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Driving across the frozen river

How to build an ice bridge across the Liard

Derek Neary
Northern News Services

Fort Simpson (Dec 07/01) - There may not have been a mass exodus from Fort Simpson Sunday, but there could have been.

The ice crossing opened. Those with cabin fever are now free to come and go as they please.

NNSL photo

Rufus Deneyoua, left, and Gerry Deneyoua used this Bombardier vehicle to groom the Fort Simpson crossing so it could open on Sunday. - Derek Neary/NNSL photo


Of course, it takes quite a bit of work before the crossing is ready for vehicle traffic. Some years it takes more work than others. It all depends on how the ice jams, according to Les Shaw, superintendent of Transportation.

Rubble ice, where the wafers stack on top of each other, requires crews to go out and chip away by hand before equipment can be spurred into action. Once the ice is at least 30 centimetres thick, a 3,000-kilogram snow CAT with a heavy-duty steel drag attached starts making passes, knocking down the remaining rough ice.

Crews use an auger, mounted on a trailer, to drill through the ice, allowing water to gush over the surface. Motorists making trips at night may notice pools of water on the crossing, but it's not to be confused with open water where the ice hasn't yet frozen at all.

The crossing is currently open to light traffic, a maximum of 5,000 kilograms. For those who get a little squeamish over the thought of breaking through the ice, worry not.

If a vehicle weighing in at 5,002 kilograms or even substantially more attempts to traverse the river, there won't be cracks rippling across the ice. Shaw said the crossing can actually withstand seven times the weight limit in place at any given time.

The Department of Transportation uses such a formula for safety purposes, he said.

Those who tempt fate beyond a reasonable limit face not only the possibility of going through the ice, such as a 61,000-kilogram tanker truck did in Fort Providence in January 2000, they could incur fines as well.

Shaw has seen seven ice crossings freeze in Fort Simpson and used to be in charge of crossings in the northern NWT. He said crews often work 10 to 12 hour shifts in the days prior to opening.

"The guys here are very quick. They only started this ice bridge 10 days ago," he said.

Crews will continue to flood the crossing, thickening the ice to the point where 64,000 kilograms can be safely transported over the ice.