Cable sweepers and "hydrophobic" coatings are part of the B.C. government's new plan to winterize the Port Mann Bridge, where last month vehicles and motorists were pummelled with ice falling from overhead cables.
More than 340 insurance claims have been filed since the Dec. 19 snowstorm, according to ICBC spokesman Adam Grossman. He said the overall cost of the claims has yet to be estimated.
"We've all seen the pictures and videos from that day," said Transportation Minister Mary Polak at a press conference Monday, referring to ice chunks that shattered windshields and tore through vehicle roofs.
Ms. Polak was joined by Mike Proudfoot, CEO of Transportation Investment Corporation (TI Corp) the Crown Corporation that manages the bridge.
"Over the past four weeks, [our engineers] have canvassed international experts and considered and refined numerous technologies," said Mr. Proudfoot in the Georgia room of Vancouver's FortisBC Centre. His team has had consultations with bridge specialists in countries such as Denmark, the U.S. and Britain.
"That hard work has resulted in a combination of solutions that will allow us to keep the bridge operating safely and efficiently," Mr. Proudfoot said, acknowledging that the de-icing measures originally installed on the bridge were clearly inadequate for storms such as the one in December.
One of the solutions includes custom-designed sweepers, which Mr. Proudfoot said will be installed and tested next week and should be fully functional by mid-February. A manually operated winch system will lower and raise the sweepers along bridge cables at approximately 200 feet per minute, while scrapers and brushes on the sweepers remove snow and ice.
Of the bridge's 288 cables, only cables that cross the roadway – 152 in total – will be fitted with sweepers. TI Corp said it thinks the Port Mann sweepers will be the first application globally of this kind of technology.
Four types of water repellents, known as hydrophobic coatings, are also being tested. The repellents are meant to reduce the adhesion of water and ice to the cables, and if a repellent passes lab tests, it will be applied this summer.
Further preventative measures include a "de-icing" spray that would be applied to the cables before a forecast snowstorm. Such sprays are also used to prevent ice buildup on aircraft and ships.
The price tag of the measures was not specified, but Ms. Polak stressed that Kiewit-Flatiron General Partnership – the private company that built the bridge – will be responsible for all costs associated with ice and snow removal.
Mr. Proudfoot said the labour costs for the manual winch system could be eliminated in the future by making the winches robotic. Until then, bridge employees will need to monitor weather conditions and, if snow starts to accumulate, will have to turn the eight winches that control the sweepers themselves.