Changes

==Origin==

==Origin==

probably from Low German, of Scandinavian origin; akin to Dan & Swedish ''barlast'' ballast; perhaps akin to [https://nordan.daynal.org/wiki/index.php?title=English#ca._600-1100.09THE_OLD_ENGLISH.2C_OR_ANGLO-SAXON_PERIOD Old English] ''bær'' bare & to Old English ''hlæst'' load, ''hladan'' to load  

probably from Low German, of Scandinavian origin; akin to Dan & Swedish ''barlast'' ballast; perhaps akin to [https://nordan.daynal.org/wiki/index.php?title=English#ca._600-1100.09THE_OLD_ENGLISH.2C_OR_ANGLO-SAXON_PERIOD Old English] ''bær'' bare & to Old English ''hlæst'' load, ''hladan'' to load  

*[http://en.wikipedia.org/wiki/16th_century 1530]

*[https://en.wikipedia.org/wiki/16th_century 1530]

==Definitions==

==Definitions==

*1: a heavy substance placed in such a way as to improve [[stability]] and [[control]] (as of the draft of a ship or the [[buoyancy]] of a balloon or submarine)

*1: a heavy substance placed in such a way as to improve [[stability]] and [[control]] (as of the draft of a ship or the [[buoyancy]] of a balloon or submarine)

A '''ballast''' tank is a compartment within a boat, ship or other floating [[structure]] that holds [[water]].

A '''ballast''' tank is a compartment within a boat, ship or other floating [[structure]] that holds [[water]].

The basic [[concept]] behind the ballast tank can be seen in many forms of aquatic life, such as the [http://en.wikipedia.org/wiki/Blowfish blowfish] or argonaut octopus, and the [[concept]] has been [[invented]] and reinvented many times by [[humans]] to serve a variety of [[purposes]]. For example, in 1849 [http://en.wikipedia.org/wiki/Abraham_Lincoln Abraham Lincoln], then an Illinois attorney, patented a [http://en.wikipedia.org/wiki/Abraham_Lincoln%27s_patent ballast-tank system] to enable cargo vessels to pass over shoals in North American [[rivers]].

The basic [[concept]] behind the ballast tank can be seen in many forms of aquatic life, such as the [https://en.wikipedia.org/wiki/Blowfish blowfish] or argonaut octopus, and the [[concept]] has been [[invented]] and reinvented many times by [[humans]] to serve a variety of [[purposes]]. For example, in 1849 [https://en.wikipedia.org/wiki/Abraham_Lincoln Abraham Lincoln], then an Illinois attorney, patented a [https://en.wikipedia.org/wiki/Abraham_Lincoln%27s_patent ballast-tank system] to enable cargo vessels to pass over shoals in North American [[rivers]].

A vessel may have a single ballast tank near its center or multiple ballast tanks typically on either side. A large vessel typically will have several ballast tanks including double bottom tanks, wing tanks as well as forepeak and aftpeak tanks. Adding ballast to a vessel lowers its center of [[gravity]], and increases the [http://en.wikipedia.org/wiki/Draft_(hull) draft] of the vessel. Increased draft may be required for proper propeller immersion.

A vessel may have a single ballast tank near its center or multiple ballast tanks typically on either side. A large vessel typically will have several ballast tanks including double bottom tanks, wing tanks as well as forepeak and aftpeak tanks. Adding ballast to a vessel lowers its center of [[gravity]], and increases the [https://en.wikipedia.org/wiki/Draft_(hull) draft] of the vessel. Increased draft may be required for proper propeller immersion.

A ballast tank can be filled or emptied in order to [[adjust]] the amount of ''ballast'' [[force]]. Ships designed for carrying large amounts of cargo must take on ballast water for proper [[stability]] when traveling with light loads and discharge water when heavily laden with cargo. Small sailboats designed to be light weight for being pulled behind automobiles on trailers are often designed with ballast tanks that can be emptied when the boat is removed from the water.

A ballast tank can be filled or emptied in order to [[adjust]] the amount of ''ballast'' [[force]]. Ships designed for carrying large amounts of cargo must take on ballast water for proper [[stability]] when traveling with light loads and discharge water when heavily laden with cargo. Small sailboats designed to be light weight for being pulled behind automobiles on trailers are often designed with ballast tanks that can be emptied when the boat is removed from the water.

In [http://en.wikipedia.org/wiki/Submarines submarines] ballast tanks are used to allow the vessel to submerge, water being taken in to alter the vessel's [[buoyancy]] and allow the submarine to dive. When the submarine surfaces, water is blown out from the tanks using compressed air, and the vessel becomes positively buoyant again, allowing it to rise to the [[surface]]. A submarine may have several types of ballast tank: the main ballast tanks, which are the main tanks used for diving and surfacing, and trimming tanks, which are used to adjust the submarine's attitude (its 'trim') both on the surface and when underwater.

In [https://en.wikipedia.org/wiki/Submarines submarines] ballast tanks are used to allow the vessel to submerge, water being taken in to alter the vessel's [[buoyancy]] and allow the submarine to dive. When the submarine surfaces, water is blown out from the tanks using compressed air, and the vessel becomes positively buoyant again, allowing it to rise to the [[surface]]. A submarine may have several types of ballast tank: the main ballast tanks, which are the main tanks used for diving and surfacing, and trimming tanks, which are used to adjust the submarine's attitude (its 'trim') both on the surface and when underwater.

Ballast water taken in to a tank from one [http://en.wikipedia.org/wiki/Body_of_water body of water] and discharged in another body of water can introduce [http://en.wikipedia.org/wiki/Invasive_species invasive species] of aquatic life. The taking in of water from ballast tanks has been responsible for the introduction of species that cause environmental and economic damage. For example, [http://en.wikipedia.org/wiki/Zebra_mussel zebra mussels] in the [http://en.wikipedia.org/wiki/Great_Lakes Great Lakes] of Canada and the United States.

Ballast water taken in to a tank from one [https://en.wikipedia.org/wiki/Body_of_water body of water] and discharged in another body of water can introduce [https://en.wikipedia.org/wiki/Invasive_species invasive species] of aquatic life. The taking in of water from ballast tanks has been responsible for the introduction of species that cause environmental and economic damage. For example, [https://en.wikipedia.org/wiki/Zebra_mussel zebra mussels] in the [https://en.wikipedia.org/wiki/Great_Lakes Great Lakes] of Canada and the United States.

[[Category: General Reference]]

[[Category: General Reference]]