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Article type: Cover
1997 Volume 96 Pages
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Article type: Appendix
1997 Volume 96 Pages
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Article type: Appendix
1997 Volume 96 Pages
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Article type: Index
1997 Volume 96 Pages
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Article type: Index
1997 Volume 96 Pages
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Midori TAKAHASHI, Osamu AMAI, Sakae NAGAOKA
Article type: Article
1997 Volume 96 Pages
1-9
Published: March 25, 1997
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In general, a computer simulation is carried out for evaluating the safety level of a future oceanic air route system where the current separation minima are reduced. In the simulation, modeling arrival-interval distributions is required for generating pseudo traffic. This paper describes the results of survey and analyses on the arrival-interval distribution for the westbound traffic crossing the boundary between Tokyo flight information region (FIR) and Anchorage FIR in the NOPAC routes. A probability density function model which consists of a weighting sum of exponential distributions with different means is proposed for approximating the empirical arrival-interval distribution.
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Osamu AMAI, Sakae NAGAOKA
Article type: Article
1997 Volume 96 Pages
11-19
Published: March 25, 1997
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The safety of the North Pacific (NOPAC) route system has been evaluated using a collision risk model. This paper describes the method and results of the estimation of the lateral overlap probability which is a key parameter of the model. The probability was estimated from the empirical distribution of cross track deviations from the assigned track of a NOPAC route, namely R 220. The data obtained from air route surveillance radars together with flight plan data were used for the analyses. The estimated lateral overlap probability value for 100NM of lateral separation, Py (100) is 2.4x10^<-8>.
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Kakuichi SHIOMI, Hiroki SATO, Ryuji OHTSUKA, Keiichiro NAKAUE
Article type: Article
1997 Volume 96 Pages
21-29
Published: March 25, 1997
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In this paper, we show the concepts of new generation air traffic management (ATM) system based on object oriented thinking and illustrate the user interface system of the controller's console designed according to the concepts. The graphical user interface of the above mentioned console is common to the airport controllers and terminal controllers, and they can access to the all air traffic control information. On this ATM system, coordination among controllers and pilot of aircraft are not distinguished, and will be processed as same object.
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Sakae NAGAOKA, Osamu AMAI
Article type: Article
1997 Volume 96 Pages
31-38
Published: March 25, 1997
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This paper deals with the method and results of a collision risk analysis for the north pacific (NOPAC) composite air route system. A collision risk due to loss of composite separation (diagonal collision risk) is estimated using model parameters estimated from various empirical data mainly obtained in the air route system. The estimated diagonal collision risk for the NOPAC routes is 4×10^<-13> [accidents/flight hour]. This diagonal collision risk is negligible compared with other collision risks such as longitudinal, lateral and vertical collision risk.
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Tatsuto YAMADA, Yasuo TAKENAKA, Naoto SATOH
Article type: Article
1997 Volume 96 Pages
39-46
Published: March 25, 1997
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Marine traffic data, for example, course, speed, gross tonnage and shape of vessel are collected in a marine traffic survey. These data were estimated by using a high resolution radar and effective image processing of an anchoring vessel. Authors made a study on the reflected power of radar wave which was caused by the edges of a target considering the fresnel zone. We indicated that the patterns of the fluctuant radar wave reflected by the edge of a vessel resembled closely the antenna reception patterns. We detected the bow and stern of the vessel within the domain of radar echo and made attempt to estimate the length of the vessel by taking account of the first fresnel radius and the beamwidth corresponding half-power points.
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Hiroshi ISHIDA, Tokujirou INOUE, Shigeaki SHIOTANI, Yoshifumi ICHIKAWA ...
Article type: Article
1997 Volume 96 Pages
47-52
Published: March 25, 1997
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The on-board experiment of the marine radar wave observation system has been carried out on waters in and near Osaka Bay and near around Izu-Oshima Island and Gotou Islands for 30 days in total in 1994. For this experiment, two types of ships, a usual small pleasure boat and the experimental vessel at sea of Techno-Super-Liner, were used. This system can obtain 2-dimesional wave information, the wavelength and the propagational direction of prevailing waves, from radar sea echo signals. The wave measuring and analytical ability and accuracy of this system showed reasonably good. When winds were relatively weak, no information of the prevailing waves was obtained visually. But the system could analyze the propagational direction of swell eventhough its wavelength was not analyzed in some cases. When winds blew relatively strong and wind waves and swell were mixed, both were not distinguished visually. But the system could distinguish and analyze both of them separately with relatively good accuracy.
