Covered bridge

Covered Bridge
The Cogan House Covered Bridge, Pennsylvania
Ancestor Truss bridge, others
Related Tubular bridge, Skyway, Jetway
Descendant None
Carries Pedestrians, livestock, vehicles
Span range Short
Material Typically wood beams with iron fittings and iron rods in tension
Movable No
Design effort Low
Falsework required Determined by enclosed bridge structure, site conditions, and degree of prefabrication

A covered bridge is a timber-truss bridge with a roof and siding which, in most covered bridges, create an almost complete enclosure.[1] The purpose of the covering is to protect the wooden structural members from the weather. Uncovered wooden bridges typically have a lifespan of only 10 to 15 years because of the effects of rain and sun. The brief moment of relative privacy while crossing the bridges earned them the name “Kissing Bridges” [2]

Bridges having covers for reasons other than protecting wood trusses, such as for protecting pedestrians and keeping horses from shying away from water, are also sometimes called covered bridges.

History and development

Baumgardener's Covered Bridge, showing the truss protected by the covering

Early timber-framed covered bridges consisted of horizontal beams laid on top of piles driven into the riverbed below. However, this construction method meant that the length between bridge spans was limited by the maximum length of each beam. The development of the timber truss circumvented that limitation and allowed bridges to span greater distances than those with beam-only structures or arch structures, whether of stone, masonry, or timber.[3]

Early European truss bridges used king post and queen post configurations. Some early German bridges included diagonal panel bracing in trusses with parallel top and bottom chords.[3] To solve the problem of deterioration of the wood upon exposure to weather, various forms of covering came to be employed.[4]

At least two covered bridges make the claim of being the first built in the United States. Town records for Swanzey, New Hampshire, indicate their Carleton Bridge was built in 1789, but this remains unverified.[5] Philadelphia, however, claims a bridge built in the early 1800s on 30th Street and over the Schuylkill River was the first, noting that investors wanted it covered to extend its life.[6] Beginning around 1820, new designs were developed, such as the Burr, Lattice, and Brown trusses.

In the mid-1800s, the development of cheaper wrought iron and cast iron led to metal rather than timber trusses, except in those areas of plentiful large timber.[3]

Examples of covered bridges

Alte Rheinbrücke Vaduz–Sevelen, a bridge connecting Vaduz and Sevelen
Interior view showing wooden beam construction
Ilmbrücke Buchfart, built in 1613

There are about 1600 covered bridges in the world.[7]

Asia

  • China: covered bridges are called lángqiáo (廊桥), or "wind and rain bridges" in Guizhou, traditionally built by the Dong. There are also covered bridges in Fujian.[8] Taishun County, in southern Zhejiang province near the border of Fujian, has more than 900 covered bridges, many of them hundreds of years old, as well as a covered bridge museum.[9][10] There are also a number in nearby Qingyuan County, as well as in Shouning County, in northern Fujian province. The Xijin Bridge in Zhejiang is one of the largest.

Europe

North America

Canada

The 1,282-foot (391 m) Hartland Bridge in New Brunswick is the longest covered bridge in the world. In 1900 Quebec, New Brunswick, and Ontario had an estimated 1000, 400, and five covered bridges respectively. By the 1990s there were 98 in Quebec,[12] 62 in New Brunswick,[13] and one in Ontario, the West Montrose Covered Bridge.[14]

United States

According to Covered Bridges Today by Brenda Krekler, as many as 12,000 covered bridges once existed in the United States; that number dropped to under 1,500 by the 1950s.[15] The National Society for the Preservation of Covered Bridges was formed in 1950,[15] and the Federal Highway Administration (FHWA) encourages the preservation of covered bridges with its Covered Bridge Manual.[16]

Today, covered bridges exist in many states:

Other covered bridges

Pont de Rohan

The term covered bridge is also use to describe any bridge-like structure that is covered. For example:

Covered bridges in fiction

Covered bridges are popular in folklore[41] and fiction. For example:

