The Rolling Bridge is a

kinetic sculpture Kinetic art is art from any medium that contains movement perceivable by the viewer or that depends on motion for its effects. Canvas paintings that extend the viewer's perspective of the artwork and incorporate multidimensional movement are ...

, and a unique type of curling

moveable bridge A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. In American English, the term is synonymous with , and the latter is the common term, but drawbridge can be limited to the narrower, historical ...

, completed in 2004 as part of the

Grand Union Canal The Grand Union Canal in England is part of the Canals of the United Kingdom, British canal system. It is the principal navigable waterway between London and the Midlands. Starting in London, one arm runs to Leicester and another to Birmi ...

office and retail development project at

Paddington Basin Paddington Basin is the name given to a long canal basin, and its surrounding area, in Paddington, London. The basin commences 500 m south of the junction known as Little Venice, of the Regent's Canal and the Paddington Arm of the Grand ...

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

Design

The Rolling Bridge was conceived by Thomas Heatherwick. It 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 cylinder A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...

s mounted vertically between the sections. When extended, it resembles a conventional

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

and

timber Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). ...

footbridge A footbridge (also a pedestrian bridge, pedestrian overpass, or pedestrian overcrossing) is a bridge designed solely for pedestrians.''Oxford English Dictionary'' While the primary meaning for a bridge is a structure which links "two points at a ...

, and is 12 metres long. To retract the bridge, the hydraulic pistons are activated and the bridge curls up until its two ends join, to form an

octagon In geometry, an octagon () is an eight-sided polygon or 8-gon. A '' regular octagon'' has Schläfli symbol and can also be constructed as a quasiregular truncated square, t, which alternates two types of edges. A truncated octagon, t is a ...

al shape measuring one half of the waterway's width at that point. The bridge won the British Constructional Steelwork Association's British Structural Steel Design Award.

Disadvantages

The Rolling Bridge could theoretically allow the passage of boats, but the small basin behind the bridge is not open to canal traffic – it is currently occupied by a fountain, and blocked by a steel barrier at surface level to prevent boats entering. It also has a very long cycle time, taking 2–3 minutes to finish moving in either direction, which compares unfavourably wit
traditional hand-operated canal footbridges
and would cause delays on a waterway with frequent boat traffic. Finally, the detour around the open bridge is very short, so the crossing is arguably not required at all. Thus, the project is primarily

public art Public art is art in any Media (arts), media whose form, function and meaning are created for the general public through a public process. It is a specific art genre with its own professional and critical discourse. Public art is visually and phy ...

rather than a practical structure for navigation. The high number of complex moving parts – fourteen

hydraulic rams A hydraulic ram pump, ram pump, or hydram is a cyclic pump, cyclic water pump powered by hydropower. It takes in water at one "hydraulic head" (pressure) and flow rate, and outputs water at a higher hydraulic head and lower flow rate. The device ...

, numerous precision bearings, and an underground machinery chamber to provide the required oil pressure – can be seen as an example of

overengineering Overengineering, or over-engineering, is the act of designing a product or providing a solution to a problem that is complicated in a way that provides no value or could have been designed to be simpler. It has been employed intentionally in si ...

, and has led to maintenance failures where the bridge is unable to move for significant periods of time. For these reasons, the design disregards established principles of architecture and civil engineering such as

form follows function Form follows function is a principle of design associated with late 19th- and early 20th-century architecture and industrial design in general, which states that the appearance and structure of a building or object ( architectural form) should p ...

. A higher-profile water crossing in London also proposed by Heatherwick – the Garden Bridge – attracted significant criticism along similar lines for mainly targeting tourists as a novelty, rather than functioning as a practical water crossing.

"Rolling" as a name and as a type

Traditional use of the term "rolling bridge" dates from at least the

Victorian era In the history of the United Kingdom and the British Empire, the Victorian era was the reign of Queen Victoria, from 20 June 1837 until her death on 22 January 1901. Slightly different definitions are sometimes used. The era followed the ...

, and is used to describe a type of retractable

drawbridge A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word ''drawbridge'' commonly refers to all types of moveable b ...

used to span a ditch or moat surrounding a fortification. That type of bridge is not hinged, and remains horizontal when it is rolled inside the gates of a fort. Modern versions are called

retractable bridge A retractable bridge is a type of moveable bridge in which the deck can be rolled or slid backwards to open a gap while traffic crosses, usually a ship on a waterway. This type is sometimes referred to as a thrust bridge. Retractable bridges d ...

s or ''thrust bridges''. One particular version of the rolling bridge type was known as the

Guthrie rolling bridge A Guthrie rolling bridge was a kind of retractable bridge, an 18th-century version of the drawbridge. It was commonly installed as the access across the narrow steep sided ditches characteristic of the polygonal forts of this era. Rolling bridg ...

, examples of which may still be seen at Fort Nelson, Portsmouth. Certain types of

bascule bridge A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- o ...

s roll on an arc; an example is the

Pegasus Bridge Pegasus Bridge, originally called the Bénouville Bridge after the neighbouring village, is a road crossing over the Caen Canal, between Caen and Ouistreham in Normandy. The original bridge, built in 1934, is now a war memorial and is the c ...

Opening times

The bridge is scheduled to open every Wednesday and Friday at noon, and every Saturday at 2 pm.

References

External links

Rolling Bridge
by Sándor Kabai, the

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