Название: The Seaman's Friend
Автор: Richard Henry Dana
Издательство: Bookwire
Жанр: Математика
isbn: 4057664622310
isbn:
Log-line.—The rate of a ship's sailing is measured by a log-line and a half-minute glass. The line is marked with a knot for each mile; the real distance between each knot being, however, 1/120 of a mile, since a half-minute is 1/120 of an hour. A knot being thus the same portion of a mile that a half-minute is of an hour, the number of knots carried off while the glass is running out will show the number of miles the vessel goes in an hour. Many glasses, however, are made for twenty-eight seconds, which, of course, reduces the number of feet for a knot to forty-seven and six tenths. But as the line is liable to stretch and the glass to be affected by the weather, in order to avoid all danger of a vessel's overrunning her reckoning, and to be on the safe side, it is recommended to mark forty-five feet to a knot for a twenty-eight second glass. About ten fathoms is left unmarked next the chip, called stray-line. The object of this is that the chip may get out of the eddy under the stern, before the measuring begins. The end of the stray-line is marked by a white rag, and the first knot is forty-five or forty-seven feet from the rag. A single piece of cord or twine is put into the line for the first knot, one knot for the second, two for the fourth, three for the sixth, and so on, a single piece of cord being put in at the intermediate knots.
Ballast and Lading.—A ship's behavior, as the phrase is, depends as much upon the manner in which she is loaded and ballasted, as upon her model. It is said that a vessel may be prevented from rolling heavily, if, when the ballast is iron, it is stowed up to the floor-heads; because this will bring the ship back, after she has inclined, with less violence, and will act upon a point but little distant from the centre of gravity, and not interfere with her stiff carrying of sail. The cargo should be stowed with the weightier materials as near as possible to the centre of gravity, and high or low, according to the build of the vessel. If the vessel is full and low built, the heavy articles should be stowed high up, that the centre of gravity may be raised and the vessel kept from rolling too much, and from being too laborsome. But a narrow, high-built vessel should have the heavy articles stowed low and near the keelson, which will tend to keep her from being crank, and enable her to carry sail to more advantage.
CHAPTER II.
CUTTING AND FITTING STANDING RIGGING.
Measuring and cutting lower rigging and lower fore-and-aft stays. Fitting the same. Measuring, cutting, and fitting topmast rigging, stays, and backstays. Jib, topgallant, and royal stays. Rattling down rigging. Cutting and fitting lifts, foot-ropes, brace-block straps, and pennants. Breast-backstays.
Cutting lower Rigging.—Draw a line from the side of the partners abreast of the mast, on the deck, parallel to the channels, and to extend as far aft as they do. On this line mark the places of each dead-eye, corresponding to their places against the channels. Send a line up to the mast-head, and fasten it to the mast by a nail above the bibbs, in a range with the centre of the mast, and opposite to the side the channel line is drawn upon. Then take the bight of the line around the forward part of the mast, and fasten it to the mast by a nail, opposite the first nail, so that the part between the nails will be half the circumference of the mast-head; then take the line down to the mark on the channel line for the forward dead-eye, and mark it as before; and so on, until you have got the distance between the mast and each mark on the channel line. Now cast off the line from the mast-head, and the distance between the end of the line and each mark will give you the length of each shroud from the lower part of the mast-head. And, to make an allowance for one pair of shrouds overlaying another, you may increase the length of the pair put on second, that is, the larboard forward ones, by twice the diameter of the rigging; the third pair by four times; and so on.
The size of the lower rigging should be as much as eight and a half inches for vessels of seven or eight hundred tons, and from seven and a half to eight for smaller vessels, over three hundred tons.
For the length of the fore, main, and mizzen stays and spring-stays, take the distance from the after part of the mast-head to their hearts, or to the place where they are set up, adding once the length of the mast-head for the collar.
The standing stays should be once and half the circumference of the shrouds.
Fitting lower Rigging.—Get it on a stretch, and divide each pair of shrouds into thirds, and mark the centre of the middle third. Tar, worm, parcel and serve the middle third. Parcel with the lay of the rope, working toward the centre; and serve against the lay, beginning where you left off parcelling. Serve as taut as possible. In some vessels the outer thirds of the swifters are served; but matting and battens are neater and more generally used.
Formerly the middle third was parcelled over the service, below the wake of the futtock staff. Mark an eye at the centre of the middle third, by seizing the parts together with a round seizing. The eye of the pair of shrouds that goes on first should be once and a quarter the circumference of the mast-head; and make each of the others in succession the breadth of a seizing larger than the one below it. Parcel the score of the dead-eye, and heave the shroud taut round it, turning in with the sun, if right-hand-laid rope, and against the sun, if hawser-laid; then pass the throat seizing with nine or ten turns, the outer turns being slacker than the middle ones. Pass the quarter seizings half way to the end, and then the end seizings, and cap the shroud, well tarred under the cap. Make a Matthew Walker knot in one end of the lanyard, reeve the other end out through the dead-eye of the shroud, beginning at the side of the dead-eye upon which the end of the shroud comes, and in through the dead-eye in the channels, so that the hauling part of the lanyard may come in-board and on the same side with the standing part of the shroud. If the shroud is right-hand-laid rope, the standing part of the shroud will be aft on the starboard, and forward on the larboard side; and the reverse, if hawser-laid.
The neatest way of setting up the lower fore-and-aft stays, is by reeving them down through a bull's eye, with tarred parcelling upon the thimble, and setting them up on their ends, with three or four seizings. The collar of the stay is the length of the mast-head, and is leathered over the service. The service should go beyond the wake of the foot of the topsail, and the main-stay should be served in the wake of the foremast. The main and spring stays usually pass on different sides of the foremast, and set up at the hawse-pieces.
The bolsters under the eyes of the rigging should always be covered with tarred parcelling, marled on.
The starboard forward shroud goes on first; then the larboard; and so on. The fore stay and spring stay go over the shrouds; and the head stays always go over the backstays.
Cutting and fitting Topmast Rigging.—For the forward shroud, measure from the hounds of the topmast down to the after part of the lower trestle-trees, and add to that length half the circumference of the mast-head at the hounds. The eye is once and a quarter the circumference of the mast-head. The topmast rigging in size should be three fifths of the lower rigging. For the topmast backstays, measure the distance from the hounds of the mast down to the centre of the deck, abreast of their dead-eyes in the channels, and add to this length one half the circumference of the mast-head. Add to the length of the larboard pair, which goes on last, twice the diameter of the rope. The size of the fore and main topmast backstays is generally one quarter less than that of the lower rigging; and that of the mizzen topmast backstays the same as that of the main topmast rigging. The size of the topmast stays should be once and a quarter that of the rigging. The topmast rigging is fitted in the same manner as the lower. The backstays should be leathered in the wake of the tops and lower yards. The breast-backstays are turned in upon blocks instead of dead-eyes, and set up with a luff purchase. The fore topmast stay sets up on the starboard, and the spring stay СКАЧАТЬ