In the brave, new world of highway bridge demolition, projects are scheduled over hours, not
days.
The Martindale Bridge crossing the Queen Elizabeth Way (QEW) near St. Catharines, Ont. was no
exception.
“We usually set some limits and allow contractors a specific number of hours to close the
highway and get the work done,” says Ministry of Transportation spokesman Will Mackenzie. “In
this case, we were scheduling 10 hours for demolition because of the wideness of the bridge.”
The overpass, constructed in 1939, once supported an intra-urban streetcar line that had long since
gone out of service. The additional lane, running alongside the vehicle lane, was eventually
devoted strictly to pedestrian and bicycle traffic.
“Because of that feature it was a unique bridge, but it didn’t have any particular historical
significance,” says Mackenzie. “After the streetcar line was taken out, the bridge still had that part
of the deck.
“Today they would use continuous welded rail, but that wasn’t the case in the 1940s. Most of that
type of rail bridge used what was essentially a viaduct filled with a gravel ballast and the track
sections were laid on top of that. It allowed for a smoother track and was also easier for railway
maintenance.”
The bridge was demolished to be replaced by a new span as part of a $183-million upgrade
contract awarded to the Dufferin Construction Company to widen the QEW. The contract
represents the last remaining section between Toronto and Niagara Falls that has not been widened
to six lanes.
“There simply wasn’t enough room to widen the highway underneath the bridge,” says
Mackenzie.
“Originally, the contractor came to us with a plan to detour traffic around the abutment, but later
they came to us and said they could do it faster and cheaper if we could close the highway for one
night.”
A new single-span four-lane underpass structure was already under construction and ready to
accept traffic as the old bridge was being demolished.
The QEW was closed at midnight on Saturday, October 16th between Highway 406 and Ontario
Street with Niagara-bound QEW traffic diverted to Highway 406 and Toronto-bound travelers
diverted to Thorold Stone Road.
“The standard procedure is to begin by laying a foot-and-a-half to two feet of gravel on the
highway to protect the existing road surface underneath from falling concrete and debris,” says
Mackenzie.
Tonnes of cushioning material were laid down in the initial minutes of demolition. The contractor
then sent in six excavators to attack the bridge simultaneously, as concrete was hammered to
rubble and hydraulic cutters sheared steel rebar. Backup units cleared away debris as the
excavators progressed. In a few hours, the road was swept clean.
“The site was cleaned up and traffic resumed along the QEW at 10:00 a.m. on Sunday as
scheduled,” said Mackenzie.