Results of a Monitoring Program of Moored Ship Response to Gravity and Infragravity Waves

An automated monitoring system was designed and operated at a coal terminal in Los Angeles Harbor, and a container terminal in Long Beach Harbor, to obtain the complete six degree-of-freedom response of moored vessels, as well as mooring line and fender reactions, to measured incident waves. A unique data set was collected on five different vessels for use in validation of a numerical, moored ship model. The system design and sample results are presented. Spectral analysis is utilized to illustrate relationships between input wave energy, ship response and reaction forces. Response to linear and non-linear (slow-drift) forcing is apparent in the spectra.