The prevention of disaster for earthquake and tsunami has become inevitable after the big disaster in 2011. The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has conducted the explanatory committee in 2020, and the obligation of head-out mooring is discussed for vessels, because the turning maneuver is not necessary and it makes the operation time shorter. In this study, we investigate the opinions of those involved in the operation of large vessels such as crude oil tankers and LNG carriers regarding safety measures. And comments are compiled on the actual conditions of emergency operations and port earthquake resistance in the event of an earthquake and tsunami, which is forecasted the occurrence of Tounankai or Nankai Earthquake and Tsunami in near future. Although the head-out mooring seems to be reasonable from viewpoint of emergency evacuation, it is found that 50-85 percent of responders do not approve yet. Some reasons who oppose this point is summarized here. And two surveys are additionally conducted as the online interview. Based on these results, this paper discusses the disaster prevention measures that can be taken by ships and ports.

Japanese government has been studying how to use the ships to enrich the content in relief measures for dealing with disaster. For more effective use, an improvement of operation and a systematize advance step by step on preparation in peace time. The Investigative commission by the government regarding “Hospital ship” from 1991 reported a negative conclusion in March 2021. In the report, the experts of the commission are aiming to solve not only the huge cost of construction, maintenance, and operation, but also the securing of hundreds of medical staff and ship staff, and the measures for utilization in peacetime, that called “Three major issues.” Just two months after the report, the Diet enacted the “Japan promote act of Hospital ship.” The law consists of articles that contradict the report of the commission. This indicates that the use of ships for disaster medical care has shifted from technical projects to political projects. This paper reconsiders the discussions by experts at the commissions, and proposes the merchant ships utilization method by utilizing barges for acute-phase disaster medical care consistency with the fundamental philosophy of said law.

In our previous study, we demonstrated a numerical simulation result of the reproduction on tsunami and ship motions of a moored large coal carrier during the 2011 Tohoku earthquake and tsunami, which encountered beyond 10 meters’ tsunami wave at H-port and suffered a severe damage on the ship and the mooring facility. The fendering system such as fender and pier was modeled practically as a serially synthetic spring. The mooring facility needs to remain and maintain a safe performance even under the tsunami disaster. In this paper, we have tried to reproduce the ship behavior in details by considering coupling effect of motions of the ship and the pier during the tsunami to understand the phenomena of fender breakage and then the ship directly contacts to the pier.

The Japan Coast Guard provides Vessel Traffic Service (VTS) in congested sea areas, which requires manual operation with a heavy workload, so there is a need for a support system to make their work more efficient. In this research, we explored the possibility of using machine learning which has been attracting attention in recent years to support VTS operators. Specifically, we developed the anomaly detection model which is based on an autoencoder. Then, we tried to detect deviations from the traffic route from images showing the positioning of vessels navigating the northern part of the Uraga Suido Traffic Route. As a result, we confirmed that the model could recognize a deviation from the traffic route as an anomaly and would be a promising model to support VTS operations.

The authors evaluate the statistical properties of winds and waves in smooth water areas established around Japan. Numerical predicted wind and wave data are homogeneous in time and space and the statistical properties are evaluated by analyzing the data over a long period of 10 years. In this paper, smooth water areas established in Sea of Japan and Sanriku Coast, the characteristics of those areas affected by topography are shown by the evaluating mean values, exceedance probabilities and comparison among the these sea areas.

At the time of large-scale disasters, we are restricted of using mobile phones and the Internet. On the other hand, many broadcast stations were quick to begin broadcasting from affected areas. We have previously reported that they evaluated receivable areas of the terrestrial digital broadcast onboard. However, it was focused on reception levels, it remains to be elucidated methodological improvements for ISDB-T reception onboard. This paper describes investigations of measuring reception levels and evaluated some systems for ISDB-T onboard. This study revealed, even a marine antenna was not high gain, improvements of MER and BER were confirmed when using a 700MHz band filter, diversity reception methods were effective. Moreover, one segment increased viewing areas onboard by approximately 20%. The author concluded, 700MHz band waves were affected even at sea hence countermeasures using 700MHz mobile phone band filters were necessary, selective diversity was effective because it was possible to switch to antennas on the land side, the one segment broadcasting system was effective onboard because it was enables viewing in areas where they were not been possible before during coastal voyages.

In this study, the meteorological knowledge necessary for deciding the operation of a ship was examined from the marine accident survey and the previous studies. By the comparison with the mariner examination, we considered the meteorological education that mariners should newly acquire to prevent marine accidents. In the marine accidents, some were caused by phenomena on the mesoscale γ to β and some were caused by mariners’ misinterpretation of meteorological information. On the other hand, in the mariner examination, most of the questions were on the synoptic scale, and also there were no questions about the latest weather forecasting technology such as satellite images and numerical weather prediction. Based on the above results, it was concluded that maritime officer needs the knowledge of the latest meteorological observation and forecasting technology as well as the uncertainty of meteorological information based on numerical weather prediction models.

The purpose of this study is to indicate the differences in communication between officer of the watch and cadet in an easy-to-understand manner. In this study, first as raising a question, the analysis communication is important for the prevention of human error and there are differences in the content of communication between the OOW and cadet even if their same process and timing of action, were described. And the experiments for the OOW and cadet were carried out to obtain their communication data and analyze the communication in bridge. In the second place, the difference of communication between them was analyzed by the communication data which were labeled by keeping ship’s course and avoiding target areas. From the result, some differences of them by time of communication and time per minute were shown. In the third, the communication data is partitioned two groups of resource sharing about ship’s position and object using basic model of resource sharing. Also the difference of them were found out as achievement rate of resource sharing visually. Finally, the way of education and evaluation using the finding from analysis of communication were proposed.

To reduce the number of collisions between ships, it is useful to estimate areas where collisions between ships are likely to occur. In recent years, many studies on the estimation have been conducted using Automatic Identification System (AIS) data, which makes it relatively easy to analyze ship movements. However, accidents involving non-AIS ships occur frequently, and thus their movements should be included to estimate the areas. In this study, we analyzed the movements of non-AIS ships in Tokyo Bay using data observed by radars, which are installed on shore around Tokyo Bay. Additionally, we estimated collision caution probability, which is one of the indexes representing the likelihood of a collision occurrence, for ships including non-AIS ships. The results were compared with the probability based only on AIS data and conventional estimates, and trends were clarified corresponding to current traffic situations.

Nankai Trough Earthquake with the large tsunami is concerned to occur currently. Tsunamis cause extensive damage to vessels in ports. In particular, breaking mooring lines is likely to lead to severe maritime disasters such as drifting, grounding and collision with other vessels or port facilities. Thus, it is important for mooring vessels in ports to prevent mooring lines from breaking due to tsunamis. However, few reports are available on the detailed mooring conditions needed for tsunami protection. In this study, we have proposed and developed “the tsunami protection measures mooring lines list” for vessels moored on wharves that indicates the mooring conditions such as material, diameter and the number of lines required to prevent mooring lines from breaking against tsunamis. The list is made by comparing two maximum mooring forces obtained from tsunami simulations using the 3D MPS method and static calculations. As a result, mooring conditions were evaluated for each tsunami height from this list, and it was indicated that a large increase in mooring forces is required for tsunami protection and that use of high-performance fiber lines such as HMPE lines and other measures which do not depend on only lines should be considered.