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WEI Xue, Kouji MURAI, Nobuyoshi KOUGUCHI, Yuichi MIYOSHI
Article type: Article
1997 Volume 96 Pages
53-61
Published: March 25, 1997
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Automatic Radar Plotting Aids (ARPA) is one of the instruments effective for aiding safe navigation in term of collision avoidance and its informations are well utilized and highly appreciated among watch officers. But a few knowledge is available how a target position was decided from a radar echo signal (ARPA position) and ARPA information is based on the past ARPA positions of targets. This article assumed 4 different target positions as an ARPA position and we performed a Monte-Carlo analysis to find the effect of 4 different target positions on the accuracy of ARPA information. The results are as follows. 1. The radar echo signal data of T. S. FUKAE MARU were collected in 36 aspect angles from 0°through 350°at 10°interval. 2. For four target positions assumed to the radar echo signal data, the statistics of each positions were obtained at 36 aspect angles using 63 scan data. 3. Monte-Carlo simulation was carried out and the results for different ARPA positions were compared with the accuracy requirement stipulated by IMO. 4. It is recommened that the nearest point to own ship in the center line bisecting the echo signal is to be chosen as an APRA position.
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Naoto SATO, Daiji ENNYU, Takaaki NISHI, Michiko YAMASHITA
Article type: Article
1997 Volume 96 Pages
63-70
Published: March 25, 1997
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Hyperbolic navigation methods for the 100kHz band are widely used for fixing the position of a ship. With the increased use of Loran-C navigation system, the positioning errors near seashore have become a problem for many fishing boats and small vessels. We measured the errors of the phase of Loran-C wave for normal incidence to coastline in Shibushi-Bay, Kagoshima. As the interference occurs between the incident and the reflected wave, the curve of the phase error becomes sinusoidal-like variation. It is shown that the experimental result is explained fairly well by numerical calculations. In this paper, the phase error is discussed with relation to the incident angle. It is found that at angle of 45°the reflection from the coastline appears to be very weak and the reflection strong at highly oblique incidence. As the usual ship-borne Loran-C receiver indicates time difference in units of 0.1μs, the region where the phase error becomes larger than ±0.1μs is considered to be significantly affected by the reflected wave from the coast. These distances from the coastline are as follows : about 2km for near normal incidence, 300m for 45°, and more than several km for 60°-75°.
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Chunming FAN, Akio YASUDA
Article type: Article
1997 Volume 96 Pages
71-77
Published: March 25, 1997
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A simple satellites monitoring system comprising 3 VSAT's is proposed to determine the three-dimensional position of JCSAT-1 communication satellite, locates at 152°on a geostationary orbit and is operated in Ku band. One VSAT is a master at Tokyo University of Mercantile Marine and the rest are slaves at Hokkaido and Kyushu Universities. The range to the satellite from the slave station is observed at the master station every 9.6ms from the arrival time of the range finding pulse of the 31-bit PN series of 64 kbps. It is transmitted from the master station and travels twice between master and slave stations via the satellite. We measure the ranges from three earth stations to the satellite by switching the reception frequency at the master station one by one and deduce the satellite position. The radius of short axis of the 95% error ellipsoid, which represented the distribution of positioning points, was 44m in the present experiment with the ranging accuracy of 2m from the master and 3.2m from slave stations. We also estimated the positioning accuracy with three earth stations at Wakkanai, Naha and Chichi Jima, using the same ranging accuracy. The estimation is also tried of the positioning accuracy on the earth in 3 geostationary satellites system with the satellites monitoring system described here. It shows that the accuracy of less than 20m is attainable in the Japanese Islands and their surrounding waters.
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Masao FURUSHO
Article type: Article
1997 Volume 96 Pages
79-86
Published: March 25, 1997
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The Marine traffic system consists of human being, vessels and environment. This study shows the physical characters of the visual environment which is the background of the visual perception of the targets at sea for safety and for a good lookout in preventing maritime traffic accidents. Author shows three points. The first is the illuminance at the place of fore inside of the navigation bridge. The second is the luminance at the view point (the sky) about 2 degrees over horizon. The third is the luminance at the view point (the sea surface) about 2 degrees under horizon. All measurements were carried out through the windshield glasses of the navigation bridge. The main results are as follows; 1. The illuminance at the place of fore inside of the navigation bridge is standardized by the sun's altitude. The relation between illuminance at the navigation bridge and the sun's altitude is under; (Sun's Altitude in degree)=(Illuminance of approximate value in lux : lx) : (more 10 degrees)=(1000〜10000 lx) (-3 degrees)=(10 lx) (10 degrees)=(1000 lx) (-6 degrees)=(1 lx) (0 degree)=(100 lx) (-9 degrees)=(0.01〜0.1 lx) 2. The luminance at the view point (the sky about 2 degrees over horizon) towards the sun's direction in case of fine weather and in summer is about 7, 000〜27, 000 cd/m^2. This luminance can be shown by the approximate formula Y=a/X+b (Y : luminance in cd/m^2, X : sun's altitude in degree, a : constant=one million, b : constant=-5, 000). 3. The luminance at the view point (the sea surface about 2 degrees under horizon) towards the sun's direction in case of less than 30 degrees of sun's altitude has sun glitter's influence which makes watch officers to prevent his visual perception.
