The Null Device
London mayor Boris Johnson is the latest voice calling for a new airport to be built in the Thames estuary to replace Heathrow:
The Mayor envisages building the airport on reclaimed sand banks two miles off Sheerness, Kent, in waters 10 to 13ft deep. It would have four runways and could be expanded to six, dwarfing the capacity of Heathrow's two fully operational runways. Planes would take off and land over the sea, solving the blight of noisy engines at Heathrow and allowing the airport to operate around the clock.
Throughout its 62-year life, London's main airport has been derided as a monument to Britain's make-do-and-mend approach to planning. Its origin was inauspicious – it opened in 1946 from an army surplus tent and had to wait until 1955 for its first permanent building. The site was only chosen as an airfield in 1943 because it was a good spot from which to scramble fighter planes to protect the capital during the war. Since then, it has grown piecemeal while the capital has sprawled around it. The east-west runways ensure that the largest built-up area possible is affected by noise pollution.The new airport would cost about £40bn to build (including the costs of running high-speed rail lines and road tunnels to it), though the default alternative mooted, expanding Heathrow, would cost £13bn and come up against noise complaints.
How much one needs to expand airport capacity, of course, is another question; there is increasing demand for flights (or has been before the recession), though that's inflated by Britain's lack of high-speed rail links, meaning that Britons, by default, fly over any distance greater than London to Birmingham. This is because flying is both faster and cheaper than catching a train. (In contrast, very few people choose flying over the train when travelling between London and Paris or Brussels.) A solution to this could be to levy a tax on domestic flights within Britain, using the revenue to fast-track modern TGV-style high-speed rail links going north and west.
Having said that, London (a hub of global trade, business and tourism) does need an airport suitable for international travel, and Heathrow does have its problems. An airport on an artificial island seems more fit for purpose.