The idea of using tanks with liquid free surface for reducing the roll motion of ships is not new. A number of researchers has studied how to design passive anti-roll tanks and as a result there now exists a good, although not quite as comprehensive as one might wish, guide for ship designers.However, all the past effort was placed on studying the performance of anti-roll tanks in damping the roll motion of the ship. Although certainly the greatest effect of introducing the anti-roll tank is to increase the roll damping, there is another important aspect which has been neglected sofar, and that is the effect it has on the ship roll restoring moment characterstics and thus the natural frequency of roll motion. This paper elaborates on the above idea and presents a case study involving an actual application to a diving support vessel. The problem addressed was made more comlicated, because the tank space was subdivided by non-water-tight longitudinal girders for reasons of structural strength. A detailed account of model bench tests is given and the method of analysing the experimental results discussed. Using the data thus obtained, the roll motion response of the vessel is computed. Based on this study, suitable girder configurationsare suggested and recommendations are made on the operation of such a device as well as on the general use of anti-roll tanks as detuning devices.
An investigation into the stabilisation effects of anti-roll tanks with flow obstructions
Eine Untersuchung der Stabilisierungseffekte von Schlingerdaempfungstanks mit Stroemungshindernissen
International Shipbuilding Progress ; 43 , 433 ; 70-88
1996
19 Seiten, 14 Bilder, 4 Quellen
Aufsatz (Zeitschrift)
Englisch
INVESTIGATION INTO THE STABILISATION EFFECTS OF ANTI-ROLL TANKS WITH FLOW OBSTRUCTIONS
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|Springer Verlag | 2005
|Roll reduction of ships using anti-roll n-tanks
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