Experimental investigation of mooring line loading using large and small-scale models

For catenary mooring lines, the relationship between excursion of the point of suspension and the length of suspended line is highly nonlinear. If the point of suspension is then set in motion, the velocity of the line result ing from a change in catenary profile induces additional nonlinear hydrodyn amic loading components. The sensitivity of the mooring line to initial and oscillatory conditions results in a complicated tension history at the poi nt of suspension, with line tensions possibly greatly exceeding those predi cted by static analyses, This paper presents results from an experimental i nvestigation into the response of a large (1:16) and small (1:70) scale sin gle-chain catenary model mooring line when subject to a comprehensive, and equivalent, range of excitation parameters. Tests were performed at purpose -built test facilities. Small-scale model tests were carried out at Univers ity College London (UCL). Large-scale model mooring line tests were complet ed at the Ship Dynamics Laboratory Canal de Experiencias Hidrodinamicas de El Pardo (CEHIPAR), Madrid, Spain. Funding for the model tests performed in Spain was provided through the European Union Access to Large Scale Facili ties-Training and Mobilisation of Researcher Program.