This is to report the gist of the VIIIth International Hydrographic Conference held at Monaco in May, 1962, especially about the discussions on certain Japanese proposals at the Charts Committee and the Nautical Documents Committee as well as about the progress at the plenary sessions, introducing for the first place an article on the echo of the Conference appeared on a French news paper.

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Japan leads the world in suffering earthquakes accompanied by Tunami. Often men, beasts, houses and ships are seriously damaged by Tunami. Tragic history caused these phenomena have occured repeatedly since ancient times. Of all the damage mentioned above, seamen are most concerned with that done to ships, and I have compiled the following list hoping that it will be of some value in lessening the damage.

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Attention should be paid upon the fact that over 90 percent of Japanese vessels were blamed for the contamination of drinking water by bacillus and alkali derived from cement. The contamination occurs during the procedures of taking, stowing and supplying, due to inadequate location of hydrant on the pier, conveyance by wooden built water barges, filling by unclean hose and pipe, and careless use of water just after cement-coating without sufficient washing. As for the method of purifying water, the use of filter layer and chlorination are rather popular, and disinfection by ultraviolet ray is tried in some vessels. Tests were made on the application of special paint for fresh water tank instead of cement. The improvement for supplying clean water should be made by the collaboration of shipbuilders, sanitary engineers and shipping firms.

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The purpose of this paper is to bring to notice the results of some investigations relating to yaw of ship moored to a bouy in heavy weather. Wind tunnel experiments have been made at the trim by the bow and stern as well as zero trim without the changes in displacement for light condition, at each of four different wind velocities and of three different scopes of mooring chain. The results are summarized as follows: (1) Yaw amplitude tends to increase with the scope of chain, and also with the inclination of hull with trim by the stern. (2) The maximum value of the tension on mooring chain is lower for the case when the hull is inclined with trim by the bow than the case when by the stern. (3) It is emphasized here that the above maximum tension does not always increase with the scope of chain. Roughly speaking there seems to be a critical value of scope at which the maximum tension has a minimum value.

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The paper describes on the sidewise forces generated by propeller action. The results of model experiments on 2 right-hand single-screw ships, not underway, are as follows: -(1) When the propeller revolves going ahead and the rudder is amidship, ship tends to fall off to port, as usually. The ratio of sidewise forces, at that case, to forward thrust generated by propeller are 2〜3%. (2) When the propeller revolves backing, the sidewise forces are reversed, that is, her stern moves to port. The ratio of that forces, at that case, to stern thrust are 15% or so, independing to rudder angle.

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When two vessels are crossing, involved risk of collision could have been considered as a rate of temporal change of successive bearings, which can be expressed by the following formula ; [numerical formula] l/ υ_<a, >, which is herein after called "allowance modulus" l: the distance between centers of each vessels, when collided with. υ_<a1> υ_b: velocity of these vessels ω: angle between courses of vessels ρ_t is "relative velocity modulus" and it is ρ_t=√<1-2(K+Δ_t)cosω+(K+Δ_t)^2> K is "speed modulus" and eguals υ_b/υ_a we shall proceed analytical studies here after by the aid of those modulus above mentioned.

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Standard container size of Japan at present is decided by following data. 1) Weight By new cargo ship list built in recent 5 years, ordinary derrick capacity is 5 tons at 66%. Wharf crane capacity is 3 tons, but increasing to 5 tons. 2) Volume Volume limitted weight is decided by container tare weight and stowed cargo density. i) Breadth By Japanese National Railway waggon data minimum breadth is 7'-2". Ordinary autotruck, minimum breadth is 6'-8". ii) Height By Japanese Road Act maximum height over ground is 11'-5". Max. cargo height is 8' over load level. J.N.R. waggon cargo height is also 8ft. But in cargo ship tween deck height is 6'-7" at 26%. According above data and economical material, standard section of container is 6ft.×6ft. at present Japan.

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In the previous report I suggested that as for log cargo, there was nothing to think about the danger caused by the subject matter and presented an experimental result on the two species of lumber, namely, Douglas Fir and Cotton Wood. The present report concerns the absorption and natural seasoning tests carried on the import lumber of Cedar and Hemlock.

