In this study, it is focused on an evaluation of speed loss from the viewpoint of the operation of appropriate main engine. Our final goal is that to be classification of the nominal speed loss due to added resistance caused by wind and waves and the deliberate speed loss by the captain order. As the first step, a time varying autoregressive modeling procedure is applied in order to analyze a time series of main engine rotational speed. As to an evaluation an instantaneous spectrum was used. The time series data measured in cargo carrier was used for the analysis. As a result, it is confirmed that against the change of ship speed, the instantaneous spectrum of the main engine rotational speed is changed clearly. Therefore, it may be possible that the cause of the speed loss can be classified by the instantaneous spectrum.
The Kanmon sea area is a marine traffic congested area and also a rich fishing ground in Japanese coastal sea area. Authors have studied any analysis of actual marine traffic condition, fishing condition, conflict condition between fishing boats and vessels in this area. As a further study, authors have investigated opinions of 29 pilots of the kanmon sea area regarding reduction of conflict between fishing boats and leading vessels by pilot in this area through a questionnaire. This paper have been analyzed opinions of these pilots, and compared past outcomes of author’s study with opinions of these pilots. These analyses revealed any detailed actual conditions of this conflict, and any differences between conditions which pilots are allowed and actual conditions of this conflict.
Survey on abundance and characteristics of drifting plastic debris that has renewed as marine environmental pollution was conducted off the west coast of Kyushu, Japan. Large-sized plastics such as plastic bottles and styrene that were able to be observed visually from the bridge of the ship were counted during daytime. In addition, small-sized microplastics such as microbeads and fiber were also investigated via towing surface plankton net (Newston net). Density (number of pieces per sea surface area) and compositions of plastic types in large and small-sized plastics between coastal and offshore regions were compared. Densities of large-sized plastics were 2.8 pcs/km2 in offshore region and 7.1 pcs/km2 in coastal region. However, densities of small-sized plastics in offshore and coastal regions were 360000 pcs/km2 and 1100000 pcs/km2, respectively. Density of microplastics off the West Coast of Kyushu, Japan was quite high, when compared to those in other marine regions. Countermeasure against emission of plastics into the East China Sea is needed at the earliest opportunity.
Between August and September 2018, the scale of Typhoons No. 20, 21, and 24 seriously affected and/or damaged ships in the Osaka Bay area. Typhoon No. 20 passed in proximity to Harima Nada while Typhoon No. 21 traversed Osaka Bay to pass in proximity to Awaji Island before landing in Hyogo Prefecture. As for Typhoon No. 24, it landed in Wakayama or Osaka Prefecture. Among the three, Typhoon No. 21 caused a majority of the ships anchored in Osaka Bay in order to avoid the effects of rough seas to suffer from the effects of anchor dragging. In fact, anchor dragging caused one of those ships to collide with the Kansai International Airport Access Bridge – an incident that had a major social impact.
The main focus of this paper is, therefore, a consideration of the ship anchorage situation in Osaka Bay. Including the aforementioned incident during Typhoon No.21, aspects of incidents that occurred during Typhoons No. 20 and No. 24 are considered and analyzed for the purpose of contributing to the prevention of such incidents in the future.
Recently, there are many cutter races held in many places. But their rowing method are each different based on their experiment method of each team. So, there is little study of evaluation for this sport. In this study, we aimed to clarify some features actually seen in the winning teams by quantifying and comparing of the boat speed or turning situations for the good prize in the cutter race. At the 62nd All Japan Cutter Race (total number of 12 teams) held in May 2018, a portable GPS terminal was attached to the bow of each total four 9-meter-long cutter boats, and the recorded the position data by every second. In this study, races are classified into three parts such as start dash (hereinafter "SD"), turning head and cruises. The boats speed, under water ratio of oar during cruising, and required time for SD are evaluated. As a result, SD has smallest time difference between teams and maximum time difference was 6 seconds. The turn can be divided into three groups from the total amount of course change value, boats speed or track pattern. Furthermore, cruise is most important as accounts for more than 80% of the total race, and there was positive correlation between the underwater ratio and the average boats speed during cruise.
Passenger fatigue has been reported as one of the causes of marine accidents. In our previous study, we found that the passengers’ standing postural motions, such as motions of the head and hip, can cause physical fatigue because of energy expenditures were increased by standing postural motions in a small marine craft. It was also reported that human standing postural motions are affected by visual stimuli. It is therefore necessary to analyze the standing postural motions when affected by visual stimuli to clarify the causes of passengers’ physical fatigue. The purpose of this study is to investigate the effects of wave direction difference projected by a ship handling simulator on human standing postural motion. Standing postural motion was evaluated by linear and angular accelerations, exercise load calculated by energy expenditure and the motion of the center of gravity (COG). Eight participants were asked to observe four types of wave images (1： image without waves, 2： 180 degrees wave direction, 3： 135 degrees wave direction, and 4： 90 degrees wave direction). The COG motions of the participants were observed in response to the wave directions projected by the simulator. We therefore found that a standing postural motion occurred as a visual response to the direction of wave projected by the simulator.
Many container terminals in the world are considering an introduction of automated container carrier system and remote control system for container handling equipment into their yard. When considering automation in a container terminal, it is necessary to construct an evaluation method to clarify functional evaluation and evaluate a layout plan in a new yard. This research aims are to develop a container handling simulation model and a functional evaluation method to be convenient to evaluate alternations of layout plans. Also, we focus on evaluating some different types of layout plans such as a parallel stacking system and a vertical stacking system by the developed functional evaluation method.