Stern

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Detailed schematic of an elliptical or "fantail" stern How wooden ships are built 78.jpg
Detailed schematic of an elliptical or "fantail" stern
The flat transom stern of the cargo ship Sichem Princess Marie-Chantal Ship transom.JPG
The flat transom stern of the cargo ship Sichem Princess Marie-Chantal

The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Originally, the term only referred to the aft port section of the ship, but eventually came to refer to the entire back of a vessel. The stern end of a ship is indicated with a white navigation light at night.

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Sterns on European and American wooden sailing ships began with two principal forms: the square or transom stern and the elliptical, fantail, or merchant stern, [1] and were developed in that order. The hull sections of a sailing ship located before the stern were composed of a series of U-shaped rib-like frames set in a sloped or "cant" arrangement, with the last frame before the stern being called the fashion timber(s) or fashion piece(s), so called for "fashioning" the after part of the ship. [2] This frame is designed to support the various beams that make up the stern.

In 1817 the British naval architect Sir Robert Seppings introduced the concept of the round or circular stern. [3] The square stern had been an easy target for enemy cannon, and could not support the weight of heavy stern chase guns. But Seppings' design left the rudder head exposed, and was regarded by many as simply ugly—no American warships were designed with such sterns, and the round stern was quickly superseded by the elliptical stern. The United States began building the first elliptical stern warship in 1820, a decade before the British. [3] USS Brandywine became the first sailing ship to sport such a stern. Though a great improvement over the transom stern in terms of its vulnerability to attack when under fire, elliptical sterns still had obvious weaknesses which the next major stern development — the iron-hulled cruiser stern — addressed far better and with significantly different materials.

Types

Transom

1. Keel (light peach) 2. Skeg (dark purple) 3. Deadwood (olive drab) 4. Stern post (forest green) 5. Filling chock (bright yellow) 6. Filling transoms (pale yellow-green) 7. Wing transom (turquoise) 8. Helm port (orange) 9. Counter timbers (pale violet) 10. Margin (indigo) 11. Horn timber (green) 12. Stern timbers (apricot) 13. Side-counter timbers (pale yellow) 14. Quarter-timbers (red) 15. Fashion timber (fuchsia) 16. Cant frames (blue) 17. Square body frames (uncolored) Illustrated marine encyclopedia 341.jpg
1. Keel (light peach) 2. Skeg (dark purple) 3. Deadwood (olive drab) 4. Stern post (forest green) 5. Filling chock (bright yellow) 6. Filling transoms (pale yellow-green) 7. Wing transom (turquoise) 8. Helm port (orange) 9. Counter timbers (pale violet) 10. Margin (indigo) 11. Horn timber (green) 12. Stern timbers (apricot) 13. Side-counter timbers (pale yellow) 14. Quarter-timbers (red) 15. Fashion timber (fuchsia) 16. Cant frames (blue) 17. Square body frames (uncolored)

In naval architecture, the term transom has two meanings. First, it can be any of the individual beams that run side-to-side or "athwart" the hull at any point abaft the fashion timber; second, it can refer specifically to the flat or slightly curved surface that is the very back panel of a transom stern. In this sense, a transom stern is the product of the use of a series of transoms, and hence the two terms have blended.

The stern of a classical sailing ship housed the captain's quarters and became increasingly large and elaborate between the 15th and 18th centuries, especially in the baroque era, when such wedding-cake-like structures became so heavy that crews sometimes threw the decoration overboard rather than be burdened with its useless weight. Until a new form of stern appeared in the 19th century, the transom stern was a floating house—and required just as many timbers, walls, windows, and frames. The stern frame provided the foundational structure of the transom stern, and was composed of the sternpost, wing transom, and fashion piece. [4]

Abaft the fashion timber, the transom stern was composed of two different kinds of timbers:

The flat surface of any transom stern may begin either at or above the waterline of the vessel. The geometric line which stretches from the wing transom to the archboard is called the counter; a large vessel may have two such counters, called a lower counter and a second or upper counter. [5] The lower counter stretches from directly above the wing transom to the lower counter rail, and the upper counter from the lower counter rail to the upper counter rail, immediately under the stern's lowest set of windows (which in naval parlance were called "lights" [6] ).

