The 9th Internarnational Hydrographic Conference, at which 37 States Members were represented, was held in the Principalty of Monaco from 18 April to 3 May 1967. The most important subject at this conference was to draft a Convention by which the International Hydrographic Bureau would be able to become a formal intergovernmental organization. The draft convention was accepted by the conference on 2 May, and representatives of 17 countries signed the convention on the following day. As for the chart, 31 items were discussed at the Chart Committee, Among them, the proposal of Japan on "Representation of the quality of the bottom on charts" was adopted, which recommends that in areas where large vessels are to lie at anchor, and where the quality of the underlayer of the bottom is known to be different from that of the surface layer, the qualities of both layers be indicated on charts. The U.S.A proposal on "Omission of detail" was also adopted, by which it is recommended that where large-scale charts exist for port areas the smaller-scale charts omit all the topographic and hydrographic details which already figure on the large-scale charts, with the exception of navigational aids and landmarks useful to coastal navigation. The proposal of France to establish a commission to study the possibility of constitution of an international set of charts was adopted, and France, Netherlands, Grest Britain, Germany, U.S.A. and Japan have been designated as the members of this commission. The Nautical Document Committee handled 19 proposals. Various views and comments were expressed and discussed as to what information is to be included in the Sailing Directions. As the result, it is recommended that Sailing Directions include all available information the objects which permit the fixing of a ship's position by means of concerningradar, and it is also resolved that the International Hydrographic Bureau shall promote the study in this connection.

View full abstract

The narrow channels at the west of the entrance of Ise-Wan are very important for the vessels of about 1,000 GT and less to pass into or out of do-Wan. We researched into the actual condition of vessel's sailing at the above channels, and obtained the following results: 1. The sailing rule, prescribed by Rule 25 paragraph 1 of Law for preventing collisions at Sea, has not always been complied with at these channels from a legal standpoint. 2. The characteristic of Seigansima Light Beacon is not fit to keep the above rule. 3. The sailling rule that vessels passing in a meeting situation shall each keep to the star-board side of the channel, shall be approved at the narrow channels in the vicinity of Seigansima. 4. In regulating some rule for vssel's sailing in any auch channels, the rule mentioned at 3 shall be duly considered.

View full abstract

Lengths and positions of medium-sized ships on the Uraga Suido were measured by the "Camera Locator" in search for the dimension of the offective area of the ships. The result shows the dimension of the area to be about 250m in the course direction and about 100m in the direction perpendicular to the course. The investigation of the result together with those 1964 and 1965 gives the dimension of the effective area to be about 8L in the course direction and about 3.2L in the direction perpendicular to the course where L is the total length of ship.

View full abstract

Traffic quantity is surveyed on the Keihin Canal for the comparison with the traffic capacity. Peak effective traffic quantity is obtained to be considerably close to the fundamental capacity of the canal. The frequency distribution of the traffic quantity is examined statistically and it is well approximated with the Poisson distribution.

View full abstract

Das Verhalten der Pulsfrequenz des Schiffuhrers (Kapitan oder Lotse) bei der Abfahrt und Ankunft eines grossen Schiffs wurde mit Hilfe von einem "Heart Rate Telemeter" untersucht, um die Ursachen der psychishen Anstrengungen bei der Schiffuhrung zu diskutieren. In folgenden Arbeitsgelegenheiten wurde die Erhohung der Pulsfrequenz demonstriert: (1) Beim Vermehrten Austausch der fur die Schiffahrt notigen Informationen ; (2) bei gestorter Wahrnehmung dieser notwendigen Informationen ; (3) bei der Entscheidung der Kontrollaktionen, Z.B. Auswahl eines Ruderwinkels, Kontrollieren der Hauptmaschinen, U.S.W. Die beobachte Steigerung der Pulsfrequenz Konnte auf psychische Anstrengung als Angstbzw. Vorsichtsreaktionen des Schiffuhrers zuzuschreiben sein. Die erhohte Pulsfrequenz schien durch Schwierige Fahrtsituationen beursacht zu sein, die sich sowohl auf die grossen Bewegungsmomente des Schiffs als auch das unbestandige Information-Kontroll-System fur die Schiffahrt beziehen sollten.

View full abstract

Using Ergonomics method, the writer attempt to examine the dynamic aspect of mental Strain of Navigators during sea navigation watch. The results are as follows: 1. Physical and mental reaction of Navigators are caused by following stimuli, for example, searching L't Ho, . alternation course and existence of other vessels. 2. Pattern of P.G.R. shows extreme difference between open sea and narrow channel, skilled and unskilled, approaching pier and sea going. 3. C.T.G. rate, in good triffic condition, shows regular fluctuation, but in traffic convergency or risk of collision shows acceleration.

View full abstract

The recording type rotary beacon receiver has been confirmed its ability by the former report and as to the practical device it is described in this paper. The experiment using all transistorized compact receiver and recorder showed that the more reliable position line can be obtained by this rotary beacon system.

