Tunkhannock Viaduct

    Tunkhannock Viaduct

    The massive Tunkhannock Viaduct carries the Canadian Pacific Railway over Tunkhannock Creek in Nicholson, Pennsylvania. The arch bridge was constructed for the Delaware Lackawanna & Western Railroad along the famed Nicholson Cutoff.


    The Leggett’s Gap Railroad, incorporated in April 1832, was intended to connect Scranton, Pennsylvania with New York. 1 The company, dormant for years, was eventually chartered in March 1849 and organized in January 1850. Construction on a line from Scranton to a connection with the New York & Erie Rail Road at Great Bend, just south of the New York state line, began shortly after.

    The railroad’s name was changed to the Lackawanna & Western Railroad (L&W) in April 1851, and the railroad opened on December 20. 1 From Great Bend, the L&W utilized trackage rights north and west over the New York & Erie Rail Road to Owego where it leased the Cayuga & Susquehanna Railroad to Cayuga Lake at Ithaca.

    The Delaware & Cobb’s Gap Railroad (D&CG), incorporated in 1849 and chartered in December 1850, was built between Scranton through the Pocono Mountains to the Delaware River where it interchanged with the Warren Railroad. 1 Before it opened, the D&CG and L&W were consolidated by the Lackawanna Steel Company to form the Delaware, Lackawanna & Western Railroad (DL&W) in April 1853.

    The consolidation of the railroads into the DL&W was to find outlets to the north and east for the vast deposits of anthracite coal in the Lackawanna and Wyoming Valleys, along with developing industrial centers where both coal and iron ore could be supplied by the DL&W. 1

    Nicholson Cutoff

    The DL&W, choked with traffic from booming coal and general merchandise shipments, sought to improve track speed and timetables by constructing two “Air Line” improvements: the New Jersey Cutoff and the Nicholson Cutoff. The Nicholson Cutoff was proposed to bypass the hilly and winding alignment between Clarks Summit and Hallstead 2 and provide a low-grade double-track line with no at-grade crossings between Scranton and Binghamton. It would be just 3.6 miles shorter but save 21 minutes of passenger train time and one hour of freight train time.

    Work began on the Nicholson Cutoff in May 1912. 2 Key to the Nicholson Cutoff was the development of the Tunkhannock Viaduct at Nicholson. The massive open-spandrel concrete bridge was designed by the DL&W’s Abraham Burton Cohen. 2 Other key railroad staff involved with the project included 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. 3

    Construction involved excavating all 11 bridge piers to bedrock 138 feet below ground. In total, excavation for the viaduct removed 13,318,000 cubic yards of material, more than half of that rock. Nearly half of the bulk of the bridge was underground, requiring the pouring of 167,000 cubic yards of concrete 3 and the usage of 1,140 short tons of steel. 6

    The new Tunkhannock Viaduct was dedicated on November 6, 1915. 7 8 It’s completion marked the opening of the Nicholson Cutoff. At the time of its construction, the bridge was the largest reinforced concrete railroad bridge ever built. 4 5

    With the decline of anthracite coal production and usage by the 1960s, traffic on the DL&W declined. The railroad was merged with the Erie to form the Erie Lackawanna (EL) in 1960, which was conveyed to Conrail in 1976, Norfolk Southern in 1997, and Canadian Pacific in 2015.

    The American Society of Civil Engineers designated the bridge as a Historic Civil Engineering Landmark in 1975, and it was listed on the National Register of Historic Places in 1977. 4 5 The National Railway Historical Society noted the bridge as being the world’s largest concrete bridge in 1990.



    • State: Pennsylvania
    • Route: Canadian Pacific Railway
    • Type: Open Spandrel Arch, Concrete Arch
    • Status: Active - Railroad
    • Total Length: 2,375 feet
    • Main Span Length: 185 feet
    • Height: 240 feet


    1. History of the Lackawanna Railroad.” Erie Lackawanna Dining Car Preservation Society, 28 Mar. 2020.
    2. The Nicholson Bridge.” Pocono.org.
    3. Simpson, C.W. “Construction Methods on Viaducts Of The Lackawanna Railroad Over Tunkhannock and Martins Creeks.” Water and Sewage Works, vol. 50-51, no. 3, Mar. 1916, pp. 94–98.
    4. Federal Register, vol. 42, no. 85, 3 May. 1977, p. 22411.
    5. NRHP assessment for Tunkhannock.” National Archives at College Park.
    6. “Progress of Tunkhannock Viaduct Construction on D., L. & W. Relocation.” Engineering Record, vol. 68, no. 22, 29 Nov. 1913, p. 594.
    7. Nicholson Viaduct.” JMF Computer Services.
    8. Tunkhannock Creek Viaduct.” Nicholson Heritage Association.

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