In this paper, the auther mentions the results of the experiment, by which he vestigated the resistance force of the caulking at the seams of outer strakes of wooden ship, and of the theoretical consideration of the effect, which the resistance force of the caulking produces on the longitudinal strength of wooden ship.

View full abstract

This paper is extension of my last paper “On the vibration of the plane structure”to the cases of plane plate structure which has at least a pair of opposite sids suported freely.

View full abstract

In this article, I solved the vibration of rectangular plate with any distributed weightI had the deflection of plate and the frequency equation in the following form;
w₀(x, y)=m₀/ρ∑^∞_m=1∑^∞_n=1λ²/λ²mn-λ²amnφmn(x, y)
and
|_1•1Δ_1•1Λ_1•1-1, _1•1Δ_1•2Λ_1•2, ……_1•1Δ_m•nΛ_m•n… _1•2Δ_1•1Λ_1•1, _1•2Δ_1•2Λ_1•2-1, …_1•2Δ_m•nΛ_m•n… • • … •_m•nΔ_1•1Λ_1•1, _m•nΔ_1•2Λ_1•2, …_m•nΔ_m•nΛ_m•n… • •…•|=0
Especially, when the weight was a concentrated one at (x, y), they were,
w₀(x, y)=m₀/ρw₀(x₁, y₁)∑^∞_m=1∑^∞_n=1λ²/λ_mn²-λ²φ_mn(x₁, y₁)φ_mn(x, y)
and 1=∑^∞_m=1∑^∞_n=1Λ_mnφ_mn²(x₁, y₁)
For the neumerical examples, I calculated the frequencies and the deflections of speciallyweightened plates with their four edges supported.

View full abstract

The author investigated whale catcher boats built in Japan in recent years, andobtained a system of initial design.
At the same time, the author mentioned the problem on lines, arrangement, construction and outfits of ocean-going whale catcher boats.
In conclusion, the author offered his opinion for future design of ocean-going whalecatcher boats.
The author wants to express his deep appreciation to see the further theoretical andexperimental researches to be made by the experts and the specialists on various uncertain points in this paper.

View full abstract

“No. 6 Nichibei-Maru”was badly damaged on her hull, sternframe and rudder etc., by grounding on the rock off Kannonsaki on March 16th, 1947. Among above damages
her sternframe was broken under bossing.
Special device was adopted for repairing the sternframe.
The repairing job was satisfactorily completed and she was put in as good a conditionas previous to the casualty.

View full abstract

The vessel entered to No. 1 dock on the 18th March for repair the bottom shellplates which had been damaged by grounding at Nojimazaki.
At the first schedule, this was temporary job, but later changed to permanent repairand undocked on the 15th August.
Meanwhile many troubles occurred by the reason of food shortage, material problem, all mechanical apparatus, D. C. machine and welding rod etc.
By the way, we have got material and welders who passed qualification test undersurvey of A. B. surveyor, Mr. Swan.
We preceded job under survey of Mr. Swan, and job was done by all welding anddamaged area was 6, 500 sq. ft. approximately, therefore this job is the first and biggestwork in Japan post-war.
I believe, we made a new record about tank water test because time is very shortand very few leakage.
The work was approved by A. B. surveyor Mr. Swan after completion of job.

View full abstract

It is said that electrification of the auxiliaries on small cargo ship is more usefulthan that of steam drive.
The O.S.K steamer “Ondo Maru”(680 gross tons) had installed a main diesel engine=of 600 B.H.P., steam driven auxiliary engines and an oil burning boiler. The fuel consumption was too much and so the next ship of same type“Mihara Maru”had installedthe electric driven auxiliaries of d.c. system, and got good result.
These valuable experiences tell us that the electrification is more useful than steam drive,
The electrification of the auxiliaries had almost adapted the d.c. system, by the reasonthat the characteristics for winch and windlass are more suitable than a. c. system. Therefore, the a.c. system for auxiliaries of cargo ship has been disregarded.
However, it is considered that the a.c. system for the auxiliaries of small cargo shipis worth studing.
Now, our company decided to build two small cargo ships of “F”type (about 510gross tons) and I am planning the electrification of the a. c. 230 volts, 60 cycles, 3 phase, for the auxiliaries.
Here we call, temporarily, the ship less than 500 gross tons, as the “small cargoship”. The ship of “F”type is installed a main Diesel engine of 550 B.H.P. and followingauxiliares, The generater for the source of these auxiliaries are two sets of 55 k.v.a. which are drived by a Diesel engine respectively.
(a) Winches 4 sets of 15 k.w.
(b) Windlass 1 _??_
(c) Capstan 1 _??_ 2 k.w.
(d) Pumps 6 _??_ of 0.75 to 5 k.w. There are other electric installations as follows:
(a) Room heaters.
(b) Ordinary illuminating lamps and navigating lamps etc.
(c) Wireless telegraphy.
(d) Radio direction finder.
(e) Echo sounding equipment.
The electrification of winch, windlass and capstan by the induction motors of polechange wound rotor type, shall have many points of consideration.
In this paper, it is concluded that the electrification of the auxiliaries on small cargo ship by a.c. system is rather suitable for quick building of ship, and cheapness ofequipments and easy maintenance of auxiliaries.

View full abstract

The hot-bulb engines have the particular progression history for marine use in thiscountry, and since the beginning of development of the powered fishing boats, they havebeen propagated as the central forces, and also applied to many small cargo boatsnowadays. On the history of their progressions, we can find that they reached to thepresent constructions and dimensions mainly due to the practical experiences rather than, not by calculations based on theory.
Therefore, we understand that all theories are included in the main dimensions of theproducts of the superior makers as experimental data.
The Author collected many design data of the hot-bulb engines produced by the superiormakers in this country, and adjusting and studying their main dimensions, he detectedthere are comparatively simple relation between them.
For examples; if D=dia. of cylinder and L=stroke of piston, stroke bore ratio L/D=1.11, length of cylinder L₁=2.32L, dia of throat of cylinder cover d=0.48D-12, length of piston L_p=1.65L, dia. of piston pin d_p=0.305D, dia. of crank shaft d_j=0.400D, length of connecting rod L₁=2.07L, etc.
These facts show that the products of each maker happen to have some standarddimensions by experiences during many years, and prove that the development of engineshas reached almost to the crest. Therefore, we may recognize that there are enoughreasons to standardize them.
The formulae obtained by these studies may be applied not only to the designs of hot-bulb engines, but also to the repairs or reconstructions works of many used engines toapproach to the level of superior ones.

View full abstract