Rolling Bridge
{ Rolling Bridge, by Thomas Heatherwick } “The Rolling Bridge at Paddington Basin in London runs on hydraulics. To retract it, an 11-kW hydraulic pump drives a master cylinder 16 inches in diameter, which in turn drives a series of 6-inch slave cylinders. These power 14 vertical shafts beneath the bridge’s hinged handrails. As the shafts rise, the railings fold in, causing the 39-foot span to curl. Because all the cylinders are driven at a constant rate regardless of the load on each bridge segment, the structure moves smoothly, taking two minutes to open or close. The pumps and related equipment are housed in the basement of an adjoining building, so the bridge is almost silent as it operates.”