View full abstract

The magnetic field of a fishing boat two years after built was compared with that of the same boat observed just after constructed; and the results obtained are summarized as follows: 1) The horizontal component of permanent field decreased at most of the points on compass bridge deck and navigation bridge deck, while increased on long sunken f'cle deck and upper deck. 2) The same was true of the vertical magnetic field. 3) The horizontal component of induced field increased in most of the points observed. 4) The fluctuation in direction of horizontal field was slight in the permanent field and in the induced field of soft iron lying athwarthships, whereas large in the induced field of that lying fore-and-aft.

View full abstract

Radar is one of the most important equipment for the ship navigation. It is now used mainly for collision avoidance and location. Near future, however, will require Radar to be used for control and guidance of the ship, too, as in the present air traffic control. Then, the relation between the orientation of the ship and its RCS is necessary. Model measurement of the ship by the Ultrasonic Waves was made for the fundamental studies. Training ship "FUKAE MARU" was took up as the model of this experiment. The result is shown.

View full abstract

The meteorological reports by ships about the sea condition of North Pacific Ocean have some imperfections, that is, the lack of data at some regions and the unreliability on the visual measurements of the sea by the crew, etc. So, we tried to calculate the velocity of the geostrophic wind and the height of the wave at more tight spot on the above ocean, using Mollie Darbyshire & L. Draper's table, with data of the World Weather Maps (Dec, 1956〜Feb, 1959), and made a model wave chart of North Pacific Ocean in winter.

View full abstract

We tried to determine Victory ship's minimal-time route between Nozimazaki off and San Francisco off in winter. For this purpose, we made a wave model chart of North Pacific Ocean in winter as the stationary wave field, and the loss of ship speed in waves was calculated by James' empirical equations relating Victory-type ship's speed to wave height and direction. Determination of the route was carried out by manually on the charts, and also by the aid of an electronic computer to solve the differential equations derived by use of the Calculus of Variations.

View full abstract

There are three methods to solve the optimum routing problems ; graphical method, the method using kinematic equationa which consist of differential equations and minimum path method in the networks. However, if some nonlinear functions are used in the optimum routing problems, the author indicated minimum path method was the best way. In general, it will take enormous time if the method is used. According to his algorithm, it could obtain the solution of optimum routing problem within several minutes using high-speed computer.

View full abstract

Chebyshev interpolation is applied to Nautical Almanac Data. The merits of this method are : (1) The same program can be used for all stars, the sun, the planets and the moon to be sighted at sea. (2) Calculation time is shorter than other methods. The author programmed formulas deciding coefficients and formulas calculating R.A., dec. and S.D.. HITAC 5020E (FORTRAN IV) requires 0.010sec to calculate above data of every celestial body. The errors are small enough for astronomical navigation at sea.

View full abstract

The error of ship's position is unable to measure actually in the ocean. Therefore, putting our view on the relative error, which is the difference between celestial observation and Loran fix, we made research on its correlation with the probability density of Loran chain by statistical method. Analyses on the measuring conditions are also made.

View full abstract

A remarkable progress has been observed in the representation of nautical charts issued by the Hydrographic Office of Japan as well as by several foreign hydrographic offices. The author reviews the progress focussing on the following points 1. Present status of chart publication by various foreign hydrographic offices. 2. Latest foreign charts and their representation. 3. Recent chart representation of the Japanese charts. 4. Recent problems in chart construction. 5. An ideal status of chart representation which is readily realizable at present.

View full abstract

The author showed that "What is the Navigation and the meaning of navigation?" and one could observe the logical structure in the navigation. Moreover, he suggested the future of navigation.

View full abstract

For the public broadcasting of APT pictures from Japan Meteorological Agency, I attempted to catch the cloud patterns in the Far East under the typical pressure distributions. The analysis was carried out in synoptic scale using the APT pictures of meteorological satellite ; ESSA 2, surface maps and 700mb isobaric maps from May 1 1966 to Sept. 30 1967.

View full abstract

This is a study for the ship's motion in sea by the use of power spectra which were estimated statistically from the records of ship's motions in sea. In this paper, the authors described on the ship's response characteristics for waves in random sea, based on the theory of irregular oscillation as the stationary stochastic process. and on the experiments which were performed in full scale ship. For the results of the analysis of the data, obtained in the experiment, the three dimensional representation for the power spectra of ship's motions is devised and shown in Fig.5-a, b, c, for an example. On these representations, the authors discussed on the relative properties of the ship's motions in random sea.

View full abstract

Upon the premise that Regulation For Preventing Collision At Sea is the only and important basic law to prevent the ships from colliding at sea, I researched here the relation of the steering and sailing rules to the route, and especially, the significance of the latter in the former, from the raison detre of the ordinary practice of seaman and its effect in Rule 29. As the practical examples, I illustrated the cases of the 4th. and 5th. routes in Kobe Port.

View full abstract

In order to prevent collision of vessels, it is important that the judgment of one vessel choosing a sailing rule for her to comply with, shall be in accord with the judgmnt of other at the lawful side. So, some principles, concerned to choose or decide on the sailing rule, are considered as follows : 1 It is not appropriate to decide on above rule to comply with by reason of whether the above mentioned point lies to which area of the under mentioned limits. 2 When two vessels are in the areas of different situation under the same rule of sailing one another and approach to the limit and its vicinity of these areas, they shall keep clear of one another. 3 When two vessels are in the sea area under the different law for sailing one another and approach to the limit and it's vicinity of these areas, one under the general law for sailing shall keep clear of other under the special law for sailng.

