1902 Encyclopedia > Sail, Sailcloth, Sailmaking

Sail, Sailcloth, Sailmaking




SAIL, SAILCLOTH, SAILMAKING. A sail is a sheet of canvas (or other material of the requisite flexibility and strength) by the action of the wind on which, when spread out or extended, a vessel is moved through the water. Sails are supported and extended by means of masts, yards, gaffs, booms, bowsprit—all technically termed "spars"—and stays or slanting ropes. In the first experiments for impelling vessels by sails the least complicated form, that of a single square sail erected on a single mast, was no doubt adopted. To the quadrangular the triangular sail would soon be added; and single sails of both these forms are known to have been used at very early periods. Subsequently the trapeziform and trapezoidal sails also came into use. As vessels increased in size, thereby requiring a greater surface of canvas to impel them, it became necessary to use not only more sails but also an increased number of masts; and the number and disposition of the several kinds of sails could be almost indefinitely varied according to the ideas of navigators, the services required of the vessels, the places in which they were employed, and the size of the crews. Thus a great variety of rig naturally arose. Leaving out of account the many nondescript styles adopted in the case of boats and small craft, all modern vessels may, for general purposes, be considered as belonging to one or other of the following categories—cutter, schooner, three-masted schooner, brigantine, brig, barquetine, barque, or full square-rigged ship; but the cardinal distinction is that by which they are classified as square-rigged or fore-and-aft-rigged (compare SEAMANSHIP and SHIP). These expressions can be easily explained by reference to any three-masted ship. The mast nearest the bow or head is known as the fore-mast, the next abaft or nearest the middle of the ship as the main-mast, and the third or that nearest the stern as the mizzen-mast. Each mast consists of several sections, that attached to the hull being called the lower or standingmast, the next above that the top-mast, the next the top-gallant-mast, above which may rise a pole or royal-mast. On each of these masts, and at right angles with it, is a yard denominated "square," which is hung (slung) by the middle and balanced. These yards are named according to their situation, those placed on the fore and main standing-masts being called respectively the fore and main lower-yards, that on the mizzen the cross-jack-yard; the yards on the top-masts are called the top-sail-yards, those on the top-gallant-masts the top-gallant-yards, and those on the royal-masts the royal-yards. To each of these yards a sail is bent or attached, taking its name from the yard; thus the principal sail upon the fore-lower-yard is called the fore-course or fore-sail; the next above, upon the fore-top-sail-yard, is the fore-top-sail; above which, upon the fore-top-gallant-yard, is the fore-top-gallant-sail; and above all, upon the fore-royal-yard, is the fore-royal. In like manner on the main-mast we have the main-course or main-sail, main-top-sail, main-top-gallant-sail, and the main-royal. Similar appellations are given to those on the mizzen-mast; in large merchant-ships, by means of a sky-sail-pole, a sail termed "sky-scraper" is sometimes set above the royals, but not so freqnently as formerly. Such square sails can be placed at right angles to the direction of the keel of the ship, a position given to them when going before the wind; the same sails can also, by means of braces, be placed obliquely to the keel with a side wind, commonly termed by seamen "on a wind" or "by the wind." In addition to these there are sails between the masts, set either on gaffs (unbalanced) or on stays, also others beyond the extremities of the ship, extended principally by means of the bowsprit, which, in addition to supporting the fore-mast by a stay, also supports the jib and flying-jib-booms for extending the sails still farther forwards; the means for extending the after-sail are the driver or spanker-boom and the gaff. Sails extended or set on gaffs and on stays are called "fore-and-aft," and are generally or approximately in a vertical plane passing through the keel; but a certain degree of obliquity can be given them by easing off the sheet or aft lower corner of the sail. A ship fitted as above described would be termed "square-rigged," the square sails predominating both in importance and in number. A square-rigged line-of-battle ship would be supplied with the following descriptions of sails1:—



Square.



Fore-course or fore-sail.

Fore-top-sail.

Fore-top-gallant-sail.

Fore-royal.

Main-course or main-sail.

Main-top-sail.

Main-top-gallant-sail.

Main-royal.

Mizzen-top-sail.

Mizzen-top-gallant-sail.

