The Causes Of Damage To Rubber Fenders

1. Ship overload
This kind of damage often occurs in rubber fenders, especially in some old rubber fenders, which often crack at weak points in the structure. Cracks are generally in the length direction of rubber fenders. D-type and V-type fenders are more common. The main reason for the cracking of rubber fenders is that the kinetic energy of the ship hitting the fenders is too large, exceeding the load that the rubber fenders can withstand. The reason for the excessive collision kinetic energy of ships is due to the excessive speed and angle of berthing. Especially when the berthing angle is large, the bow of the ship contacts the pier and rubber fenders before the middle of the ship, causing strong impact energy to concentrate on one or several fenders, resulting in damage to the rubber fenders. The excessive collision function of ships is caused by factors such as berthing larger than the designed ship type and tonnage at the dock, as well as the impact of wind and waves on ships.
2. Poor anchoring and connection
This situation has occurred in various types of rubber fenders. The rubber fenders have abnormal phenomena such as looseness, displacement, and falling into the sea. The main reason for this phenomenon is the poor technical condition of the bolts or iron chains used to anchor the fenders, or the failure to keep up with maintenance. The anchoring bolts, iron chains, and other metal materials used to fix the fenders corrode rapidly in marine environments and are difficult to replace, resulting in poor fixation of the rubber fenders and seriously affecting their normal use. Although some anchor bolts are designed with consideration for replacement conditions, they are often not ideal in practical use. The V-shaped rubber fender anchor bolts are in the form of pre embedded bolt boxes. The original design intention was to facilitate the maintenance and replacement of anchor bolts, but in practical use, they cannot be replaced due to corrosion of iron parts, deformation of bolts, and other reasons, which affects the quality of rubber fender fixing, causing fender detachment and damage.
3. Friction damage
This situation generally occurs in fixed V-shaped and D-shaped fenders. Fenders are mainly damaged by chipping, cracking, and surface abrasion. The main reason for this damage is the excessive friction between the rubber fenders and the ship. When the ship docks at a high tangential speed, the rubber fenders in contact with the hull are forced to move forward with the ship due to excessive friction, causing the fenders to be sheared and damaged. In addition, during mooring operations, the vessel sometimes needs to move forward and backward, as well as swaying left and right or up and down caused by waves and currents. In this case, when the friction coefficient between the ship and the rubber fender is as high as 0.4 (such as when the mooring rope is pulled too tightly), it is possible to cause damage to the fender.