International Shipbuilding Progress - Volume 3, issue 26

Authors: van Aken, J.A. | Tasseron, K.

Article Type: Research Article

DOI: 10.3233/ISP-1956-32601

Citation: International Shipbuilding Progress, vol. 3, no. 26, pp. 517-527, 1956

Authors: Newman, A.D.

Article Type: Research Article

Abstract: The prime requirements of bearings for marine geared turbines, reliability and efficiency, are considered. It is shown that the correct choice of length/diameter ratio and clearance ratio is essential in order to attain these requirements, and it is indicated that for the conditions which occur in most marine turbine and gear bearings, relatively short bearings with length/diameter ratio between two-thirds and one-third, and clearance ratios between one and two thousandths of an inch per inch diameter, give the best results. Bearing and shell materials are discussed. The advantages of high-tin whitemetal as bearing material are shown, and the relative …merits of non-ferrous and ferrous shell materials are considered. It is concluded that the best general design is one of thin whitemetal on a steel shell; the shell may be of normal thickness or it may be of thin shell type, and the advantages of this design are considered. The requirement of utmost reliability in a marine bearing involves if possible the ability for limited operation under a condition of lubricating oil failure. The shortcomings in this respect of present bearings are mentioned, and an improved design which overcomes them is described. Show more

DOI: 10.3233/ISP-1956-32602

Citation: International Shipbuilding Progress, vol. 3, no. 26, pp. 528-539, 1956

Authors: Kumai, Toyoji

Article Type: Research Article

Abstract: The characteristic values of the torsional vibration of a beam of variable cross section and with variable mass distributions like a ship’s form are computed from the solutions of the fundamental equation, and the formula for estimating the torsional vibration criticals of a ship’s hull by the use of the computed one is presented. The effects of the deck openings upon the torsional rigidity and of the virtual inertia of the entrained water mass in the case of torsional vibration on the natural frequencies are taken into account. The results of calculations are compared with measured ones in two types …of cargo vessels. Show more

DOI: 10.3233/ISP-1956-32603

Citation: International Shipbuilding Progress, vol. 3, no. 26, pp. 540-546, 1956

Authors: van Manen, J.D.

Article Type: Research Article

DOI: 10.3233/ISP-1956-32604

Citation: International Shipbuilding Progress, vol. 3, no. 26, pp. 547-550, 1956

Authors: Hillman, Harry F.

Article Type: Research Article

Abstract: Although metals and plastics are becoming more prominent as hull materials in the small boat industry and in particular, mild steel in the construction of commercial craft, wood is still the most important material used in the construction of yachts, pleasure craft and smaller work boats. It is the purpose of this paper to give a general outline of the common shipbuilding woods and their properties, and to point out some of the important but lesser known facts about these woods. It is also intended to point out relatively little known sources of information about wood and its uses. For …the purpose of discussion, the woods are divided into four groups: The hardwoods, the soft woods, tropical hardwoods and the lesser known tropical woods. Show more

DOI: 10.3233/ISP-1956-32605

Citation: International Shipbuilding Progress, vol. 3, no. 26, pp. 551-559, 1956