Browse > Article
http://dx.doi.org/10.5574/KSOE.2013.27.6.022

Improved design for mooring line with lumped weight at seabed  

Song, JaeHa (Korea Research Institute of Ship and Ocean engineering (KRISO/KIOST))
Shin, SeungHo (Korea Research Institute of Ship and Ocean engineering (KRISO/KIOST))
Jung, DongHo (Korea Research Institute of Ship and Ocean engineering (KRISO/KIOST))
Kim, HyeonJu (Korea Research Institute of Ship and Ocean engineering (KRISO/KIOST))
Publication Information
Journal of Ocean Engineering and Technology / v.27, no.6, 2013 , pp. 22-26 More about this Journal
Abstract
The purpose of this study was to improve the design of a mooring line by attaching a lumped mass to it on the seabed. A numerical analysis of the redesigned mooring system is performed to analyze the effect of the weight of the attached lumped mass using the commercial software Orcaflex. The ultimate tension of the mooring system with the lumped mass is compared with that of a bare mooring line in the original design. An appropriately designed weight for the lumped mass is found to induce a critical lifted point in the mooring line by floater motion in the ultimate condition to move toward the floater position from the anchor point, while maintaining a similar safety factor for the mooring line. On the other hand, it is shown that excess weight for the lumped mass induces snapping in a mooring line, resulting in low safety factor for the mooring system. The distance between lumped weights is shown to be a minor parameter affecting the safety of a mooring line, although a shorter line has an advantage from an economic point of view. Using the optimal weight for the lumped mass attached to the mooring line on a seabed reduces the mooring line length and installation area occupied by a mooring system under real sea conditions.
Keywords
Mooring line design; Lumped weight; Weight and distance; Numerical analysis;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 IMO Res. A.749(18), Code on Intact Stability for All Types of Ships Covered by IMO Instruments.
2 American Petroleum Institute (API), 1996. Recommended Practice for Design and Analysis of Stationkeeping Systems for Floating Structures. API Recommend Practice 2SK, 2nd Edition.
3 Berteaux, H.O., 1976. Buoy Engineering (Ocean Engineering, a Wiley Series). Umi Research Pr
4 Chen, X., Zhang, J., Ma, W., 2001. On Dynamic Coupling Effects between a Spar and Its Mooring Lines, Ocean Engineering, 28(7), 863-887.   DOI   ScienceOn
5 Det Norske Veritas, 2001. Offshore Standard DNV_OS_E301, Position Mooring, Det Norske Veritas
6 Jung, D.H., Nam, B.W., Shin, S.H., Kim, H.J., Lee, H.S., Moon, D.S., Song, J.H., 2012. Investigation of Safety and Design of Mooring Line for Floating Wave Energy Conversion. Journal of Ocean Engineering and Technology, 26(4), 77-85.   DOI   ScienceOn
7 Kim, Y.B., 2009. Motion Response and Mooring Analysis of Mobile Harbors Moored in Side-by-Side. Journal of Ocean Engineering and Technology, 23(6), 53-60.
8 Korea Institute of Ocean Science and Technology (KIOST), 2011a. Proposal Report on Technology for Wave/Wind Hybrid Development.
9 Korea Institute of Ocean Science and Technology (KIOST), 2011b. Detail Design Report on Wave Energy Conversion in 500kW Class.
10 Nam, B.W., Hong, S.Y. Shin S.H., Hong S.W., Kim K.B.,, 2012. Prediction of the Hydrodynamic Performance of the Floating Pendulum Wave Energy Converter in Regular and Irregular Waves. International Conference of ISOPE2012, Rhode, Greece, 607-612.