This document specifies methodologies for:

1. the design, analysis and evaluation of stationkeeping systems for floating offshore structures;
2. the assessment of stationkeeping systems for site-specific applications of mobile offshore units and construction units.

Originally developed for floating structures used in the oil and gas industry, this document is now also used in the renewable energy sector. The extent of application of this document to floating structures used in other industries is at the discretion of the relevant standard entity and its users. For example, IEC 61400-3-2 for floating wind applies this document to determine stationkeeping system responses while incorporating its own load conditions, safety factors, and environmental return periods.

This document is applicable to the following types of stationkeeping systems, which are either covered directly in this document or through reference to other guidelines:

• spread mooring systems;
• single point mooring systems;
• dynamic positioning systems;
• thruster-assisted mooring systems.

This document is not applicable to:

• stationkeeping systems which do not have redundancy against failure of any single component, e.g., single anchor leg moorings (SALMs);
• stationkeeping systems which use any means other than mooring lines or thrusters such as tower soft yoke systems, or tension leg platforms (TLPs) that use tendons.

The requirements for this document address spread mooring systems and single point mooring systems with mooring lines composed of steel chain, steel wire or synthetic fibre rope.

This document is applicable to all aspects of the life cycle of mooring systems. It includes requirements relating to the selection of mooring components, mooring system configuration and performance, components design, installation, post-installation survey, and as-installed assessments as needed for mooring integrity management.

For mooring systems deployed in ice-prone environments, additional requirements in ISO 19906 apply.