3 Solutions Identified to Improve Port Mann Bridge Safety
After the recent events on the Port Mann Bridge, engineers working on the project have assessed the concerns and identified solutions to help prevent snow and ice build-up from happening again on the bridge cables. They’ve come up with three ways, all working together, to improve safety. They include:
1) Custom-designed cable sweepers: custom-designed devices fitting around the outside of the bridge cables and move along their lengths to remove snow and ice before it can build up. The sweepers are currently being put together, with installation and additional testing planned this week. The sweepers will be installed on all 152 bridge cables crossing the roadway.
2) Hydrophobic coatings: four types of hydrophobic coatings (which reduce adhesion of water and ice to surfaces) are being tested, on the bridge and in labs, to confirm which may perform best on the Port Mann Bridge cables. These include water, ice and snow-repellent solutions that can be applied to the existing cable sheaths to determine how effective and compatible they are with the Port Mann Bridge.
It’s important to test the coating as it could affect the aerodynamic response of the cable sheaths. Those sheaths are ringed with a raised lip that winds around the cables, acting to shed rainwater from the cable sheaths and prevent streams of water from forming along the cables. Long streams of water could mess with the cables’ aerodynamics. That’s not good. So, pending the outcome of the testing, if it’s good to go on the coating, it’ll be applied this summer when it’s warm and dry.
3) De-icing Solution: could be applied to the bridge cables as a preventative measure in addition to the other two solutions. The de-icing solution would be applied to the bridge cables before a forecasted snow storm. If this sounds familiar, it’s because similar solutions are used to prevent ice build-up on aircraft and ocean-going ships. FYI – this concoction is non-corrosive and environmentally friendly, too.
So will the installation of the sweepers impact traffic? Maybe. This winter, the cable sweepers will be installed using an interim system. If it gets snowy, they’ll be raised and lowered using a temporary winch system that, when in operation, will require the closure of a lane in each direction. Next winter, when the sweepers are permanently installed, they’ll be parked at the top of the cables with winches mounted on top of the towers. No lanes closures will be needed.
Source, Photo: TranBC