A vessel on the ocean which stops her ergine has the wind from abeam or a little aft, and she starts side drifting. We tried to make clear the relation between the quantity of side drifting and wind velocity, and furthermore attempted to separate the wind effect to a vessel from the wave or swell one by an experiment of a model ship. For this purpose we embarked on the Atsumi, the observation ship at TANGO POINT, about a month and made several experiments.

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It is obvious that the up-set of sailing boat arises when the heeling angle of them on account of wind force exceeds the angle of vanishing stability in its magnitude. In this paper, the author, relying on some assumption, studied about the righting moment of the boats, and the wind-pressure acting in transverse direction and trying to heel over the boat, and then computed the maximum angles of inclination in various wind and boat conditions. In the result, it was understood that the heeling angles increased remarkably, in the same speed of wind, when the boat was sailing at a low speed, or when the wind force changed suddenly, and that some characteristics of heeling angles lied.

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The calculating formulas of the transfer D_T and advance D_A were obtained as follows, in my previous report. [numerical formula] where V_0: initial speed in knot. t_0: putting time of helm angle in sec. The coefficients k, m and n are, in this paper, expressed by the functions of initial speed, helm angle, rudder area ratio & c. according to the results of systematic experiments by a model boat.

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It is well Known that the Persian Gulf in summer is undurable hot. Almost all the crews of oil tankers, engaging in Persian line operations, complain of the physical and mental fatigue caused by adverse climatic conditions. The auther investigated the climatic conditions at several spots in the crew quarter of an oil tanker on her Persian line. The results obtained were as follows; 1) The climatic conditions in the crew quarter on the Persian Gulf differ considerably from those on the other oceans. Generally speaking, the climate in the Persian Gulf is continental and very hot. 2) The effective heat stream into the crew quarter seemed to be caused by the solar radiation on the boat deck and also by the heat yielded in the engine room. As the measure for the insulation of the solar radiation, the permanent awning is desired. And it is also noticeable that the insulation of the engine casing is quite imperfect. But the accomplishment of the insulation will result in reduction of heat loss during the night, and accordingly refrigerating equipment is indispensable for the ship sailing to the Persian Gulf.

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The Sperry Gyrofin Stabilizer consists of two actively controlled underwater fins, projecting from opposite sides of the ship near its center. The fins, controlled continuously and automatically, co-operate in applying roll stabilizing moments to the ship. Stabilizing moments are ordered by the stabilization system to counteract disturbing moments applied to the ship by the wave action. For descriptive purposes, the stabilization system has two major divisions, the control system which orders the proper stabilizing moment, and the stabilizer fin machinery units which apply the ordered stabilizing moment to the ship. The stabilizer control deduces the disturbing moment being applied to the ship from measurements of the ship's response to those disturbances. Sensing instruments detect and measure several functions of the ship's roll motion and supply the basic data needed to compute roll stabilizing moments. A computer then orders each stabilizier fin machinery unit to apply a fin lift force to the ship which will produce a stabilizing moment equal and opposite to the disturbing moment. Although responding independently to ordered stabilizing moments, the stabilizer machinery units co-operate to apply fin angles which produce equal lift forces. Stabilizing moment applied is, therefore, in the form of a pure couple. The desirable equality of fin lift forces in the Sperry stabilizer is assured first by the equality of fin lift orders to each fin, and second by the "lift Control" feature. With lift Control, each fin servo control system compares the measured actual fin lift with the ordered lift and tilts the fin to maintain continuous equality between actual lift and ordered lift. Two equipments of the Sperry Gyrofin Stabilizer have been installed in passengers "Mariposa" and "Montery", displacements of approximately 20, 000 tons, speeds of about 20 knots, and it is reported that the sea trials were very successful.

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This engine remote controller is designed to control the fishing boat 1, 800* engine from the boat bridge and the engine room. Bridge control panel send the electric signal to the oil hydraulic power unit and engine control levers are moved by the hydraulic cylinder. Turning the knob of the panel, the engine speed is changed to the selected speed and held constant automatically. Starting, running, stopping, on and off the clutch and change of rotating direction can be controlled easily at the bridge, turning the switch or lever. We took particular care of interlocking during each of the above operation.

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The principal heeling errors are due to the induction by earth's field in soft iron rod e and k and to the vertical component of permanent magnetism in the ship R, where e is the athwartship component of soft iron passing through the compass and k the for and aft component. By the Poisson's equation, the heeling errors due to e and k vary as sin2i when the ship is heeled through an angle i, but that due to R varies as sini. By the schematic experiment, we confirmed that the above relation is hold. Usually the heeling error is represented to vary as i. So when i increases, the heeling errors are not accurately represented by the latter expression. We discussed about the errors by the latter expression, and find that if the heeling errors are precisely measured the perfect correction of the heeling error is possible.

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When two vessels have encountered on the sea, the subsequent relation of them are computed by vectorial quantity. The electric engineers have dealt the sinusoidal alternating voltage with vector, and the writer has applied the sinusoidal alternating voltage to compute the relation of two vessels and manufactured a electric computer for trial.

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A new type gyrocompass and some new auto pilots have been completed by Hokushin Electrie Works, Ltd., Tokyo. The gist of the special features of these new products are as stated below: 1. Hokushin-Plath air cooled gyrocompass type "C" Since 1955, Hokushin Electric Works, Ltd. manufactured about 150 sets of Hokushin Plath air cooled gyrocompass which were installed on various kinds of ships creating a very good reputation, the new product has been completed by rationalizing the design and construction of Hhe above gyrocompass and simplifying the handling method of the same. 2. Hokushin Auto-Pilot "Deluxe" This lated type is designed by changing new type Hokushin Two Unit Auto-Pilot to a "double" system, thereby ensuring enough security of the operation in addition to original excellent functions. 3. Hokushin-Nakamura Auto-Pilot Telemotor This is a new product which is made by combining in a stand Hokushin E.W. Auto-Pilot and the Nakamura's Telemotor of Tokyo Kikai, Ltd. 4. Auto-Pilot for Fishing Boat and Medium sized ship In addition to all the functions provided with and auto-pilot for fishing boat and medium ship, this new prcduct is provided with hand steering device which is operated by means of remote control steering and steering wheel.

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Nearshore waves aroused by the strong onshore wind in the case of typhoon or of gusty wind due to frontal passage of cyclone are marked developed in the surf zone of open coast or near the river entrance, which demands the warning to fishing vessels. We can distinguish two types of them, i.e. (1) Open coast onshorewind type, (2) Rivermouth crossed-wave type. Some examples are illustrated as those, (i) sea-disaster of Doya Maru (due to typhoon Maris), and (ii) sea disaster of Hyoei Maru (due to river mouth pyramidal wave.)

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We surved southern ocean currents during two monthes from January 1st, to March 10th, 1957. Recurvature drift as clockwise is found as the contact region of the east wind drift arround the Antarctica and the west wind drift streamed eastward from 1at. 45°S. to 1at. 60°S.

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