After the completion of the floating disaster prevention bases, it is recognized that the regular training exercises are quite important, The procedures to dispatch the FDPB in the case of Osaka Bay, for example, are as follows.

　

Criteria of action

When devastating disaster such as a big earthquake occurred in some area in which the Disaster Relief Act will be invoked, the anti-disaster headquarters of the prefecture, city, and town will ask the Kinki Regional Development Bureau of the Ministry of the Land, Infrastructure and Transport, to send the Floating Disaster Prevention Basis for relief works. The Bureau will make the decision of dispatching the FDPB.

　

Coverage area

The coverage area of the FDPB is that it can reach in about one day after the completion of the preliminary arrangements and towed in 4 knots/h (7.4 km/h). In the case of Osaka Bay, almost all the area of the bay will be covered by the above-mentioned restriction. For example, Kobe Port is 20 km from Osaka Port and it will take about three hours, and Wakayama-Shimozu Port 75 km with approximately 10 hours.

　

Policy

Required time that the anti-disaster headquarter at the suffering site can use the FDPB will be 48 hours from the request. It will take one day for the preparation to leave the base port. At the mooring base port, the connecting bridge is removed and is loaded onto the FDPB with a crane ship. Disconnection of the FDPB from the dolphins is also carried out with a crane ship. Supporting goods, construction materials and machinery needed at the suffering district are procured and will be loaded to the FDPB. The route of transportation will be applied to the Japanese Maritime Safety Agency. It will take one day to tow the FDPB to the suffering district and to moor it at a fixed space.

　

It is considered that the anti-disaster headquarter will use the FDPB for two weeks after it is dispatched. The reason is that the quay walls suffered from the Hanshin-Awaji Earthquake almost recovered its function by a rapid restoration works after 14 days of the disaster. Another reason is that the amount of the land transportation cargo has exceeded that of the sea and air transportation after about 15 days of the disaster. If the anti-disaster headquarters request the FDPBs staying to extend, it will be possible to extend the time at most one month from the arrival. The expenditure of money on dispatch will be borne by the anti-disaster headquarter that requested the dispatch.

　

Results and suggestion obtained from the training exercises

Based on the training exercises conducted on February 5, 2002, at Osaka Port, some comments and suggestions are described below. As it has passed about one year from the previous exercise, it took much time to release the mooring chains because rust had eaten deeply into the space of pin and anchor shackles. The work at the narrow space on the dolphin and the requirement of truck crane because of the very heavy weight of mooring chain (about 1.3t) and anchor shackles, also contributed to require a great deal of time for release preparation. Because of the restriction of the arrangement of wharfs, the four anchor winches of a derrick were moored asymmetrically, and the FDPB should be pulled out carefully between the narrow spacing of about 15 cm clearance on one side surrounded by the four fixed dolphins. The technique to pull out the FDPB parallel to the normal line of the dolphins is important to avoid the minor collision. It took much time to bring wires needed for the replacement of connecting bridge and another equipment for the preparation of towing. One of the reasons is that the shipping of a truck crane is impossible on the wharf. This time, the tent was left as it is. In case of emergency, however, opening of a hutch and removal of the tent for the usage of a heliport are needed. Such points at issue should be carefully considered.

　

Based on the training exercised conducted on September 1, 2001, at Yokohama Port, some comments and suggestions are described below. It was recognized to prepare the criteria to leave off the work at rough seas. The leave off criteria is as follows:

　

　

Take shelter of the FDPB itself is not necessary.

　

A 25t hanging rafter crane was used to open the hatch (4.1t) and hanging of temporarily used mooring chains (3.6t/chain). In case of emergency, however, is it possible to provide such a crane promptly? It will be impossible to make lighter the hatches because the upper deck is designed for, the 25t truck crane to be able to work on it. Therefore, it is a precondition to prepare hanging crane and necessary equipment before the relief action. As the weight of the connecting bridge is 50t, a large crane will be required. The structure of the bridge is designed to be able to float on the sea and can be towed to the destination. The arrangement of anchor chains under normal conditions is complicated and difficult to release, especially the anchor chains are quite heavy and the structure of dumpers are so complicated. The chains should be small to 78 mm in diameter and the dumpers for chains should be improved to open release type from above and below.

　

　

With the Great Hanshin-Awaji Earthquake as a turning point, three types of Floating Disaster Prevention Bases have been constructed. They are disposed in Tokyo, Ise, and Osaka Bays. Based on the training exercises and direct experiences, some suggestions and proposals for improving the FDPB system are obtained.

　

Kozawa, T., Y. Miyachi, T. Koizumi, K. Wada, and Y. Matsushita. 2000. Provision of Floating Disaster Prevention Basis. In Proceedings of the Techno-Ocean International Symposium, 623-628 (623-626. In Japanese). Japan: Techno-Ocean 2000 International Symposium Secretariat, Japan.