Anchors and associated gear are for holding ships in light to moderate weather conditions. For more adverse weather, drifting or slow steaming (hove-to) would be the safer option. The Nautical Institute gives this advice after a tanker lost its anchor in force 6-7 winds.
In addition, the Institute points out that vessels in ballast are particularly vulnerable to wind effects, which ‘should be considered when anchoring’. The incident with the tanker was covered in a recent Mars Report. These reports are compiled (anonymously) by The Nautical Institute to prevent other accidents from happening. A summary of this incident:
A tanker in ballast dropped anchor and six shackles of chain in the early evening to await a berth for loading. Winds were force 4, but stronger winds were forecast, so the main engines were kept on standby.
Early the next morning, with winds now gusting to force 6-7, the officer of the watch (OOW) deduced that they were dragging anchor as the vessel had departed its swing circle. The anchor party mustered on the foredeck, but by the time they had done so, the vessel had already reached a speed of about 2.8 knots.
Once at the anchor station, the personnel realised that the vessel was not dragging anchor, but that the anchor had been lost. The main engine was engaged and the vessel was able to safely make its way out of the anchorage.
Information concerning loads on anchor systems can be found at the OCIMF website.
Mars Reports
This accident was covered in the Mars Reports, originally published as Mars 202035, that are part of Report Number 332. A selection of this Report will also be published in SWZ|Maritime’s July/August 2020 issue. The Nautical Institute compiles these reports to help prevent maritime accidents. That is why they are also published on SWZ|Maritime’s website.
More reports are needed to keep the scheme interesting and informative. All reports are read only by the Mars coordinator and are treated in the strictest confidence. To submit a report, please use the Mars report form.
