BIG WHEEL WOULD KEEP ON TURNIN' : LONDON MAY BUILD 500-FOOT CONSTANT MOTION FERRIS WHEEL BY THAMES.

Byline: John Darnton The New York Times

Deciding to roll in the millennium in a big way, London is preparing to construct a 500-foot-tall Ferris wheel - the largest in the world - that would rotate continuously on the south bank of the Thames and provide nearly 1,400 presumably non-acrophobic riders with spectacular views of the city's landmarks.

Current plans call for the giant wheel to be up for only five years, from 1998 to 2002, although historians might point out that the Eiffel Tower, designed for the International Exposition of 1889, was theoretically also a temporary structure.

The project is not for the aesthetic purist who might prefer the more classical lines of Charles Barry's Westminster clock tower that houses Big Ben (320 feet tall) or Christopher Wren's dome crowning St. Paul's (384 feet) or even Horace Jones' garish but distinctive Tower Bridge (a mere 120 feet).

But it will offer what the others lack - a central vantage point from which to survey them and all of London. In fact, a passenger perched at the top would have, weather permitting - which is no small caveat here - a 60-mile view, taking in everything from Windsor Castle in the west to the Thames barrier and Gravesend in the east.

The idea of the giant wheel, promoted by boosters who predict that it will draw 2 million paying passengers a year, has been bouncing around on drawing boards and computer mock-ups for two years now. But it will receive a big push Wednesday, when British Airways will announce the underwriting of a substantial part of the cost of 9.5 million pounds ($14.3 million).

As designed by David Marks Julia Barfield Architects Ltd., the wheel would turn constantly at a low speed, allowing people to hop on and off. Sixty capsules would carry up to 960 riders on a single rotation lasting 20 minutes, while historical and sightseeing commentaries play over loudspeakers. The architects believe that 60 percent of the energy to drive the wheel could be derived from harnessing the tidal flow of the Thames and that solar power would be used to heat and cool the capsules.

The wheel would set a new record for height. The current record holder is the Cosmoclock 21 in Yokohama, Japan, which is 344 feet, 6 inches tall. In the United States, the tallest is the Texas Star in Dallas, at a height of 212 feet, 6 inches.

The London site is in the Jubilee Gardens between Westminster and Waterloo Bridges, a stone's throw from the Houses of Parliament. It will form part of a vast regeneration of the south bank that includes the new Tate Museum of Modern Art, to be built in an existing power station, refurbishment of the South Bank Arts Center by Sir Richard Rogers, the new Globe Theater that will open next year, and even an Olympic-size swimming pool floating on the river.

The Millennium Commission, which derives funds from the new national lottery and is expected to hand out some (British pounds) 1.6 billion ($2.4 million) by 2000, is not contributing to the project. The only block to construction might come from objections raised at public hearings, but so far few critics have turned up.