Nautical mile 1 sea mile", followed by "For most practical purposes distance is measured from the latitude scale, assuming that one minute of latitude equals one nautical mile". One tenth of a nautical mile is a cable length. The derived unit of speed is the knot, defined as one nautical mile per hour. The metre was originally defined as of the meridian arc from the North pole to the equator passing through Dunkirk. The Earth’s circumference is therefore approximately 40,000 km. The equatorial circumference is slightly longer than the polar circumference – the measurement based on this (40,075.017 km x x =
Capstan (nautical) In yachting terminology, a winch functions on the same principle as a capstan. However, in industrial applications, the term "winch" generally implies a machine which stores the rope on a drum. Hydraulically powered capstans were sometimes used in railway goods yards for shunting, or shifting railcars short distances. One example was Broad Street goods station in London. The yard was on a deck above some warehouses, and the deck was not strong enough to carry a locomotive, so ropes and capstans were used instead. Capstan (nautical) A capstan is a vertical-axled rotating machine developed for use on sailing ships to