Gowanus Canal: Culver Viaduct / Ninth Street Bridge / Smith Street Station
This is actually two bridges in one.
The upper Culver Viaduct houses the IND Smith/9th Street Station opened on 7/1/1933 and is the highest elevated station in the NYC subway system, sitting 91 feet over the Gowanus Canal. It has two truss spans surrounding the platforms.
Underneath the subway station is a vertical lift bridge for 9th Street (NYC BIN #2240240). This bridge opened in 2000 to replace a deteriorated bascule bridge originally built in 1903 on the same contract with the Union and Third Street bridges further up the canal. The lift span is 82 feet to provide a channel width of 60 feet under three lanes of traffic and two sidewalks. When raised, the lift span provides a vertical clearance of 60 feet above mean high water. Because the bridge sits underneath another bridge, the normal configuration of two counterweights over the roadway on either side was not possible while providing the maximum clearance, necessitating the unusual use of four counterweights - one on each pillar. The bridge was designed by Hadesty and Hanover, LLP Consulting Engineers
The viaduct concrete deteriorated considerably over the years and a fabric cladding was wrapped around the supporting structure to prevent chunks of concrete from falling off and causing damage or injury. (NY Times 2009).