-
Article type: Cover
Pages
Cover1-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover2-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Kiyoshi TERAI, Fumiyoshi KANATANI, Ryoichi SUZAWA, Hiroyuki MATSUMURA, ...
Article type: Article
Pages
1-10
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Shipyards throughout the nation are energetically endeavoring to rationalize and modernize the assembly stage of hull construction. As a result, due to the standardization of the production process with the enlargement of blocks and the wider application of the conveyor line system, it has become necessary to jumbolize the hardware and other manufacturing facilities. Under such circumstances, we saw the installation of this welding machine under the knowhow of the one-side automatic welding machine with ultra-multi electrodes as plate joining facility of the new assembling plant of the 600,000-ton tanker construction dock of KHI Sakaide Work. This welding machine has four sets of 3-electrode, submerged arc welding heads which can perform simultaneously parallel welding of thick plates of four welded joints in maximum by concentration control system. Along with the adoption of the practical crack prevention method for the end cracking of the welded parts, which was a bottle neck of one-side automatic welding technique, the introduction of this welding machine into the production line contributes greatly to the economy of labor-saving. This article deals with the outline of this welding machine and its operating conditions.
View full abstract
-
Takashi HASHIMOTO
Article type: Article
Pages
11-20
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Recently, tank-coating work for large oil tankers is increasing. From the view-points of working processes, circumstances and qualities, it is important to paint blocks on the pre-erection stages and also in the inside of a building. The followings are to report about the ventilation, heating and dust collecting for the painting factory at the Sakai Shipyard of Hitachi Zosen. Inside the factory, there are various kinds of dusts in surface preparation, solvent vapor and paint mists in paint spray. Therefore, the ventilation is very important. For thispurpose, continuous air flous (air curtain) are introduced near the side wall. The other air flows are sent from the overhead ceiling, one of them being to the block itself and the other to the above of the block. Latter air flows carry dusts, solvent vapor and paint mists to the air curtain. By this system, these substances are easily removed from the inside of this factory. In addition, this factory has a heating system for drying of paint film and a dust collecting system.
View full abstract
-
Itsuo KAWAI, Takuo KISHIMOTO, Seizo SHIBUTANI
Article type: Article
Pages
21-24
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Almost all of ocean going vessels, today, are intended to be operated with an unattended machinery space, therefore, high reliability and easy maintenance of automation equipments are required especially for main engine remote control divice. A new control device for governor handle of main engine remote control system developed by MHI Kobe shipyard has unique transmitters and function generator to convert the out-put signal from linear order signals to non-linear control signals. The above mentioned transmitter is of special transformer type called "LINIAX" without any contact parts, and lead wires for translation from mechanical movements to electric signals. The function generator is composed of an IC operational amplifier and has trimming potentiometers for adjusting of knuckle points and gains of the out-put signal, because the order transmitter is combined with a telegraph handle. A pneumatic actuator of MHI make is used for governor handle of engine side. We believe that MHI's new engine remote control device will show high reliability and easy maintenance.
View full abstract
-
Seiji MASUDA, Takaaki YUASA
Article type: Article
Pages
25-30
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
As a new mooring method of very large tankers at the outfitting quay, a two points mooring method has been adopted at Sakai Shipyard of Hitachi Shipbuilding & Engineering Co., Ltd. since August 1972. The two points mooring, consisting of two lines of anchor chain at the bow and the stern and their catching devices, has remarkable abvantages compared with the conventional wire rope mooring as follows: (1) In case of the wire rope mooring, it was quite difficult to arrange many lines so that they might have equally balanced load, and there was a risk of wire rope breaking at heavy wind. Meanwhile, two lines of chains are able to be arranged to have equal load at the bow and the stern part, and the maximum load of chain will be kept under the proof load of anchor chain. As large size anchor chain of high tensile (124 mm dia. of grade 3) being used, these lines are more endurable to the wearing-out, impact load and corrosion than the conventional wire rope mooring. Considering those items, the two points mooring is superior to the wire rope mooring in view of the safety of mooring strength. (2) As mooring chains being limited only to two, instead of more than 18 lines of mooring wire ropes, working hours for handling heavy mooring lines have been distinctly reduced. (3) Many mooring ropes are quite obstructive to the crane travelling and operation. The two points mooring improves the working area of outfitting quay and made the crane travelling free.
View full abstract
-
Shoichi NAKAMURA, Keinosuke HONDA
Article type: Article
Pages
31-42
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In this paper a method of estimating the holding power of the anchor in the sea bottom soil mixed with sand and clay is presented. The coefficient of holding power of the anchor, λ_e, is approximately obtained as follows: [numerical formula] where e_s and e_c are the mixture ratio of sand and of clay in the bottom soil, while λ_s and λ_c are the ratio of maximum dragging pull to the weight of the anchor obtained by model tests in sand and in clay respectively. The effects of shape factors of the anchor and conditions of soil on the holding power may be predicted using the results of model anchor tests, and it is confirmed that the calculated results show fairly good agreement with the results of actual anchor test. Moreover, a dragging stability index is proposed to clarify the expression of dragging stability of the anchor.
View full abstract
-
Takanori MATSUOKA, Kinji BABA
Article type: Article
Pages
43-52
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Recently, the finite element method is often used for structural analysis. This method, however, requires preparation of cumbersome input data and the long running time of a computer for calculation. Accordingly, we intended to develop programs for specific subjects by taking into account the accuracy needed, easy application of the program, etc. Usually, structures are composed of not only beam-elements, but also connection parts of these beam-elements. We developed our program by the finite element method combined with the beam theory for the in-plane stress analysis. In this program, the amount of input data is reduced by treating plate-elements of the same type by common data. These elements can be easily applied for elements rotationed, turned inside out and homologous. The results of calculation are poor in accuracy for some cases, and we studied the nature of the error and established a method to minimize it.
