The Rolling Bridge was conceived by British designer Thomas Heatherwick. The bridge consists of eight triangular sections hinged at the walkway level and connected above by two-part links that can be collapsed towards the deck by hydraulic cylinders. When extended, it resembles a conventional steel and timber footbridge. To allow the passage of boats, the hydraulic pistons are activated and the bridge curls up until its two ends join, to form an octagonal shape.
Thomas Heatherwick’s Rolling Bridge, completed in 2004 at Grand Union Canal Paddington Basin, London, is one of the most unique bridges in the world. A small pedestrian crossing, it is designed to curl up to allow boats through the inlet and uncurl again over the water.
"Consisting of 5 steel beams that rise and fall using hydraulic jacks, Merchant Square footbridge by Knight Architects & AKT II spans a 20-metre width of the Grand Union Canal in Paddington Basin." The bridge is a kinetic sculpture that rises "to allow canal boats to pass along the waterway." Quoted from link (3 of 4 images)