The rubber fender is loose, falling off, falling into the sea and other abnormal phenomena. The main reason for this phenomenon is that the technical conditions such as anchoring, fender bolts or chains are not good, or the maintenance is not in place. Anchor bolt, anchor chain and other metal fixed materials rust quickly in the Marine environment, it is not easy to replace, resulting in poor stability of rubber fender, seriously affecting the normal use of fender. In mooring operations, the ship sometimes needs to move back and forth, as well as the ship caused by waves, side to side or up-and-down airflow, etc. In this case, when the coefficient of friction between the ship and the rubber fender is 0.4 (such as the mooring line is too tight), the rubber cross plate may cause damage to the fender.

Rubber fender is mainly made of natural rubber and synthetic rubber through vulcanization. The compound is uniform, no bubbles, no impurities, dark color, cracks and other defects damage the quality of the product.

1 Ship overload

This damage often occurs in rubber fenders, especially some older rubber fenders, which often crack at weak points in the structure. The cracks are usually in the direction of the length of the rubber fender. D and V fenders are more common. The main reason for the rupture of the rubber fender is that the kinetic energy of the ship hitting the fender is too large to exceed the load that the rubber fender can bear. The reason that the kinetic energy of the ship is too large 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 of the ship contacts the pier and the rubber fender in the middle of the hull, resulting in strong impact kinetic energy concentrated on one or more fenders, which causes damage to the rubber fender. The ship's impact function is too large. In addition to the above reasons, there are the ship's dock is larger than the design of the ship type and tonnage, and the impact of wind and waves on the ship.

2 Friction

This usually occurs with fixed V-fenders and D-fenders. The main damage phenomena of fender are falling Angle, crack and surface scratch. The main cause of this damage is too much friction between the rubber fender and the boat. When the ship docks at a large tangential speed, the contact part of the rubber fender and the hull is forced to move forward with the ship due to excessive friction, resulting in shear damage to the fender. In addition, during mooring operations, the ship sometimes needs to move back and forth, as well as side-to-side or up-and-down rocking caused by waves and currents. In this case, when the coefficient of friction between the ship and the rubber fender is 0.4 (such as the mooring line is too tight), the fender may be damaged.

3 Poor anchoring and connection

This happens on all kinds of rubber fenders. The rubber fender has some abnormal phenomena such as loosening, falling off and falling into the sea. This is mainly due to poor technical conditions, such as bolted or chain connections to anchorages or failure to keep up with maintenance. Metal materials such as anchoring bolts and chains fixed on the fender corrode rapidly in the Marine environment and are not easy to replace, resulting in poor fixing of the rubber fender, which seriously affects the normal use of the fender. Although some anchoring bolts are designed with replacement conditions in mind, they are often not ideal in actual use. For example, V-shaped rubber bolts are in the form of a embedded bolt box. The original design is to facilitate the repair and replacement of the anchor rod, but in actual use, due to the rust of iron parts, bolt deformation and other reasons can not be replaced, affecting the quality of the rubber fender, resulting in the fender falling off and damage.