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Takashi OKAZAKI, Kanemichi KASAHARA
Article type: Article
1997 Volume 96 Pages
87-94
Published: March 25, 1997
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A Camera image has the excellent resolution comparable with human's sight. In an integrated navigation-bridge system, various information are supplied to bridge console. So, it would be helpful to replace the look-out by navigator's eye with the camera image. From the image, many navigational informations can be extracted quantitatively by the number of pixels, instead of eye-measurement. A CCD-camera is a quite useful device for such purposes. The authors made experimental studies to estimate ship's heading, using the theory of "vanishing point and three dimensional vector". Picking out two parallel components from target ship's photograph, a vanishing point is decided as the apparent intersection of parallels. Then, three dimensional vector m is calculated by following formula. m=1/√<a^2+b^2+f^2>{abf} where, a, b is x, y coordinates of vanishing point and f is the focal distance. The result of experiment shows average estimation error of ship's heading remains less than 10°and this method is feasible, provided if some improvements are made.
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Hiroshi ISHIDA, Toru CHIKAMI
Article type: Article
1997 Volume 96 Pages
95-100
Published: March 25, 1997
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On the 17th of January, 1995, the Southern Hyogo Great Earthquake hitted the Hanshin District and damaged it seriously. At the earthquake, many ships were sailing, anchoring, fishing and so on, and many seamen and fishermen had experienced quite abnormal shocks and/or phenomena on board. The questionnaire research was made on abnormal experiences and phenomena they had on board and their actions at that time. It showed that many of them felt severe vertical shocks as their ships stroke aground and/or serious engine troubles like explosion. And in many ships, many actions were taken to recognize and manage their safety against such emergency, and those worked relatively well eventhough some ships did not get suitable actions. On the other hand, many ships faced serious difficulty getting contact with the competent authorities concerned and had earth quake information from TV. Fishery situations were also seriously changed.
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Kiyoshi HARA, Takahiro TANAKA
Article type: Article
1997 Volume 96 Pages
101-109
Published: March 25, 1997
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If there were no traffic regulations on the water, a ship could go freely. So, she would have wide choice of routes and course lines on the way to the destination. And if we could set the course line automatically, and it were efficient and safe one, not merely it would lighten burden on the navigator, but aid her to avoid running ashore. In this paper, the authors proposed the algorithm to set the tactical route and the strategic course line, and analyzed the navigator's Subjective risk Judgement for Land (SJ_L) which based on experiments using maneuvering simulator. Moreover, the authors studied what SJ_L level the navigator adopted on common navigation. Finally, some examples of the course line which based on the automatic setting procedure were indicated.
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Keisuke TSUJI, Hiroki IWASAKI, Yasumi KOTOH, Akinori YOKOBATAKE, Yoshi ...
Article type: Article
1997 Volume 96 Pages
111-118
Published: March 25, 1997
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We recognized that the maneuvering training with the shiphandling simulator was very useful for navigators and cadets. But it was scarcely showed the concrete example how useful training with the simulator. The authers made an attempt to analyze the effect of the simulator training, depended upon the comparison of cadets' maneuvering data about the training with small training ship (Oshima Maru : 226GT) between the experience group with simulator and no exprience group. As the result, the cadets of the experience group genrally maneuved the ship with more fearlessly decisive than of no exprience group. It was showed they had a right understanding powers of this ship with simulator training.
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Hiroaki KOBAYASHI, Kinzo INOUE, Yasuo ARAI, Teruhisa FUJII, Makoto END ...
Article type: Article
1997 Volume 96 Pages
119-125
Published: March 25, 1997
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When the training of shiphandling techniques is provided, we always have the problems that the objective of the training is ambiguous and that the effect of the training is not clear. To imporve the above problems, authors make a proposal of a new concept that the shiphandling techniques consist of elemental techniques and verify the concept by experiments. As a result, the reasonability of the proposed concept is confirmed. Consequently, the proposed concept is found to be contribution to the efficiency and the evaluation of effectiveness of the future training.
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Hiroaki KOBAYASHI, Kinzo INOUE, Yasuo ARAI, Teruhisa FUJII, Makoto END ...
