Naval ARCHITECTURE (continued)

After these dimensions are settled, may be considered the timbers which form the sides of the ship. A frame of timbers, which appears to be one continued piece, is composed of one floor-timber, U, whose arms branch outward to both sides of the ship: (See plate I. PIECES of the HULL) two or three futtocks, V V, and a top-timber, W. The futtocks are connected to the upper arms of the floor-timbers on each side of the ship, and serve to prolong the timber in a vertical direction: and the top-timbers are placed at the upper part of the futtocks for the same purpose. All these being united, and secured by cross-bars, form a circular inclosure, which is called a frame of timbers (couple d'un vaisseau, Fr.) And as a ship is much broader at the middle than at the extremities, the arms of the floor-timber will form a very obtuse angle at the extreme breadth; but this angle decreases in proportion to the distance of the timbers from the midship-frame, so that the foremost and aftmost ones will form a very acute angle. Floor-timbers of the latter sort are usually called crutches.

Plate I

Shipwrights differ extremely in determining the station of the midshipframe; some placing it at the middle of the ship's length, and others further forward. They who place it before the middle allege, that if a ship is full forward, she will meet with no resistance after she has opened a column of water; and that the water so displaced will easily unite abaft, and by that means force the ship forward; besides having more power on the rudder, in proportion to its distance from the centre of gravity: this also comes nearer the form of fishes, which should seem the most advantageous for dividing the fluid.

When the rising of the midship-floor-timber is decided, we may then proceed to describe the rising-line of the floor, on the stern-post abaft, and on the stem afore.

The heighth of the lower-deck is the next thing to be considered. It is determined in the middle by the depth of the hold; and some builders make it no higher than the stern; but they raise it abaft as much above its heighth in the middle as the load-water-mark, or draught of water abaft, exceeds that afore. With regard to the heighth between decks, it is altogether arbitrary, and must be determined by the rate of the ship, and the service she is designed for.

It is also necessary to remember the sheer of the wales, and to give them a proper banging; because the beauty and stateliness of a ship greatly depend upon their figure and curve, which, if properly drawn, will make her appear airy and graceful on the water.

We come now to consider the upper-works, and all that is above water, called the dead-work: and here the ship must be narrower, so that all the weight lying above the load-water-line may thereby be brought nearer the middle of the breadth, when of course the ship will be less strained by the working of her guns, &c. But although some advantages are acquired by diminishing the breadth above water, we must be careful not to narrow her too much; as there must be sufficient room left on the upper-deck.

Reference Works