According to the judges, the plants – which were installed and commissioned at Snap Lake, near the Arctic Circle, and Victor, in Canada – demonstrated De Beers’ ability to accomplish a uniquely challenging task in the most arduous physical conditions.
“It is hard to imagine a more inhospitable site to build a plant than one close to the Arctic Circle, where temperatures are known to plummet to minus 50 degrees,” the judges pointed out. “Not only was special steel suitable for such conditions required, but working conditions were gruelling and the logistics proved to be a nightmare,” they added.
Modularisation of recovery plants for diamond mines has existed in South Africa for a few years. The Steel Awards in 2005 recognised modular diamond recovery plants built for Venetia mine in Limpopo.
In the project entered for 2007, De Beers used the technique of constructing a modular plant near to industry, and equipping the plant, including the steel structure, mechanical handling and separating equipment, electrics, mechanicals, piping and instrumentation; then breaking down the module into sections small enough to transport by road (although abnormally large in terms of road ordinance); and finally delivering it to site, where it can be quickly assembled and commissioned.
This is clearly an optimal way of overcoming difficulties associated with a far-off site. Within the borders of South Africa, modular plant designers have the relative luxury of abnormally large module sizes, but when it comes to shipping the module to Canada it is not so simple, as modules are restricted to standard shipping container sizes.
PRECISION PLANNING WON THE DAY
Erecting the plant is a relatively simple part of the exercise when fabricating and assembling on a user-friendly site close to all facilities. But with export work, the discipline of ensuring that all items are sent in the right sequence has even more critical consequences – particularly on a project destined to be delivered to the Artic Circle. In this project, assembly and equipping were carried out in a Vereeniging yard, and the containers were then transported and shipped.
In northern Canada, large sections of the territory are swamp-like, lake-filled areas with no roads at all in many instances. Transporting goods through this area can be done only in winter, when roads are created by nature in the form of frozen lakes on which the trucks can travel.
Erection of the plant then occurs in the spring and summer, when all the components and equipment have been stored and are ready for use during the next winter. One winter missed is a lost opportunity, because teams must then wait an entire year before major deliveries can resume. It is thus a project programme which is largely controlled by nature.
While the structures had to be designed to the Canadian S16 steel design, this was not an issue for the steel design team, as South African codes are based on the S16 document. In addition to the conditions mentioned above, a further complication for the fabricator was the need to conform to the Canadian Welding Bureau’s requirements. With well-trained and competent welders and an ISO 9000 quality programme, this hurdle was cleared with ease.
“This was an exercise in excellent project planning, team work and co-operation, incorporating logistics of an exceptionally high standard,” the judges felt. “The specialised use of structural steel in this project was truly deserving of the award.”
The project team consisted of: De Beers as the mine owner and developer; UWP Consulting Engineers as the structural steel designers; DRA Mineral Projects as the engineering, procurement and contract management engineers in South Africa; and Cosira International as the structural steel contractors. PCC were the quantity surveyors on the project.
Steel Awards 2007 was hosted by the Southern African Institute of Steel Construction (SAISC), and the principal sponsor of the event was DSE Structural Engineers and Contractors. The partner sponsors were: Robor, Kulungile Metals, the Association of Steel Tube and Pipe Manufacturers of SA, Trident Steel, Mac Steel Service Centres SA, Cadex Tekla Structures, Bolt and Engineering Distributors and Group 5 Projects.