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The Delaware River Viaduct is a reinforced concrete railroad bridge across the Delaware River about south of the Delaware Water Gap that was built in 1908-10 as part of the Lackawanna Cut-Off rail line. It is the sister to the line's larger Paulinskill Viaduct. The Delaware River Viaduct also crosses Interstate 80 on the east (New Jersey) side of the river and Slateford Road and the Lackawanna Railroad's "Old Road" (now Delaware-Lackawanna) on the west (Pennsylvania) side. Abandoned in 1983, it is part of a New Jersey Transit proposal to restore passenger service to Scranton, Pennsylvania. The bridge is long and high from water level to the top of the rail, and is composed of five spans and two spans. The footings were excavated down to bedrock, which ranges from to below the surface.〔Cohen, A. B. "The Delaware River Viaduct." ''Purdue Engineering Review,'' No. 6 (1909-10): 13.〕 A total of of concrete and 627 tons of reinforcing steel were used to construct this bridge. Construction of the bridge was described in an article by Abraham Burton Cohen, then a draftsman for the Delaware, Lackawanna and Western Railroad, who went on to design the Tunkhannock Viaduct, an even larger structure on the railroad's Summit-Hallstead Cutoff.〔Cohen, A. B. "The Delaware River Viaduct." ''Purdue Engineering Review,'' No. 6 (1909-10): 9-18.〕 The bridge was completed on December 1, 1910, about a year before the Cut-Off opened, which allowed construction trains to haul building materials to work sites east of the bridge.〔''The Lackawanna Railroad in Northwest New Jersey'', Larry Lowenthal and William T. Greenberg, Jr., Tri-State Railway Historical Society Inc. Publication, 1987, p. 74〕 The bridge was originally envisioned as a curved bridge with a 1°30" curve that would have allowed speeds of 80 mph (129 km/hr).〔1906 Survey Map of the Delaware Valley Cut-Off, September 1, 1906〕 But the design was altered to include a tangent (straight) stretch of track across the bridge, a 1°30" curve on the New Jersey side and a 3°30" curve on the Pennsylvania side of the bridge. This tighter curve required trains to slow to 50 mph (80 km/hr). No other curves on the 28-mile Cut-Off were sharper than 2°. The viaduct is the largest reinforced concrete structure built with a continuous pour process. There is no known evidence to support the oft-told legend that several workers fell into the concrete during construction and could not be extracted because of the need to keep pouring. The tracks were removed by Conrail in March 1989, five years later than the rest of the New Jersey section of the Cut-Off. The bridge has deteriorated more quickly than its sister, the Paulinskill Viaduct, perhaps because it spans a larger river, or perhaps because its design did not permit the addition of an inspection crawlway, alone among the Lackawanna's four concrete viaducts. NJ Transit has proposed to restore rail service along this line into Pennsylvania. The agency's projections indicate that restoring the Delaware River Viaduct would be the most expensive part of the project. ==See also== *List of bridges documented by the Historic American Engineering Record in Pennsylvania *List of crossings of the Delaware River 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Delaware River Viaduct」の詳細全文を読む スポンサード リンク
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