Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-10T16:39:37.688Z Has data issue: false hasContentIssue false

Roll Motion of a Ship and the Roll Stabilising Effect of Bilge Keels

Published online by Cambridge University Press:  02 October 2008

Santiago Iglesias Baniela*
Affiliation:
(Universidad de La Coruña, Spain)
*
(E-mail: sbaniela@udc.es)

Abstract

The roll motion of a ship on waves is one of the six degrees of freedom and is the most difficult to predict since it deals with a motion similar to a spring-mass damper system, poorly damped by ship generated waves, in addition to the action of waves from the high seas. This problem increased from the second half of the 19th century when sailing propulsion was replaced by steam machines and iron replaced wood, which led to design modifications in ships affecting transversal stability, with the result of an increment in the ship's roll motion. As a consequence, it has been necessary to develop different systems which, on the one hand, increase the natural period of this motion in order to decrease its amplitude and reduce the risks that the wave encounter frequency would resonate with the natural frequency of the ship's motion; and on the other hand, to generate a damping effect to this motion. Bilge keels, passive stabilisers with no moving parts, form the simplest and cheapest element that may be incorporated on a ship to reduce this motion. This paper studies roll motion in general and then analyses bilge keels from different points of view.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Clark, I. C. (2005) “Ship Dynamics for Mariners1st edition. The Nautical Institute, LondonGoogle Scholar
Clark, I. C. (2001) “The Management of Merchant Ship Stability, Trim and Strength”. The Nautical Institute, LondonGoogle Scholar
Gillmer, Thomas C., Johnson, Bruce. (1982.) “Introduction to Naval Architecture”, Naval Institute Press, Annapolis.CrossRefGoogle Scholar
Graham, R (1989) “The effects of hull form on the roll damping of war shipsSociety of Naval Architects & Marine Engineers, Jersey (USA).Google Scholar
Ikeda, Y (2004) “Prediction methods of roll damping of ships and their application to determine optimum stabilisation devicesMarine Technology, 41 (2).Google Scholar
Ikeda, Y (2004) “Principles of Naval Architecture. Vol III: Motions in Waves and Controllability”, (1989) Society of Naval Architects & Marine Engineers, Jersey (USA).Google Scholar
Ikeda, Y (2004) “Principles of Naval Architecture. Vol. II: Resistance, Propulsion and vibration”, (1988) Society of Naval Architects & Marine Engineers, Jersey (USA).Google Scholar
Pursey, H. J. (1983) “Merchant Ship Construction7th edition. Brown, Son & Ferguson, Ltd., Nautical Publishers, Glasgow.Google Scholar
Pursey, H. J. (1983) “Merchant Ship Stability6th edition revised. Brown, Son & Ferguson, LTD, Nautical Publishers, Glawgow 1983.Google Scholar
Sellars, F. H., Martin, J. P., (1992) “Selection and evaluation of ship roll stabilization systems”, Marine Technology, SNMAE 29 (2).Google Scholar
Taylor, D. A. (1998) “Merchant Ship Construction4th edition. IMarEST Publications, London.Google Scholar
Taylor, D, Tang, A. (2006) “Merchant ship naval architecture”, IMarEst, LondonGoogle Scholar
Tristan, Perez, (2005) “Ship Motion Control”, Springer-Verlag, LondonGoogle Scholar
Tupper, Eric C. (2004) “Introduction to Naval Architecture4th edition, Butterworth-Heinemann, London.Google Scholar
Zaojian, Zou. Lecture Notes “Ship Manoeuvring and Seakeeping”, (p. web http://cem.sjtu.edu.cn).Google Scholar