Mizzen-royal.

Studding-sail-fore.

Studding-sail-fore-top.

Studding-sail-fore-top-gallant.

Studding-sail-main-top-gallant.



Fore-and-Aft.



Fying-jib.

Jib.

Second jib.

Fore-gaff-sail.

Fore-try-sail (storm-sail).

Main-gaff-sail.

Main-try-sail (storm-sail).

Mizzen-try-sail (storm-sail).

Spanker.

Stay-sail-fore (storm-sail).

Stay-sail-fore top.



In the fore-and-aft-rig the principal sails are of course fore-and-aft; a cutter (vessel with one mast) when fully equipped carries the following:—



Fore-and-Aft.



Jib-top-sasil.

Jib.

Fore-sail.

Boom-main-sail.

Gaff-top-sail.



Square.



Square-sail (set fying).



The several sides of a sail have separate names applied to them, the upper part or side being known as the "head," the lower part as the "foot" ; the sides in general are called "leeches," but the weather or side edge where the wind enters the sail, of any but a square-sail, is called the "luff," and the other edge the "after-leech." The two top corners are "earings," but the top corner of a jib, &c. (triangular, one corner only), is the "head" ; the two bottom corners are in general "clews" and the weather clew of a fore-and-aft-sail or of a course while set is the "tack."

The relative importance of particular sails in the working of a ship varies according to conditions of weather, and is a matter for the judgment of the officer in command. The following table, however, shows approximately what sails are commonly set "by the wind," presuming that the effect on the ship in relation to her stability is safe:—

TABLE



FOOTNOTE (page 153)

1 Some ships (merchant-liners) have two jibs, inner and outer, and their top-sails also in two parts, upper and lower or cap-top-sails, an arrangement which makes it easier to reduce or shorten sail; they also have a mizzen course (cross-jack), and carry several light stay-sails so as to catch every breath of wind.



To the casual observer sails when spread and in use appear merely as so many large pieces of cloth; but some of them are of very considerable size : it is not at all un-usual in full square-rigged ships for a main-course or main-sail to contain 1000 yards of canvas (24 inches wide), and a main-top-sail nearly as mnch,—the single suit for such a vessel comprising upwards of 10,000 yards. Courses and top-sails are made reducible; in the British navy they are reduced by means of reefs (two in courses, four in top-sails), each fitted with spilling, slab, and reef lines and becket, and toggles on the yard (reef-points throughout being now obsolete). In the merchant service double top-sails—upper and lower—are much in use on account of handiness in reducing sail; there is also "patent reefing gear," such as Cunningham’s, which allows reefing to be done as much as possible from deck. The dimensions of masts and yards, quantity of canvas or area of sail, centre of gravity of each sail (from which the moment of sail is obtained and compared with the moment of stability), centre of effort of the sails, and other important calcula-tions necessary in relation to the body of the vessel are made by constructors and naval architects.

Sailcloth is obtainable from any description of fibrous material capable of being woven into cloth, having sufficient compactness and closeness of texture, and possessing the requisite strength for sustaining the heavy pressure which sails often have to bear in severe weather. Several descriptions of fibre might be enumerated which would to a certain extent serve for sailcloth but for the absence of quality of endurance or resistance; hemp has been and is now occasionally used, as also a mixture of cotton and linen yarn, or cotton only,—especially in America; but, in the United Kingdom FLAX (q.v.) is the usual staple material, since, when well manufactured, it possesses the qualities of flexibility and lightness, and, what is still more important, the element of strength in a very large degree.

