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THE SEAMAN'S FRIEND
CONTAINING A TREATISE ON PRACTICAL SEAMANSHIP
By RICHARD HENRY DANA JR.
Dover Publications, Inc.Copyright © 1997 Dover Publications, Inc.
All rights reserved.
GENERAL RULES AND OBSERVATIONS.
Construction of vessels. Tonnage and carriage of merchant vessels. Proportions of the spars. Placing the masts. Size of anchors and cables. Lead-lines. Logline. Ballast and lading.
CONSTRUCTION OF VESSELS.—As merchant vessels of the larger class are now built in the United States, the extreme length of deck, from the after part of the stern-post to the fore part of the stem, is from four and a half to four and three fourths that of the beam, at its widest part. The Damascus, of 700 tons' measurement, built at Boston in 1839, and considered a fair specimen of our best freighting vessels, had 150 feet from stem to stern-post, and 32 feet 6 inches extreme breadth. The Rajah, of 530 tons, built at Boston in 1837, had 140 feet length, and 30 feet beam;—being each in length about four and six tenths their beam.
A great contrast to this proportion is exhibited in the most recent statistics (1841) of vessels of the same tonnage in the English navy; as the following table will show.
These may, perhaps, be considered the extremes of ship-building; and between these there is every grade of difference.
TONNAGE AND CARRIAGE OF MERCHANT VESSELS.—The amount a vessel will carry in proportion to her tonnage, depends upon whether, and to what extent, she is full or sharp built. A sharp-built vessel of 300 tons' measurement, will carry just about her tonnage of measurement goods. A sharp-built vessel of 200 tons or under would probably carry less than her measurement; if over 400 tons, she would increase gradually to fifty per cent. above her measurement. A sharp-built vessel of 600 tons, is generally rated at 900 tons carriage. A full-built vessel of 300 tons, after the latest model of American freighting vessels, will carry 525 tons, or seventy-five per cent. above her measurement; and one of 500 tons would carry full double her measurement.
The following table may give a pretty fair average.
PROPORTIONS OF SPARS.—There is no particular rule for sparring merchant vessels; some being light, and others heavy sparred; and some having long topmasts and short lower masts, and others the reverse. The prevailing custom now is, to spar them lightly; the main yard being a little less than double the beam; and the others proportioned by the main. Most merchant vessels now have the yards at the fore and main of the same size, for convenience in shifting sails; so that the same topsail may be bent on either yard.
The following table, taken from the "Seamen's Manual," will show the average proportions of the spars of merchant vessels of the largest class, as formerly built.
Main-mast, two and a half times the ship's beam.
Fore- mast, eight ninths of the main-mast.
Mizzen-mast, five sixths of the main-mast.
Bowsprit, two thirds of the main-mast.
Topmasts, three fifths of the lower masts.
Topgallant masts, one half the length of their topmasts.
Jib-boom, the length of the bowsprit.
Main-yard, twice the beam.
Fore-yard, seven eighths of the main-yard.
Maintopsail-yard, two thirds of the main-yard.
Foretopsail-yard, two thirds of the fore-yard.
Crossjack-yard, the length of the maintopsail-yard.
Topgallant-yards, two thirds of the topsail-yards.
Mizzentopsail-yard, the length of the maintopgallant-yard
Royal-yards, two thirds of the topgallant-yards:
Spritsail-yard, five sixths of the foretopsail-yard.
Spanker-boom, the length of the maintopsail-yard.
Spanker-gaff, two thirds of the boom.
For the thickness of the spars, the same book allows for the lower masts one inch and a quarter diameter at the partners, for every three feet of length; and nine tenths in the middle and two thirds under the hounds, for every inch at the partners. For the yards, one inch at the slings, and half an inch at the yardarms, within the squares, for every four feet of the length. For the breadth of the maintop, one half of the beam, and of the foretop, eight ninths of the maintop.
The following are the proportions of the spars of the ship Damascus, before mentioned, built in 1839.
PLACING THE MASTS.—For a full-built ship, take the ship's extreme length and divide it into sevenths. Place the foremast one seventh of this length from the stem; the mainmast three sevenths from the foremast, and the mizzenmast two sevenths from the mainmast. If a vessel is sharp-built, and her stem and sternpost rake, her foremast should be further aft, and her mizzenmast further forward, than the rule of sevenths would give. A common rule for placing the foremast, is to deduct three fifths of a ship's beam from her length, for the curvature of the keel forward, which is called thekeel-stroke, and place the mast next abaft the keel-stroke.
SIZE OF ANCHORS AND CABLES.—Various rules have been adopted for the weight of a ship's anchors. A vessel of 100 tons will generally have a best bower of 6 cwt. and a small bower of 5 cwt.; the weight of both being eleven pounds to a ton of the vessel. As a vessel increases in size, the proportion diminishes. A vessel of 700 tons will usually carry a best bower of 27 cwt. and a small bower of 24 cwt.; the weight of both being seven and a half pounds to a ton of the vessel. The stream should be a little more than one third the weight of the best bower. The anchor-stock should be the length of the shank; its diameter should be half that of the ring, and its thickness one inch at the middle and half an inch at each end for every foot in length. Chain cables are usually ninety fathoms in length, for large-sized vessels, and sixty for small vessels, as schooners and sloops. The regulation of the United States Navy for chain cables, is one inch and a half for a sloop of war, and one and a quarter for brigs and schooners. In the merchant service, a ship of 400 tons would probably have a best bower cable of one and five sixths, and a working bower of one and a quarter inches. A ship of 700 tons would have a best bower of one and five eighths, and a working bower of one and a half inches. Chain cables have a shackle at every fifteen fathoms, and one swivel at the first shackle. Some have two swivels; and formerly they were made with a swivel between each shackle.
LEAD-LINES.—The hand-lead weighs usually seven pounds, and the hand-line is from twenty to thirty fathoms in length. The deep-sea-lead (pro. dipsey) weighs from fourteen to eighteen or twenty pounds; and the deep-sea-line is from ninety to one hundred and ten fathoms. The proper way to mark a hand-line is, black leather at 2 and 3 fathoms; white rag at 5; red rag at 7; wide strip of leather, with a hole in it, at 10, and 13, 15 and 17 marked like 3, 5 and 7; two knots at 20; 3 at 30; and 4 at 40; with single pieces of cord at 25 and 35.
The deep-sea-line has one knot at 20 fathoms, and an additional knot at every 10 fathoms, with single knots at each intermediate 5 fathoms. It sometimes has a strip of leather at 10 fathoms, and from 3 to 10 is marked like the hand-line.
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 strayline. 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 cran i, and enable her to carry sail to more advantage.CHAPTER 2
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 tour 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 trestletrees, 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 on the larboard side of the bowsprit.
All the fore-and-aft stays are now set up on their ends, and should be leathered in their nips, as well as in their eyes.
The main topmast stay goes through a heart or thimble at the foremast-head, or through a hole in the cap, and sets up on deck or in the top; and the mizzen topmast stay sets up at the mainmast-head, above the rigging.
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