Copyright © Philip M. Parker, INSEAD. Terms of Use.

Rig

Specialty Definition: Rig

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Specialty Definition: Heimdall

(From Wikipedia, the free Encyclopedia)

Heimdall ("pole of the world") is one of the gods in the Norse Mythology. He is the guardian that is to blow the Giallar horn if a danger approaches Asgard. His senses are so acute that he can hear the grass grow and he can see to the end of the world; he also required very little sleep. He is moreover the guardian of the Bifrost Bridge.

During Ragnarok, Heimdall was destined to kill and be killed by Loki.

He was a god of light, son of nine different mothers (the children of either Geirrendour or Aegir, called billow maidens). His hall was called Himinbjorg and his horse was Gultopp.

Another name for Heimdall is Rig ("ruler") as well as Gullintani ("gold tooth" -- he had golden teeth).

As Rig, Heimdall participated in the creation of mankind. Rig was travelling and happened upon a farm. It was owned by Ai and Edda. They offered Rig shelter and a low quality meal. He slept between the pair at night; Edda gave birth nine months later to a son whom they named Thrall. Thrall grew up strong and ugly. He married Thir and had twelve sons and nine daughters. They became the serfs of Norse society.

On his second journey, Rig came across a nice house owned by a craftsman and a farmer, Afi and Amma. The food was mediocre and they once again let him sleep between them. Nine months later, a son, Karl, was born. He married Snör and they had twelve sons and ten daughters, becoming the ancestors of the peasants of Norse society.

On his third trip, Rig came to a mansion inhabited by Fadir and Modir. They gave him excellent food and, nine months later, Modir gave birth to a beautiful baby named Jarl. Rig taught Jarl runes and other magic, as well as the language of the birds. Jarl then gathered some men and captured some land, then married Erna, with whom he had eleven sons, the ancestors of the warriors in Norse society.

Hilda R. Ellis Davidson [Gods and Myths of Northern Europe] sees a link from Heimdall to the Vanir. Unfortunately the Heimdallargaldr, a poem about the god known to Snorri Sturluson, has been lost.

Alternate: Heimdallr (Old Norse)

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Heimdall."

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Rig

(From Wikipedia, the free Encyclopedia)

• In Norse mythology, see Heimdall.
• In Hinduism, see Rig Veda.
• In abstract algebra, see Rig (algebra).
• Rigging is the arrangement of sails on a sailing vessel.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Rig."

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Rig (algebra)

(From Wikipedia, the free Encyclopedia)

In abstract algebra, a rig is an algebraic structure, similar to a ring, but without an analogue of subtraction. The term "rig", which originated as a joke, is meant to suggest that rigs do not have "negative" elements.

Definition

A rig is a set R equipped with two binary operations + and *, such that:

1. + is a commutative monoid with identity element 0; that is:
   1. (a + b) + c = a + (b + c);
   2. 0 + a = a;
   3. a + 0 = a;
   4. a + b = b + a.
2. * is a monoid with identity element 1; that is:
   1. (a * b) * c = a * (b * c);
   2. 1 * a = a;
   3. a * 1 = a.
3. * distributes over +; that is:
   1. a * (b + c) = (a * b) + (a * c)
   2. (a + b) * c = (a * c) + (b * c)

The symbol * is usually omitted from the notation; that is, a * b is just written ab. Similarly, an order of operations is accepted, according to which * is applied before +; that is, a + bc is a + (b * c).

The difference between rings and rigs, then, is that the operation + yields only a monoid, not necessarily a group.

A rig is called commutative if its multiplication is commutative.