Article type: Article
1997 Volume 96 Pages
127-137
Published: March 25, 1997
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Simulator training has been spread over the world. But it has just been introduced in Japanease maritime society. In foreign countries, several points to improve toward the simulator training are reported in some research projects. Authors propose educational and training curricula using ship handling simulator based on the concept of elemental shiphandling techniques. It makes possible to clarify the purpose of the educational and training curricula and improve the efficiency of it. In this paper, the authors propose such curricula for cadets, officers and captains & pilots. And the reasonability of the curricula for cadets is verified. Finally, the authors propose the required specification of the ship handling simulators to be used for the purposed curricula.
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Koichi KONDO, Tomoji TAKAMASA, Shogo HAYASHI
Article type: Article
1997 Volume 96 Pages
139-148
Published: March 25, 1997
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In recent years, major maritime nations such as Japan, Russia and Norway have been investigating the use of the NSR (Northern Sea Route) as a sea route between the Far East and Europe, linking the eastern and western parts of the Eurasian continent. In this study, as part of the examination of suitable merchant ships for the NSR, we make an economic comparison between diesel container ships taking the Suez Canal route and NSR nuclear-powered icebreaking container ship carrying the MRX (Marine Reactor X), which is currently being developed at the Japan Atomic Energy Research Institute. Compared to diesel container ships going via the Suez Canal, the transportation cost of NSR nuclear-powered container ship in the first year after commissioning is 40-110% higher and the RFR (Required Freight Rate) is 10-70% higher. If the nuclear reactor in nuclear-powered container ship, which is the reason for higher cost, were replaced by the cassette-type MRX, the reusability of the MRX would reduce this cost difference between nuclear-powered and diesel ships. The study also shows that in terms of the total cost including sales opportunity costs, NSR nuclear-powered container ship can compete sufficiently with diesel container ships on the Suez Canal route.
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Kiyoshi Hara, Shaoxiong Huang
Article type: Article
1997 Volume 96 Pages
149-155
Published: March 25, 1997
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There are big and rapid changes in the field of ship operation. The changes require to advance the skill level and to decrease the number of crew member on board. The safety level of ship operation is required to become much higher by means of such as ISM code and PSC in the international maritime society. Authors proposed a method to evaluate the performance of ship operation using Data Enveloped Analysis (DEA) in order to find out which ship must be focused on the improvement of the performance to increase the total performance of a fleet. The performance is defined by the ratio of the causalities and the time delay on ship's schedule to investments such as cost of seafarers and a ship. The results indicated that the performance of each ship was able to be relatively evaluated on the basis of the most efficient ship by DEA. The possible measures to improve the performance were also discussed.
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Susumu KUWASHIMA, Hideki HAGIWARA, Naoto IWASAKA
Article type: Article
1997 Volume 96 Pages
157-165
Published: March 25, 1997
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Ship needs a long time to sail across the ocean and often falls in with severe rough weather. And ship pitches and rolls violently on the way in rough sea. In the past and the present, winds, waves and ship's motion have been described by crew every 4 hours. Authours developed a voyage recorder which automatically measures and recoreds the data of encounter winds, waves and ship's motion. The results of such measured data are reported in the previous paper. In this paper, some characteristics of fluctuation of engine output and propeller revolution in rough sea which data are newly measured and recorded are reported. That are (1) ship's motion becomes violent in response to rough sea, (2) consumption of fuel oil are proportion to engine output, (3) engine output increases in order to prevent a reduction of propeller revolution, (4) propeller revolution decreases slightly in response to rough sea in spite of setting to be constant, (5) propeller revolution is commonly forced to decrease in order to reduce violent ship's motion, (6) ship's speed decreases in more than certain rough sea even if propeller revolution is kept to be constant.
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Kazuhiko KATO, Shigeo SHIGETA, Toshio KOBAYASHI, Yoshio MURAYAMA, Hiro ...
Article type: Article
1997 Volume 96 Pages
167-173
Published: March 25, 1997
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The purpose of this study is to investigate the mehtod of estimating navigators' work-load by the autonomic nervous activities which are given by the spectral analysis on the changes of heart beat interval (R-R interval). Experimental ships manoeuvring tasks in the simulator, which were on fairway with other vessels, were performed by four subjects that were 3 captains and a chief officer. We recorded a R-R interval during the tasks and analyzed the changes of the records every for 5 minutes by means of Coarse-graining spectral analysis (CGSA method). We accumulated power spectrum of three frequency bands; Lo=0〜0.15Hz, Hi=0.15〜0.8Hz, total=0Hz〜, Lo/Hi and Hi/Total were calculated to evaluate sympathetic (SNS) and parasympathetic (PNS) nervous activities. The SNS activities increased and the PNS activities decreased when there were vessels which were crossing or nearing. On the contrary, when those vessels didn't exist, the SNS activities decreased and the PNS activities increased. We calculated the average number of other vessels that crossed or closed to their vessel every for 5 minutes to evaluate the marine traffic environment. It was not recognized that the correlation between the average and heart rate. However, there was the positive correlation between the average and the SNS. These results suggest that the method of estimating by autonomic nervous activity by CGSA on heart beat interval changes is a useful to evaluate navigators' work-load.
