Prior to open sea trials, mooring system design is a major concern for technology developers. The main focus for designer engineers is to ensure that the extreme forces experienced during exceptional weather conditions are adequately taken into account. Consequently, as these are seen as the main enemies of the system, calculations based on such forces form the basis of on-paper design work.
However, five-year’s practical experience at BiMEP test site shows that mooring systems do not usually fail due to their reaching, or exceeding, the maximum stresses they could theoretically withstand. Having analysed the behaviour of several single mooring marker devices deployed at BiMEP, it can be observed that there are other reasons for mooring line failure. Primarily, these are related to the choice of material, component selection, design geometry and the installation process.
Placing insufficient importance on variables other than extreme forces at the design stage can be responsible for mooring line failure.