FULL-SCALE INVESTIGATION OF BERTHING IMPACTS AND EVALUATION OF A HYDRAULIC-PNEUMATIC FLOATING FENDER

Abstract

Two experimental hydraulic-pneumatic floating fenders (camels) were in-service tested in protected and exposed harbors. Due to their high energy-absorption characteristics, the fenders were effective in reducing damage to piers, pier-fender systems, and berthing or moored ships. Their performance relative to a number of individual ship-impacts is discussed, conclusion^drawn, and recommendations made. Measurements as a function of time of ship velocity, berthing force, position of point of impact, and energy absorption by fenders are presented and discussed for 35 berthings involving 14 ships of from 1,400 to 17,600 tons displacement. Load-deflection and energy-absorption curves of the hydraulic and pneumatic fender bags are presented and discussed, and results compared with those predicted by theory. Berthing forces and energy-absorption characteristics are analyzed statistically; their relationships with point of impact are compared with those established with a model of a tanker by the Hydraulic Research Station, Wallingford, England. The resistance to ship motion including hydrodynamic effect is analyzed. It is concluded that hydrodynamic effect is an important parameter which requires further investigation. It is recommended that full-scale tests of berthing impact at exposed harbors be continued and that model tests of berthing impact be initiated, particularly tests of the resistance to ship motion, so that hydrodynamic mass can be properly evaluated.