Mooring lines are provided by vessel while the shore provides the mooring points. Wire ropes provide a more rigid mooring system than fibre ropes. When a high degree elastically is required, fibre ropes would be a better choice. The mixed usage of wire ropes and fibre ropes is not recommended because of the uneven tensioning of ropes. Owing to different material properties associated with wire ropes and fibre ropes, it is almost impossible to allocate uniform tension on both types of wires. As a result, there is possible occurrence of overloading in some ropes.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.

In marine environment, the cover to reinforced concrete in exposure zones is specified to be much larger than normal concrete (e.g. 75mm). Based on past experimental studies, the concrete cover is identified to be directly related to the corrosion failure of marine structures.

In Eurocode 1 under Ultimate Limit State the probability of failure is less than 10^-4 while under Serviceability Limit State the probability of failure is less than 10^-2. For corrosion aspects, it is normally classified under SLS state. For OPC concrete with 50mm cover, the corrosion probability is found to be more than 10^-2. However, with the use of 75mm cover, the corrosion probability is about 10^-3, which fulfills the Eurocode requirement.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.