References

  1. ↑ "Covered bridge". Encyclopædia Britannica. Retrieved 8 October 2012.
  2. ↑ "West Montrose Covered Bridge – The Kissing Bridge (built in 1881)". Township of Woolwich. Archived from the original on 3 August 2015. Retrieved 16 August 2015.
  3. 1 2 3 "Covered Bridge Manual". U.S. Department of Transportation. Retrieved 9 October 2012.
  4. ↑ "History/Design". Pennsylvania Covered Bridges. Retrieved 26 February 2015.
  5. ↑ Marshall, Richard G. (1994). "Carleton Bridge". New Hampshire Covered Bridges: A Link With Our Past. Concord: New Hampshire Department of Transportation. OCLC 31182444.
  6. ↑ Kopas, Virginia (30 March 2012). "Pennsylvania is among the tops in the number of covered bridges". Pittsburgh Post-Gazette. Archived from the original on 10 October 2012. Retrieved 9 October 2012.
  7. ↑ "World Guide to Covered Bridges". WoodCenter.org. Iowa State University Institute for Transportation. Retrieved 9 October 2012.
  8. ↑ "Fujian Bridges!". Amoymagic.mts.cn. 17 January 2004. Retrieved 4 January 2012.
  9. ↑ "Museum of Ancient Bridges, Taishun County". China.org.cn. 27 June 2002. Retrieved 4 January 2012.
  10. ↑ "Langqiao.net" (in Chinese). Archived from the original on 8 August 2007.
  11. ↑ "Swiss Timber Bridges".
  12. ↑ "Ponts couverts". Transports Quebec. Archived from the original on 24 February 2012. Retrieved 26 September 2012.
  13. ↑ "New Brunswick Covered Bridges". Archived from the original on 23 July 2012. Retrieved 8 October 2012.
  14. ↑ "West Montrose Covered Bridge". Region of Waterloo. Archived from the original on 19 January 2011. Retrieved 31 October 2009.
  15. 1 2 Evans, Benjamin D.; Evans, June R. (2004). New England's Covered Bridges: A Complete Guide. University Press of New England. p. 10. ISBN 978-1-58465-320-2.
  16. ↑ Covered Bridge Manual. U.S. Department of Transportation. Retrieved 28 November 2012.
  17. ↑ Hoover, Mildred Brooke; Rensch, Hero Eugene; Rensch, Ethel Grace; Abeloe, William N. (2002). Kyle, Douglas E., ed. Historic Spots in California (5th ed.). Stanford University Press. p. 107. ISBN 978-0-8047-4482-9.
  18. ↑ "Knights Ferry SHP: California's Longest Covered Bridge". Pashnit.com. Retrieved 28 November 2012.
  19. ↑ Henderson, Lyndee Jobe (2010). Off the Beaten Path: Illinois, A Guide to Unique Places (10th ed.). Morris. p. 110. ISBN 978-0-7627-5025-2.
  20. ↑ Vlach, John M. (1980). "Joseph J. Daniels and Joseph A. Britton: Parke County's Covered Bridge Builders". In Dégh, Linda. Indiana Folklore: A Reader. Indiana University Press. p. 22. ISBN 978-0-253-10986-6.
  21. ↑ Dregni, Eric (2006). Midwest Marvels: Roadside Attractions Across Iowa, Minnesota, the Dakota, and Wisconsin. University of Minnesota Press. p. 84. ISBN 978-0-8166-4290-8.
  22. ↑ "Kentucky's Thirteen Existing Covered Bridges". Covered Bridges in Kentucky. Retrieved 5 September 2017.
  23. ↑ "Maryland's Six Existing Covered Bridges". Maryland Covered Bridges. Retrieved 1 July 2014.
  24. ↑ "Covered Bridge". Zumbrota Covered Bridge. Retrieved 16 July 2014.
  25. 1 2 Starbuck, David R. (2006). The Archaeology of New Hampshire: Exploring 10,000 Years in the Granite State. University Press of New Hampshire. p. 153. ISBN 978-1-58465-562-6.
  26. ↑ Belman, Felice; Pride, Mike, eds. (2001). The New Hampshire Century: Concord Monitor Profiles of One Hundred People Who Shaped It. University Press of New England. p. 209. ISBN 978-1-58465-087-4.
  27. 1 2 Richman, Steven M. (2005). The Bridges of New Jersey: Portraits of Garden State Crossings. Rutgers University Press. p. 92. ISBN 978-0-8135-3510-4.
  28. ↑ Hairr, John (2007). North Carolina Rivers: Facts, Legends, and Lore. History Press. pp. 119–20. ISBN 978-1-59629-258-1.
  29. 1 2 Moore, Elma Lee (2010). Ohio's Covered Bridges. Arcadia Publishing. p. 7. ISBN 978-0-7385-8430-0.
  30. ↑ "Swamp Meadow Covered Bridge". VisitRhodeIsland.com. Retrieved 11 July 2013.
  31. ↑ "Campbell's Covered Bridge – Gowensville, South Carolina". SCIWAY. Retrieved 23 June 2016.
  32. ↑ "Covered Bridges in Tennessee". Tennessee Department of Transportation. Retrieved 28 November 2012.
  33. ↑ Allen, Richard Sanders (1983). Covered Bridges of the Northeast (2nd ed.). Stephen Greene Press. p. 50. ISBN 978-0-8289-0439-1.
  34. ↑ Barna, Ed (1996). Covered Bridges of Vermont. Countryman Press. ISBN 978-0-88150-373-9.
  35. ↑ "Washington Covered Bridge Map". www.coveredbridgemap.com. Retrieved 26 April 2018.
  36. ↑ McKee, Brian J. (1997). Historic American Covered Bridges. ASCE Press. p. 143. ISBN 978-0-7844-0189-7.
  37. ↑ Gierach, Ryan (2003). Cedarburg: A History Set in Stone. Acadia Publishing. p. 145. ISBN 978-0-7385-2431-3.
  38. ↑ "Smith Rapids Covered Bridge". TravelWisconsin.com. Retrieved 16 August 2015.
  39. ↑ Chrimes, Mike (1991). Civil Engineering, 1839–1889. London: Alan Sutton. p. 47. ISBN 1-84015-008-4.
  40. ↑ Gesell, Laurence E (1992). The Administration of Public Airports. Chandler, AZ: Coast Aire. pp. 114–115. ISBN 0-9606874-7-5.
  41. ↑ Dégh, Linda, ed. (1980). Indiana Folklore: A Reader. Bloomington: Indiana University. p. 42. ISBN 978-0-253-20239-0.
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