Plate [II]. fig. 10. The drum-head is a broad cylindrical piece of wood, resembling a mill-stone, and fixed immediately above the barrel and whelps. On the outside of this piece are cut a number of square holes, parallel to the deck, to receive the bars.
The pivot, or spindle, d, which is shod with iron, is the axis or foot upon which the capstern rests, and turns round in the saucer, which is a sort of iron socket let into a wooden stock or standard, called the step, resting upon, and bolted to the beams.
Besides the different parts of the capstern above explained, it is furnished with several appurtenances, as the bars, the pins, the pawls, the swifter, and the saucer, already described.
The bars are long pieces of wood, or arms, thrust into a number of square holes in the drum-head all round, in which they are as the radii of a circle, or the spokes to the nave of a wheel. They are used to heave the capstern round, which is done by the men setting their breasts against them and walking about, like the machinery of a horse-mill, till the operation is finished.
The pins, e, are little bolts of iron thrust perpendicularly through the holes of the drum-head, and through a correspondent hole in the end of the bar, made to receive the pins when the bars are fixed. They are used to confine the bars, and prevent them from working out as the men heave, or when the ship labours. Every pin is fastened to the drum-head with a small iron chain; and, that the bars may exactly fit their respective holes, they are all numbered.
The pawls, f, fig. 10. are situated on each side of the capstern, being two short bars of iron, bolted at one end through the deck to the beams close to the lower part of the whelps; the other end, which occasionally turns round on the deck, being placed in the intervals of the whelps, as the capstern turns, prevents it from recoiling or turning back by any sudden jerk of the cable as the ship rises on the sea, which might greatly endanger the men who heave. There are also hanging pawls g, g, fig. 12, used for the same purposes, reaching from the deck above to the drum-head immediately beneath it.
Plate ii. To pace Capstern.
The swifter, is a rope passed horizontally through holes in the outer ends of the bars, and drawn very tight: the intent of this is to keep the men steddy as they walk round, when the ship rocks, and to give room for a greater number to assist by pulling upon the swifter itself.
The most frequent use of the capstern is to heave in the cable, and thereby remove the ship, or draw up the anchor. It is also used to wind up any weighty body, as the masts, artillery, &c. In merchant-ships it is likewise frequently employed to discharge or take in the cargo, particularly when consisting of weighty materials that require a great exertion of mechanical powers to be removed.