This type of damage often occurs in rubber fenders, especially some old rubber fenders, which often crack at weak points in the structure. The crack is generally in the length direction of the rubber fender. D-type and V-type fenders are more common. The main cause of cracking of the rubber fender is that the kinetic energy of the ship striking the fender is too large to exceed the load that the rubber fender can withstand. The reason for the excessive kinetic energy of the ship is that the speed of the ship and the angle of the ship are too large. 

In particular, when the angle of the ship is large, the bow contacts the pier and the rubber fender before the middle of the hull, causing strong impact kinetic energy to concentrate on one or several fenders, causing damage to the rubber fender. The ship's impact function is too large. In addition to the above reasons, there are ships with docks that are larger than the designed ship type and tonnage and the impact of wind and waves on the ship.