Large chunks of snow and ice had fallen from the cables in December.
A custom-designed cable sweeper has been developed that will be fitted around the bridge cables and used to remove snow and ice before it can accumulate. In addition, engineers have identified highly water repellent, or hydrophobic, coatings and de-icing sprays that could be applied to the bridge cables to further prevent the accumulation of snow and ice.
The sweeper fits around the outside of the bridge cable and is lowered and raised along its length using a specially-designed winch, while scrapers and brushes on the sweeper remove snow and ice build-up. Fabrication of the sweepers is now under way and installation and additional testing will begin this week. The sweepers will be installed on the 152 bridge cables that cross the road.
To complement the cable sweepers, four types of hydrophobic coatings are now being tested to confirm which may perform best on the cables. Tests will be conducted on the bridge, as well as in a specialised laboratory where specific and severe weather conditionscan be recreated.
In addition, engineers have identified a de-icing solution that can be applied to the bridge cables as a further preventative measure. Similar to de-icing applications on aircraft, the solution would be sprayed onto the bridge cables. The product, which is also used to de-ice ships, forms a barrier that prevents the formation of ice.
The government of British Columbia, Transportation Investment Corporation and Kiewit/Flatiron said that they are confident that this combination of solutions will prevent the accumulation of snow and ice on the bridge cables.