Elliptical

Diagram of a circular stern as designed by Sir Robert Seppings Circular stern diagram.jpg
Diagram of a circular stern as designed by Sir Robert Seppings

The visual unpopularity of Seppings's circular stern was soon rectified by Sir William Symonds. In this revised stern, a set of straight post timbers (also called "whiskers", "horn timbers", or "fan tail timbers" [8] ) stretches from the keel diagonally aft and upward. It rests on the top of the sternpost and runs on either side of the rudder post (thus creating the "helm port" through which the rudder passes) to a point well above the vessel's waterline. Whereas the timbers of the transom stern all heeled on the wing transom, the timbers of the elliptical stern all heel on the whiskers, to which they are affixed at a 45° angle (i.e., "canted") when viewed from overhead and decrease in length as they are installed aft until the curvature is complete. The finished stern has a continuous curved edge around the outside and is raked aft.

The counter stern of SS Constitution was shared with her sister ship, SS Independence Ss Constitution1953.jpg
The counter stern of SS Constitution was shared with her sister ship, SS Independence

Other names for the elliptical stern include a "counter stern", in reference to its very long counter, and a "cutaway stern". [9] The elliptical stern began use during the age of sail, but remained very popular for both merchant and warships well into the nautical age of steam and through the first eight decades of steamship construction (roughly 1840–1920). Despite the design's leaving the rudder exposed and vulnerable in combat situations, many counter-sterned warships survived both World Wars, and stylish high-end vessels sporting them were coming off the ways into the 1950s, including the US-flagged sisters SS Constitution and SS Independence.

Cruiser

As ships of wooden construction gave way to iron and steel, the cruiser stern—another design without transoms and known variously as the canoe stern, parabolic stern, and the double-ended stern—became the next prominent development in ship stern design, particularly in warships of the earlier half of the 20th century. [10] The intent of this re-design was to protect the steering gear by bringing it below the armor deck. The stern now came to a point rather than a flat panel or a gentle curve, and the counter reached from the sternpost all the way to the taffrail in a continuous arch. It was soon discovered that vessels with cruiser sterns experienced less water resistance when under way than those with elliptical sterns, and between World War I and World War II most merchant ship designs soon followed suit.

Others

Illustrations of several kinds of stern: Fig. 21 Fantail; Fig. 22 Transom; Fig. 23 "Compromise"; Fig. 24 "V" stern; Fig. 25 Round; Fig. 26 Torpedo; Fig. 27 Canoe Sterns.jpg
Illustrations of several kinds of stern: Fig. 21 Fantail; Fig. 22 Transom; Fig. 23 "Compromise"; Fig. 24 "V" stern; Fig. 25 Round; Fig. 26 Torpedo; Fig. 27 Canoe

None of these three main types of stern has vanished from the modern naval architectural repertoire, and all three continue to be utilized in one form or another by different sets of designers and for a broad spectrum of uses. Variations on these basic designs have resulted in an outflow of "new" stern types and names, only some of which are itemized here.

The reverse stern, reverse transom stern, sugar-scoop, or retroussé stern is a kind of transom stern that is raked backwards (common on modern yachts, rare on vessels before the 20th century); the vertical transom stern or plumb stern is raked neither forward nor back, but falls directly from the taffrail down to the wing transom. The rocket ship stern is a term for an extremely angled retroussé stern. A double ended ship with a very narrow square counter formed from the bulwarks or upper deck above the head of the rudder is said to have a pink stern or pinky stern. [4] The torpedo stern or torpedo-boat stern describes a kind of stern with a low rounded shape that is nearly flat at the waterline, but which then slopes upward in a conical fashion towards the deck (practical for small high-speed power boats with very shallow drafts). [12]

A Costanzi stern is a type of stern designed for use on ocean-going vessels. Its hard-chined design is a compromise between the 'spoon-shaped' stern usually found on ocean liners, and the flat transom, often required for fitting azimuth thrusters. The design allows for improved seagoing characteristics. It is the stern design on Queen Mary 2, and was originally proposed for SS Oceanic and Eugenio C , both constructed in the 1960s. [13]

The hard-chines of a Costanzi stern on Queen Mary 2 Queen Mary 2 - geograph.org.uk - 477372.jpg
The hard-chines of a Costanzi stern on Queen Mary 2

A lute stern is to be found on inshore craft on the Sussex, England, shore. It comprises a watertight transom with the topside planking extended aft to form a non-watertight counter which is boarded across the fashion timbers curving outward aft from the transom. Some working boats and modern replicas have a similar form of counter, built to be water tight as described in the "transom stern" section above. These are being confused with lute sterns but as a lute is not watertight, a better term is needed. Chappelle in American Small Sailing Craft [14] refers to a Bermudan boat with this form of counter, using the term "square tuck stern" to describe it. The term "tuck" is used in the northwest of England for this area of the hull at the sternpost, and for the bulkhead across the counter if one is fitted.

