This International Standard specifies requirements of anchor winches for position keeping, and temporary and emergency anchoring of mobile offshore units, particularly drill-ships, semi-submersible drilling rigs and accommodation platforms. These requirements do not apply to anchor winches which are used for other purposes such as hauling the vessel as is the case for pipelaying, ploughing, pile-driving and crane vessels. NOTES 1 Where national regulations and the rules of classification societies differ from this International Standard, they take precedence. 2 The attention of users is drawn to the mandatory adoption of some standards by international organizations or national administrations.