Tunkhannock Viaduct

Tunkhannock Creek Viaduct (also known as the Nicholson Bridge and the Tunkhannock Viaduct) is a concrete deck arch bridge on the Nicholson Cutoff rail line segment of the Norfolk Southern Railway Sunbury Line that spans Tunkhannock Creek in Nicholson, Pennsylvania. Measuring long and towering when measured from the creek bed ( from bedrock), it was the largest concrete structure in the world when completed in 1915 and still merited "the title of largest concrete bridge in America, if not the world" 50 years later.

Built by the Delaware, Lackawanna and Western Railroad (DL&W), the bridge is owned today by Norfolk Southern Railway and is used daily for regular through freight service.Norfolk Southern completes acquisition of Delaware & Hudson South Line
PRNewswire, September 18, 2015

The DL&W built the viaduct as part of its Nicholson Cutoff, which replaced a winding and hilly section of the route between Scranton, Pennsylvania, and Binghamton, New York, saving , 21 minutes of passenger train time, and one hour of freight train time. The bridge was designed by the DL&W's Abraham Burton Cohen; other key DL&W staff were G. J. Ray, chief engineer; F. L. Wheaton, engineer of construction; and C. W. Simpson, resident engineer in charge of the construction. The contractor was Flickwir & Bush, including general manager F. M. Talbot and superintendent W. C. Ritner.

In 1975, the American Society of Civil Engineers or ASCE designated the bridge as a National Historic Civil Engineering Landmark. ASCE noted that at the time of its construction from 1912 to 1915, it was the largest reinforced concrete railroad bridge ever built.

The bridge was also listed on the National Register of Historic Places on May 3, 1977.FEDERAL REGISTER, VOL 42, NO. 85-TUESDAY, MAY 3, 1977, page 22411. In 1990, the National Railway Historical Society placed a historical plaque on the structure noting its size as the world's largest concrete bridge, completing the Summit cut-off project for the Delaware, Lackawanna and Western Railroad.

History

Construction on the bridge began in May 1912 by excavating all 11 bridge piers to bedrock, which was up to below ground. In total, excavation for the viaduct removed of material, more than half of that rock.

Almost half of the bulk of the bridge is underground. At mid-construction, of concrete had gone into its substructures, and it was estimated that construction would require of concrete and of steel. The steel estimate proved accurate; the bridge ultimately used a bit less concrete than expected: , making the total weight approximately .

The bridge was dedicated on November 6, 1915, along with the opening of the Nicholson Cutoff.

Construction photos along with a short history of the bridge were published by the Nicholson Area Library in a brochure in 1976. It was listed on the National Register of Historic Places on April 11, 1977.

Since 1990, the local community has celebrated the building of the bridge on the second Sunday of September with "Nicholson Bridge Day", a street fair, parade, and other activities. The 100th-anniversary celebration was held in September 2015.

Recognition

In 1975 the American Society of Civil Engineers or ASCE designated the bridge as a National Historic Civil Engineering Landmark.Society for Industrial archeology newsletter, November 1975, Vol. 4, No. 6. ASCE noted that at the time of its construction from 1912 to 1915, it was the largest reinforced concrete railroad bridge ever built.Herbert Hands, ASCE news release dated January 22, 1975

ASCE recognized the bridge as "not only a great feat of construction skill" but also a "bold and successful departure from contemporary, conventional concepts of railroad location in that it carried a mainline transversely to the regional drainage pattern, effectively reducing the distance and grade impediments...". At the time, the decision was made to build the bridge out of reinforced concrete, railroad engineers had little experience with this material.

The bridge was also listed on the National Register of Historic Places on May 3, 1977. In 1990, the National Railway Historical Society placed a historical plaque on the structure noting its size as the world's largest concrete bridge, completing the Summit cut-off project for the Delaware, Lackawanna and Western Railroad.

Gallery

Tunkhannock Viaduct under construction 1914.JPG, Tunkhannock Viaduct under construction in 1914
TunkhannockViaductFromAir.jpg, Tunkhannock Viaduct from the air
Nicholson-Viaduct.JPG, Tunkhannock Viaduct, as seen from Route 11
Compared to the town.JPG, Viaduct over Nicholson, PA

See also

*Starrucca Viaduct
* Lackawanna Cut-Off
*List of bridges documented by the Historic American Engineering Record in Pennsylvania
* National Register of Historic Places listings in Wyoming County, Pennsylvania

References

Further reading

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External links

*
NicholsonBridge.com
enthusiast site about the bridge and its environs
*
Tunkhannock Viaduct
Historic Civil landmark at the American Society of Civil Engineers site

takes over ownership of the Tunkhannock Viaduct in 2015.
A Thing Colossal and Impressive
article by Pennsylvania Center for the book with extensive source listing for the structure.

{{National Register of Historic Places

Open-spandrel deck arch bridges in the United States
Railroad bridges on the National Register of Historic Places in Pennsylvania
Bridges completed in 1915
Viaducts in the United States
Historic Civil Engineering Landmarks
Bridges in Wyoming County, Pennsylvania
Historic American Engineering Record in Pennsylvania
Delaware, Lackawanna and Western Railroad bridges
Concrete bridges in Pennsylvania
Norfolk Southern Railway bridges
National Register of Historic Places in Wyoming County, Pennsylvania