A moveable bridge is a bridge that moves to allow passage for (usually) boats or barges. By making the bridge movable it may be made low, which avoids the expense of high piers and long approaches, greatly reducing the cost of the bridge. The principal disadvantage is that the traffic on the bridge must be halted when it is opened for passages. For seldom used railroad bridges over busy channels the bridge may be left open and then closed for train passages. For small bridges bridge movement may be enabled without the need for an engine. Some bridges are operated by the users, especially those with a boat, others by a bridgeman, sometimes remotely using video-cameras and loudspeakers. Generally the bridges are powered by electric motors, whether operating winches, gearing, or hydraulic pistons. A log bridge in the French Alps near Vallorcine. ...

There are often traffic lights for the road and water traffic, and moving barriers for the road traffic. A stoplight in Mexico City. ...

Types of moving bridges

• Bascule bridge
• Curling bridge
• Drawbridge
• Folding bridge
• Jetway
• Lift bridge
• Retractable bridge (Thrust bridge)
• Submersible bridge
• Swing bridge
• Table bridge
• Tilt bridge
• Transporter bridge
• Armoured vehicle-launched bridge

Salmon Bay Bridge, Seattle, USA; a single leaf through truss with an above-deck counterweight A bascule bridge is a drawbridge with a counterweight that continuously balances the span, or leaf, throughout the entire upward swing in providing clearance for boat traffic. ... The curling bridge, at Paddington Basin, London. ... It has been suggested that this article or section be merged with Bascule bridge. ... Hörnbrücke in Kiel An example of a Folding Bridge is the Hörnbrücke (Hörnbridge or Hoernbridge) in the city of Kiel in Schleswig-Holstein. ... A Jetway, jet bridge or aerobridge/airbridge is a moveable bridge, normally enclosed, which extends from an airport terminal allowing passengers to board an airplane without having to go outside. ... A lift bridge over the Erie Canal at Lockport. ... The bridge deck of a Retractable bridge can be rolled backwards to open a gap for crossing traffic, usually a ship on a waterway. ... A moveable submersible bridge lowers the bridge deck below the water level to permit crossing ship traffic instead of raising it like a lift bridge or table bridge. ... A swing bridge is a bridge that has as its primary structural support a vertical locating pin and support ring at or near to its center, about which it can then pivot horizontally as shown in the animated illustration below. ... A table bridge is a moveable bridge in which the deck moves along the vertical axis. ... Gateshead Millennium Bridge A tilt bridge is a bridge that tilts. ... The Newport Transporter Bridge A transporter bridge (also ferry bridge or aerial transfer bridge) is a type of movable bridge that carries a segment of roadway across a river. ... An armoured vehicle-launched bridge (or AVLB) is a combat support vehicle, sometimes regarded as a subtype of combat engineering vehicle, designed to assist militaries in rapidly deploying tanks and other armoured fighting vehicles across rivers. ...

See also

• Bailey bridge and Medium Girder Bridge - transportable or relocatable bridges.
• Pontoon bridge - may be built with a barge or boat-like section that may be moved for passage.