Offloading cyanide at Rosebel’s dock
Many of the world’s raw material deposits are located in remote and very often inhospitable locations, presenting complex logistical challenges for mining operations. Devising an economically viable way to get the necessary people and equipment in and the resulting product out is crucial to achieving operational profitability.
Such was the challenge for the individuals charged with finding a way to access the diamond deposits in the farthest reaches of Canada’s Northwest Territories and riches in gold buried deep in the jungles of the Republic of Suriname. Although the logistical, engineering and climatic environments couldn’t be more dissimilar, they both called for ingenuity, forbearance and a very healthy respect for the power of Mother Nature.
Tibbitt to Contwoy Winter Road
Diamonds in the rough
The discovery of diamonds in Canada’s Northwest Territories in the early 1990s sparked a modern-day gold rush. However, it quickly became apparent that these diamonds were certainly no “easy pickings.” It would necessitate creating all the facilities and infrastructure required to excavate and process these valuable deposits from open pit and underground mines — not exactly an easy task when situated more than 100 kilometres north of the tree line.
One of the key factors to the viability of the northern mining industry has been the creation of what is reputed to be the world’s longest heavy haul ice road. Built over frozen lakes connected by 64 portages, the 600-kilometre Tibbitt to Contwoy Winter Road (TCWR) traverses some of the most forbidding landscape imaginable, to serve as the main supply road for four diamond mines and numerous mineral exploration projects. A record 11,000 truckloads or 330,002 tonnes of fuel, ammonium nitrate (prill), equipment, cement and other supplies were delivered via the ice road in 2007, while in this past road season (2008), 7,484 loads or 245,585 tonnes were hauled north.
A joint venture between BHP Billiton Diamonds Inc. and Diavik Diamond Mines Inc. holds the license to build the TCWR each year. Since 1998, the joint venture has contracted Nuna Logistics Limited (Nuna) to construct and maintain the road. The individual mines — including EKATI, Diavik, Jericho and Snap Lake — then contract various trucking companies to haul freight up this road.
According to John Zigarlick, chairman of Nuna, using an outside contractor was essential to the project. Zigarlick, who was the president of Echo Bay Mines for 16 years, was the visionary behind the winter road and has been involved with its evolution for the past 26 years. “The joint venture didn’t want hauling companies building the road because they have an incentive to haul as much as they can, whereas our top priority is safety,” he explained. “We don’t have that internal pressure to get more volume across.” Zigarlick said that they employ three crews to perform thousands of ground penetration radar tests to determine ice thickness.
The importance of ice profiling to ensure road safety is key, reiterated Erik Madsen, the director of winter road operations for the joint venture.
Integral to this objective is the use of ex-military vehicles called Hagglunds, the first pieces of equipment put on the southern portion of the ice, which is the last to freeze over. “The Hagglunds require 12 inches of ice to sustain their weight, but they’re amphibious, so if they happen to break through the ice they will float, allowing the operators to get out,” explained Madsen. They travel along the historical route of the road clearing or pushing the snow down while using ground-penetrating radar to continuously measure ice thickness. “That way, we can get flood crews out to the areas where the ice is thinner, drill holes and conduct focused flooding to build up the ice,” he explained.
Once the profiles indicate that the ice reaches a thickness of 16 inches, snow cats are able to get out and clear the snow faster along the route. Surprisingly, Madsen said that one of the biggest challenges is not actually building the road, but keeping the snow off of it. “Snow acts as an insulator and doesn’t allow the air to get at the ice to build it,” he explained. As the ice becomes thicker, progressively heavier equipment is allowed on the road. All of this equipment necessary to build the road is land-locked year-round at three camps strategically located along the route. A thickness of 28 inches is generally attained around the beginning of February, at which point hauling activity can safely begin.