Cable length
Encyclopedia
A cable length or cable's length is a nautical unit
of measure equal to one tenth of a nautical mile
or 100 fathoms, or sometimes 120 fathoms. The unit is named after the length of a ship's anchor
cable in the age of sail
. The definition varies:
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...
of measure equal to one tenth of a nautical mile
Nautical mile
The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
or 100 fathoms, or sometimes 120 fathoms. The unit is named after the length of a ship's anchor
Anchor
An anchor is a device, normally made of metal, that is used to connect a vessel to the bed of a body of water to prevent the vessel from drifting due to wind or current. The word derives from Latin ancora, which itself comes from the Greek ἄγκυρα .Anchors can either be temporary or permanent...
cable in the age of sail
Age of Sail
The Age of Sail was the period in which international trade and naval warfare were dominated by sailing ships, lasting from the 16th to the mid 19th century...
. The definition varies:
- International: nautical mileNautical mileThe nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
, or 185.2 mMetreThe metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology... - Imperial (AdmiraltyAdmiraltyThe Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...
): Admiralty mileNautical mileThe nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...
(185.2 metres (607.6 ft)), or 101 fathomFathomA fathom is a unit of length in the imperial and the U.S. customary systems, used especially for measuring the depth of water.There are 2 yards in an imperial or U.S. fathom...
s- The traditional British fathom varied from 5½ feet to 7 feet in the Merchant NavyMerchant NavyThe Merchant Navy is the maritime register of the United Kingdom, and describes the seagoing commercial interests of UK-registered ships and their crews. Merchant Navy vessels fly the Red Ensign and are regulated by the Maritime and Coastguard Agency...
.
- The traditional British fathom varied from 5½ feet to 7 feet in the Merchant Navy
- U.S. customaryUnited States customary unitsUnited States customary units are a system of measurements commonly used in the United States. Many U.S. units are virtually identical to their imperial counterparts, but the U.S. customary system developed from English units used in the British Empire before the system of imperial units was...
(US Navy): 120 fathoms (720 feet, 219.456 m)