View full abstract

We had given careful concideration to the interpretation of Collision Regulations Rule 16 (c) and the meaning of Radar plotting as provided for the Recomendations on the use of Radar, and then had applied the regulations to the typical cases of the Shipping Inquiries on the Court of Japan during past about 10 years between Radar equipped vessels. By this research on the collisions, we obtained the results as follows : (1) Distance into collision from first contact Miles ships 8' over…4 (13%) 2' over…15 2' under…13 (40.6%) (2) Time into collision from first contact 20 minutes before…10 ships 20 minutes after…22 ships (63%) (3) Speed in Fog (Fitted w/Radar) Initial speed…17 ships (65%) Moderate speed…9 ships (4) Fog signals Mostly not avaiable (5) Range Unknown (6) Recomendations on the use of Radar Not observed strictly at all As a result of the investigation, we have concluded that the proper Radar plotting by The Recomendations is the most effective procedure at present for Radar Navigation in fog, and if any vessels would practised the plotting, we should have to make reduce our casualties deal with shipborne Radar.

View full abstract

When determing a ship's position by the running fix, past explanations have been vague and far from reality, because the nautical distance and its error must bc treated as the functions of a ship's speed and sailing time, and also the error of transferred position line is the function of the time. The author studied this problem from the view-point of the theory of probability. When determing a ship's position by a bearing and a transferred position line, the best time for the second observation is when the probability density of the determined ship's position is at maximum value. To get the values he solved the conditional equation (1') and indicated the results in table 1. The sailing times to meet those terms are shown in table 2. Here the error of transferred position line was treated as 0'.75√t (t: sailing hours) based on the experiment [1] But, when the weather is stormy and the effects of ocean and tidal currents are strong, to transfer the first position line is difficult, and on the other hand, when the sea is calm and the current is feeble, the estimated magnitude is small, and then the error of estimation is naturally considered to be a small amount. From this point of view, he assumed the coefficient to 1'.05 for unfavorable conditions and 0'.45 for the favorable conditions, and calculated the optimum angles, the results are shown in table 3 and they differ little from the values in table 1. However according to the idea advocated by some people that the error of estimation is in proportion to the sailing time, the error is considered to be 0'.53t (s.d), and the calculated optimum angles based on this way of thinking are indicated in table 3. The results differ somewhat from the aforesaid results. Making the second observation at the best time, i.e. when the probability density of the determined ship's position is at maximum value, has a drawback that the chance occurs after the ship is abeam the object. And so, secondly, he studied the determination of a ship's position by use of two transferred position lines and a bearing when a ship is abeam the object. The results gotten by the equation (2) are indicated in table 4. As shown in the table, it is interesting that the best angle of observation is situated between 45° and 47° without regard to V, d, a and α. Against them, if he treats the error of estimation as 0'.53t (s.d), the conditional equation indicated by (3) is formed and the results are shown in table 5.

View full abstract

Side-drifting of a ship is caused by the force of the wind on the upper structure of the ship, drift currents increasing with the wind, rolling caused by the wind waves and swells, and ocean and tidal currents. To investigate the effect of the wind on side-drifting, it was necessary to carry out an experiment in which it was possible to removing the effects by the other causes. The authors planned to measure the lee way when the ship's course was 45°and 135°in relation to the direction of the true wind. The method 1. This experiment was carried out on the Oshoro-maru, a fishery training ship of Hokkaido University, when her speed was 3.5, 6, 9, 12kt, in the Bering Sea. 2. The corner reflector which was connected to the salmon-gill net was selected as the datum point of the experiment. In this case, the reflector was allowed to drift along with the ship influenced by currents and waves, but not by the wind. 3. As shown in Fig.1 the observers on the ship measured the distance and the bearing of the reflector by radar at observation points 1 & 2, and calculated the course and the lee way. The result 1. The relation between the true (absolute) wind velocity and the lee way is shown in Fig.2, and the relation between the proportional coefficient (K) in Fig.2 and the ship's speed is shown in Fig.3. 2. The relation between the apparent (relative) wind and the lee way are shown in Fig.4, and the relation between the proportional coefficient in those figures and the ship's speed is shown in Fig.5.

View full abstract

When Typhoon No.6420 passed in and around Osaka-Wan in Sept.1964, we had a hard experience, which almost vessels riding at anchor found it was no longer possible to steam up head to wind and the anchors started to drag. Therefore, in order to investigate on the anchoring in the stormy weather, we carried out the full-scale tests on JIS-stockless anchor presently being utilized by the Japanese merchant ship, that's to say, we researched as a first step of this study the connections between the nature of the sea bottom and the attitude of the anchor when letting go anchor, and these tests were made in the mud bottom of Osaka-Wan, in the sand bottom of Harima-Nada. From the results of these tests we may truthfully say that the anchor started to peneterate in the sand bottom, but that the anchor fluke were mostly opening upward and were not trend of trip in the soft mud bottom.

View full abstract