http://www.odditycentral.com/page/101
Heatherwick Rolling Bridge
By Spooky on September 23rd, 2008 

When the Heatherwick Rolling Bridge is in 
its horizontal position, there’s nothing 
remotely strange about it, just another 
steel and wood-made bridge in London. But 
that all changes when it curves up until 
its two ends touch, to let boats pass. When 
curled, Heatherwick Bridge resembles an old 
watermill wheel.

Heatherwick Studio’s Rolling Bridge opens 
every Friday at noon but if the winds exceed 
30 mph, the hidraulics may be unable to handle 
them, so the bridge doesn’t open.


http://www.heatherwick.com/rolling-bridge/
video (option at bottom of their web page)

http://en.wikipedia.org/wiki/File:Curlingbridge.jpg

http://www.evolo.us/architecture/rolling-bridge-thomas-heatherwick/
Diagrams & operation