Pero's Bridge, Bristol, UK

Eilis O'Connell with Ove Arup
Date Built
Completed 1999
St Augustine's Reach in Bristol Harbour
Named after an African slave, Pero Jones, who was brought to Bristol in 1873, this rather odd looking bridge spans Bristol's Floating Harbour and provides pedestrian access to such attractions as At-Bristol and the Bristol Aquarium.  This footbridge is composed of two fixed sections with a central span made up of a bascule bridge.  The horns provide an artistic solution to the counterweights needed to facilitate the lifting of that section. 

As you can see above, a hydraulic piston is used to raise and lower the deck.  The rolling action of the bridge is kept in alignment by the "teeth" below the horns that fit into a track on the top of the concrete pier.