Kenneth A Cubbin
Whenever a community wants to expand an airport in order to increase business opportunities, the local population inevitably
complains loudly. Such a situation is presently occurring over a proposed expansion of the Piedmont Triad International Airport
(GSO) in Greensboro, North Carolina. If redevelopment plans go ahead, GSO's expansion will facilitate construction and operation
of a major FedEx cargo hub due to open in 2005. However, there is substantial local resistance to the proposed FedEx facility.
Despite recent job losses in the tobacco and textile industries in central North Carolina, some airport area residents feel
they will be negatively impacted by increased airport traffic -- much of which will occur in normal sleeping hours -- and
are vocally objecting to trading the tranquillity of their home for community employment opportunities.
This is a perfect example of NIMBY -- not-in-my-backyard. Want to expand the airport? Then be prepared for a lot of noise:
both from airplanes, and whining residents. In typical fashion, North Carolina developers continue to build and sell houses
in areas around GSO thereby assuring added voices to the chorus of objection. And, if a city wishes to build a new
airport to accommodate passenger growth as New Yorkers would say, Forget aboud it! If local residents can't stop it,
environmentalists will; either that, or the airport will be prohibitively distant to the metropolis to be convenient.
With air traffic growth at critical levels and the air transportation infrastructure strained to capacity some pundits
predict that air travelers are doomed to lengthy delays in the future. But this may not be case. Lateral-thinking, Japanese
engineers may have the answer: Why not build airports on the sea?
Innovation Follows Need
As an island nation with limited land resources, Japan has aggressively reclaimed land this century for various uses, such
as harbor facilities, urban function facilities, supply distribution centers and airports. Practically all shallow sea areas
have already been reclaimed in Japan and further expansion will need to be undertaken on deeper sea areas. Problems associated
with deep sea land reclamation include higher costs, longer construction periods and significant negative environmental impact.
After recommendations by the Transport Technological Council and private industry moguls to the Japanese Minister of Transport
in 1993, research and development of ultra-large floating structures began. In 1995, the Technological Research Association
of Mega-Float (TRAM), consisting mainly of shipbuilders and steelmakers, was formed and charged with the project of building
a floating experimental runway with an anticipated life in excess of 100 years. The planned experimental runway would be 1,000
meters long, 60 meters wide and 3 meters deep. Everyone involved with the project was aware that, if successful, the possible
uses of massive floating structures could prove virtually limitless.
Research and Development
TRAM set a period of 3 years for the research and development stage. It was determined that the R & D process could
be split into five major sections. They were:
1. Development of specific design technology,
2. Development of construction methods for joining sections at sea,
3. Research into how to achieve the required durability (more than 100 years),
4. Research into how the structure would be affected by operations once completed, and
5. Environmental impact studies.
It was decided to construct the floating structure much thinner than conventional wisdom. With a depth to length ratio
of approximately 1/1000, this would create problems in elastic movement that would need to be overcome; this was largely accomplished
by diligent calculations by engineers and the use of tank test models.
Of course, an ultra-large floating structure would be far too large to manufacture on shore in one piece, therefore, it
was decided that segments of Mega-Float would be constructed at various locations, towed to location (much the same way as
oil platforms) and connected at sea. This meant that specific processes needed to be developed where precise measurements
could be maintained while attaching structures that would be subject to the sea's surface movement.
Ultra-long durability required research into new anti-corrosive materials, such as Titanium-clad plates, and the development
of a monitoring and repair system for underwater components. This was necessary to counteract the anticipated stress problems
that would occur from vibrations and other factors associated with normal operations once the structure was functioning.
Of increasing concern in todays society is the impact that such a structure might have on the ecology. It was generally
thought that a floating structure would have little impact on the environment because the water would flow normally underneath
and no pollutants would be discharged into the sea. However, due diligence demanded that an iterative process of environmental
assessment be set in place during construction and operation of Mega-Float.
The construction phase began in 1998 and, thanks to the extensive R & D program, was completed late 1999 at a cost
of approximately $149 million. The major sections (six units) were joined in Tokyo Bay and secured by a steel-pile mooring
system that was developed during the R & D phase. This tethering system was thought to accommodate tidal and wave movements
while affording the structure limited impact from earthquakes. One possible benefit of having a floating runway that is virtually
impervious to earthquakes is the emergency relief it might facilitate in the event that a close major city is decimated by
such a calamity. A floating runway might have proved invaluable on January 17, 1995, when a 6.9 earthquake hit the Kobe district
of Japan resulting in 5,502 deaths and major damage to local infrastructure.
Scheduled flight tests, using Dornier Do 228s and Britten-Norman Islanders, began last June and were completed successfully.
After exhaustive testing, consensus among those involved with the Mega-Float project is that viability of a landing field
at sea has been proven sufficiently to warrant consideration of future projects
New Tokyo Airport?
This has led some to speculate that Tokyo's third airport will be a floating structure built in Tokyo Bay. If true, a major
airport constructed in this fashion is estimated to cost approximately $9.6 billion and take 4 to 5 years to build. As a comparison,
New Kansai International Airport in Osaka, which was built on reclaimed land and opened in 1994, took seven years to construct
and cost $13.5 billion.
On the other hand, others warn that operational tests using large jet transport aircraft have yet to be conducted on floating
runways, particularly in adverse weather conditions. And, in the event of a large ship colliding with the structure, it has
not been guaranteed that the edifice would not rupture and sink. Therefore, it is doubtful that Tokyo's new airport will be
built as a floating structure until many further tests and experiments are completed. However, if a fully operational airport
were to be constructed using this technology, it may look something like the accompanying artists impression.
Financial backers of the Mega-Float project see the technology used to construct floating edifices such as hotels, recreational
facilities, garbage collection stations and even entire communities. (Anybody else wonder whether Kevin Costner is a financial
While these structures will still require a sheltered location, there are many sites in every continent that might accommodate
expansion into the sea. Advantages of floating structure development are:
Almost all sheltered sea areas can be utilized regardless of depth and condition of subsoil,
Earthquakes have relatively little impact on floating structures, although tsunamis (large waves caused by earthquakes)
may be a problem in unsheltered areas of Japan and other countries,
Floating structures do not change the ecosystem and, therefore, have little negative impact on the environment,
Construction costs and time to complete are less for floating structures than building similar structures on reclaimed
Floating structures can easily be extended, and
Floating structures can be relocated to another site if required.
So, what is the likelihood of an A300XX landing on a giant floating airport in the middle of Tokyo Bay in ten or fifteen
years? Before you answer that question, factor in two considerations. Firstly, with 90% of the earths surface covered with
water, it seems completely logical that mankind should develop a method of utilizing the sea to his advantage.
Secondly, advances in technology occur exponentially; what seems impossible today, will appear matter-of-fact to future
generations. And lastly, there is a general nostalgia felt by all those in aviation for the grand old days of water-based
operations. Therefore, the impetus to build an airport on the sea may prove unstoppable. After all, isn't this the next best
alternative to landing on floats?
All I know is that when the air traffic controller of the first floating, commercial airport clears a large jet transport
to land, I want to see a diminutive gentleman in a white suit shout from the tower, "The plane! The plane!"
Then, I'll believe.
Ken - Cubbin Consulting -- Airlines Economics, Marketing, Safety, Training and Project Management