Examples

• The simplest nontrivial example is the rig N of natural numbers (including zero), with the ordinary addition and multiplication. Likewise, the non-negative rational numbers and the non-negative real numbers form rigs. All these rigs are commutative.
• Any ring is automatically also a rig.
• The idealss of a ring form a rig under addition and multiplication of ideals.
• Square n-by-n matrices with non-negative entries form a rig under ordinary addition and multiplication of matrices.
• Any distributive lattice is a rig under join and meet.
• In particular, a Boolean algebra is a rig under these operations (as well as a Boolean ring under different operations).
• The set of cardinal numbers smaller than any given infinite cardinal form a rig under cardinal addition and multiplication. (We can't form a rig of all cardinal numbers because they do not form a set.)

Rig theory

Much of the theory of rings continues to make sense when applied to arbitrary rigs. In particular, one can generalise the theory of algebras over commutative rings directly to a theory of algebras over commutative rigs. Then a ring is simply an algebra over the commutative rig Z of integers. Some mathematicians go so far as to say that rigs are really the more fundamental concept, and specialising to rings should be seen in the same light as specialising to, say, algebras over the complex numbers.

Further generalisations

A near-rig does not require addition to be commutative, nor does it require right-distributivity. That is, laws 1.4 and 3.2 in the definition above are dropped. Just as cardinal numbers form a rig, so do ordinal numbers form a near-rig.

In category theory, a 2-rig is a category with functorial operations analogous to those of a rig. That the cardinal numbers form a rig can be categorified to say that the category of sets (or more generally, any topos) is a 2-rig.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Rig (algebra)."

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Sail-plan

(From Wikipedia, the free Encyclopedia)

A sail-plan is a formal set of drawings, usually prepared by a marine architect. It shows the various combinations of sail proposed for a sailing ship.

The combinations shown in a sail-plan almost always include three configurations:

A light air sail plan. Over most of the Earth, most of the time, the wind force is Force 1 or less. Thus an effective sail plan should include a set of huge, lightweight sails that will keep the ship underway in light breezes.

A working sail plan. This is the set of sails that are changed rapidly in variable conditions. They are much stronger than the light air sails, but still lightweight. An economical sail in this set will include several sets of furling ties. so a sail can be flown in varying amounts of wind.

A storm sail plan. This is the set of very small, very rugged sails flown in a gale, to keep the vessel under way and in control.

In all sail plans, the architect attempts to balance the force of the sails against the drag of the underwater keel in such a way that the vessel naturally points into the wind. In this way, if control is lost, the vessel will avoid broaching (turning edge-to-the wind), and being beaten by breaking waves. Broaching always causes uncomfortable motion, and in a storm, the breaking waves can destroy a lightly-built boat.

The architect also tries to balance the wind force on each sail plan against a range of loads and ballast. The calculation assures that the sail will not knock the vessel sideways with its mast in the water, a capsize and possible sinking.

Sailing frigate and its rigging.

Terminology

In English, courtesy of the British Admiralty, all sail-plans call a sail by the same name, no matter what their sail-plan. Once a sail is named, its ropes have standard names according to their use. So once a sailor learns the standard names for the sails, he knows the terms for all the parts on any sail-plan.

A sail plan is made by combining just a few basic types of sails:

• A fore and aft sail is one that, when flat, runs fore and aft. These types of sails are the easiest to manage, because they often do not need to be relaid when the ship changes course.
• A gaff rigged sail easier to manage than a square rigged sail but more difficult to handle than a triangular or Bermuda sail. A gaff-rigged sail is a fore-and-aft sail shaped like a truncated triangle whose upper edge is held up by a pole called a gaff, controlled by two ropes called vangs, (Dutch for pulls). Due to the weight of the gaff high above the deck and the extra lines required to control it the gaff rig requires more work to manage than a Bermuda rigged sail. Also the top of the gaff rigged sail tends to twist away from the wind reducing its efficiency. However, due to the extra boom on the top edge of the sail the gaff rigged sail is considered more sturdy than a triangular sail and the center of effort is typically lower, somewhat reducing the angle of heel (leaning of the boat caused by wind force on the sails) compared to a similar sized Bermuda rigged sail.
• A square sail is a square piece of canvas. It is one of the hardest to manage, but also one of the most efficient sails. To furl and unfurl this sail, sailors would walk on "ratlines" under the yard-arm holding the top of the sail.
• A lateen sail is a triangle with one or two sides attached to a wooden pole. This is one of the lowest drag (the sailing term is windage) sails, and it's often easy to manage.
• A bermuda or marconi sail is a triangular sail with one point going straight up.
• A stay-sail is a piece of cloth that has one or two sides attached to a stay, that is, one of the ropes or wires that helps hold the mast in place. A staysail was classically attached to the stay with wooden or steel hoops. Sailors would test the hoops by climbing on them.
• A jib is a stay-sail that flies in front of the foremost vertical mast.
• a bowsprit is a horizontal mast on the bow (front) of the boat.

