Sioux Narrows Bridge
New Sioux Narrows Bridge opened in 2007.
Coordinates49°24′48″N 94°05′53″W / 49.413272°N 94.097954°W / 49.413272; -94.097954
CarriesHighway 71/Trans-Canada Highway
CrossesSioux Narrows (Lake of the Woods)
LocaleSioux Narrows, Ontario
Maintained byOntario Ministry of Transportation
ID number9340
Characteristics
DesignTruss arch bridge, steel with wood cladding; formerly built entirely of wood.
History
Opened1936 (original)
November 12, 2007 (new)
Location

The Sioux Narrows Bridge is a bridge on Highway 71 at Sioux Narrows, Ontario, which spans the Sioux Narrows strait between Regina Bay and Whitefish Bay on Lake of the Woods.[1]

Built in 1936 as an all-wooden truss bridge made of Douglas fir timber treated with creosote,[2] it was at 210 feet (64 m) the longest single-span wooden bridge in North America.[3] The bridge overlooks the site of an 18th-century battle in which the local Anishnaabe and Cree nations defeated an invading force of Sioux.

Due to its unique construction, the bridge was designated a heritage site under the Ontario Heritage Act.[4]

Reconstruction

New Sioux Narrows Bridge in winter

In the early 1980s, study found that the load capacity of the trusses remained adequate, but there was significant overstress on the deck.[4] In 1982, the bridge was reconstructed using a new prestressing technique, by which the deck planks were laid on their edges and squeezed together with hydraulic jacks to form a watertight slab, and then supported with steel reinforcing rods.[5]

In the 1990s and early 2000s, the deteriorating quality of the structure necessitated load and lane restrictions on the bridge,[6] with heavy trucking vehicles forced to detour via Ontario Highway 502 through Dryden or Ontario Highway 622 through Atikokan.[7] Finally, a temporary bridge was built in 2003,[7] and the wooden bridge was dismantled.

The decision was finally made to balance the need for structural improvements and durability with the structure's heritage by building the new bridge out of steel, but cladding the steel trusses in wood to preserve the original bridge's appearance.[8][9]

Construction began on the new bridge in 2006,[10] and the bridge was reopened to traffic in November 2007.[11] The bridge was briefly closed on July 1, 2008, in order to stage its official opening ceremony.[12] Bill Thompson, the mayor of the town at the time of the bridge's reopening, was the grandson of a construction worker who had worked on the original bridge.[12] Some pieces of salvaged timber not used in recladding the new steel trusses were used to create artworks of the bridge for sale as a municipal fundraiser.[12]

See also

References

  1. ↑ "Steel design rescues historic Ontario timber bridge". Daily Commercial News, June 11, 2009.
  2. ↑ Baidar Bakht and Aftab Mufti, Bridges: Analysis, Design, Structural Health Monitoring, and Rehabilitation. Springer Science+Business Media, 2015. ISBN 9783319178431. p. 207.
  3. ↑ "Wood bridges". The Globe and Mail, April 13, 1984.
  4. 1 2 Roger A. Dorton and Ranjit S. Reel, "Methods for Increasing Live Load Capacity of Existing Highway Bridges" in National Cooperative Highway Research Program: Synthesis of Highway Practice, Vol. 249 (1997). Transportation Research Board, ISSN 0547-5570. p. 34.
  5. ↑ "Method to save wood bridges proves successful in Ontario". The Globe and Mail, March 9, 1984.
  6. ↑ "Weight restrictions now in effect on Sioux Narrows Bridge". Truck News, September 26, 2003.
  7. 1 2 "Sioux Narrows bridge reopens". Sudbury Star, December 23, 2003.
  8. ↑ "Broaden horizons in Sioux Narrows". Winnipeg Free Press, July 17, 2010.
  9. ↑ Radolli, R. and Krisciunas, R. (2008). "Sioux Narrows Bridge — Context Sensitive Replacement of a Heritage Timber Truss Bridge". Structures Congress 2008: pp. 1-10. doi: 10.1061/41016(314)15
  10. ↑ "Ontario invests millions in Northern highways". Northern Life, June 16, 2006.
  11. ↑ "Sioux Narrows Bridge Almost Complete". CKDR-FM, November 12, 2007.
  12. 1 2 3 "Sioux Narrows commemorates Canada Day with official bridge opening". Kenora Daily Miner and News, July 2, 2008.
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