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Keiko MIYAZAKI, Yoji MUROHARA, Michitoshi ISOZAKI, Shigeyoshi YOSHIMOT ...
Article type: Article
1997 Volume 96 Pages
175-184
Published: March 25, 1997
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A project of a high speed craft, Techno-Super-Liner had been held and a prototype ship "Hishou" was constructed. A part of final experiment of "Hishou" had been executed to investigate the way of safety navigation of a high speed craft encountering with an ordinary speed ship by Ship Research Institute in 1995. The experiment was done both at sea and on our simulator. We got some subjective evaluation results for safety navigation from participants who had evaluated Hishou's safety on the experiment. Based on their subjective evaluation results, we investigated the way of safety navigation for Hishou in congested sea area and reported it in our last paper of the Japan Institute of Navigation. In this paper we carried out more detailed investigation of the subjective evaluation results. The participant mariners were classified into 3 classes which were ordinary ship's captain, officer and Hishou classes. Their subjective evaluation results were compared among 3 classes. Then it was found that Hishou and the captain classes determined their recognition of the encountering situation severer than the officer's one. As the items which had been used on their judgement of collision danger were examined by Principal Components Analysis, we found differences between captain class and officer class. By comparison between the onboard experiments and the simulators', a simulator was conceded to be an effective tool getting mariner's characteristics. Finally we offered basic criteria of Hishou's safety navigation.
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Makoto ENDO, Koji YOKOI, Kiyoshi TACHI, Hiroaki KOBAYASHI, Muneya TAKE ...
Article type: Article
1997 Volume 96 Pages
185-193
Published: March 25, 1997
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In order to estimate the manoeuvrability of the new training ship Wakashio-maru IV, in which a bow thruster and a stern thruster were installed, some model tests were carried out. This paper mainly deals with experimental results of side thruster model tests and the hydrodynamic mathematical models of side thrusters which the authors proposed. The side thruster model tests consisted of the following 7 kinds of tests. (1) Propeller open tests on the side thruster impeller model. (2) Side thruster model tests with 0m/s towing velocity. (3) Side thruster model tests installed in the 1m model ship with 0m/s circulating water velocity. (4) Side thruster model tests installed in the 3m model ship of Wakashio-maru under longitudinal motions. (5) Pressure distribution measurements around the thruster nozzles on the thruster model installed in the 1m model ship under longitudinal motions. (6) Side thruster model tests installed in the 3m model ship of Wakashio-maru under oblique motions. (7) Pressure distribution measurements around the thruster nozzles on the thruster model installed in the 1m model ship under oblique motions. Results of the above side thruster model tests shows the accuracy and usefulness of the proposed hydrodynamic mathematical model of side thrusters.
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Akinori YUMURO, Hiroshi UCHINO
Article type: Article
1997 Volume 96 Pages
195-202
Published: March 25, 1997
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In order to clarify nonlinear effects on time optimal control for ship maneuvering motions, the authors make numerical simulation with respect to the optimal control input for course changing maneuver. Calculations of the optimal control are made for a tanker and a car-ferry ship. The simplified nonlinear equation developed by Nomoto, which describes directly ship's response to the rudder angle, is employed. This report deals with the effects of a hysterisis loop formed by the so-called r-δ curve and linearization of the nonlinear equation. From the results of numerical calculation, it is indicated that the nonlinearity has a considerable effect on the first execution time at which the rudder is deflected to the opposite side. However, significant difference in the terminal time is not found between the nonlinear system and the linearized system. As a result, it is pointed out that the optimal rudder behaviour through the bang-bang control is related to both turning quality and course-keeping quality of the ship.