Sails were classically made of hemp or cotton. They are now made from polyesters (Dacron and Mylar™), sometimes reinforced with crystalline hydrocarbons (Kevlar and Spectra™). Some large, lightweight sails are made of polyamides (Nylon).

Ropes are almost as important:

• standing rigging does not change position. Usually it braces the masts.
• running rigging is used to adjust sails and anchors.
• a line is a rope.
• a stay is a rope that doesn't move, part of the standing rigging.
• a vang is a rope used to pull something around.
• a sheet is a rope used to adjust the position of a sail so that it catches the wind properly.
• a block is a pulley that can be tied to the end of a rope. The sheave is the wheel. A fiddle block has two or more sheaves in one block. A snatch-block can be closed around a line, to grab the line, rather than threading the end of the line through the block.
• A shackle is a piece of metal to attach two ropes, or a block to a rope, or a sail to a rope. Customarily, a shackle has a screw-in pin which often is so tight that a shackle-key must be used to unscrew it. A snap-shackle doesn't screw, and can be released by hand, but it's usually less strong or more expensive than a regular shackle.
• halyards are the ropes on which one pulls to hoist something. E.g. the main-top-gallant-halyard would be the rope on which one pulls to hoist (unfurl) the main-top-gallant-sail.
• running lines are made fast (unmoving) by belaying them to (wrapping them around) a binnacle.

Ropes were classically made of manila, cotton, hemp or jute. They are now made of stainless steel (301), galvanized steel, polyester (Dacron), polyamides (Nylon), and sometimes crystallized hydrocarbons (Kevlar and Spectra™).

The standard terminology assumes three masts, from front to back, the fore-mast, main-mast and mizzen-mast. On ships with less than three masts, the tallest is the main-mast. Ships with more masts number them. Some barks (see below) have had as many as twelve masts.

The heights of the sails are named roughly after the bravery of the man needed to work on each, except the skysail, which existed only on American clipper ships.

From bottom to top, the sails of each mast are named by the mast and position on the mast, e.g. for the main-mast, from lowest to highest: main-sail, lower-main-top-sail, upper-main-top-sail, main-gallant, main-royal, and main-skysail. The sails for the foremast are called fore-sail, lower-fore-top-sail, etc. For the mizzenmast, mizzen-sail, etc.

On many warships, sails above the lower-top-sails were mounted on temporary masts ("top-masts" or "top-gallant-masts") held in wooden sockets called "tabernacles." These masts and their stays could be rigged or struck as the weather and tactical situation demanded.

In light breezes, the working square sails would be supplemented by studding sails out on the ends of the yardarms. These were called as a regular sail, with the addition of "studding." For example, the lower-main-top-studding-sail.

The staysails between the masts are named by the highest point (the danger) to which a sailor must climb to furl or unfurl the sail. The name is from the sail immediately below the highest attachment point of the stay holding up the staysail. Thus, the mizzen-top-gallant-stay-sail can be found dangling from the stay leading from above the mizzen (third) mast's top-gallant (fifth) sail to some place (usually two sails down) on the second (main) mast.