The fantail stern describes a stern that starts at the water and widens as you go upwards. This is famous on many 19th century tea clippers and the ill-fated RMS Titanic .

A bustle stern refers to any kind of stern (transom, elliptical, etc.) that has a large "bustle" or blister at the waterline below the stern to prevent the stern from "squatting" when getting underway. [15] It only appears in sailboats, never in power-driven craft.

Related Research Articles

Hull (watercraft) Watertight buoyant body of a ship or boat

A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top, or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline.

Rudder Control surface for fluid-dynamic steering in the yaw axis

A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull (watercraft) or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics.

Boat building Design and construction of floating vessels

Boat building is the design and construction of boats and their systems. This includes at a minimum a hull, with propulsion, mechanical, navigation, safety and other systems as a craft requires.

Deck (ship) Part of a ship or boat

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the horizontal structure that forms the "roof" of the hull, strengthening it and serving as the primary working surface. Vessels often have more than one level both within the hull and in the superstructure above the primary deck, similar to the floors of a multi-storey building, that are also referred to as decks, as are certain compartments and decks built over specific areas of the superstructure. Decks for some purposes have specific names.

This is a glossary of nautical terms; some remain current, while many date from the 17th to 19th centuries. See also Wiktionary's nautical terms, Category:Nautical terms, and Nautical metaphors in English. See the Further reading section for additional words and references.

Bow (watercraft) Forward part of the hull of a ship

The bow is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. The aft end of the boat is the stern.

Length between perpendiculars Form of ship length measurement

Length between perpendiculars is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. When there is no sternpost, the centerline axis of the rudder stock is used as the aft end of the length between perpendiculars.

Draft (hull) Vertical distance between the waterline and the bottom of the hull (keel)

The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water.

Sailing yacht Private sailing vessel with overnight accommodations

A sailing yacht, is a leisure craft that uses sails as its primary means of propulsion. A yacht may be a sail or power vessel used for pleasure, cruising, or racing. There is no standard definition, so the term applies here to sailing vessels that have a cabin with amenities that accommodate overnight use. To be termed a "yacht", as opposed to a "boat", such a vessel is likely to be at least 33 feet (10 m) in length and have been judged to have good aesthetic qualities. Sailboats that do not accommodate overnight use or are smaller than 30 feet (9.1 m) are not universally called yachts. Sailing yachts in excess of 130 feet (40 m) are generally considered to be superyachts.

Transom (nautical) Flat part of a boats squared stern

A transom is the vertical reinforcement which strengthens the stern of a boat. This flat termination of the stern is typically above the waterline.

Tongkang

Tongkang or "Tong'kang" refers to several type of boats used to carry goods along rivers and shoreline in Maritime Southeast Asia. One of the earliest record of tongkang has a background of 14th century, being mentioned in Malay Annals which was composed no earlier than 17th century. One passage mentioned it as being used by Majapahit empire during the 1350 attack on Singapura.

Lambo (boat)

The term lambo or lamba refer to two types of traditional boats from Indonesia.

<i>Comus</i>-class corvette

The Comus class was a class of Royal Navy steam corvettes, re-classified as third-class cruisers in 1888. All were built between 1878 and 1881. The class exemplifies the transitional nature of the late Victorian navy. In design, materials, armament, and propulsion the class members resemble their wooden sailing antecedents, but blended with characteristics of the all-metal mastless steam cruisers which followed.

<i>Sparrow Hawk</i> (pinnace)

The Sparrow-Hawk was a 'small pinnace' similar to the full-rigged pinnace Virginia that sailed for the English Colonies in June 1626. She is the earliest ship to participate in the first decades of English settlement in the New World to have survived to the present day.

<i>Pinas</i> (ship)

The pinas, sometimes called "pinis" as well, is one of two types of junk rigged schooners of the east coast of the Malay peninsula, built in the Terengganu area. This kind of vessel was built of Chengal wood by the Malays since the 19th century and roamed the South China Sea and adjacent oceans as one of the two types of traditional sailing vessels the late Malay maritime culture has developed: The bedar and the pinas.

