Saskatoon city council has decided that the bridge to replace the city’s existing, but condemned, 104-year-old Traffic Bridge will incorporate much of the look of the current bridge, including its iconic steel Parker truss design, and a handful of heritage aspects.
Saskatoon city council has decided that the bridge to replace the city's existing, but condemned, 104-year-old Traffic Bridge will incorporate much of the look of the current bridge, including its iconic steel Parker truss design, and a handful of heritage aspects.
The new modern steel truss bridge will also include five spans, rather than the four that council had been contemplating.
Driving lanes on the new bridge will be increased to 3.3 metres from 2.9 metres and the new bridge will feature two pedestrian walkways rather than the current one. The appearance of the pedestrian handrail and boardwalk, as well as the bolts, truss height and length, and lattice pattern in the steel are heritage aspects that are expected to be preserved. Council finalized the plans at a meeting in late June.
City of Saskatoon bridge and project engineer Brad Walter said the city initially believed it could save money by shortening the new bridge from five spans to four.
But eventually Walter found that the work involved in accommodating a shorter bridge would have driven the cost about $1 million to $2.5 million higher.
“It was a valid option,” he said. “Originally, we thought it would cost less, but it ended up costing more.”
The current Traffic Bridge connects the neighbourhood of Nutana at Victoria Avenue on the north side of the Saskatchewan River embankment with downtown at 3rd Avenue South.
It presently towers above a road running perpendicular to it called Saskatchewan Crescent, as well as a park and bike path. Because the embankment at Nutana is so steep, a four-span bridge would have faced major grading issues, requiring lots of work to correct.
Besides cost, members of the public and community groups such as the Nutana Community Association voiced displeasure at the option during the city’s extensive Traffic Bridge Needs Assessment.
A four-span option with retaining walls and an overpass-style bridge, they argued, would change the character of the new bridge and park.
“The definition of a span is simply the distance between supports, for example, a pier or abutment,” Walter explained. “In the four-span option, everything remains the same, but the last span over Rotary Park would have been replaced with a roadway on top of an embankment and a new overpass over Saskatchewan Crescent.
“The increased grade on the bridge would have been undesirable. And yes, the embankments would have changed Rotary Park. The only way to avoid that would have been to build high retaining walls that would not have been visually pleasing,” he acknowledged.
The City of Saskatoon will begin the tendering process for construction of the new bridge this summer. The Request for Qualifications (RFQ) is expected to go out in mid to late July to parties interested in competing for construction of the new bridge project.
Once the search is narrowed down to three proponents, Walter said, they will be asked to submit a full proposal, likely in September.
“We don’t expect the actual design build team to be chosen until early spring 2012,” he said.
The City has hired Stantec as its owner’s engineer (OE). According to Walter, the role of the OE is to assemble the RFQ and Request for Proposal documents for the design-build and to provide consulting services from the beginning of the project through to construction.
“Based on experience, qualifications, interviews, etc., the list will then be narrowed down to three final proponents, i.e. three separate design-build teams consisting of a contractor and a designer/consultant,” he said.
It is estimated construction time on the new steel truss bridge will run 18 to 24 months, and the cost to replace the Traffic Bridge will be between $27 and $34 million.
Traffic Bridge has been a favourite with Saskatoon residents ever since it first opened to vehicular and pedestrian traffic in 1907.
Traffic Bridge was designed by the provincial Department of Public Works and is the oldest surviving steel Parker truss bridge in the province. It consists of one 175 feet (56m) span at each end with three central spans each 200 feet (64m) long supported on concrete piers and abutments.
The substructure contract was awarded to prominent Winnipeg contractor, John D. Gunn and Sons Ltd., and the bridge’s steel superstructure was fabricated at the Canadian Bridge Company plant in Walkerville (now Windsor), Ontario and erected by the McDiarmid Company of Winnipeg, Manitoba.
..i110b.jpg ..pCITY OF SASKATOON ..c The Request for Qualifications for the new bridge in Saskatoon is expected to go out in mid to late July to parties interested in competing for construction of the new bridge project. Once the search is narrowed down to three proponents, they will submit a full proposal, likely in September.
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