How long is the anchor chain?
First of all, it should be noted that the length of the anchor chain should not be calculated in meters, but in the most commonly used nodes in navigation. The length of each section of the anchor chain is about 27.5 meters. Here it is necessary to explain how this unit came about.
The length of the anchor chain is not the same as the speed unit used in navigation. It is actually derived from the imperial unit, fathom. The length of a fathom is about 1.8288 meters. Because of the strong navigation of the British Empire, it became an international standard. Later, it was uniformly stipulated that the length of the anchor chain was 27.5 meters. In actual use, each section between the anchor chain is composed of a shackle, and the sections are connected by detachable links. The links are usually painted white so the crew can know how many lengths of chain have been launched.
The last section of the chain is usually sprayed red to warn the crew that the end of the chain has been reached. Usually, the anchor chain is fixed on the chain drum. If the ship has not completed the deceleration before the release, the anchor chain is likely to break and fly out of the ship. In order to prevent this from happening, the penultimate anchor chain is usually sprayed yellow, similar to the usage of traffic lights.
According to international practice, each anchor chain of a large commercial vessel is usually only 12 to 13 knots, and the length is calculated between 330 meters and 357.5 meters. However, this is only a vague standard value, and it needs to be determined according to the number of outfitting of a ship. The calculation method of the number of outfitting is very complicated, so I won't go into details here. You only need to understand that if the number of outfitting of a ship is larger, it means that the ship will be more affected by wind and waves at sea. Requires heavier anchors, thicker chains and cables, etc. Generally speaking, the number of outfitting of warships is higher than that of ordinary freighters, but it is not suitable to continue to lengthen the anchor chain after reaching 13 knots, because it will prolong the time of anchoring, so it is necessary to thicken the anchor chain, or even need multiple anchor chains. Guaranteed stability.