Types Stern

1 types

1.1 transom
1.2 elliptical
1.3 cruiser
1.4 others

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)

in naval architecture, term transom has 2 meanings. first, transom can refer of individual beams run side-to-side or athwart hull @ point abaft fashion timber; second, transom can refer flat or curved surface panel of transom stern. in sense, transom stern product of use of series of transoms, , hence 2 terms have blended.

the stern of classical sailing ship housed captain s quarters , became increasingly large , elaborate between 15th , 18th centuries, in baroque era, when such wedding-cake-like structures became heavy crews threw decoration overboard rather burdened useless weight. until new form of stern appeared in 19th century, transom stern floating house—and required many timbers, walls, windows, , frames. stern frame provided foundational structure of transom stern, , composed of sternpost, wing transom, , fashion piece.

abaft fashion timber, transom stern composed of 2 different kinds of timbers:

transoms – these timbers extend across low parts of hull near rudder, , secured (notched and/or bolted) sternpost. transom located @ base of stern, , uppermost of main transoms, typically called wing transom; principal transom below , level lower deck called deck transom; between these 2 series of filling transoms. if stern had transoms above wing transom, no longer affixed sternpost. first of these might called counter transom; next window sill transom; above that, spar deck transom. larger vessel, more numerous , wider transoms required support stern.
stern timbers (also called stern frames) – these timbers mounted vertically in series; each timber typically rests or steps on wing transom , stretches out (aft) , upward. not reaching way taffrail called short stern timbers, while called long stern timbers. 2 outermost of these timbers, located @ corners of stern, called side-counter timbers or outer stern timbers. stern timbers collectively determine backward slope of square stern, called rake -- is, if stern timbers end producing final transom falls vertically water, considered transom no rake; if stern timbers produce stern degree of slope, such stern considered raked stern.

the flat surface of transom stern may begin either @ or above waterline of vessel. geometric line stretches wing transom archboard called counter; large vessel may have 2 such counters, called lower counter , second or upper counter. lower counter stretches directly above wing transom lower counter rail, , upper counter lower counter rail upper counter rail, under stern s lowest set of windows (which in naval parlance called lights ).

elliptical

diagram of circular stern designed sir richard seppings.

the visual unpopularity of seppings circular stern rectified sir william symonds. in revised stern, set of straight post timbers (also called whiskers , horn timbers , or fan tail timbers ) stretches keel diagonally aft , upward. rests on top of sternpost , runs on either side of rudder post (thus creating helm port through rudder passes) point above vessel s waterline. whereas timbers of transom stern heeled on wing transom, timbers of elliptical stern heel on whiskers, affixed @ 45̊ angle (i.e., canted ) when viewed overhead , decrease in length installed aft until curvature complete. finished stern has continuous curved edge around outside , raked aft. other names elliptical stern include counter stern, in reference long counter, , cutaway stern. elliptical stern began use during age of sail, remained popular both merchant , warships nautical age of steam , through first 8 decades of steamship construction (roughly 1840–1920), despite fact design left rudder exposed , vulnerable in combat situations.

cruiser

as ships of wooden construction gave way iron , steel, cruiser stern—another design without transoms , known variously canoe stern, parabolic stern, , double-ended stern—became next prominent development in ship stern design, particularly in warships of latter half of 20th century. intent of re-design protect steering gear bringing below armor deck. stern came point rather flat panel or gentle curve, , counter reached sternpost way taffrail in continuous arch. discovered vessels cruiser sterns experienced less water resistance when under way elliptical sterns, , between world war , world war ii merchant ship designs followed suit.

others

illustrations of several kinds of sterns: 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 3 main types of stern has vanished modern naval architectural repertoire, , 3 continue utilized in 1 form or different sets of designers , broad spectrum of uses. variations on these basic designs have resulted in outflow of new stern types , names, of itemized here.

the reverse stern, reverse transom stern, sugar-scoop, or retroussé stern kind of transom stern raked backwards (common on modern yachts, rare on vessels before 20th century); vertical transom stern or plumb stern raked neither forward nor back, falls directly taffrail down wing transom. rocket ship stern term extremely angled retroussé stern. double ended ship narrow square counter formed bulwarks or upper deck above head of rudder said have pink stern or pinky stern. torpedo stern or torpedo-boat stern describes kind of stern low rounded shape flat @ waterline, slopes upward in conical fashion towards deck (practical small high-speed power boats shallow drafts).

a costanzi stern type of stern designed use on ocean-going vessels. compromise between spoon-shaped stern found on ocean liners, , flat transom, required fitting azimuth thrusters. design allows improved seagoing characteristics. stern design on queen mary 2, , proposed ss oceanic , eugenio c, both constructed in 1960s.

the constanzi stern of queen mary 2

a lute stern found on inshore craft on sussex, england shore. comprises watertight transom topside planking extended aft form non-watertight counter boarded across fashion timbers curving outward aft transom. working boats , modern replicas have similar form of counter, built water tight described in transom stern section above. these being confused lute sterns lute not watertight, better term needed. chappelle in american small sailing craft refers bermudan boat form of counter, using term square tuck stern describe it. term tuck used in northwest of england area of hull @ sternpost, , bulkhead across counter if 1 fitted.

the fantail stern describes stern has stern starts @ water , widens go upwards. famous on many 19th century tea clippers , ill-fated rms titanic.

a bustle stern refers kind of stern (transom, elliptical, etc.) has large bustle or blister @ waterline below stern prevent stern squatting when getting underway. appears in sailboats, never in power-driven craft.