Why is one section of the anchor chain 27.5 meters long?
The specifications of many classification societies define the length of a single section of the anchor chain as 27.5 meters or slightly less. Why is it 27.5 meters long? It has to start with the United Kingdom. A long time ago, United Kingdom was the empire on which the sun never set that spanned the oceans and lasted for centuries. In that era of great navigation, Britain accumulated rich experience. Navigation is an industry that pays special attention to tradition and inheritance, so many ancient habits and requirements have been passed down from generation to generation.
Everyone knows that the UK is a country that uses the imperial system, which is incompatible with the metric system invented in continental Europe. Although the mainstream today is to use the international metric system, the imperial units represented by the United States and the United Kingdom are still widely used.
The length of a single section of the anchor chain is derived from the imperial unit ‘fathom (hundred)’, which is a unique unit of length used at sea. 1 fathom is approximately equal to 1.8288 meters, which is roughly the length of a person’s arms spread out (easy to measure at sea) ), one section of anchor chain is taken as 15 fathom, which is more than 27.43 meters. When converting to the metric system, the last digit is erased and 27.5 meters is taken directly. So it became a convention that has been followed down.