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Masayoshi KUBO, Shunsuke TAKAOKA
Article type: Article
1997 Volume 96 Pages
203-211
Published: March 25, 1997
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Environmental conservation and energy saving have become very important in recent years. Positive preventative method should be also taken in the marine transport. Sail equipped vessel is one of the countermeasures answering the request. However, present sailing-rig has following fundamental faults : (1) Difficulty of maneuvability in harbor (2) The dangers of dragging anchor for wind effect at anchoring In order to remove these defects, we develop an universal sailing-rig that allows each sail to move independently. The results of the experiment on the effect of the sailing-rig on ship are summarized as follows : (a) The manevability becomes easy as same as normal vessel. (b) Anchoring is improved and becomes safe. (c) Sailing performance is improved for a light breeze. (d) The cost of maintenance is decreased because of soft sail.
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Kazuya OGAWA
Article type: Article
1997 Volume 96 Pages
213-221
Published: March 25, 1997
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A new coating system using a non-polluting and antifouling type of silicone paint was presented in the previous paper. The reasons why this proposed coating system has an effectiveness for the prevention of bio-foulings on FRP ship hulls are investigated from the viewpoint of the physical properties of the coated film. As a result of investigations which were done both by measuring a contact angle and a sliding angle of a drop of water on the silicone coated film, and by observing the repelling appearance of colored water sprayed on this film, it was found that the existence of a plasticizer, which is contained as an ingredient in the chlorinated rubber paint being used as an undercoat, has a positive effect on the preventing properties of the silicone coated film. And it can be considered that a sliding angle would be a more useful index to an evaluation of the prevention of bio-foulings than a contact angle.
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Osamu NAGATA, Tsuneo ITAGAKI, Masayuki TUCHIYA
Article type: Article
1997 Volume 96 Pages
223-228
Published: March 25, 1997
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The strength of aged inflatable life rafts has been investigated with pressure test for main air tubes. But, according to a few investigations of damaged drift inflatable life rafts after shipwreck, the most reasons of damage occurrence depend on shortage of adhesive strength between two air tubes. The strength of air tubes would be stronger with the static tension by air tube pressure test, compared with the tearing force at the adhesive parts. And, the adhesive parts of aged life raft may be broken by crumpling force of waves during drift. Therefore, several tests were conducted to know the forementioned effects for the four kinds of inflatable life raft aged 0 to 20 years. The main results are as follows; (1) Tearing tests of adhesive test pieces of main tubes are effective to know the strength shortage of aged inflatable life raft compared with pressure test for main air tubes. (2) The tearing strength will be decreased after adding repeated tensile stress corresponding to wave force during drift on the sea.
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Masayoshi KUBO, Yasuo MAEDA, Nobuyuki MOCHIZUKI, Shinji MIZUI, Yutaka ...
Article type: Article
1997 Volume 96 Pages
229-238
Published: March 25, 1997
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In order to improve harbor tranquility, breakwaters are often constructed. Above all, offshore detached breakwaters are set up when the wave direction varies with seasons or the water is deep. Consequently the harbor has multi-openings. In this paper, new calculation models are introduced. These models are applicable to harbors which have some offshore detached breakwaters. Some details about the new models are given in the 2nd chapter. In the 3rd chapter, the numerical results are compared with previous study. Then the models are applied to some harbors. The obtained results are summarized as follows; (1) Using this new models, wave patterns in harbors with multi-openings can be predicted. (2) Mathematically, the existance of offshore detached breakwaters is considered in the models. (3) Offshore detached breakwaters in front of habor entrance are not so effective for the control of harbor oscillation. (4) By constructing an opening at the inner and the end part of the harbor, wave patterns can be changed entirely.
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Masayoshi KUBO, Katsuhiko SAITO, Tsuyoshi OKI
Article type: Article
1997 Volume 96 Pages
239-249
Published: March 25, 1997
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In the previous papers, we proposed the prevention system of ship separation from quay wall. In this paper, we carry out a small scale model test which is similar to an actual mooring ship in order to clear some problems for practical application. The obtained results are summarized as follows : (1) Cut off water parts of the facility are set up by the double structures. The first part is effective for the early stage of pumping out of water and then the second part becomes effective. (2) After pumping out of the water from the system, the cut off water stress of the system is concentrated on the first part. (3) The mooring force should be decided in total balance of forces and moments of the system, that is, mooring forces are necessary for the early stage of pumping out of water. However, too much mooring forces induce separation of the ship's body from the bottom of the system.
