Editing Swing bridge (section)

==Disadvantages==
[[File:Swing Bridge and ferry in motion.jpg|thumb|250px|right|An example of how small swing bridges like this one may be pivoted only at one end, but that does require substantial underground structure to support the pivot. [[Victoria & Alfred Waterfront]], [[Cape Town]].]]
* In a symmetrical bridge, the central pier forms a hazard to navigation. Asymmetrical bridges may place the pivot near one side of the channel.
* Where a wide channel is not available, a large portion of the bridge may be over an area that would be easily spanned by other means.
* A wide channel will be reduced by the center pivot and foundation.
* When open, the bridge will have to maintain its own weight as a balanced double [[cantilever]], while when closed and in use for traffic, the live loads will be distributed as in a pair of conventional [[truss]] bridges, which may require additional stiffness in some members whose loading will be alternately in [[compression (physical)|compression]] and [[tension (mechanics)|tension]].
* If struck from the water near the edge of the span, it may rotate enough to cause safety problems (see [[Big Bayou Canot rail accident]]).