong platform for continued growth. Located two kilometres from the company’s existing Doyon Mine operation in Northern Quebec, within one of Canada’s most prolific gold production areas, its Westwood advanced exploration project began in 2004 to identify potential new deposits. A raise boring machine is already excavating an initial shaft and, once this is complete, the sinking of the main 5.5m diameter exploration shaft will begin.
This accelerated exploration programme puts pressure on DavyMarkham to meet an extremely tight contract deadline, although work is currently progressing to schedule. The principal components were first subject to a rigorous engineering analysis process to predict stress levels and deflections at all critical points in the hoist, with the drums themselves modelled using Finite Element studies, which accurately represent the thickness of materials to be used throughout the structure. This process enabled DavyMarkham to recommend a smaller 18ft diameter service hoist with geared drive, as the optimum size commensurate with duties, rather than the more expensive 19ft diameter, direct drive configuration originally specified.
Both double drum hoists are being manufactured at DavyMarkham’s Sheffield works in halves, for ease of transportation and assembly on site. The drum shells will be precisely 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 drumside 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, generously rated to give an L10 life of 200,000hrs. 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 IAMGOLD 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.
On the drives side, ABB will be supplying a water-cooled ACS6000 series multidrive coupled to a 6800kW AC synchronous motor for the main production hoist, with an ACS800 multidrive and two 1205kW cast iron induction motors for the service hoist. It will also provide its well-proven digital hoist control and safety supervisory system, to monitor the hoist operating speed envelope and ensure reliable and accurate control of brake systems and other hoist subsystems. This will be linked to a Type PA1 hoist operator control station and Hoistlogger monitoring system, for an intuitive, simple and clear means of mine hoist operation when full production starts in 2012.
Further enquiries to DavyMarkham at Prince of Wales Road, Sheffield S9 4EX, telephone 0114 244 9971, email kevin.parkin@davymarkham.com
Press Contact David Gent Tel: 01706 220388 Email: david@davidgent.com