Sailing Ship Hull
The first thing to be established in the draft of a ship is her length; and as a ship of war, according to her rate, is furnished with a certain number of cannon, which are placed in battery on her decks, it is necessary that a sufficient distance should be lest between the ports to work the guns with facility, and particularly to leave space enough between the foremost gun and the stem, and between the aftmost gun and the stern-post on each side, on account of the arching, or inward curve of the ship towards her extremities.
When the length of a Ship is determined, it is usual to fix her breadth by the dimensions of the midship-beam. On this occasion the shipwrights, for the most part, are conducted by rules founded on their own observation; for having remarked, that some vessels, which by repeated experience have been found to answer all the purposes of navigation, have a certain breadth in proportion to their length, they have interred that it would be improper to depart from this proportion: but as other ships have been constructed with different breadths, which were equally perfect, a variety of different general rules have been adopted by these artists, who are accordingly divided in their opinions about the breadth which ought to be assigned to a ship relatively with her length, while each one produces reasons and experience in support of his own standard.
Those who would diminish the breadth allege, that a narrow vessel meets with less resistance in passing through the water; 2dly, That by increasing the length she will drive less to leeward; 3dly, That according to this principle, the water-lines will be more conveniently formed to divide the fluid; 4thly, That a long and narrow ship will require less sail to advance swiftly; that her masts will be lower, and her rigging lighter; and, by consequence, the seamen less fatigued with managing the sails, &c.
Those, on the contrary, who would enlarge the breadth, pretend, 1st, That this form is better fitted to receive a good battery of guns; 2dly, That there will be more room to work the guns conveniently; 3dly, That by carrying more sail, the, ship will be enabled to run faster; or, that this quality will at least overbalance the advantage which the others have of more easily dividing the fluid; 4thly, That, being broader at the load-water line, or place where the surface of the water describes a line round the bottom, they will admit of being very narrow on the floor, particularly towards the extremities; and, 5thly, That a broad vessel will more readily rise upon the waves than a narrow one.
From such opposite principles has resulted that varicty of standards adopted by different shipwrights; and a servile imitation of these mechanical methods has, to the great reproach of the art, produced all these rules of proportion: for the various models they have adopted indisputably prove their doubt and uncertainty with regard to their proper standard.
In vessels of war, the general dimensions are established by authority of officers appointed by the government to superintend the building of ships. In the merchants service, the extreme breadth, length of the keel, depth in the hold, heighth between-decks and in the waist, are agreed on by contract; and from these dimensions the shipwright is to form a draught suitable to the trade for which the ship is designed.
In projecting the draught of a vessel of war, the first article to be considered is her length. As all ships are much longer above than below, it is also necessary to distinguish the precise part of her heighth, from which her length is taken: this is usually the lower gun-deck, or the load water-line. It has been already observed, that water-lines are described longitudinally on a ship's bottom by the surface of the water in which she floats, and that the line which determines her depth under the water is usually termed the load-water-line. In this draught it will be particularly necessary to leave sufficient distance between the ports.
Joshua Humphreys, the designer of the US Navy's first six frigates, that included Constitution, had two criteria to satisfy, to out gun the next rate ship and to out-sail adversaries. The solution required a never-before-built design. The successful integration of the two design criteria demanded an innovated technical solution to the problems of strength of materials and hull design. Humphreys understood that optimization of the two criteria became mutually exclusive when building a hull. The fine entry and run required for sailing qualities and the weight of a heavy armament causes particular problems for wooden hull sailing ships. Combining the weight of the guns and the buoyancy curve of a fast sailing hull results in a force that distorts the hull. The distortion known as "hog" is the bending along the length of the keel. It is the same curve that resembles the curve of a hog's back. With minimal buoyancy, the ends of the ship tend to drop down under the weight loads of the guns, while the center midbody, being more buoyant, rises upward. Humphreys recognized the need to stiffen the hull to resist the forces causing hogging.
