Extra wind protection will be installed on the Deh Cho Bridge this summer to help avoid another broken cable.
One of the bridge’s 24 giant cables failed in 2023, a fault traced to a metal adjustment bar connecting the cable to its anchor on the bridge.
At an engineering and geoscience symposium in Yellowknife last week, Michael Paulsen of Associated Engineering said the fatigue that caused the initial fault is likely attributable in part to the wind and cold weather the bridge must endure.
Paulsen said dampers will be installed on all 24 cables to provide extra protection along the kilometre-long bridge, which spans the Mackenzie River outside Fort Providence.
The NWT’s Department of Infrastructure, confirming the plan, said the dampers are designed to reduce vibrations in the cables caused by the wind. The original bridge design did not include them. A basic video monitoring system will also be installed later this summer, the department stated by email on Thursday.
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Repair work after the 2023 cable failure took almost two years, with the bridge reduced to one lane for most of that time. Last fall, the NWT government said the total repair cost was around $7 million.
The Department of Infrastructure said the cost of supplying and installing the dampers was included in the contract awarded for the overall repair work on the bridge. The cost of the dampers is approximately $70,000.
The bridge initially cost more than $200 million to build, a sum the territory will gradually repay for decades to come.
Paulsen spoke at a two-day symposium held by Napeg, the NWT and Nunavut association representing engineers and geoscientists.
Elsewhere at the symposium, representatives of the Grays Bay road and port project – which seeks to ultimately connect the Arctic coast in Nunavut to Yellowknife – reiterated that they are targeting an earliest construction start date of 2030.
