Behavior of a Moored LNG Ship in Swell Waves
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 129, Issue 1
Abstract
In the design of oil and gas terminals, six degrees of freedom (SDF) models are often used to calculate the motions of the moored ship and forces in mooring lines and fenders. Although the SDF simulation programs have been used for more than 20 years, there is still little verification of the results with prototype measurements. This paper includes the results of a verification of one of these SDF models using prototype measurements as reference data. The prototype measurements consisted of mooring line loads of liquefied natural gas (LNG) carriers at berth for periods during which environmental conditions were recorded. A study was carried out to simulate these conditions in the model and to compare the model results with the measurements. In addition to mooring line loads, the computed vessel motions have been analyzed. For the studied berth situation, the yaw motion resulting from swell waves is quite dominant and is causing large breast line forces. An empirical expression has been derived to calculate the yaw motions of the moored LNG carrier in swell waves. This expression is a first step in defining a general expression to estimate maximum yaw motions and mooring forces to be used in preliminary harbor design.
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References
Ligteringen, H., and Moes, J. (2001). “Motions of moored ships in long waves.” Int. Conf. on Port and Maritime R&D and Technology, Singapore.
Pinkster, J. A. (1980). “Low frequency second order wave exciting forces on floating structures.” PhD thesis, Delft Univ. of Technology, Delft, The Netherlands.
Molen, W. (2001). “Computer simulation of the behavior of an LNG carrier moored to an open jetty.” MSc thesis, Delft Univ. of Technology, Delft, The Netherlands.
van der, Mol, A., Ligteringen, H., and Waanders, A. J. (1986). “Motions of moored vessels, a statistical approach.” 1st Australasian Port, Harbour and Offshore Engineering Conf., 141–145.
van Oortmerssen, G. (1976). “The motions of a moored ship in waves.” PhD thesis, Delft Univ. of Technology, Delft, The Netherlands.
van Oortmerssen, G., Pinkster, J. A., and van den Boom, H. J. J., (1986). “Computer simulation of moored ship behavior.” J. Waterw., Port, Coastal, Ocean Eng. 112(2), 296–308.
Information & Authors
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Published In
Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 129 • Issue 1 • January 2003
Pages: 15 - 21
Copyright
Copyright © 2003 American Society of Civil Engineers.
History
Received: Jan 15, 2002
Accepted: Jul 10, 2002
Published online: Dec 13, 2002
Published in print: Jan 2003
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