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The author investigates in this paper into the ships yawing, employing the records of an actual ship steered by some quatermasters, from navigators' point of view, especially about the relation between the magnitude of amplitude and the disturbing forces such as gusts, winds, and waves, and another several point of ships yawing. And the following results are obtaind: (1) The relation between the wind forces and the occurrence rate of yaw-angle increased above 3.5 degrees during the navigation varied complicatedly, but the more waves become higher the more rate increased nearly proportional. (2) The relation between the ships yawing oscillations in an hour and the frequency of occurrence of yaw-angle increased above 3.5 degrees varied higher inverse proportional with some variation. (3) When the yaw-angle increased above 3.5 degrees the yawing get some consecutiveness. (4) The ships yawing that yaw-angle increased above 8〜9 degrees immediately decaying to her apointed course, but the another smaller ones occupy much oscillations on account of decaying and sometimes, those diverge from the course.

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Some formulas for converting distance on a rhumb line track into distance of latitude and longitude are approximate equations, and their errors are negligible in practical use. But in special cases, their assumptions may lead to unthinkable results. For example, in low latitude departure in Marcator's Sailing becomes greater than difference of longitude, and true middle latitude on terrestrial ellipsoid is not between two latitudes passing on two points. To research these subjects, it is necessary to take the correct equation of meridian length and departure in navigational formulas. The objects of this paper are to point out the errors of each formula in navigational Dead Reckoning computation and to discover the real relation between True Mid Lat Sailing, and also point out the errors of Marcator's Sailing in which the geographical miles are used and Parallel Sailing assumed by spherical earth.

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There are condiserable troubles for separating and correcting the coefficient B of magnetic compass deviation. The following chart and table are designed for this purpose of correcting the value to be adjusted by Flinders bar. If the B_1 is corrected at a position of Tokyo bay and then B_2 is obtained at a given position, the value shown in the chart multipled by B_2 will be the value to be corrected by Flinders bar at that postion. If the values of intensity of geo-magnetic field at the first and second position will be given, the table will be available in the same purpose.

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This equipment is capable enough to measure any known depth with sufficient accuracy. It has two recorders-one in scale ranges of 0-2, 000 metres and 0-2, 200 metres, and the other of 0-200 metres. The repetition interval of the sound impulses is 2, 000 metres or 2, 200 metres. The range of the second recorder can be picked out of the range of the first recorder under 100 metres step-phasing. Scale marks are fed independently of driving mechanism, and thus the synchronization between the synchro-oscillater and the drive-moter is continually shown on the recording paper. The time marks of 5 minute interval are also driven electronically with the synchro-oscillater. This equipment showed good performances on the field tests.

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Owing to the complicated construction method and process of the fishing-vessel through Block-system, it is far from easy for us to elucidate the ship-magnetism of it. After having consulted, however, the materials got from the research-ships attatched to the Faculty of Fisheries, Kagoshima University, the "Kagoshima-maru", and the "keitenmaru" the author managed to clarify the following items. (1) As to the yearly fluctuation of the subparmanent magnetism of the vessel-body, it may be said that it decreases with the lapse of time, reaching its extenction during the term covering 1〜3 years, though some differences might be taken into account in accordance with the variations in the vessel-kind, building-process and the outfitting conditions. (2) Generally, the fitted magnetic-compass is to be more magnetized while it is under out-fitting than while it lies, before launching, on the ship building barth. (3) The fixed term of the parmanent magnetism of the vessel-body, is to be ascertained most appropriately by the yearly comparition of the co-efficients of deviation B with C, both of which being observed at thg magnetic equator.

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The development of the beacon systems for navigation radars is hampered by the radar interference due to the side-lobe response of the antenna. Here is proposed the "In-band Double Frequency Beacon System", in which two reply frequencies are transmitted simultaneously or altenately. One frequency is slightly higher and the other is slightly lower than each of two extreme frequencies between which ship radars usually operate. This system enables ship radars to display the beacon reply and the radar echo separately by the on-off operation of the AFC.

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