The jibs, the staysails between the first mast and the bowsprit, were named like staysails, except the middle one was called a jib, and the top one was called a flying jib.

For inscrutable reasons, the stays below a bowsprit are martingales, and those above it bracing the bowsprit are bobstays. The martingales are often the strongest stays on a ship, and often constructed of chain.

The stays on a ship roughly form hoops of tension holding the masts up against the wind. Many ships have been "tuned" (or "raked") by tightening the rigging in one area, and loosening it in others. The tuning can create most of the stress on the stays in some ships. This was a common emergency procedure on sailing warships.

In a bark or barkentine, each mast only has one gaff-sail, and this is always the lowest sail on the back of the mast. Barks are famous for being easy to sail.

Almost every type of tall ship had a gaff-sail on the mizzenmast, and called it the spanker.

A ship would fly its ensign and anchor light off a drop line from the spanker's gaff.

Some standard sail plans are:

• sloop a single jib or staysail and a bermudan or gaff mainsail lifted by a single mast. The mainsail is managed with a spar on the underside called a "boom." One the best-performing rigs, it is the fastest for up-wind passages. It's popular with amateurs because of its simplicity and potential for high performance. On small boats, it is a very simple rig. On larger sloops, the large sails pull dangerously, and one must manage them with winches.
• cutter, Like a sloop with two jibs in front. Better than a sloop for light winds. It's easier to manage, too. But, it has (very) slightly less up-wind ability than a sloop because it has more windage.
• yawl, is like sloop with a mizzen that extends over the stern. The mizzen is usually small, and is often intended just to help point the boat upwind and balance it when going downwind. It is commonplace for badly-designed yawls to sail faster with the mizzen removed.
• ketch, is like a yawl, but the mizzenmast is often much larger, and does not extend past the stern. The purpose of the mizzen is to make the sails smaller and more manageable than they would be on a sloop with the same sail area. The shorter masts also reduce the amount of ballast needed to keep the boat upright. Generally the rig is safer and less prone to broaching or capsize than a comparable sloop. The ketch is a classic small cargo boat.
• catboat, a single gaff-rigged sail. This is the easiest sail-plan to sail, and is used on the smallest and simplest boats. The catboat is a classic fishing boat. A popular movement among home-built boats uses this simple rig to make "folk-boats." One of the advantages is that there's no boom to hit one's head or knock one into the water, as there are in the sloop-derived boats. However, the gaff is mechanically complex, and adds weight high in the rigging. The gaff's fork is held on by a rope threaded through beads called trucks. The gaff must slide down the mast, and therefore prevents any stays from bracing the mast. This usually makes the rig even heavier, requiring even more ballast.
• baringer: A cheap, small sailing rig. When the term went out of use, no-one noticed, which implies that the type of rig remained in use under a different name. The best guess is that they were small single-masted gaff-rigs, a type that can still be purchased today.
• gunter is a small boat with a two-part take-down mast. Usually the mast can be erected with a halyard, and when retracted lies easily in the bottom of the boat. The British Admiralty used gunters widely as utility rigs for small boats. The mast would fit in a step-hole, or tabernacle in the bow of the boat. The general type of boat would be a row boat or whale-boat. Most often the sail would be rigged on a gaff, with no boom for easy tending and safety (no boom means the boom can't hit anyone). Gunters can have any single-masted rig, including sloops and cutters.
• schooner, a two-masted gaff-rig. It mounts jibs and staysails, and often little triangular top-sails. One of the easiest types to sail, but it goes poorly to up-wind without the topsails. The extra sails and ease of the gaff sails makes it easier to operate and faster than a sloop on all points of sail other than up-wind. A schooner is a classic yacht, fishing, small cargo and passenger boat. On all rigs, upwind passages are noisy, slow and have uncomfortable wave motion. Most sailors avoid them when they can. Therefore, many sailors prefer a schooner to a sloop: They say, why sacrifice performance on other points of sail to go upwind, if you rarely go upwind?
• brig or brigantine a gaff-rigged mast as the last of two masts. The forward mast could be square-rigged, sloop-rigged, or cutter-rigged and the rig was stilled called a brig. Two gaff-rigged masts are a schooner, of course. The gaff rig could be either a main or mizzen, as long as it was last.
• barkentine is a bark or brig in which the first of (usually two) masts is square-sailed, and the rest gaff-rigged. Some sailors who have sailed on them say it is a poor-handling compromise between a bark and a ship, though having more speed than a bark or schooner.
• bark, a series of gaff-rigged sails, one per mast, with staysails between the masts. Lower-speed, especially to windward, but requiring fewer sailors than a ship. This is a classic slow-cargo ship.
• ship a series of square-rigged masts, with stay-sails between. Ships originally had exactly three masts. Faster, but requiring more sailors than a bark. The ship was the classic sailing warship because it had the highest performance on all points of wind.
• Bragana or felucca: A classic in the Mediterranean or Indian Ocean: three lateen sails in a row.
• xebec, a three master with square-rgged first mast, and two lateen sails following. This is a north african pirate's cheap approximation of a warship.
• junk the standard Chinese design: Elliptical sails made flat with bamboo inserts, permitting them to sail well on any point of sail. Easy to sail, and reasonably fast. Some of the largest sailing ships ever constructed were junks for the Chinese treasure fleets. Junks also customarily had internal water-tight rooms, kept so by not having doors between them. Usually they were constructed of teak or mahogany.

