The ship is overloaded This kind of damage often occurs on solid rubber fenders, especially some old solid rubber fenders, which often crack in the weak parts of the structure. Cracks are usually along the length of the solid rubber fender. D-type and V-type rubber fenders are more common. The main reason for the cracking of the rubber fender is that the kinetic energy of the ship hitting the fender is too large, which exceeds the load that the rubber fender can withstand. The reason for the excessive impact kinetic energy of the ship is that the berthing speed and angle are too large. Especially when the berthing angle is large, the bow contacts the dock and rubber fenders before the middle of the hull, causing strong impact kinetic energy to concentrate on one or more fenders, causing damage to the rubber fenders. In addition to the above reasons, the impact of the ship is too large, the berthing of ships exceeding the designed ship type and tonnage at the dock, and the impact of wind and waves on the ship.
Poor anchoring and connection This has happened with various solid rubber fenders. Rubber fenders are loose, dislocated, falling into the sea and other abnormal phenomena. The main reason for this phenomenon is that the technical condition of the bolts or chains that fix the rubber fenders is poor, or maintenance is not carried out in time. The metal materials such as anchor bolts and chains used to fix the fenders corrode quickly in the marine environment and are difficult to replace, resulting in poor fixation of the rubber fenders and seriously affecting the normal use of the fenders. Some anchor bolts are being designed, and although replacement conditions are considered, they are often not ideal in actual use. For example, V-shaped rubber fender anchor bolts take the form of embedded bolt boxes. The original design intention was to facilitate maintenance and replacement of anchor bolts, but in actual use, they could not be replaced due to iron corrosion, bolt deformation, etc., which affected the fixing quality of the rubber fender, causing the fender to fall off and be damaged.
Friction damage Typically occurs with fixed V- and D-shaped fenders. Rubber fenders are mainly damaged by corner drops, cracks, surface scratches, etc. The main cause of this damage is excessive friction between the rubber fender and the ship. When the ship comes ashore at a large tangential speed, due to excessive friction, the contact part between the rubber fender and the hull is forced to move forward with the ship, causing the fender to be sheared and damaged. In addition, during mooring operations, the ship sometimes needs to move forward and backward, as well as the ship rocking side to side or up and down caused by waves and currents. In this case, when the friction coefficient between the ship and the rubber fender is greater than 0.4 (for example, being pulled by the mooring line if it is too tight), damage to the fender may occur.
