Sewickley Bridge
Encyclopedia
The Sewickley Bridge is a steel continuous truss bridge
Continuous truss bridge
A continuous truss bridge is a truss bridge which extends without hinges or joints across three or more supports. A continuous truss bridge may use less material than a series of simple trusses because a continuous truss distributes live loads across all the spans; in a series of simple trusses,...

 spanning the Ohio River
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...

 at Sewickley, Pennsylvania
Sewickley, Pennsylvania
Sewickley is a borough in Allegheny County, Pennsylvania, west northwest of Pittsburgh along the Ohio River. It is a residential suburb of Pittsburgh. The population was 3,827 at the 2010 census...

 and Moon Township, Pennsylvania
Moon Township, Pennsylvania
Moon Township is a township along the Ohio River in Allegheny County, Pennsylvania, United States. Moon is a part of the Pittsburgh Metro Area and is located northwest of Pittsburgh. The origin of its name is unknown for certain, although it has been suggested that it derives from a...

 carrying State Route 4025 and the Orange Belt. It was built by American Bridge Company
American Bridge Company
The American Bridge Company is a privately held civil engineering firm specializing in the construction and renovation of bridges and other large civil engineering projects, founded in 1900, and headquartered in Coraopolis, Pennsylvania, a suburb of Pittsburgh.-Products and industry positioning:The...

 and opened October 21, 1981. Its center span is 750 feet (228.6 m) long and the side spans are each 375 feet (114.3 m) long. The bridge deck contains two vehicle lanes and a pedestrian sidewalk. It crosses 73 feet (22.3 m) above the river. The bridge is owned by the Pennsylvania Department of Transportation
Pennsylvania Department of Transportation
The Pennsylvania Department of Transportation oversees transportation issues in the Commonwealth of Pennsylvania. The administrator of PennDOT is the Pennsylvania Secretary of Transportation, currently Barry Schoch Presently, PennDOT supports over of state roads and highways, about 25,000...

.

The current bridge is the second bridge to occupy the site; the original Sewickley Bridge opened September 19, 1911, after 26 months of construction. The bridge was a lattice-beam cantilever truss design, built by the Fort Pitt Bridge Works and officially named the Ohio River Bridge No. 1.

By the late 1970s, the bridge had deteriorated badly. The bridge was closed for emergency repairs from January 30 to May 20, 1977, and also from January 11 to March 2, 1979. A replacement bridge was ordered and the design was completed in late 1979. The old Sewickley Bridge closed for the last time on May 14, 1980.

To reduce construction costs, the piers from the original bridge were reused for the new bridge. This meant that the old bridge had to be completely demolished before the new bridge could be built. The central 350 feet (106.7 m) suspended span was lowered onto barges and floated away, while the rest of the bridge was dismantled piece by piece to maintain balance of the cantilever arms. The crossing was closed for a total of 17 months before the new bridge opened. The new bridge mimicked the old bridge's shape and scale, although it used box members instead of lattice beams and was of a continuous truss design instead of a cantilever-and-suspended-span design.

The original bridge was capped by four decorative finial spires; at least three of these were saved and put on public display. One sits in a park in downtown Sewickley, along with the keystone-shaped builder's plaque from the original bridge. Another is near the old Sewickley train station between route 65 and the river, near the north end of the current bridge; the third spire is at Station Square
Station Square
Station Square is a indoor and outdoor shopping, dining and entertainment complex located in the South Shore neighborhood of Pittsburgh, Pennsylvania, United States....

 in Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...

.

The location of the bridge is 40°31′59"N 080°11′16"W (40.5331234°, --80.1878365°), at an elevation of 692 feet (211 m).

External links

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