Diagonal riders are wooden support structures. They are cut into the overhead lower deck beams and follow the curve of the hull to the keelson, the area protecting the keel or spine of the ship. The purpose of diagonal riders is to prevent hogging, or the curvature of the ship's keel, which occurs when weight and buoyancy factors cause the ship's bow and stern to sag and forces the keel to rise in the middle. Diagonal riders are made of laminated white oak. Laminated wood is comprised of small pieces of selected wood that is glued and pressed together to make pieces long enough to use for a particular task, then cut into the shape needed. When the ship was designed, the oak riders were not made of laminated wood; however, laminating is integral to preserving the supply of white oak trees now.
The Bow chaser is the bending or rounded part of a ship forward; the stem or prow.
The practice of protecting ships with carved figures dates back to the Phoenicians, Egyptians, and Greeks and continued well into the 19th century, when it would reach its peak. The ship's figurehead was an ornamental head or figure mounted under the bowsprit so that its eyes could find the way and, directly or indirectly, influence the outcome of the journey. Originally outfitted with a figurehead depicting Hercules clothed in a lion's skin and holding the unfurled Constitution, CONSTITUTION was forced to replace this figure when it was severely damaged in a collision with another ship during the Barbary Wars. A billethead, smaller and less ornamental, bearing winged dragons would then grace CONSTITUTION's bow until the end of the War of 1812. The wartime dragons were then traded in for the even less decorative stars-and-flourishes billethead. When CONSTITUTION next returned to Boston, the figurehead was replaced bythat of President Andrew Jackson. One of the most notorious figures in American life at that time, President Jackson's likeness sparked a rally of anti-Democrats, demanding a new figurehead for CONSTITUTION. Despite vehement protest, the figurehead remained, though not for long. In the middle of the night on July 3, 1834 a single marauder decapitated the image of President Jackson, making off with most of the figure's head. Despite a reward offered for the culprit, his identity was never learned. The figure of President Jackson was quickly repaired and graced the bow of CONSTITUTION for another forty years. Stars-and-flourishes then replaced the Andrew Jackson figurehead, which remains CONSTITUTION's figurehead to this very day.
The projecting pieces of timber near the bow served as crane booms for hoisting the anchors to the rail. The "Cat" is the complication of tackle that is used to raise the anchor from the waterline to the catheads. The cat tackle has a multiple block to aid in lifting the anchor up to the cathead. In other words, once you raised the anchor and stowed the main cable, you need to tie up the anchor where it wouldn't swing free and damage the ship. That was the cathead. Once raised, the anchors would then be secured to the catheads until they were ordered cast off again. The anchor ring is catted by the large hook attached to the projecting cathead. Generally, a Cathead is the outside spool on a winch, used in handling hauling lines and in topping and lowering booms. Catheads may derive their name from the carvings or cast iron caps in the form of cats or lions, the cat in the eighteenth century being a royal pet. These decorative heads were often plated in gold, and were one of the few ornaments found on a warship.
The Hawse is the part of a ship's bow in which the hawse holes for the anchor chains are located. Each anchor has its own set of anchor cables running from its location on the ship, around the anchor capstan, and down through the Hawse Pipes. These cables need a place to go to prevent them from lying on the deck in open space; this is where the Hawse Pipes come into play. The Hawse Pipes are tubes leading the anchor chain from the deck on which the windlass is located down and forward through the vessel's bow plating. The cables run down through either set of pipes depending whether it is on the starboard side or the port side of the gun deck. The anchor cables are then stacked neatly on the orlop deck. Hawse pipes were designed for the anchor cable to run through and in most all cases that is what they were used for. The Hawse Bag is a conical-shaped canvas bag, stuffed with sawdust, oakum, or similar material, and fitted with a lanyard at apex and base, used for closing the hawse pipes around the chain to prevent shipping water through the pipes; also called a "jackass", "hawse plug", or "hawse block".
Aft of the enlisted men's quarters is the Wardroom, which contained the accommodations for warrant officers, midshipmen (student officers), and officers. The Wardroom is where they dined, spent their leisure hours, and where they received visitors in port. Access to the filling room and the copper-lined powder magazine was provided by a hatch located on the starboard side of the Wardroom.
|Join the GlobalSecurity.org mailing list|