The effect of wear and corrosion of steel components on the integrity of mooring systems for floating offshore installations. Mooring integrity Joint Industry Project Phase 2
Mooring integrity for floating offshore installations is an important safety issue for the offshore oil and gas industry. This report is one outcome from Phase 2 of the Joint Industry Project on Mooring Integrity. This work ran from 2008 to 2012 and had 35 industry participants. It followed the Phase 1 work described in HSE Research Report RR444 (2006). The Phase 2 work compiled research on good practice and an overview is given in HSE Research Report RR1090 (2017).
This report considers how the wear and corrosion of steel components in offshore mooring is affected by material properties, design and operation. The report focusses on chains and connecting components such as shackles, as well as considering components that mooring lines are in contact with, such as fairleads. The report identifies the main material properties of interest: hardness; surface properties; chemical composition; micro-structure and inclusions. It describes requirements in standards for specifications for materials. Corrosion aspects covered are: mechanisms and reactions; vulnerability of components; methods for protection of steel exposed in seawater. Wear aspects covered are: principles; the influence of material properties, friction and the seawater environment; considerations for different components. It identifies synergistic effects of wear and corrosion in the seawater environment that may result in higher wear rates.
This Research Report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors and do not necessarily reflect HSE policy.