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Masayoshi KUBO, Yoshifumi MUROMOTO, Katsuhiko SAITO, Toshiharu YOSHIDA
Article type: Article
1997 Volume 96 Pages
251-257
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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We have studied on the ship entering problem at fishery harbor under severe weather condition. In order to realize the easy entering into harbor, we propose "marine guide fence" which contains floaters. In this paper, we investigate the relation betweeen compression and deflection of the floater. The obtained results are summarized as follows : (1) If a relation between stress σ and strain ε of floater is obtained, it is easy to estimate the deflection and compression characteristics of real floater. (2) The characteristics of the cylinder with cylindrical hollowness can be approximately given by subtracting compression force of the inner cylinder from compression force of the outer cylinder. However, the above approximation contains about 20% error, so the estimated value must be attenuated by multiplying a correction coefficient. (3) The characteristics of the cylinder containing pipe is approximately given by the one of the cylinder of diameter a which is equal to the thickness of the above cylinder. However the above approximation contains about 20〜30% error, so the estimated value must be attenuated by multiplying a correction coefficient. (4) If we obtain the ratio of plane compression of the floater and the floater compression by the frame and ship's model, the characteristics of the real floater in the marine guide fence can be approximately estimated. (5) Carrying out two kinds of expriments of collision angle of 60 deg. and 90 deg., it is clear that the diffrence of the characteristics is negligible.
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Masayoshi KUBO, Masanori TSUGANE, Kenji SASA, Shigeki SAKAKIBARA
Article type: Article
1997 Volume 96 Pages
259-267
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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In some ports facing to open sea, moored ships sometimes move so hard that cargo handling or mooring becomes difficult, and the mooring lines or fenders have broken in serious case. Then we focus on the wave and wind conditions of inside and outside of a port facing to Sea of Japan where moored ships move hard in winter and find the existence of the "long period wave". One year wave data of inside and outside of other port facing to East China Sea are observed and the spectrum analysis of them is done, and we ensure the existence of long period wave exist and its energy increases inside of the port. Firstly, we simulate the phenomenon of moored 60, 000 DWT bulk ship motions using wave data included "long period wave". Secondly, we change mooring methods and simulate the ship motion at the same condition, and then compare the ship motions, mooring line tensions and fender reaction forces. As the result, we consider the effect of the better mooring methods in ports facing to open sea in case of stormy weather.
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Masayoshi KUBO, Kazusei YAMAMOTO, Kenji ASAKI
Article type: Article
1997 Volume 96 Pages
269-274
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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In the previous report, the authors discussed that the tension of mooring ropes was different before and behind a fair leader, and that the strength of mooring ropes decreased near a fair leader under a constant load. In this paper, the strength of mooring ropes is examined under the repeated load in order to estimate the fair leader effect. The obtained results are summarized as follows : (1) Breakage of fiber ropes occurs surely near a fair leader under the repeated load, even if a fair leader works smoothly. (2) The breakage occurs at the load less than the strength of the ropes under the repeated load. The load is 50% of the strength in this experiment. (3) The smaller the angle of mooring rope at a fair leader is, the fewer the repetition till the breakage becomes.
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Katsuhiko SAITO, Masayoshi KUBO
Article type: Article
1997 Volume 96 Pages
275-282
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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There are some countermeasures against shifting cargo. But the quantitative evaluation of cargo motions in the oscillating force and the effect of the countermeasures are not cleared. This paper deals with the characteristics of pull down of palletized cargo in the oscillating force, for example, earthquake or oscillation in transportation process. Some basic physical models using actual palletized corrugated container are carried out. A palletized container shows complex movements in six degree of freedom under one dimensional horizontal inertia force. A new shifting parameter of the palletized cargo is proposed to indicate the quantitative displacement of shifting. The influence of the frquency on the number of oscillations when the first container pulls down from a pallet is considered together with the effect of the palletized pattern and the countermeasures.
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Mitujirou KATUHARA, Michihiro KAMEYAMA, Osamu MIYATA, Yosio TAKASUGI, ...
Article type: Article
1997 Volume 96 Pages
283-293
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Simulation program of human escape on board is made to search for escape safety of passenger ship. Escape area is described by networking of node-path-space system. It is assumed that human walk on path rationally and that individuals choose the shortest route to assemble station. The parts of the route on deck except where he is, is defined as virtual distance. This is psychological parameter. Six demonstrations on board are carried out to verify simulation program. Number of testees is 126, 88 or 76. Walking speed, maximum flux of human flow and escape time are measured by video pictures. Branching points of human flow are observed. After demonstration testees answer a questionnaire on their mental state at decision of route. For practical use simulation is compared with demonstration and good agreements are obtained.
