Carroll Street Bridge

The Carroll Street Bridge is a retractable bridge in New York City, crossing the Gowanus Canal in Brooklyn. It carries a single wooden-decked lane for one-way eastbound vehicular traffic and two walkways. Completed in 1889, it is operated by the New York City Department of Transportation, with an average of about one thousand crossings each weekday. It is the oldest of the four remaining retractable bridges in the United States and is an official city landmark. Description The Carroll Street Bridge is composed of a span supported by a pair of riveted steel plate girders. The span is wide and contains one eastbound lane of vehicular traffic and one walkway to either side. It carries the street of the same name within the neighborhood of Gowanus, Brooklyn. The posted restrictions are a height limit of and a weight limit of . The roadway on either side is made of Belgian blocks. On average, , one thousand vehicles cross the bridge each weekday. The movable portion of the span is painted bright blue and shaped like a trapezoid. Carriage truck frames, supported by wheels, are located underneath the girders. When the bridge is retracting, these frames run along three timber-supported steel rails that run diagonally on the western bank of the canal to the south of the span, which opens up a channel for ships to pass. The frames are moved by a series of pulleys. Originally, the span was retracted using a steam engine, but today it is powered by an electric motor. Swinging gates on either side close off the span whenever the Carroll Street Bridge is in the open position. An operator's house is located on the bridge's western end along the southern sidewalk. The booth is normally unmanned, but a bridge attendant can travel to the operator's house within two hours in case the bridge needs to be opened.