International Shipbuilding Progress - Volume 20, issue 232

Authors: Vassilopoulos, L.

Article Type: Research Article

Abstract: The prediction of loads experienced by a rotating propeller blade is of great importance in propeller design, especially in view of the recent increase in failures of propeller blades and pitch control mechanisms. In this paper, analytical expressions are derived for the forces and moments induced on a propeller blade due to uniform shaft rotation. Methods are then outlined for the numerical evaluation of these expressions using digital computers. An approximate formula is also derived for the centrifugal spindle torque on a controllable-pitch propeller blade, displaying explicitly the influence of independent variations in skew and rake. A discussion is finally …given of the implications of these results in blade design. Show more

DOI: 10.3233/ISP-1973-2023201

Citation: International Shipbuilding Progress, vol. 20, no. 232, pp. 441-448, 1973

Authors: Duc Bau, Huynh

Article Type: Research Article

Abstract: This paper’s purpose is to describe an improved method of solving the problems of pressure distribution of bulk ore cargoes in large bulk carriers, assuming rigid plastic condition. The method was proposed by Mr. Sokolowski in his soil mechanics course. However Sokolowski’s general theory is too complex. The paper will show how with appropriate assumptions this complexity may be avoided. An approximate formula for practical purpose is proposed for the pressure distribution over the inner bottom in the case where the cargo lays in cone shape.

DOI: 10.3233/ISP-1973-2023202

Citation: International Shipbuilding Progress, vol. 20, no. 232, pp. 449-460, 1973

Authors: Schwanecke, H. | Laudan, J.

Article Type: Research Article

DOI: 10.3233/ISP-1973-2023203

Citation: International Shipbuilding Progress, vol. 20, no. 232, pp. 461-466, 1973

Authors: Shaher Sabit, A.

Article Type: Research Article

Abstract: An overall analysis of the resistance and propulsion results of the SSPA Cargo Liner Series has been presented in Reports No. 66 and 67, which provided designers with diagrams for preliminary prediction of speed and power of forms designed according to the SSPA Cargo Liner Series. However, the corresponding hull offsets together with the geometric particulars has hithetro not been defined in the same fashion. This paper presents diagrams and simple formulae from which the hull offsets together with the main geometric particulars of any intermediate form within the range of the Series can be determined. The hull offsets …adequately define both below and above-water forms up to depth/draught ratio of 1.80. The hull offsets so generated would be fair as regards normal design office scale drawing, and can be used in other preliminary design calculations such as hydrostatics, capacities, cross-curves of stability, floodable length, ……etc. Mathematical expressions were developed to represent the diagrams for the hull surface generation and they were used together with the formulae for the calculation of the main geometric particulars to form a computer program for the generation of the hull surface and calculation of the main geometric particulars of any intermediate form. Show more

DOI: 10.3233/ISP-1973-2023204

Citation: International Shipbuilding Progress, vol. 20, no. 232, pp. 467-480, 1973