Windlass damage when weighing anchor in gale force winds
A vessel was anchored in an exposed roadstead with gale conditions expected after a few hours. As a precaution, the Master had brought the vessel up to 8 shackles on the port anchor with the starboard anchor on the seabed to reduce anticipated yaw. A short time after anchoring, the vessel began to yaw. The intensity of the yawing increased, and eventually, the port cable began to slip, overcoming the combined holding power of the brake and the guillotine stopper.
The decision was taken to get underway, and the starboard anchor was weighed. The crew then began to weigh the port anchor, using engines to reduce the load on the cable. The wind strength was increasing steadily and the windlass struggled to recover the cable when, suddenly and without warning, the dog clutch shattered and the cable ran out of control. Fortunately, no one was injured and the securing arrangement of the bitter end held. The cable was subsequently slipped and the vessel was taken out of service due to the damage to the windlass and the loss of her anchor.
Safety lessons from investigation
1） The selected location for anchoring did not provide sufficient shelter to prevent the vessel’s anchoring equipment from being subjected to excessive loads;
2） The guillotine bar’s locking pin had not been engaged;
3 ）The vessel’s SMS for anchoring operations contained no reference to the use of the locking pin when anchoring;
4 ）The severe yaw that developed was due to the windage of the vessel’s superstructure, which generated forces in excess of the design load of the anchoring equipment.
Recommendations
Owners and operators are strongly advised to review their SMS procedures for anchoring to ensure they address the above safety issues and, specifically:
1) That masters have clear guidance on the capability of their vessel’s anchoring system, including any limitations of the anchor system components, including that of the windlass;
2) Effects of windage in various load conditions;
3) Risks associated with excessive yaw;
4) Guidance on anchoring is vessel-specific and highlights that, when at anchor, the weight of the cable should be taken on the guillotine fittings, which should be correctly engaged (Nautical Institute,
Mooring and Anchoring Ships, Volume 1, 2009. ISBN: 978 1 870077 93 4).
（译文参考：船舶管理部 培训分析师 傅恒星编译）
强风中起锚时锚机损坏
狂风中，一艘船在外锚地锚泊希望能躲几个小时。船长为了防止意外船舶偏荡，左锚出链8节，右锚抓底，抛锚完成后不久，船舶开始偏荡，随着偏荡幅度越来越大，最终锚链克服了来自制链器和锚机刹车的联合阻力开始向外滑动。
船长决定立即起锚开航，绞起右锚后。为减轻锚链负荷，用车配合船员收左锚。此时风力持续增强，锚机艰难的一点点收回锚链，在没有任何征兆的情况下锚机的爪式离合器突然碎裂，但是锚链立即失去了控制向外滑落，幸运的是锚链安全装置--末端弃链器起了作用，没有人员受伤，最终锚链还是完全滑落入海，该轮由于锚机受损且锚丢失而无法继续营运。
从事故调查中获得的教训：
1）选择的抛锚为敞开水面，无法为船舶提供充足的庇护，防止锚泊设备承受过度负荷。
2）止链器的保险销没有放置到位。
3）该轮安全管理体系（SMS）关于锚泊操作程序中未包含锚泊后使用制链器保险销固定的要求。
4）船舶上层建筑受强风影响后出现严重走锚，其所产生的力量远超过锚泊设备设计负荷。
建议：
强烈建议船东和管理者评审其SMS中锚泊作业程序，确保体系中缺陷得到纠正，尤其上述安全问题
1）船长应该非常清楚船舶锚泊系统的能力，包括系统部件的任何限制特性，同时也包括绞盘性能。
2）在不同载荷情况下风力对船舶的影响。
3）严重偏荡的相关风险
4）指导锚泊作业，是船舶特有的需强调的一项工作，在锚泊状态时，锚链重量应该由正确设置的制链器承担。