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Kazuo HITOMI, Kojirou YOSHIDA, Kenji YAMANE, Tuneo ITAGAKI
Article type: Article
1997 Volume 96 Pages
295-302
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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The passage of the marine evacuation system (MES) is provided with so that persons may descend safely from the embarkation station to the floating platform. The types of the passage have inclined slide and vertical chute. In addition, a vertical type has the spiral and zigzag. Three types manufactured in Japan were used and the research was done from 1993 to 1996. The first point of the research purpose is to obtain the relation between the descending speed and the acceleration tolerance value. The second point is to solve a problem which of the descent examination by the subject or dummy should be done. The third point is to discuss a method of the measurement and the evaluation. The research result is summarized as follows. 1) Even when subjects received such the impact acceleration which exceeds 20g in the descent examination, their body were not injured. This reason is to be provided for the cushion being composed of the floor made of the synthetic rubber and the sea water by the floating platform. 2) In the subject examination, the acceleration value varies by the method of applying the brake, the descending posture and the human body characteristic. In the dummy examination, because the descending speed and posture and structural materials are constant, the variations of acceleration value are few. And, this result is the average value to the subject's result. The clear conclusion whether either examination was proper was not obtained. However, the impact acceleration measurement system developed as a data logger of a portable type can easily do either examination. 3) The acceleration measured at all examinations complies to Einband's tolerance value and the Japanese standard of MES. This standard is becomes a standard to demand safety compared with Einband's tolerance value and an appropriate evaluation method.
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Masayoshi KUBO, Tae KOMUNE, Katsuhiko SAITO, Kenji SASA, Masanori TSUG ...
Article type: Article
1997 Volume 96 Pages
303-311
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Recently long period waves and sudden growing waves cause breakage of mooring ropes and over compression of fenders and damage moored ships. In this paper we study on determining the judgement of survival mooring conditions for a specific port by using the wave statistics in ports and harbors and weather data. The obtained results are summarized as follows : (1) By using the existing wave statistics, the useful characteristics for judgement of survival mooring conditions for the port is obtained. (2) The wave height is the most important for the judgement of survival conditions. So we define new parameters as a maximum wave height and a growth rate of wave height in order to clarify the relation between wave heights and atmospheric pressures. (3) Studying the correlations between above new parameters, the characteristics of wind and moving low pressures, we can obtain available informations for judgement of survival mooring conditions. (4) Since there exists the time difference between the neighboring harbors when the maximum wave heights happen, it is useful to exchange the wave height informations to judge the mooring conditions.
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Masayoshi KUBO, Masanori TSUGANE, Kenji SASA, Shigeki SAKAKIBARA
Article type: Article
1997 Volume 96 Pages
313-322
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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A lot of studies about mooring ship motions have done in recent decades, but they are focused on cargo handling criteria. At some ports in open sea, mooring ships move so hard and sometimes mooring lines or fenders are broken. So, when we think about mooring criteria, we have to consider a lot of parameters. In this paper, we study about these parameters and we pick up some cases of mooring accidents at the harbor face to Pacific Ocean. And we find out the results as follows : (1) We can't argue about the mooring criteria correctly if we focus only on ship motions. (2) We can clear up the relation between cargo handling criteria and the mooring criteria. (3) Mooring accidents tend to take place in winter season than other seasons in these cases. (4) In most of those accident cases, mooring ships should shift to offshore earlier stage. (5) The required time length when ships shift to offshore depends on the ship type, the cargo handling way, etc. (6) The difficulty of wave prediction makes so hard to make out mooring criteria. (7) We have to consider long period wave in case of considering the mooring criteria. (8) There are trade off relations between the safety of mooring ship and the berth efficiency. (9) It is necessary to grasp the effect of moored ship motions by wave and wind correctly, if we want to avoid mooring accidents.
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Masayoshi KUBO, Shinji MIZUI, Junzoh SETO, Kazuhiro INOUE, Hidetoshi T ...
Article type: Article
1997 Volume 96 Pages
323-331
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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In the previous paper, we tried to simulate the irregular wave trains by the small ship repeated turning. As the result, it was found that the irregular waves could be made easily. In this paper, we carry out an experimental study on the ship motions of entering fishing boat under these waves. The obtained results are summarized as follows : (1) The rolling angle is piled up by the ship's turning and the severe waves at ship entering into harbour. The angle of inclination increase in inverse proportion to the radius of turning circle. (2) The fishing boat which is entering harbour in quartering sea arises rolling and yawing motions at once. These coupling motions seem to have important connection with a ship capsizing phenomenon near harbour entrance. (3) It is found that the waves beneath the running fishing boat correspond with the accelerations of heaving and the inclinations of these waves correspond with the accelerations of surging.
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Article type: Appendix
1997 Volume 96 Pages
App3-
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1997 Volume 96 Pages
App4-
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1997 Volume 96 Pages
App5-
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1997 Volume 96 Pages
App6-
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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Article type: Cover
1997 Volume 96 Pages
Cover2-
Published: March 25, 1997
Released on J-STAGE: January 15, 2017
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