International Shipbuilding Progress - Volume 4, issue 32

Authors: Hootsen, A.

Article Type: Research Article

Abstract: A short description is given of the Bergensfjord double-acting two stroke loop-scavenged main engines, which are of the same design as for the m.s. Oslofjord , the only difference between the two engines being the number of cylinders. Results of test-bed and trial trip are included to show the performance of the engines. The increasing demand for tanker propulsion units wih ratings of up to 10,000 b.h.p. and over called for a Diesel engine with minimum maintenance requirements and high exhaust temperature for maximum steam production. Together with the new application of turbo-charging for two-stroke engines, …this induced Stork to develop a new single-acting two-stroke engine with uniflow scavenging, specially constructed for the application of turbo-charging by means of exhaust-driven turbo-blowers and adapted for the use of heavy fuel. A description of this engine type is given together with performance curves. The sound constructional principles which have been responsible for the satisfactory service results and the reliability of the double-acting engine were incorporated in the new design and the service results of this new engine so far have been completely satisfactory. Show more

DOI: 10.3233/ISP-1957-43201

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 187-199, 1957

Authors: Baier, L.A.

Article Type: Research Article

DOI: 10.3233/ISP-1957-43202

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 200-203, 1957

Authors: Watanabe, Yoshihiro | Inoue, Shosuke | Yamanouchi, Yasabumi | Manabe, Daikaku | Kato, Hiroshi | Sato, Mitsuo | Motora, Seizo | Masuda, Yoshiro | Uchida, Mamoru

Article Type: Research Article

Abstract: The authors have developed a standard of stability for passenger ships engaged in Ocean-going and Coasting Services. This standard was worked out in a similar manner to that for Smooth Water Area and Small Craft by the Ministry of Transportation with the cooperation of Tokyo and Kyushu Universities, Nippon Kaiji Kyokai, etc. In preparing this standard, investigations have been made on the various external forces affecting stability such as wind, waves, shipping of sea water, shift of weights on board, steering, as well as metacentric height, dynamical stability, maximum righting arm, etc.: Whereupon the method of judging the stability …has been developed as follows: 1. Dynamical stability as criterion. Amongst external forces, the effects of wind and waves have been considered. Let us assume that, a ship is listed under the statical transverse heeling moment due to steady wind, and the ship is subjected dynamically to a gust when the ship is at he maximum angle of roll to windward due to waves. In order that the ship has sufficient dynamical stability: work ratio C > 1 2. Maximum righting arm as criterion. The external forces, due to shipping of sea water, shift of heavy weights on board, steering, etc. have been considered G Z m must satisfy either of the following formulae: G Z m ≧ 0.0215 B or G Z m ≧ 0.275 ( m ) 3. Metacentric height as criterion. The G M criterion is the same as that for ships engaged in Smooth Water Area when wind pressure and shift of passengers have been taken into consideration: G M ≧ ( 1.1 A h + ∑ k n B ¯ ) B / 100 f Δ , f ≦ B / 5.5 Show more

DOI: 10.3233/ISP-1957-43203

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 204-217, 1957

Authors: Davidson, Kenneth S.M.

Article Type: Research Article

DOI: 10.3233/ISP-1957-43204

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 218-219, 1957

Authors: Kumai, Toyoji

Article Type: Research Article

Abstract: Some investigations into the flexural vibrations of ships’ hulls have been carried out. The author points out that such higher modes of hull vibration as are resonant with the propeller blade force excited through hydrodynamic action is considered as shearing vibration. The vibration profiles of the higher modes of hull vibration for certain assumed distributions of shear rigidity and of mass are calculated based on shearing vibration. Also, the natural frequencies of the fundamental mode to the eight-node mode of the vertical vibration of a cargo vessel, for example, are calculated based on shearing vibration taking the corrections for bending …moment and rotatory inertia of the hull section into account. To obtain a simple method for the estimation of the natural frequencies of hull vibration including the higher modes in the initial design, stage an empirical formula based on shearing vibration is presented. The empirical factors of the formula are determined based on data which have been supplied to the author by the leading shipbuilders in Japan. Show more

DOI: 10.3233/ISP-1957-43205

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 220-228, 1957

Authors: van Manen, J.D.

Article Type: Research Article

DOI: 10.3233/ISP-1957-43206

Citation: International Shipbuilding Progress, vol. 4, no. 32, pp. 229-238, 1957