Experimental Measurements and Numerical Prediction of the Effect of Waves on Mooring Line Forces for a Container Ship Moored to Pile Supported and Solid Wall Docks

The conditions of a moored container ship are examined by a physical model in a wave basin and by a numerical simulation. Each condition, wave period, significant wave height and wave direction, was isolated and tested for a 50:1 scale model of a 710 ft ship and model dock. The dock construction, solid sheet wall or pile supported, was varied to add another aspect of a moored vessel. Mooring lines were modeled using 14 springs in typical mooring line arrangement to simulate the elastic properties. Loads experienced on mooring lines and fenders during different wave conditions were recorded using in line force transducers. Each wave property increased the loads on the mooring lines and fenders as it intensified, except in few conditions. The loads throughout the ship also decreased for the tests run with a pile constructed dock. The bow line received the greatest load and the greatest range of loads of all the lines. The greatest average load was 175 kips experienced by the bow line during a 20 second period, 6 feet wave coming perpendicular to the ship. The results of the solid wall dock setup were compared to the results from the numerical simulation data, aNySIM. Numerical results showed similar trends as the experimental but at a lower magnitude, with a maximum percent difference of 36%