View full abstract
-
Takanori MATSUOKA, Hiroaki ODA
Article type: Article
Pages
53-61
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Two types of construction are found in the side structures of bulk-carriers: (1) one in which the frame-ends are connected with brackets, and (2) the other in which the frame-ends are connected with the transverse rings. Many investigators have developed useful methods of structural analysis for bulk-carriers, and the problems involved have almost been settled, except the effects of discontinuity found in the side structures. For analyzing these effects, this report presents the results of model tests carried out and the analysis of their results. Moreover, on the basis of the analysis, methods for analyzing actual ships have been developed and two ships, which are shown in Table 1, were analyzed and the values obtained by the analysis were found considerably in good agreement with the measured ones.
View full abstract
-
Nobuyoshi MORI, Masako TANAKA
Article type: Article
Pages
63-71
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
As adhesives become strong, the chances that they are used in constructions have recently increased. Above all, adhesive-bonded composite materials, as shown in Fig.1, made of different kinds of materials are applied in the field of ship equipment. So, it seems to be most important to examine the effect of temperature upon the strength of these objects. When these pieces are given a certain steady-state temperature, because of the difference of coefficients of linear expansion, shearing stress occurs in the adhesive layer and it becomes the main cause for the damage of these pieces. In this paper, the distribution of this adhesive shearing stress is solved by an analytical method, based on the assumption that adhesives are elastic in low temperatures. The relation between the temperature that makes the shearing stress at the facing surfaces of these pieces the ultimate shearing strength and their lengths is obtained, and compared with experimental results. Besides, for the case that there are un-adhesive parts in the adhesive layer, shearing stress is obtained. And the effective adhesive length is examined. In order to minimize the maximum shearing stress, two kinds of adhesive are used in the adhesive layer and the distribution of shearing stress in this case is obtained. Results are as follows; 1) Adhesive shearing stress is proportional to both the temperature and the difference of coefficients of linear expansion in the layers. 2) Adhesive is not damaged below a critical temperature: [numerical formula] Therefore, this critical temperature may be used as the criterion of the design. 3) Effective adhesive length: l_e is approximated by the following equation at g_3≦1.5: [numerical formula], where β≧3, β=√<(g_4)(g_3)>l. (4) In the case that two kinds of adhesive are used, the maximum shearing stress can be made less than in the case of one kind of adhesive and it can be minimized, if shear modulus ratio and mutual boundary situation of the adhesives are properly chosen.
View full abstract
-
Toshihiko ARII
Article type: Article
Pages
73-77
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
In this paper, an attempt is made to estimate the resistance performance of high speed passengers and ferries using the theory of wave-making resistance. It has been confirmed that this method is useful for the estimation of powering performance of those ships.
View full abstract
-
Hideo SASAJIMA, Ichiro TANAKA, Wataru KOTERAYAMA, Masami HIKINO
Article type: Article
Pages
79-89
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
The problem of viscous effect on thrust deduction becomes increasingly important in recent years. The authors attempt to make an introductory study on this problem in this report. Two bodies of revolution of fine and full forms are used as the model. Resistance increase due to propeller suction, pressure distribution over the surface and the boundary layer velocity distribution with and without propeller action are measured in a circulating water tunnel. The results are compared with calculation and the frictional part of thrust deduction is shown to be small.
View full abstract
-
Kuniji KOSE, Jongsam KIM, Hiroaki KOBAYASHI
Article type: Article
Pages
91-100
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
The zig-zag test technique is now widely used to assess steering quality of ships. The rudder movement at the test can be interpreted as a bang-bang control against yaw angle deviation. In the present paper a new zig-zag test that employs a bang-bang control against yaw-rate, instead of yaw angle, is proposed. This modification makes it possible to set up the limit-cycle in the sustained zig-zag motion of any amplitude in a few minutes and thus gives a good means of definitive manoeuvres particularly convenient for marginally stable and unstable ships. The procedure of the new technique and some discussions about it are given, including a comparative study on the convensional zig-zag test and the new one. Some actual results of this technique with a car-ferry, a few super-tankers, both in full size, and a tanker model are also given.
View full abstract
-
Yoshiki HIRANO, Minoru SAKAO, Noboru NOMURA
Article type: Article
Pages
101-107
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
Various kinds of work done at sea are often characterized by far lower efficiency than in work performed on land. This is true of the self elevating platform (S.E.P.), the subject of this paper. Although the S.E.P. is designed to be able to resist winds below 60 meters per second and waves below 10 meters high, the regulations forbid installing it on the sea bottom or its removal from there under conditions involving winds of more than 10 meters per second or waves of more than 1.5 meters high, for the purpose of protecting its lengthy legs. But the necessity of standby time to wait for the recovery of good weather means poor efficiency. This paper mathematically proves, through a study of the rolling characteristics of the S.E.P., the effectiveness of an automatically controlled anti-rolling device in decreasing its rolling by means of compressed air.
View full abstract
-
Article type: Appendix
Pages
108-110
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App1-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App2-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App3-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App4-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Appendix
Pages
App5-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
-
Article type: Cover
Pages
Cover3-
Published: June 30, 1973
Released on J-STAGE: March 30, 2018
CONFERENCE PROCEEDINGS
FREE ACCESS
