Fender berthing energy

Fender berthing energy is the kinetic energy the fender system must absorb when a ship contacts the berth, the governing quantity in fender selection. It is the ship’s displacement and approach velocity normal to the berth, modified by the berthing coefficient, the eccentricity, virtual-mass (added-mass), and softness factors. PIANC WG211 sets the method and the partial factors. Underestimating approach velocity is the classic design error: energy scales with the square of velocity, so a small misjudgement of berthing speed undersizes the whole system.