Engineers working on the Port Mann Bridge say that a custom-designed cable sweeper that will be fitted around the bridge cables will prevent the buildup of snow and ice that led to a dangerous shower of ice bombs in December.
The B.C. Ministry of Transportation and Infrastructure announced Monday the cable sweepers will be installed on the 152 bridge cables that cross over the roadway.
The cable sweepers fit around the outside of the bridge cables, and are lowered and raised along the length of the cables using a specially-designed winch. Scrapers and brushes on the sweeper remove snow and ice buildup.
Engineers are also evaluating a selection of highly water-repellent coatings, and have identified a de-icing solution, all of which could be used on the bridge's cables.
The sweepers were developed by the B.C. government, the Transportation Investment Corporation, and Kiewit/Flatiron after snow and ice on the bridge cables fell onto the deck during the December storm, damaging dozens of vehicles.
Scott Cassels, the president of Kiewit Infrastructure Group Inc., said that the research and testing phase is almost complete.
"We must finish real-world testing, but we believe that the cable sweepers, coatings and de-icing sprays will be effective enhancements to the bridge," he said in a written statement released by the B.C. government.
Fabrication of the sweepers is underway, and installation and additional testing is set to begin later this week.
Transportation Minister says fixes coming soon
B.C.'s Minister of Transportation and Infrastructure has admitted there were design flaws with the bridge's cables and says the installation of the cable sweepers will begin this week.
In an interview with CBC Radio One's Stephen Quinn On the Coast, Mary Polak said the cables were originally designed with a shaped sheathing that was meant to gradually move water and ice away from them.
"It didn't work and that's the reason that we set out to work with Kiewit, work with T.I. Corp and develop solutions that we believe are going to keep this from ever happening again," said Polak. "This is in the immediate solution range so we will begin installation this week."
Polak added that, while she was not aware of who would pay for the cable sweepers, the fact that Kiewit has covered the costs of coming up with the solution leaves her hopeful taxpayers will not be on the hook for added expenses.
As for the icy bridge deck of the Port Mann that contributed to a 40-car pile up on January 3rd, Polak says that incident cannot be blamed on the new river crossing.
"We have not seen any evidence that the design of the bridge played any role in the black ice incident," said Polak, "in fact further information has come to light such that across the Lower Mainland, while the Port Mann Bridge received the bulk of the attention, there was a rise in ICBC claims for those incidents by 20%."
Despite that, maintenance crews will use a different solution of brine and crystallized salt on a more consistent basis in order to keep the bridge deck free of black ice moving forward.