Dunlap's Creek Bridge

Dunlap's Creek Bridge
Coordinates

40°01′18″N 79°53′17″W / 40.02167°N 79.88806°W / 40.02167; -79.88806[1]

Dunlap's Creek Bridge
Coordinates 40°1′18″N 79°53′17″W / 40.02167°N 79.88806°W / 40.02167; -79.88806Coordinates: 40°1′18″N 79°53′17″W / 40.02167°N 79.88806°W / 40.02167; -79.88806
NRHP Reference # 78002398[2]
Added to NRHP July 31, 1978
Carries National Road
Crosses Dunlap's Creek
Locale Brownsville, Pennsylvania
Characteristics
Design arch bridge
Material cast iron
Longest span 24.4 metres (80 ft)[3]
Number of spans 1
History
Designer Richard Delafield
Construction begin 1836
Construction end 1839

File:Dunlap creek bridge jet lowe 1983.jpg

Dunlap's Creek Bridge was the first cast iron, metal arch bridge in the United States. It was designed by Richard Delafield and built by the United States Army Corps of Engineers.[4] Constructed from 1836 to 1839 on the National Road in Brownsville, Pennsylvania, it remains in use today. It is listed on the National Register of Historic Places and is a National Historic Civil Engineering Landmark (1978). It is located in the Brownsville Commercial Historic District and supports Market Street, the local main thoroughfare. Due to the steep sides of the Monongahela River valley, there is only room for two short streets parallel to the river's shore and graded mild enough to be comfortable to walk before the terrain rises too steeply for business traffic.

View of the once vibrant business strip, the Market Street historic district. Market Street's lowest stretch runs north of the ramp off the West Brownsville bridge for 3-4 blocks (about the scene here), whereafter it begins a steady climb to the end of the re-routed U.S. Route 40 bridge built at a much higher elevation near the site of the original settlement, the Tavern, Trading Post, and Inn near today's Bowman's Castle.
Plaque commemorating the first cast iron bridge built in the United States. This plaque is near or at the place the above picture of the Market Street was taken.

History

There have been four structures on this site. The first two collapsed in 1808 and 1820. The third, a wood-framed structure, needed replacement by 1832.[5]

This bridge is constructed using five parallel tubular ribs, each made of 9 elliptical segments to form the 80 feet (24 m) arch.[4]

See also

Notes

    References

    1. ↑ The First Cast Iron Bridge: Historical Marker Database
    2. ↑ National Park Service (2008-04-15). "National Register Information System". National Register of Historic Places. National Park Service.
    3. ↑ Dunlap's Creek Bridge at Structurae
    4. 1 2 Jackson, Donald C. (1996). Great American Bridges and Dams. New York: Wiley. ISBN 0-471-14385-5.
    5. ↑ Murphy, Kevin (June 1984). "Dunlap's Creek Bridge" (PDF). Historic American Engineering Record. Washington, D.C.: Library of Congress. p. 1. Retrieved February 1, 2014.



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