Could an innovative floating village breathe new life into London's Royal Docks?
The arrival of container ships on the world's major trading routes revolutionised the quantities of cargo and the manner in which it was transported. Not only this, but it transformed the way in which cargo was handled and thereby the look and feel of docks in the world's great cities.
The new vessels were vastly larger than conventional cargo ships; they needed bigger terminals and the deeper channels that were found at the estuaries of rivers. The old inner-city docks began to lose their primary function and became neglected, even derelict. City authorities had a problem: what should be done with the disused docks?
Developers have taken on the problem in various ways: Canary Wharf ignored the water and built round the docks; others saw that water had possibilities and came up with imaginative projects, plans and ideas.
London mayor Boris Johnson has launched an international competition to find developers to create a floating village in the Royal Victoria Dock in London. Once full of life, vigour and bustling endeavour, Victoria Dock grew uneconomical and, like all areas in decline, needs to be given relevance in the modern world.
What are the options?
The sight of flood defensive walls being swept away in New Orleans when Hurricane Katrina swept through, not to mention the untold devastation left behind by two high-profile tsunamis in the last decade, has made people ponder the possibilities of building on water, rather than trying, Canute-like, to hold it back. There is currently a swell of interest in using floating technology in domestic areas.
Mike Luddy joined the Royal Docks Management Authority (RoDMA) as managing director two years ago, with the aim of creating a master plan for the regeneration of all the Royal Docks - the Royal Victoria, the Royal Albert, the King George V and the Pontoon dock.
The Royal Victoria Dock plan is the first phase in the development of the whole area. It was opened in 1855 to replace earlier docks that were becoming too small for iron-clad steam vessels. Plaistow Marsh was an ideal site as the land was easy to excavate and road and rail links were close. Luddy worked with Ian Ritchie Architects on a whole range of aspects to develop the area.
Luddy believes that the docks should be made up of a mixture of features: some 500-800 homes, single and detached, linked in some areas by boardwalks; leisure and retail facilities, as well as a hotel and serviced apartments. He also envisages a marina, private moorings and other waterside activities.
It will be a challenge to attract architects and developers that want to work with the non-traditional element of water. The project will start as soon as a developer has been appointed, which Luddy hopes will be by Christmas 2013 or mid-2014.
Ian Ritchie also has strong views on what the dock should look like. He has a vision of it as a 21st-century Venice that conveys pictures of a variety of buildings framing canals along routes of varying widths, each with their own character and charm.
Ritchie's strategy of "creative living on the water" foresees that buildings on the water "will align their own 'grand canal'" with channels of water permeating into the "'floating' streets".
At the strategy's core is a flow of connected spaces - both hard and water routes. The hard routes are connected via a series of boardwalks and narrow streets, either floating or fixed structures. The narrow streets have a "Venice character while the boardwalks offer a place to gather and relax". Ritchie believes it will be a challenge "not only to humanise the scale of the docks while still celebrating their scale, but also to turn water into building land without losing the water, without damaging the ecology and respecting the need for people's safety and security".
The technology and design chosen to exploit the docks will depend on the developer. Overall it concerns the construction of floating buildings that can be made secure by anchoring or connecting them to piles driven into the the bottom of a dock or river and attaching them to a device that allows them to rise or fall with water levels.
One company that has been developing floating homes technology is Hydro Properties. It is engaged in a floating village project further up the Thames at Surbiton Filter Beds, where 64 floating homes on a pontoon are planned.
Hydro Properties' engineer Carl Nelson outlines the process. "Buildings are constructed on concrete elements that float like a ship's hull. They are attached by teflon roller joints to galvanised 900mm diameter steel pylons driven into the dock's bottom. This enables buildings to rise on the pylons by six metres according to water conditions."
With this technology no foundations are laid. Superstructures are built on top of a buoyant basement, which floats on a body of water. When basement units are placed in water, their weight is balanced by buoyancy forces due to displaced water - Archimedes' principle. All power, utilities, water and sewers are connected to the mainland by unplasticised polyvinyl chloride conduits.
Buildings in Venice were constructed on top of stakes driven into a layer of sand and compressed clay in the lagoon. The stakes were mostly of Slovenian alder, which has good water resistance properties.
A growing trend
Many countries have been carrying out research and putting into practice floating technologies. Luddy was impressed by the Ijburg project on artificial islands of dredged sand on the eastern side of Amsterdam.
As in most floating technology projects, components for buildings are made off site. For the Ijburg project they are fabricated 70km away on a production line. Then they are transported on canals to Ijburg.
The buildings are deployed as individual units but are linked by pontoons. Also in Holland, in Maasbommel, are amphibious houses with a hollow concrete cube at the base to give them buoyancy. The buildings are secured by piles, while rings are attached to allow movement according to water flows. The houses can withstand a rise in the water of up to four metres. Electricity and water are pumped in through flexible pipes.
Hafen City, Hamburg, is the site of a vast redevelopment of old docks located on the Elbe marshes. With only a relatively small section of floating houses, piles are a necessary foundation and have to be driven about 20m into a low-load-bearing sand level. The authorities have a different approach; instead of appointing one developer, they stipulate the conditions for concrete bases and building heights and then let individual owners complete their own designs.
An intuitive landscape
Floating technology is being used not just for major projects, but also for domestic undertakings as it becomes increasingly difficult to get permission to build houses on flood plains.
There is a movement away from building containing walls and barriers to hold back rising water. Instead, architects are looking at designing houses that float.
Recently, Marlow Council approved the building of a floating home by architects Baca. The company has designed a timber-framed house that rests on a concrete hull or platform set in a concrete dock, with four dolphins, or posts, to keep it in place.
It has been designed in several layers. A garden will act as a natural early warning flood system, with terraces set at different levels designed to flood incrementally and alert the occupants before the water reaches a threatening level. The architects call this an 'intuitive landscape'.
The lowest terrace will be planted with reeds, another with shrubs and plants, another will be lawn, and the highest step will be a patio with access into the dining room. If the Thames bursts its banks, water pressure will lift the home from the dock and allow it to float up to the water level. Success in these projects could lead to a review of the construction of buildings in areas that are prone to flooding. Houses might then be built on land that was once deemed unsuitable.