TransLink ‘pretty pleased’ with tire socks, despite concerns about durability
TransLink is looking at expanding the use of tire socks during snowy days this year in spite of having some issues with durability last winter.
TransLink developed a Snowy Weather Action Plan after the winter of 2016-17, which saw numerous snowstorms disrupt transit service across the region. A key component of last winter’s plan was testing tire socks — fabric tire covers that have Kevlar threads running through them — on buses that run up and down Burnaby Mountain.
TransLink was the first transit authority in North America to use tire socks to improve traction on buses. The devices have been used for years on tractor-trailers and passenger vehicles.
“The trials we did were really limited in scale, but we were pretty pleased with the results,” said TransLink spokesman Chris Bryan. “But the durability wasn’t quite where we’d like it to be.”
According to a report from Coast Mountain Bus Company on last year’s Snowy Weather Action Plan, the devices were used once in December and once in February.
Although they worked well and there was positive feedback from drivers, the socks were not as durable as expected. They typically lasted for about two hours or 50 kilometres before wearing out. Based on testing done by the California Department of Transportation using tractor-trailers, the devices should last for about 100 km on wet roads before failing.
On Dec. 19, there was wet snow and rain at the bottom of the hill and heavier snow near the top. Two runs were completed that day with the first ending at the information tunnel and the second going all the way to the bus loop. The roads were wet with no snow for about 60 per cent of the route and the tire socks became saturated and “slapped” the wheel wells at speeds just over 30 km/h. There was also some tearing on the tread and side wall on the streetside tire sock.
Two sets were used and the buses travelled 44 km on each set.
The next time the socks were used was Feb. 23. The weather was more severe and six buses were diverted to have tire socks installed. The devices lasted two to three trips (44 to 66 km per set) before separating at the seam between the tread and side wall and needing replacement. Fifteen sets of tire socks were used.
During training, testing and the two snow events, a total of 19 sets were used at a cost of $230 per set, a total bill of $4,370.
After last winter’s testing, TransLink is now looking at ways to improve the durability of the tire socks, Bryan said.
Coast Mountain Bus Company is looking at adding a second layer of stitching or extra fabric around the seam between the side wall and tread of each sock with the goal of reducing the likelihood of ripping.
The bus company is also working with manufacturer AutoSock to come up with a new prototype, which it hopes to have available for testing during the 2019-20 winter season.
TransLink is still deciding whether to expand the program to other trouble spots such as Vancouver, Burnaby, North Vancouver, White Rock and Coquitlam.
The total cost of expanding usage fleet wide — training, parts, labour — based on five snow days would be roughly $600,000 per year, according to the report.
“These look like a good solution, but there are some costs involved and training and staff time, so we want to make sure we do our due diligence and go about this in a smart way,” Bryan said.