Futuristic Green Float project will test limits of technology

Japanese scientists, engineers and financiers have begun work on a project that will make the construction excesses of Dubai look timid: a tower 1km (3,300ft) high and a vertical farm balanced on a floating concrete lilypad.
By the year 2025, it is claimed, all the necessary technology should be ready to start building — assuming a suitable patch of calm, equatorial ocean can be identified.
At first glance, the Green Float project seems highly improbable: artificial rafts have never been built on this scale before, much less ones capable of supporting what will be, by far, the world’s tallest building. Even the investment bank Nomura, which is the chief facilitator of the project, has not speculated on how much it will cost or who will pay for it.
Energy will be drawn from solar power, so plentiful sunshine is a must, while the structure of the island demands reliably calm waters, low wind speeds, predictable temperature and a low risk of tsunamis or typhoons.
The project is expected to lure a number of Japan’s largest technology groups and the research work has already begun at leading universities and engineering companies.
The engineering giant Shimizu envisages building the tower from super-light alloys derived from the magnesium in seawater. Once an island with a diameter of 3km is created, each new floor of the tower will be built at ground level, pushing the previous floor down into the sea. When the 1,000-metre mark is reached, the tower will be raised to its full height. The huge circular base will be part mangrove plantation, part cornfields and part livestock ranch — all built on a lattice of 7,000-tonne honeycomb pontoons.
Each floating city, suggests the blueprints, will power and feed itself, supposedly providing a carbonneutral habitat for 50,000 people.
Eventually, the idea is to string more floating units together, creating a “lilypad” flotilla of man-made islands capable of sustaining a total population of one million people.