A swing bridge is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its centre of gravity, about which the turning span can then pivot horizontally as shown in the animated illustration to the right. Small swing bridges as found over canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.
In its closed position, a swing bridge carrying a road or railway over a river or canal, for example, allows traffic to cross. When a water vessel needs to pass the bridge, road traffic is stopped (usually by traffic signals and barriers), and then motors rotate the bridge approximately 90 degrees horizontally about its pivot point.
Read more about Swing Bridge: Advantages, Disadvantages
Famous quotes containing the words swing and/or bridge:
“wherever we recognize the image of God let us reverence it; though it swing from the gallows.”
—Herman Melville (1819–1891)
“Crime seems to change character when it crosses a bridge or a tunnel. In the city, crime is taken as emblematic of class and race. In the suburbs, though, it’s intimate and psychological—resistant to generalization, a mystery of the individual soul.”
—Barbara Ehrenreich (b. 1941)