In January, the northern section of the Sgt. Aubrey Cosens VC Memorial Bridge in Latchford, Ontario suffered a partial collapse. Three suspenders, which connect the arch and deck of the bridge, broke as two tractor trailers were crossing the bridge. The two drivers were not injured after the 180mm thick roadway dropped 2m. Officials believe the structure, first built in the 1960s, failed after one of the coldest nights of the winter at -25 degrees C caused the steel to snap.
With the closing of the bridge, traffic had to detour into Quebec causing lengthy detour delays of a minimum of one to one and a half hours and caused financial losses from added fuel expenses, driver labour, and missed opportunities for trucking and freight companies.
The loss of the bridge also had a devastating effect on the local economies that catered to the winter trade and also closed area schools because buses could not cross the river.
Latchord Mayor, George Lefebvre explains the impact that the closure had on the local area. "Route 11 and the Sgt. Aubrey Cosens VC Memorial Bridge are part of the Trans Canada Highway system. The loss of the bridge not only affected a major trucking route, but it also shut down our community and schools."
About 6,500 vehicles a day travel this section of the highway, including 900 transport trucks according to the Ontario Trucking Association.
"Everyone in the town was hurting until the one-lane (emergency) bridge went up," says Ed Kalnins, head contractor of Miller Paving, which installed the first temporary bridge. "The damaged bridge isolated businesses because trucks and cars could not reach service stations, restaurants, and so on. Local people thought it was a disaster."
Ministry of Transportation Ontario officials decided two temporary bridges were needed to eliminate lengthy detours into Quebec, to help reopen local schools, and to get money back into the local economy. Also, the MTO decided to immediately shore the existing bridge using Acrow trusses as falsework to stabilise the bridge and prevent further damage.
The first one, a single-lane, 45m-long bridge, would be constructed to get traffic moving across the Montreal River again. The second emergency bridge, which would be built alongside the 45m bridge, would be a two-lane (9.15m wide) 125m-long bridge with a footway and would be used for a minimum of nine months until the Sgt. Aubrey Cosens Bridge could be repaired.
Ken Scott, president of Canadian firm Acrow, which specialises in detour and emergency bridges, attended a meeting on-site with MTO officials to discuss the situation.
"The MTO needed an immediate solution in Latchford," says Scott. "Acrow's modular bridges are perfect for these emergency situations because they can be constructed with minimal amount of labour and built rapidly."
Acrow's bridges are a prefabricated modular steel bridge system. The entire bridge is kept in stock so that it can be shipped immediately and assembled very quickly. The Acrow 700XS Bridge System was supplied for both the 45m and the 125m crossings.
Acrow's rapid response to emergencies helped out in the Latchford disaster.
The company first received a call from the Ministry of Transportation on 14 January and met MTO officials at the site the following day. Together, they decided to install a 45m, one-lane bridge immediately to partially relieve the situation. On 16 January, steel for the bridge left Acrow's warehouse in Carlstadt, New Jersey in the USA.
Within 12 days of the initial phone call to Scott, contractors erected the first one-lane, 45m modular bridge. Crews worked around the clock in some of the harshest conditions to complete the job. Temperatures hovered consistently between -40 degrees C to -10 degrees C.
"Unfortunately, we were working during the coldest weather of the year up here in Canada," says Kalnins. "But we had an experienced crew and we've worked with Acrow bridges before so everything went smoothly."
"I have to hand it to the crew out there," Scott says. "They completed both the one-lane bridge, and the two-lane bridge in dangerously cold conditions. However, even in these tough conditions, both bridges were up and running ahead of schedule."
To expedite the one-lane bridge, it was decided to limit it to a 45m span. This meant it was necessary to fill the river in and thus reduce the opening to the length of the span. Traffic lights were installed at both ends of the 45m bridge to allow traffic to alternate north and south. After completion of the two-lane bridge, workers removed the 45m bridge and the fill to allow for the heavier river flow during the spring thaw.
The Province of Ontario requested bids for the design and supply of the 125m two-lane structure. Acrow won the bid and began the installation of the 125m bridge immediately in dangerous conditions. Temperatures hovered between -40 degrees C and -30 degrees C, making it very challenging on the crew and machines.
Acrow was under stress not only from the weather, but also from the completion deadline. The province imposed a liquidation damage penalty of US$50,000 to Acrow, if the bridge was not delivered on time.
Forty-five days after the Sgt. Aubrey Cosens VC Memorial Bridge collapsed, the 125m two-lane bridge was completed ahead of schedule, bringing the Canadian community of Latchford back to normal
"These bridges have been really successful on getting our community running again," Mayor Lefebvre says. "They have been a real godsend."