See also

• Rigging

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Sail-plan."

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Abbreviations & Acronyms: Rig

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Synonyms within Context: Rig

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Modern Usage: Rig

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Commercial Usage: Rig

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Image Slideshow: Rig

Photos: Rig More pictures...

Illustrations: Rig More pictures...

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Photo Album: Rig

Thumbnail	Description & Credit	Thumbnail	Description & Credit
	Jerrie Cobb, Lady Pilot, testing Gimbal Rig in AWT. Credit: NASA.		Project Mercury - AWT Gimbaling Rig. Credit: NASA.
	Trolley rig - Hauling slack from sounding line prior to sounding Off of ISIS. Credit: Coast & Geodetic Survey Historical Image Collection.		Hauling in sounding line of trolley rig using hand crank on boat deck Off of ISIS. Credit: Coast & Geodetic Survey Historical Image Collection.
	An offshore oil rig on an artificial island. Credit: America's Coastlines.		Three-pole one-line rig catching Bigeye tuna in the Galapagos Islands area. Credit: Fisheries.
	Bigeye tuna caught with three-pole one-line rig. Credit: Fisheries.		An oil rig blew out spewing crude oil into Timbalier Bay. The rig is surrounded a boom to contain the oil. Credit: NOAA Restoration Center.
	Deployment of CTD and water sampling bottles. Oil rig in background. Operations on the NOAA Ship OREGON II. Credit: Sailing for Science - the NOAA Fleet Then and Now.		Workers rig nets to harvest catfish from the Delta Pride Catfish farms in MS.. Credit: USDA.
Source: pictures compiled by the editor from various references; see picture credits.

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Digital Photo Gallery: Rig
 

"OCEANS" by Matthew Mcnulty Commentary: "OFF KAUAI, ON A 42FT KETCH RIG."	"Gasoline Tanker" by Matthew Maaskant Commentary: "A large rig refuels a gas station. Visit http://www.qr5.com ."
Source: photographs selected by the editor, with permission from the photographers.

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Non-Fiction Usage: Rig

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Usage Frequency: Rig

Source: compiled by the editor from several corpora; see credits.

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Usage in Company Names: Rig

Source: compiled by the editor from Icon Group International, Inc.

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Cities: Rig

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Copyright © Philip M. Parker, INSEAD. Terms of Use.