Next-Generation Marine Structure and the Future Vision of the Sea

Even in Japan, the development of an "ocean vision", which sees beyond the 21st century, has become a pressing need. In terms of technology, innovative ideas could contribute to the new development of this vision. From the point of view of future generation marine structures, this article deals with massive floating structures such as the integrated EEZ management station and disaster prevention wide area mobile station and their functions.

1. What do we need?

To control the order and use of the sea in the 21st century, a concrete vision of the sea is required, and Japan should establish it. In this paper, I would like to make one proposal, specifically a "next-generation marine structure" and to describe its functions in the hope that I will contribute to establishing Japan's vision of the sea.

2. New trends in the order and use of the sea

As is widely known, the United Nations Convention on the Law of the Sea was adopted by contracting members, including Japan. The significance, however, is not well understood by people in general. In the course of the discussions held over a long period of time until the Convention was adopted, the global environment problem appeared more imminent than before, and the conditions surrounding mankind changed greatly. Our views of the world and the earth also changed greatly. As a result, we saw the emergence of the entirely new concept that the sea is a common property of mankind, and this concept was introduced to the Convention. Three mainstays of this concept were defined in the preamble of the Convention: (1) the peace of the sea, (2) the economic aspects of the sea, and (3) environmental problems. The Convention states that the sea is a common property of mankind and it must be conserved and protected for mankind.
In Japan, various problems will also appear more imminent in the 21st century: the global environment problem, problems related to resources and energies, food problems, low birth rates, aging society, and so forth. With these problems in mind, I organized the sea-related activities being conducted in Japan into a table, as shown in Table 1, based on the three principles of the "21st Century Ocean Grand Design" proposed by the Japan Federation of Industrial Organization: (1) to know the sea well, (2) to use the sea wisely, and (3) to protect the sea.
We must manage our society efficiently to maintain the high living standard and vitality of Japan, while at the same time dealing with the problems and fulfilling our responsibilities. The proposed marine structure to be installed in the sea must be optimized and achieve low cost even though they are installed for uses of security, international contributions and technological strategies. In proposing and designing the next-generation marine structure, high performance and efficiency must be realized.

3. Next-generation marine structure

I would like to make the following proposals about marine structures that Japan should introduce to conduct activities on the sea:

1. "Offshore center for global environmental research" to be established offshore and in waters along coastal areas: this is based on the principle "to know the sea."
2. "EEZ comprehensive ocean management base" to be established offshore: this is based on the principle "to protect the sea."
3. "Base for the development of methane hydrate and other deep-sea resources," "wide-area mobile disaster prevention base," "marine structure for coastal development," and "structure for expanding the living space of mankind to the ocean" to be established offshore: this is based on the principle "to use the sea."

Of these proposals, the "EEZ comprehensive ocean management base" and the "wide-area mobile disaster prevention base" are described here.

(1) EEZ comprehensive ocean management base

To effectively control the vast 200-nautical-mile economic zone of Japan, it is important to establish bases at appropriate points and to handle various events that occur inside the exclusive economic zone. Sea patrolling and policing can be done with no problem if land bases can be used, but to deal with international affairs quickly, it is necessary to access each important sea zone in the shortest possible time. Therefore, offshore bases are necessary, specifically floating sea bases. I propose an offshore facility in which personnel can stay for a long period inside the exclusive economic zone, particularly along the demarcation line of the economic zone, to maintain the order of the sea or to conduct surveys. Because the maintenance of the order of the sea involves a variety of different activities, it is assumed that the personnel of government authorities and agencies, researchers, engineers, trainees, etc., can stay and conduct activities. To enable people in the facility to maintain close communication with their counterparts on land, use of helicopters and airships, which are recently attracting a great deal of attention for their transportation capacity and cruising distance, is proposed. To enable people performing a great diversity of different activities to live together for a long period of time, the facility must have high wave-resistance and low motion performance, and provide plenty of space and the same working environment as that on land. The facility must also be designed to be used for different purposes: scientific investigations, learning, information gathering, and so forth. As a facility that can meet all these needs, I propose a spar-type floating body (vertical tower-type floating body). This floating body can be used as a storage warehouse, a lodging facility, a research building, a recreational facility, an airship berthing facility, and so forth.

(2) Wide-area mobile disaster prevention base

In the Great Hanshin-Awaji Earthquake that occurred in 1995, ships and floating bodies in the Kobe Port remained almost undamaged. Based on this experience, a pontoontype floating disaster prevention base (flat box-type floating structure) was established in Tokyo Bay, Ise Bay and Osaka Bay, though its range of activity is limited to a relatively calm coastal area. In the disasters that have occurred recently, the eruption of Mt. Usu and that on Miyake Island, it was strongly desired that a disaster prevention base as the headquarters for countermeasures be established offshore near the area affected by the eruption to direct the shipment of goods and to perform rescue operations. Given this background, I propose that a floating wide-area mobile disaster prevention base. If a serious disaster occurs, it can cruise on the open sea and reach the disaster area quickly, stay on the sea close to the disaster area, and function as a command center for directing the operations, transporting goods, and rescuing people. The possibility that it may conduct activities in the East Asian region should be taken into consideration. It must be designed to allow a large helicopter to land and take off and with medical and lodging facilities, as well as a warehouse function.