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:
“And I have asked to be
Where no storms come,
Where the green swell is in the havens dumb,
And out of the swing of the sea.”
—Gerard Manley Hopkins (1844–1889)
“London Bridge is broken down,
Dance o’er my lady lee,
London Bridge is broken down,
With a gay lady.
How shall we build it up again?
Dance o’er my lady lee,”
—Unknown. London Bridge (l. 1–6)