National Maritime Research Institute Mitaka, Tokyo, JAPAN

fukuto@nmri.go.jp

　

A Bridge Navigational Watch Alarm (BNWA) system, which has a verbal communication system as a human-machine interface, is introduced. The BNWA is installed in a user-friendly navigation support system (NSS) developed by Japan Coastal Tanker Association, National Maritime Research Institute (Former Ship Research Institute) and Mitsubishi Heavy Industries, Ltd. The NSS was developed to support safety one-person bridge operation (OPBO). It has many navigation support functions such as an ECDIS, a track control system (TCS), etc. A verbal comunication system, which is composed of a speech recognition system and an artificial voice synthesizer, is used as a human-machine interface to satisfy demands on the interaction with the officer of the watch (OoW) and the NSS given by active users. The BNWA uses also verbal communication system to reset it and to give alarms to OoW with an artificial voice. The NSS including the BNWA has been used to a coastal LPG carrier (749GT) for 5 years and the NSS was already used for 5 ships. Through her commercial runs, the BNWA and the NSS were evaluated its effectiveness by active users. As the result, it is confirmed that they were reliable and usable enough for practical use at sea. The BNWA is well accepted by active users; because the voice alarms and actions to the BNWA is easy enough and they do not interrupt ongoing tasks, especially looking out ships around.

　

　

Tokyo University of Mercantile Marine Etchujima, Tokyo, JAPAN

shoji@ipc.tosho-u.ac.jp

　

Owing to the increase of bridge and offshore structures near ship's waterways as well as marine traffic, ship collision accidents with these structures have been increasing. To keep safety from ship collision accidents with these structures, various kinds of protective device are planned.

　

The pelprene protective device is used for this purpose. In order to design of this protective device for ship collision, it is necessary to investigate the strength of ship as well as the strength of protective device. In this study authors investigated this issue. That is, on the strength of ship bow they introduced a simplified formula for calculation of ship bow strength related to gross tonnage of ship based on relation between various ship bow dimensions, which are dept of ship, thickness of plate, entrance angle of bow, frame space and so on. On the strength of protective device they introduced an experimental formula for calculation of reaction force of protective device related to indentation of ship bow from the various parameters, which are form factor, height of unit piece, bending elastic modulus of material and so on. The scale effect was also considered.

　

From these formulas case study was put in practice. For example on small sized ship with several ship's speed calculation was executed. From the calculated result authors could show the effectiveness of this type of protective device for small sized collision.

　

　

College of Science and Technology, Nihon University Funabashi, Chiba, Japan

dearytyi@mb.infoweb.ne.jp

　

An on board system for wave data analysis and application to ship operation has been developed. The system consists of wave probes, accelerometers, a soft-ware of analysis and a wave data display tool. The former two are used to estimate the encountering wave surface elevations on ship hull. The main parameters of waves, i.e., the wave direction, the mean wave period or wave length and the significant wave height are calculated by using the encounter wave elevation data at three positions on ship side.

　

The obtained wave parameters are used to show the situation of own ship at sea on the figures of operational guidance, so that the master can judge how to change the ship course or speed for preventing dangerous situations.

　

This paper presents the method of wave direction analysis using cross spectra of wave data at three positions and the examination of the method by numerical simulations and model experiments in directional waves.

　

As to an application of the obtained wave data on board to ship operation, an automatic display system on PC has been developed. The present speed and course of ship relative to the wave conditions are shown on a polar diagram, the V/T-diagram, as function of [ship speed]/[wave period] (V/T) and [encounter angle](X). The dangerous zone to encounter to high wave groups in following and quartering seas is indicated on the diagram. The test results on actual vessel at sea will be presented.