The Rolling Bridge
[4][5][6] It also has a very long cycle time, taking 2–3 minutes to finish moving in either direction,[3][5][7] which compares unfavourably with traditional hand-operated canal footbridges and would cause delays on a waterway with frequent boat traffic.[3] The high number of complex moving parts – fourteen hydraulic rams, numerous precision bearings, and an underground machinery chamber to provide the required oil pressure – can be seen as an example of overengineering, and has led to maintenance failures where the bridge is unable to move for significant periods of time.[3][8] For these reasons, the design disregards established principles of architecture and civil engineering such as form follows function.Traditional use of the term "rolling bridge" dates from at least the Victorian era, and is used to describe a type of retractable drawbridge used to span a ditch or moat surrounding a fortification.That type of bridge is not hinged, and remains horizontal when it is rolled inside the gates of a fort.
Guthrie rolling bridgebascule bridgePegasus BridgeCoordinatesPedestriansTruss bridgekinetic sculpturemoveable bridgeGrand Union CanalPaddington BasinLondonThomas Heatherwickhydraulic cylinderstimberfootbridgeoctagonalBritish Constructional Steelwork Association'spublic arthydraulic ramsprecision bearingsoverengineeringform follows functionGarden BridgeVictorian eradrawbridgeretractable bridgesFort Nelson, Portsmouthbascule bridgesMerchant Square FootbridgeList of bridges in LondonWolfram Demonstrations Project