THE improbable idea of building a huge, floating airport known as Floatport three miles off the coast of San Diego has been bobbing around the city for more than two decades.
Now, with several technologically advanced floating projects being built in other countries, greater appreciation for minimizing environmental impact on land, and coastal cities bulging with people, Floatport may be drifting into more probable waters somewhere in the world.
The $2 billion project is largely the visionary design of San Diego architect Donald Innis. "The main criticism of the idea over the years," he says, "is that it has never been done before, which I see as an asset, not a liability."
For many years, San Diego city officials have squabbled over the need for a new international airport to replace small Lindbergh Field, located in the city. Noisy flight patterns crisscross the city, bringing environmental problems as well as safety concerns.
The airport handles about 100,000 flights a year, but the number is expected to double by 2050. It has few international flights, because the runways are too short for larger planes.
Designed to be located in the Pacific Ocean three miles off Point Loma, Floatport would be a double-decked concrete structure covering from 150 to 250 acres. Included in the design are two 12,000-foot runways. The structure could be linked to land by either a tunnel or bridge, or possibly by hydrofoil boats.
Floatport would stay afloat by means of a unique modular construction never tried before, although the principles involved are well-known. Each module would be 180 feet square, composed of open-bottom concrete cylinders 20 feet in diameter and approximately 40 feet high.
"There is a cap on the cylinder," says Mr. Innis, "and flotation is derived by displacement of air in the cylinder. Each cylinder acts like a shock absorber. And as the waves move under the platform, the cylinders with higher air pressure are permitted to vent to the lower pressure ones through turbines that convert the power to electricity." Cables connected to pilings would moor Floatport to the ocean floor.
Innis is co-chairman of Float Inc., a small group promoting the Floatport concept and holding the patents. "We're pursuing two paths to construction," says John Nichelson, an engineer and secretary of Float Inc., "private means and government backing. We've reached a stalemate trying to get a consensus of political opinion in San Diego to at least get a fair shake for the project."
In fact, Floatport has been turned down twice by the San Diego Association of Governments (SANDAG), a long-range strategic planning organization charged with establishing criteria for a new airport. SANDAG currently favors construction of an international airport known as Twinports, in collaboration with the Mexican government, on the border about 24 miles south of San Diego.
"[Floatport] was first evaluated in l972," says Gary Bonelli, a spokesman for SANDAG, "and then in l990 when we updated our airport studies, we looked at some of the potential offshore sites again. [Floatport] fell out of the running early on because of prohibitive costs and major hurdles, such as the possibility of an environmental accident at an offshore facility, danger to marine life, and other concerns."
The San Diego Port Commission, a nonvoting member of SANDAG, operates Lindbergh Field. "SANDAG is charged with looking for a land-based airport," says Don Hillman, assistant port director, "but if they are unable to do that, then Floatport might become an option. The port commission is not charged with finding a new airport."
Joe Leary, president of Floatport Inc., says that the environmental impact of a floating airport is minor compared with a land-based airport.
"This project is one of the most environmentally benign projects there could be," he says. "First, you don't render uninhabitable about 20 square miles with concrete as you would with a land-based airport. People have a tendency to lump us with landfills, which are environmentally damaging. As for safety, no populations would exist under flight paths. When an air accident occurs, it's usually during landing and takeoff with damage to surrounding structures." Floatport proponents acknowledge that construc tion costs would be higher than a land-based airport. But when land-acquisition costs are considered too, Floatport is about equal in cost with an airport on land.
What gives Floatport some additional credence these days are offshore facilities being built in several countries.
Japan is building a 3,000-acre artificial island three miles offshore in Osaka Bay to service Kansai International Airport. In all, Japan has 20 offshore projects in various stages of planning and construction, including a nine-square-mile floating residential and commercial city known as Ocean Communications City, with a price tag of $200 billion.
Just above the Great Barrier Reef in Australia, the John Brewer Reef Floating Hotel has been built to withstand winds as high as 120 miles per hour. The structure measures 300 feet long by 90 feet wide. Anchored to the reef, the hotel is designed to rotate in strong winds, somewhat like a weather vane. There is also discussion by Honolulu officials and the University of Hawaii about the feasibility of an enormous floating structure three miles offshore that could include office buildings, condominiums, and other facilities. Officials say it could ease population pressures on Honolulu.
"Many scientists and engineers who have looked at Floatport," says Howard Blood, chairman of the National Ocean Research Exploration Center, a nonprofit marine research center in San Diego, "recognize its possibilities and engineering validity."
Walter Monk, an oceanographer at Scripps Oceanographic Institute, thinks Floatport is a "perfectly good, sensible idea" for San Diego or anywhere else. "Considering the cost of downtown real estate," he says, "and safety and noise factors, it is a very interesting idea. I think most people are so scared of trying anything that hasn't been done before. We wait until the Japanese do it. If we could get the United States Department of Defense to build one, then the city people would be more likely to have t he courage to consider it seriously."
For Floatport designer Innis, his 20-year wait has not broken his tenacity to see Floatport accomplished.
"I would say that we have an excellent chance of one of these being built somewhere in the world in the next eight to 10 years," he says. "San Diego is a natural for it because of all the universities and colleges here in the marine sciences. All we need are the politicians to take a serious look at this. If it is built here, people from all over the world will be pounding a path to this city to see what we have done and how it was done. But if it's built somewhere else, that's OK with me."