The following points may be regarded as of primary importance for securing sailcloth or canvas of a superior quality and durability. Whatever flax is used, it is absolutely necessary that the "warp" and "weft" of the canvas be spun wholly from the "longs," be free from blacks and any mixture of short flax, well dressed or heckled, and that the yarn be well and evenly spun and properly twisted. Both warp and weft yarn should be twice boiled with the best American pot and pearl ashes, and carefully and thoroughly washed and cleansed. No acid chloride of lime or other preparation of chlorine, nor any deleterious substance, should be used in any stage of the process, otherwise the integrity of the fibre will most probably be interfered with ; the only advantage got is that the cloth looks much whiter, which for yachts and pleasure-boats is perhaps desirable, but for naval and mercantile uses is not at all necessary. The yarns are first boiled a sufficient length of time in a solution of the best American potash, in fixed proportions of ashes, green yarn, and water, then mill-washed (beating process), and subse-qiiently carefully washed in a considerable stream of clear running water, and wrung. They are again boiled for a sufficient length of time in a solution of American pearl ashes, in clue proportions of ashes, green yarn, and water, then carefully rinsed, or washed in a clear stream of water, carefully dried, and frequently shaken in the course of drying, so that the fibres of the flax may be equally stretched. These repeated boilings, &c, have the effect of cleansing, bleaching, softening, and removing all vegetable impurities which may be hanging about ; no starch, tallow, paste, or weaver’s dressing of any description should be used, otherwise the fabric will tend to mildew if allowed to remain damp for any time. Sail-cloth is made in bolts, mostly 24 inches wide, but also 18 inches wide, and for yachting purposes frequently still less wide, upon the ground that the narrower the cloth the flatter and better will the sail stand to its work. It is generally made of eight different quanties in respect of thickness, numbered 1 to 8 accordingly ; the heavier numbers—Nos. 1, 2, and 3—are used for storm and other sails that have to do heavy work, the remaining numbers for the lighter descriptions of sail. The weight of each bolt of canvas 24 inches wide, from Nos. 1 to 6 inclusive for 39 yards in length and for Nos. 7 and 8 for 40 yards in length, is about as follows, viz., No. 1, 46 1b ; No. 2, 43 ; No. 3, 40 ; No. 4, 36; No. 5, 33 ; No. 6, 30 ; No. 7, 27 ; No. 8, 25 1b. The weight of each bolt of narrower canvas is in proportion. The warp (or lengthwise) should consist of the following proportions of clean unstarched yarn, viz.:—

TABLE

As a rule about 40 yards in length may be considered as the average content of each bolt. Particular attention should be paid to the weaving, that the texture be struck sufficiently close, and the selvages be evenly and well manufactured; what is termed a slack selvage (that is, one selvage longer than the other) is not only awkward for the sailmaker but unsatisfactory both in wear and appearance, the slack side showing itself puckered. Sailcloth made upon these conditions is very likely to be a good article ; tests, however, can be applied, generally to strips I inch wide from Nos. 1 to 6 inclusive, and l 1/2 inch wide from Nos. 7 and 8. Weft and warp (24 inches in length) in each case are placed in a small testing machine, which has a dial plate with a spring under-neath ; vices are attached to grip the strips, one vice to the spring, the other in connexion with a long screw with a handle; by turning this handle the vices are drawn asunder until the strip breaks, and the hands on the dial-plate indicate the strain in pounds. The following is a fair test of strength for the various numbers of good sailcloth:—

TABLE

It is not at all unusual, however, to find some sailcloth stand a strain considerably in excess of this. Freedom from blacks, twist and spun of the yarn, stiffening, calendering, &c., can be discovered by observation and a magnifying glass, excessive dressing by a little tincture of iodine.

Sailmaking is a very old branch of industry in connexion with the navy and commerce, and it still continues to be important notwithstanding the enormous extent to which steam is now employed in navigation.

