Fender
A Fender is an energy-absorbing device placed between a vessel and a berth, jetty or another ship to prevent damage from the impact of berthing and the movement of a moored ship. Quay fenders range from simple rubber blocks and cylindrical units to large pneumatic (Yokohama) fenders and cone or cell fenders on modern berths.
Fenders are sized to the largest ship the berth serves and its berthing speed, so they absorb the berthing energy without exceeding the reaction force the hull and structure can take. Ships also rig portable fenders when going alongside another vessel for a ship-to-ship transfer.
A berthing ship carries a large amount of kinetic energy; the fender is what absorbs it safely instead of the hull plating or the quay. Correctly rated fenders prevent structural damage and let bigger ships berth at a given structure, which is why fender selection is a key part of berth design.
What is a Yokohama fender?
A large floating pneumatic rubber fender, widely used for ship-to-ship transfers and for berthing very large vessels, named after its original Japanese manufacturer.