Hydraulics contributed many wonders to the world. This is such an industry, that can be applied in all sectors. You might have heard about different hydraulic bridges. The important purpose of such bridge is to allow road transportation without blocking water traffic. Rolling bridge, swing bridge, bascule bridge, folding bride, etc.. are some categories of the hydraulic bridge. You can find more on rolling bridge facts here.
Also, Read: Advantages of Hydraulic Bridge
The rolling bridge(also known as curling bridge) located at Paddington Basin, London, is one among the unique marvelous creation of hydraulics that connects both ends of Grand Union Canal. In 2005, the English designer Thomas Alexander Heatherwick developed this rolling bridge as a part of a redevelopment of Paddington Basin. This 12.9 meters long truss bridge is build using triangular steel segments, hydraulic actuators, and lightweight deck to carry pedestrians. The British Structural Steel Award for 2005 was won by this rolling bridge.
Let's discuss some advantages of the rolling bridge in London. Unlike other types of hydraulic bridges, the rolling bridges are economical in terms of space requirements. Rolling bridge has a simple, self-contained structure that is fixed only to one side of the canal. The bridge rolls up smoothly and precisely leaving nothing behind on the other side of the canal. During the roll-up process, the bridge acts as a freestanding sculptural object. The advantages of hydraulics make the bridge operation smoother, accurate and quiet. The construction cost is the only drawback of a rolling bridge.
When it is in unrolled position, the bridge resembles a conventional straight footbridge build using steel handrails and timber. This bridge takes 3 minutes(180 seconds) to roll into an octagonal shape from a straight structure. The operators can control the bridge and they can pause the rolling process at any instant.
Also, Read: Basics of Hydraulics
What about the design and working of the rolling bridge?
We can start with the design. The rolling bridge is divided into eight triangular sections, with each containing a platform and trapezium railing. An extendable vertical bar(hydraulic cylinder) is hinged to the two arms connecting adjacent railings. The rolling bridge in London will have fourteen hydraulic cylinders in total on the bridge. When the hydraulic piston/ram extends, the bridge rolls up uniformly to provide access to water traffic. The rolling up process will ends only when the two sides of the bridge join together and form an octagonal structure. To function as a truss bridge, the hydraulic piston/ram will retract.
Now, we can discuss the hydraulic operation involved in the rolling bridge. Similar to all other hydraulic systems, the rolling bridge also contains basic components like pumps, hoses, cylinders, etc. The 11kW hydraulic pump of the rolling bridge will drive the 400mm hydraulic cylinder. This hydraulic cylinder is connected with fourteen 160mm slave cylinder and each of the slave cylinders will operate one among the fourteen 100mm hydraulic cylinders on the bridge. The flexible hoses connect and transfer fluid from slave cylinders towards the cylinders on the bridge. All the major components like pump, master cylinders and slave cylinders are placed separately on another platform next to the bridge structure.