The Shipbuilders' Association of Japan (SAJ) has proposed to the Ministry of Land, Infrastructure and Transport (MLIT), Tokyo Metropolitan Government and other official bodies the use of a floating airport structure utilizing Mega-Float technology for the planned further expansion of Tokyo's Haneda Airport.

　Toshimichi Okano, Chairman of the SAJ (concurrently Chairman of Mitsui Engineering & Shipbuilding Co., Ltd.), said:"By using the Mega-Float technology, you can build an offshore airport in a shorter period of time and at a lower cost. This construction method is almost free from extra costs and delays due to unpredictable factors, and an airport built in this way would have the further advantages of enhanced friendliness to the environment and a high resistance to earthquakes. I am confident that it is the best option for the planned Haneda Airport expansion project."

　The MLIT, now studying the idea of building a third airport in the Greater Tokyo area, is trying to accelerate the further expansion of Haneda Airport as a first step toward addressing the expected increase in air transport demand up to 2025.

　Previously, the Japanese shipbuilding industry had proposed that a floating structure, which would be less costly to build and unaffected by soft ground, be used when Kansai International Airport was in the planning stage, but the proposal was not accepted due to the lack of a performance record.

　In December 1993, the Transport Technology Council recommended that development of technology for huge floating offshore structures (Mega-Float) should be addressed as a matter of national government policy. In response, the shipbuilding industry teamed up with steelmakers to establish the basics of Mega-Float technology, and built a 1,000-meter-long demonstration model of a floating airport. Using this model, they developed, and confirmed the soundness of, necessary techniques for the construction and use of such airports. The joint developers carried out further demonstration tests for the taking off and landing of aircraft on the Mega-Float model, and completed their developmental project with satisfactory results.

　As a result, in March 2001, the MLIT's discussion group for the feasibility of Mega-Float type airports arrived at the conclusion that "Mega-Float type airports 1,000 to 4,000 meters in length would be technically feasible." Incidentally, a 2,500-meter strip is being proposed for the expanded Haneda Airport.

　The developmental project undertaken by the Technological Research Association of Mega-Float was completed in March 2001. The association then looked into whether or not the Mega-Float structure could be effectively applied to the Haneda Airport expansion project. The study has led to the conclusion that the various advantages made possible by Mega-Float make this technology the best choice for the project: "The Mega-Float airport could be built more quickly at less cost; would be unaffected by ground quality, accordingly resulting in a smaller gap between the planned and the actually completed state, and be resistant to earthquakes; permit utilization of the internal space; be friendly to the environment, easy to expand, relocate or remove; allow ready raising of the strip surface, and not disturb the flow of water if installed at the mouth of the Tama River."

　Encouraged by this conclusion, the SAJ has decided to approach the MLIT, Tokyo Metropolitan Government and other official bodies concerned to promote the adoption of the Mega-Float structure. Said SAJ officer, "We expect Mega-Float technology to be selected as the truly appropriate method for the further expansion of Haneda Airport, when the social environment is so vastly changing as indicated by rising calls for more efficient public works, greater friendliness to the environment and more strict accountability requirements under the information disclosure system."

　A floating airport consists of a floating body, which is the main structure, and mooring equipment for keeping the floating body in a fixed position. For linking with an existing airport, a bridge that can both follow tide fluctuations and permit taxiing of aircraft will be provided.

　The floating body will be a structure comprising a combination of steel plates and frames. As such, a significant amount of space will be made available within the floating body.

　This internal space can be utilized for a number of purposes, including the storage of supplies for use during a natural disaster, over and above accommodating the airport's own equipment and machinery and facilities within the airport.

　The mooring equipment serves not only to keep the floating body in position but also to allow it, with the use of fenders, to ride out oscillations caused by an earthquake.