1523 Dexin Building, Yangzhou,
1. Ship overload
This kind of damage often occurs in the rubber fender, especially in some old rubber fender, which often cracks in the weak part of the structure.
Cracks are generally in the length direction of the rubber fender.
D and V fender 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 high, which exceeds the load that the rubber fender can bear.
The reason for the excessive kinetic energy of ship collision is that the ship's speed and Angle are too large.
Especially when the ship is at a large Angle, the bow contact the wharf and the rubber fender before the middle of the ship, resulting in a strong impact kinetic energy concentrated on one or several fenders, resulting in the damage of the rubber fender.
In addition to the above reasons, there are also ships whose berthing is bigger than the designed ship type and tonnage, and the influence of wind and wave on the ship.
2. Poor anchorage and connection
This has happened in all kinds of rubber fenders.
The rubber fender is loose, out of position, falling off into the sea and other abnormal phenomena.
The main reason for this phenomenon is the poor technical condition of bolts or chains anchored to the fender, or the failure to keep up with the maintenance.
The anchor bolts and chains and other metal materials of fixed fender corrode rapidly in the Marine environment and are not easy to be replaced, resulting in the poor fixation of rubber fender, which seriously affects the normal use of fender.
Although the replacement condition is considered in the design of some anchor bolts, it is often not ideal in practical use.
For example, V type rubber fender bolt is in the form of embedded bolt box.
The original design was intended to facilitate the repair and replacement of anchor bolts. However, in practical use, it could not be replaced due to corrosion of iron parts, deformation of bolts and other reasons, which affected the quality of rubber fender fixation and caused the fender to fall off and damage.
3. Friction damage
This situation usually occurs in the fixed V - and d-type fender.
The fender is mainly damaged by falling Angle, cracking and surface abrasion.
The main reason for the damage is that the friction between the rubber fender and the ship is too great.
When the ship landed at a high tangential speed, the contact between the rubber fender and the hull was forced to move forward together with the ship due to excessive friction, which caused the fender to be damaged by shear.
In addition, during the mooring operation, the ship sometimes needs to move back and forth, as well as the left and right or up and down of the ship caused by waves and currents.
In this case, the friction coefficient between the ship and the rubber fender is greater than zero.
Damage to the fender may be caused when the rope is pulled too tight.