Stern Gerlach Medal

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.

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, 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. 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. 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regarded by many as simply ugly—no American warships were designed with such sterns, and the round stern was quickly superseded by the elliptical stern.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. 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

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.

Abaft the fashion timber, the transom stern was composed of two different kinds of timbers:
*Transoms – These timbers extend across the low parts of the hull near the rudder, and are secured (notched and/or bolted) to the sternpost. The transom located at the base of the stern, and the uppermost of the main transoms, was typically called the ''wing'' transom; the principal transom below this and level with the lower deck was called the ''deck'' transom; between these two were a series of ''filling'' transoms. If the stern had transoms above the wing transom, they would no longer be affixed to the sternpost. The first of these might be called a ''counter'' transom; next up was the ''window sill'' transom; above that, the ''spar deck'' transom. The larger the vessel, the more numerous and wider the transoms required to support its stern.
*Stern timbers (also called ''stern frames'') – These timbers are mounted vertically in a series; each timber typically rests or "steps" on the wing transom and then stretches out (aft) and upward. Those not reaching all the way to the taffrail are called ''short stern timbers'', while those that do are called ''long stern timbers''. The two outermost of these timbers, located at the corners of the stern, are called the ''side-counter timbers'' or ''outer stern timbers''. It is the stern timbers collectively which determine the backward slope of the square stern, called its rake – that is, if the stern timbers end up producing a final transom that falls vertically to the water, this is considered a transom with no rake; if the stern timbers produce a stern with some degree of slope; such a stern is considered a raked stern.

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. 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").

Elliptical

The visual unpopularity of Seppings's circular stern was soon rectified by Sir William Symonds

HOME


Content is Copyleft
Website design, code, and AI is Copyrighted (c) 2014-2017 by Stephen Payne


Consider donating to Wikimedia



As an Amazon Associate I earn from qualifying purchases