Northport Bridge

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Coordinates: 48 ° 55 ′ 21 ″  N , 117 ° 46 ′ 36 ″  W.

Northport Bridge
Northport Bridge
use WA-25.svg Washington SR 25
Crossing of Columbia River
place Northport , Washington
Entertained by Washington State Department of Transportation (WSDOT)
construction Gerber girder - truss bridge
overall length 470 m
Longest span 154 m
building-costs 1,751,587 US dollars
start of building 1946
completion 1951
location
Northport Bridge (Washington)
Northport Bridge

The Northport Bridge is a two-lane road bridge in Northport , in northeast Washington state, USA. It leads Washington State Route 25 over the Columbia River , which passes the border with Canada about ten kilometers north and becomes British Columbia Highway 22 . The Gerber beam - truss bridge replaced a converted 1951 the road bridge railway bridge from 1897. The bridge is from the Washington State Department of Transportation(WSDOT) and had an average daily traffic volume of 900 vehicles in 2012. In 1995 it was listed on the National Register of Historic Places (NRHP # 95000624).

history

Northern Stevens County Railways from Washington 1898
( Columbia & Red Mountain Railway)Carré rouge.JPGCarré rouge.JPG
Columbia & Red Mountain Railway railway bridge circa 1900

The entrepreneur Daniel Chase Corbin built the Spokane Falls & Northern Railway in northeast Washington in the early 1890s , which ran from Spokane (until 1891 Spokane Falls ) northwards via Colville to Marcus and from here along Columbia via Northport to the British Columbia border . In order to reach the silver mines near Nelson in Canada , Corbin extended the route to the northeast with the Nelson & Fort Sheppard Railway until 1893 . A few years later, the Columbia & Red Mountain Railway was a branch from Northport to the gold, silver and copper deposits in Rossland . For this north running route the Columbia had to be crossed in Northport, for which only the second bridge over the US-American part of the river was built by 1897. By acquiring the majority of the shares in 1898, the Great Northern Railway (GN) gained control of Corbins railway companies and built another northwest branch from Marcus along the Kettle River with the Washington & Great Northern Railway until 1902 , with the third bridge over the Columbia in the United States (the first built the Northern Pacific between Kennewick and Pasco until 1888 ).

After World War I , the price of copper fell and the mines in Rossland closed. The operation of the Columbia & Red Mountain Railway became uneconomical and finally stopped in 1922. The GN sold the route including the bridge in Northport to Stevens County and the Canadian province of British Columbia. After removing the rails, the bridge was provided with wooden planks and the rest of the track was expanded into a road. The mostly wooden truss bridge served as a road bridge for thirteen years from 1923, but had to be shut down at the end of 1946 due to structural defects and replaced by a car ferry .

In August 1946, the then Washington Department of Highways commissioned the construction of a new bridge. A few hundred meters up the river, MacRea Brothers began erecting the substructure and the access to the new steel truss bridge. An extreme spring flood in 1948 led to the underwashing ( scouring ) of the almost completed southern pillar of the river, which then tilted and finally had to be blown up. The new pillar was then lowered deeper into the river bed. In addition, the originally planned 100-meter-long pile of earth was dispensed with at the southern entrance and the following girder bridge was extended . The General Construction Company was entrusted with the changes, and the construction of the tanning beam was then carried out by the Midland Structural Steel Company . The completed bridge was opened on June 13, 1951. The old railway bridge had in the meantime partially collapsed and was finally completely demolished in 1950.

description

South portal of the road bridge 2019
The Washington State Route 25 in red, interstate highways in Washington in blue

The total of 470 m long structure is divided from south to north in a 205 m long girder bridge of eleven reinforced concrete - -beam consisting of two to four haunched T cost objects are constructed, and are supported at their ends of separate reinforced concrete pillars. A 256 m long truss , which is designed as a tanner girder , follows the southern approach . This, in turn, consists of a 51 m long anchor arm towards the bank, a 43 m long boom arm towards the middle of the river and a suspension beam with a length of 68 m articulated in between . The steel girder rests on four massive reinforced concrete pillars and has a span of 154 m between the central river pillars . On the north side there is a short girder bridge 6.4 m long.

The tannery girder has a straight upper chord which is only slightly inclined at the ends and to which the roadway runs parallel at the level of the lower chord of the suspension girder. In relation to the pillar supports, the height of the outer lattice girders increases to about twice the height of the suspension girders, creating a characteristic triangular shape below the roadway. The Washington Department of Highways previously chose a similar design for the Grand Coulee Bridge (1936) or the Kettle Falls Bridge (1941), among others .

At normal water level, the clear height below the lower flange of the suspension bracket is about 23 m. The approximately 10 m wide lattice girder provides space for two lanes totaling 7.3 m as well as a footpath separated by protective barriers, 0.9 m wide on the outside. When completed, the bridge spanned Primary State Highway 22 , renamed Washington State Route 25 in the 1960s, running north from Davenport to the Canadian border, where it becomes British Columbia Highway 22 .

See also

literature

  • The Northport Bridge. In: Engineering Record, Building Record and Sanitary Engineer. Vol. 44, No. 16, 1901, p. 367 f.
  • Robert H. Krier, J. Byron Barber, Robin Bruce, Craig Holstine: Columbia River Bridge at Northport. National Register of Historic Places Registration Form, National Park Service, 1995.

Web links

Commons : Columbia River Bridge at Northport  - Collection of Images, Videos, and Audio Files

Individual evidence

  1. ↑ a b The Northport Bridge. In: Engineering Record, Building Record and Sanitary Engineer. Vol. 44, No. 16, 1901, p. 367 f.
  2. ^ FM Barone: Nelson & Fort Sheppard Railway. In: Canadian Rail. No. 412, 1989, pp. 151-157, here p. 151.
  3. ^ BNSF - Kennewick-Pasco Bridge. BridgeHunter.com, accessed July 2, 2020.
  4. ^ Donald B. Robertson Encyclopedia of Western Railroad History: Oregon, Washington. Caxton Press, 1986, ISBN 978-0-87004-366-6 , p. 279 and p. 295 f.
  5. ↑ Jeremy Mouat: Roaring Days: Rossland's Mines and the History of British Columbia. University of British Columbia Press, 2011, ISBN 978-0-7748-4267-9 , pp. 31 f.
  6. ^ Northport Bridge (Old). BridgeHunter.com, accessed July 1, 2020.
  7. ^ A b Bridging the Columbia: The Columbia and Red Mountain Railroad Bridge. Northport Washington Historical Society, accessed July 1, 2020.
  8. ^ A b Robert H. Krier, J. Byron Barber, Robin Bruce, Craig Holstine: Columbia River Bridge at Northport. National Register of Historic Places Registration Form, National Park Service, 1995.
  9. ^ Robert W. Hadlow: Washington State Cantilever Bridges, Olympia, Thurston County, WA. Historic American Engineering Record, HAER No. WA-106, Washington, DC 1993.
  10. ^ Northport Bridge. HistoricBridges.org, accessed July 2, 2020.
  11. ^ Twenty-fourth Biennial Report of the Director of Highways, 1950-1952. WSDOT Library Digital Collections, accessed July 2, 2020.