Seven mechanisms that contribute to mooring line failure

Seven mechanisms that contribute to mooring line failure: 

1 – Wear:  
This can occur when the mooring line rubs on adjacent line components at connecting links, fairleaders, bending shoes, etc. 

2 – Fatigue damage:  
This can be due to crack initiation and propagation from repetitive axial and bending stress. 

3 – Abrasion:  
When chain gets in contact with the seabed, sediments can be abrasive and friction can erode the chain. 

4 – Corrosion:  
Rust and corrosion can result from chemical reactions between the material and the surrounding environment. The growth of marine life (algae, barnacles…) can further contribute to the need to replace the mooring line to avoid failure. 

5 – Damage:  
Chain, wire rope or polyester rope can get damaged during installation operations or inspection operations, as well as from dropped objects, and other external events. 

6 – Flawed materials:  
Impurities in the materials, improper heat treatment, improper or non-compliant assembly, or poor coating or lubrication are all reasons that can lead to a weaker material, and consequently to failure. 

7 – Excessive tension:  
Mooring lines should be inspected after exposure to severe environmental conditions (storms, hurricanes…) or extreme loads. 

Several steps can be taken to mitigate mooring system components damage, from regular inspection to routine maintenance operations.