The Sewickley Bridge is a steel continuous truss bridge spanning the Ohio River between Sewickley and Moon Township, Pennsylvania, carrying State Route 4025 and the Orange Belt. It was built by American Bridge Company and opened on October 21, 1981. Its center span is 750 feet (230 m) long and the side spans are each 375 feet (114 m) long. The bridge deck contains two vehicle lanes and a pedestrian sidewalk. It crosses 73 feet (22 m) above the river. The bridge is owned by the Pennsylvania Department of Transportation.
Sewickley Bridge from upstream.
|Carries|| 2 lanes of the Orange Belt|
1 pedestrian walkway
|Design||continuous truss bridge|
|Total length||1,500 feet (460 m)|
|Longest span||750 feet (230 m)|
|Clearance below||73 feet (22 m)|
|Opened||October 21, 1981|
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-foot (110 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; 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 in Pittsburgh. The fourth is on display across the river in Coraopolis.
The location of the bridge is  at an elevation of 692 feet (211 m).(40.5331234°, -80.1878365°),