Bedar (ship)

The term bedar,, is applied to a wide variety of boats of the east coast of Malaysia that carry one or two junk sails and lack the typical transom stern of the perahu pinas. These junk rigged boats are usually built in the Terengganu area. The stern of the bedar is a classical "canu" or "pinky stern," being a typical "double ender", a bit like a modern ship's lifeboat, with a very full turn of the bilge and with markedly raked stem and stern. They came in small versions as small one-masted fishing vessels - anak bedar and were built as big as 90 feet over deck (LOD). The majority of the bedars were usually 45 to 60 feet over deck. The bedar, like all Terengganu boats, was built of Chengal wood by the Malays since the 19th century and roamed the South China Sea and adjacent oceans as a highly seaworthy traditional sailing vessel.

In naval architecture, a taffrail is the handrail around the open deck area toward the stern of a ship or boat. The rear deck of a ship is often called the afterdeck or poop deck. Not all ships have an afterdeck or poop deck. Sometimes taffrail refers to just the curved wooden top of the stern of a sailing man-of-war or East Indiaman ship. The rails of these wooden sailing ships usually had hand-carved wooden rails, often highly decorated. Sometimes taffrail refers to the complete deck area at the stern of a vessel.

Palari (boat)

Palari is a type of Indonesian sailing vessel from South Sulawesi. It was mainly used by the people of Ara and Lemo Lemo, for transporting goods and people. This vessel is rigged with pinisi rig, which often makes it better known as "Pinisi" instead of its name. In Singapore, palari is known as "Makassartrader".

The Capri 26 is an American trailerable sailboat that was designed by Frank W. Butler and Gerry Douglas as a cruiser-racer and first built in 1990.

This is a list of nautical terms starting with the letter S.

References

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  2. Burney, William (2006) [1815], Falconer's New Universal Dictionary of the Marine, London: Chatham Publishing, p. 457, ISBN   1-86176-204-6
  3. 1 2 Canney, Donald L. (2001), Sailing Warships of the U.S. Navy, Annapolis: Naval Institute Press, OCLC   201931743
  4. 1 2 Steel, David (1805), The Shipwright's vade-mecum, London: Navigation-Warehouse, pp. 120, 136, OCLC   34631820 , retrieved 23 July 2011
  5. 1 2 Hedderwick, Peter (1830), A Treatise On Marine Architecture, Edinburgh: Published for author, p. 122, OCLC   220933246 , retrieved 29 July 2011
  6. Mondfeld, Wolfram zu (2005), Historic Ship Models, New York: Sterling, p. 104, ISBN   1-4027-2186-2
  7. "Sir Robert Seppings". HMS Unicorn. Retrieved 2020-03-16.
  8. Hall, Henry (1884), Report on the Ship-Building Industry of the United States, Washington, D.C.: Government Printing Office, p. 168, OCLC   11633113 , retrieved 5 May 2011
  9. "Glossary-"Counter" (or "Cutaway") Sterns". Naval History & Heritage Command. 17 March 2007. Retrieved 24 July 2011.
  10. Schneekluth, Herbert; Bertram, Volker (1998) [1987], Ship Design for Efficiency and Economy (Second ed.), Woburn: Butterworth-Heinemannn, ISBN   0-7506-4133-9 , retrieved 23 July 2011
  11. Leitch, Albert Clark (1920). Victor W. Pagé (ed.). Motor Boats and Boat Motors. New York: Norman W. Henley. p. 32. OCLC   314767880.
  12. Whitney, William Dwight (1911), Smith, Benjamin E. (ed.), The Century Dictionary and Cyclopedia, vol. 9, New York: The Century Company, p. 481, OCLC   1062940 , retrieved 1 May 2011
  13. Maxtone-Graham, John (2004). Queen Mary 2: The Greatest Ocean Liner of our Time. Bulfinch Press. p. 21. ISBN   0-8212-2885-4.
  14. Chapelle, Howard Irving (1951). American Small Sailing Craft: Their Design, Development, and Construction . Norton. ISBN   9780393031430.
  15. Chapelle, Howard Irving (1971) [1936], Yacht Design and Planning, New York: WW Norton & Company, pp. 80–81, ISBN   0-393-03756-8