The operations of the sailmaker may be stated as follows. The dimensions of mast and yards and sail plan being supplied, the master sailmaker is enabled to determine the dimensions of each sail—after due allowance for stretching—in terms of cloths and depth in yards—if a square sail, the number of cloths in the head, number in the foot, and the depth in yards ; if a fore-and-aft sail (triangular), the number of cloths in the foot, and the depth in yards of the luff or stay and of leeeh or after-leech ; if a fore-and--aft sail (trapezium form), the number of cloths in the head, number in foot, and the depth of mast or luff and of after-leech. These particulars obtained, there is got out what is technically termed a "casting," which simply means the shape, length, &c., of each in-dividual cloth in the sail. These figures are given to the cutter, who proceeds to cut out the sail cloth by cloth in consecutive order, numbering them 1, 2, 3, 4, &c. ; the series of cloths thus cut out are handed over to the workman, who joins them together by care-fully made double flat seams, sewn with twine specially prepared for the purpose, with about 120 stitches in a yard. In the heavy sails the seam is about an inch and a half in width and in the British navy stuck or stitched in the middle of the seam to give additional strength; the seams in the lighter sails are about an inch wide. The whole of the cloths are then brought together, and spread out, and the tabling (or hemming, so to speak) is turned in and finished off with about 72 stitches to a yard. Streugthening pieces or "linings" are affixed where considered necessary, in courses and top-sails such pieces as reef-bands, middle-bands, foot-bands, leech-linings, bunt-line cloths; in top-sails (only) a top-lining or brim; in other and lighter sails such pieces as mast-lining clew and head, tack, and corner pieces; holes, such as head, reef, stay (luff), inast, cringle, bunt-line, &c., are also made where re-quired, a grommet of line of suitable size being worked in them to prevent their being cut through. The next thing to be done is to secure the edges of the sail,—an important operation, as much depends upon this whether the sail will stand well and do its work efficiently. Bolt-rope, a comparatively soft laid rope made from the finer hemp yarn (Italian) is used for this purpose; in the British navy it ranges from 1 inch (increasing in size by quarter inches) up to 8 inches inclusive, the size selected for each part of a sail being determined by the amount of strain it will have to bear; it is then neatly sewn on with roping twine specially prepared, the needle and twine passing between and clear of every two strands of the rope in roping. Where slack sail has to be taken in, it is the practice to leave it to the judgment of the sailmaker; but where possible it is better to set up the rope by means of a tackle to a strain approximate to what it will have to bear when in use, and whilst on the stretch mark it off in yards, as also the edge of the sail in yards, so that by bringing the marks to-gether in roping the sail will stand flat. In the British navy the largest size of rope sewn on to a sail is 6 inches ; sizes above this are used for foot and clew ropes of top-sails and courses, being first wormed, parcelled (that is, wound round with strips of worn canvas), tarred, and served over with spun yam ; the foot of the sail is then secured to it by being marled in. Where two sizes of bolt-rope used in roping a sail have to be connected, it is effected by a tapered splice. Cringles (similar to the handle of a maund) formed by a strand of bolt-rope, mostly having a galvanized iron thimble in them as a protection, are then stuck where necessary, as at the corners, sides or leeches, mast or luff ; they are required either for making stationary or hauling "taut" by tackle or otherwise certain parts of the sail when in use. Fore-and-aft sails, such as spankers, gaff-sails, and storm try-sails, are reduced in size by reef-points made of stout line (4 to 20 1b), crow-footed in the middle, a hole being pierced through every seam; one-half of the point is passed through and the crowfoot sewn firmly to the sail; the number of reefs depends upon the size of the sail, and the reefs are placed parallel to the foot. The sails-now finished in respect of making-have to be fitted, that is, such ropes have to be attached to each of them as are necessary for proper use ; such ropes may be summarily stated as follows:—head-earings, robands, reef-ear-ings, reef-lines, spilling and slab lines, reef-tackle pendant, reef-points, bow-line bridles, bunt-line toggles, bunt-becket, leech-line strops and toggles, toggles in clews, sheet ropes, down-haul, lacings, head and stay, tack-rope (gaff top-sail), tack lashing, bending strops, matting, and gaskets.

The tools and appliances of a sailmaker are not very numerous:—a bench about 7 feet long and 15 inches high, upon which he sits to perform the greater part of his work; palms for seaming and roping to fit the hand, made of hide lined with leather, a plate properly tempered being fixed in it having chambers to catch the head of the needle, thus acting as a thimble in forcing it through the several parts of canvas in seaming, and between the strands and through the canvas in roping; needles of various sizes, that for seaming being the smallest ; and fids, splicing, serving, and stretching knife, rubber, sail-hook, bobbin for twine, and sundry small articles. (E. JE.)








Search the Encyclopedia:



About this EncyclopediaTop ContributorsAll ContributorsToday in History
Sitemaps
Terms of UsePrivacyContact Us



© 2005-16 1902 Encyclopedia. All Rights Reserved.

This website is the free online Encyclopedia Britannica (9th Edition and 10th Edition) with added expert translations and commentaries