-
Article type: Cover
Pages
Cover1-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover2-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Toshio YOSHIDA, Wasuke MATSUNAGA, Kiyoshi TERAI, Shuzo SUSEI
Article type: Article
Pages
1-6
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
It was only recently that the A.B. specification was established for ship structure steel plates up to 50 mm thick plate and there are many problems yet to be solved in connection with the use of such extra wide size plates in the actual constructions of mammoth vessels, such as the 65,000 or 100,000 DWT tankers which will be built in near future. However, at the time when only the plates thinner than 38 mm (1^1/2") in A.B. rule had been specified, there occurred a case, in which 47 mm thick steel plates were applied for almost all the upper deck constructions in shipbuilding as mentioned below. In the previous papers, authors reported their decision for the practical use of 47 mm thick steel plates in the upper deck construction of 45,000 DWT ore and oil carriers, basing on the investigations made from the view points of both the performances and the procedures of their welded joints. After such decision, three actual ships have been built, in which investigations were made to confirm their previous conclusions on the following items : (1) The mechanical and impact tests of the ship steels to ensure their performance in the case of normalized plate of extra wide size. (2) The non-destructive inspection of the welded joints by radiographic technique to ensure the result of preventing restraint crack by the welding procedure based upon Lehigh restraint test. (3) The measurement of the deflection of the welded joints. In this paper, authors have obtained the results of these investigations, which are summarized as follows : 1. It is generally possible that the commercial 47 mm thick ship steel plates in the condition of fully killed and normalized have sufficient notch toughnesses as expected. However, care should be taken in their heat treatments, sush as normalizing to prevent lack of tougbness and in the actual ships 8% of the plates show such lower specific absorbed energies of V-Charpy impact tests at 0℃ as from 3.0 to 6.0 kg-m/cm^2. On account of this steel arrangement in actual ships should be so arranged, following the results of material tests in steel manufacturer, that higher ductile plates would be occupied the part of ship where high stress conditions would occur. 2. No problem, such as cracking, has been caused in the actual welded joints by the proper procedures decided following the preliminary test results. 3. In order to minimize the angular distortion of the welded joints it is better to use symmetrical double Vee groove edge preparations and apply proper prespringings by restraint jigs.
View full abstract
-
Isao KAMATA, Yoshihiro OTSUKA
Article type: Article
Pages
7-9
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
It is often experienced by shipbuilding engineers that inner insulating materials burn up by welding of outfits onto the deck, wall or ceiling of refrigerating cargo chambers, etc. In the paper, from Rosenthal's solution of the differential equation for heat distribution during welding, a theoretical formula is derived which will prevent fire in the above mentioned workings. Experiments inform that some differences exist between the theory and practice, which is, principally, due to the unsatisfactory boundary condition used in the theory.
View full abstract
-
Makoto KATAYAMA
Article type: Article
Pages
10-13
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In shipyards facing toward narrow river or sea, drag weights are used to stop a launched ship. Recently, newly built ships have greater dimensions, which circumstance requires heavier drag weights and obliges to estimate frictional coefficient more precisely. We re-measured frictional coefficient of concrete blocks and chains used in our shipyard at present. Moreover, experiments were made on concrete blocks placed on wooden sleigh, concrete blocks painted with Semtex, concrete blocks on building way covered with river sand, etc. We found that frictional coefficient of concrete blocks on building way covered with river sand is approximately 0.48 and is twice as high as without sand. This results has been applied to launchings of newly built ships and weight of drags could be decreased to about 63%.
View full abstract
-
Ryohei YAMADA, Shoshi HIGASHIYAMA
Article type: Article
Pages
14-19
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In compliance with recent trend of building vessels of a large capacity, the evaporation capacity of marine boiler installed thereon has been now rapidly increasing as well as steam temperature and pressure. As the matter of course, the single stage feed water pump employed to such boiler is required to have large capacity up to approx. 130 m^3/h and high discharge pressure up to approx. 75 kg/cm^2 in order to meet with high performance of boiler. Since the requirement has been mostly filled up with foreign engineering up to recent time, it is eagerly demanded by all the shipbuilders in this country to develop their domestic engineering. Mitsubishi Kobe Shipyard & Engine Works has recently succeeded in accomplishing a remarkable research on developing an advanced design of feed water pump under subsidization of the Transportation Ministry. We are now introducing the outline of our research.
View full abstract
-
Isamu NISHIJIMA, Ukio TOMITA, Masatoshi OBI
Article type: Article
Pages
20-25
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
This report explains the analysis of suction performance of centrifugal pump by introducing the method of Net Positive Suction Head, (called NPSH) generally used in U.S.A.. We made a scheme for suction performance by expressing the following two kinds of NPSH on the pump characteristic curve; namely NPSH available at suction piping apparatus and NPSH required to operate safely without cavitation. We, herewith, are going to report a result of analising the suction performance of cargo oil pump in a tanker by utilizing these schemes. Further, the bore of relief valve can be reasonably determined by NPSH, which is arranged to prevent a rise of temperature in casing at the shut-off condition. However, this problem will be omitted in this report. Firstly we show how to make these schemes. In these schemes, the following factors are shown on one plane; delivery head, suction piping loss, the height of pump installation, required NPSH, vapore pressure of water, delivery resistance. By these schemes, it becomes clear at what point the cavitation begins to occur when the oil level in oil tank decreases. Secondly we illustrate how the characteristics of cargo oil pump change in the following operation; 1. Operating under cavitation. 2. Throttling delivery valve to avoid cavitation. 3. Reducing revolution to avoid cavitation. One example of calculation in an actual oil tanker is described.
View full abstract
-
Issei SUETSUGU
Article type: Article
Pages
26-34
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In the treatise previously presented by the Writer entitled "On the Classification of the Vibration at the Stern of Single Screw Vessels by its Cause of Occurrence, and the Principle of its Prevension," at the Spring Meeting of the Society of Naval Architects of Japan, 1958, the Writer stated his view on the uniform section beam which is comparatively easy to deal with. Further to the above, the Writer hereby collectively reports of the results of his two experiments, viz., one by applying the theory of stern vibration, with a view to bringing this theory closer to the actual conditions of vessels, to the so-called "Timoshenko Beam" wherein the effects of shear rigidity and rotary inertia are taken into consideration, and the other by applying the theory to a kind of variable section beam to observe the effect of the unevenness of rigidity distribution in vessel's hull.
View full abstract
-
[in Japanese]
Article type: Article
Pages
35-38
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
[in Japanese]
Article type: Article
Pages
39-45
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
46-49
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App1-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App2-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App3-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App4-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App5-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App6-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover3-
Published: March 31, 1960
Released on J-STAGE: February 24, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
