Petroleum and natural gas industries — Specific requirements for offshore structures — Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units
ISO 19901-7:2013 specifies methodologies for - the design, analysis and evaluation of stationkeeping systems for floating structures used by the oil and gas industries to support production, storage, drilling, well intervention and production, production and storage, drilling, well intervention, production and storage, and - the assessment of stationkeeping systems for site-specific applications of mobile offshore units (e.g. mobile offshore drilling units, construction units, and pipelay units). ISO 19901-7:2013 is applicable to the following types of stationkeeping systems, which are either covered directly in ISO 19901-7:2013 or through reference to other guidelines: - spread moorings (catenary, taut-line and semi-taut-line moorings); - single point moorings, anchored by spread mooring arrangements; - dynamic positioning systems; - thruster-assisted moorings. Descriptions of the characteristics and of typical components of these systems are given in an informative annex. The requirements of ISO 19901-7:2013 mainly address spread mooring systems and single point mooring systems with mooring lines composed of steel chain and wire rope. ISO 19901-7:2013 also provides guidance on the application of the methodology to synthetic fibre rope mooring systems, and includes additional requirements related to the unique properties of synthetic fibre ropes. ISO 19901-7:2013 is applicable to single anchor leg moorings (SALMs) and other single point mooring systems (e.g. tower soft yoke systems) only to the extent to which the requirements are relevant. ISO 19901-7:2013 is not applicable to the vertical moorings of tension leg platforms (TLPs).