Water-lines
it will be observed, have an important place in all three planes on the draft plan. Upon them and upon the frame stations chiefly devolves the function of exhibiting the hull form.
On the half-breadth plan, the water-lines appear much in the same way as, for example, the lines of angle bars forming the deck margin in a large ship present themselves to an observer looking down on the skeleton of the vessel from an elevation. On the body plan, the frame stations appear just as the actual framework of the vessel would, when erected, present itself to anyone looking at it end on.
Other lines appearing on the draft plan, not so essential for exhibiting the hull form as the others, but of the greatest importance as means towards securing accuracy and fairness of the water-lines and frame stations, are buttock and bow-lines, and diagonals. The former represent the intersection with the contour of the hull surface of imaginary vertical planes parallel with the centre plane of the vessel fore and aft. On the half-breadth plan and body plan they appear as straight lines, and on the longitudinal elevation as curved lines. They convey a fair impression both of the after end and counter of the vessel, and of the contour of the forward end and bow.
The diagonals represent the intersection with the hull surface of imaginary planes, which are arranged to be as nearly perpendicular to that surface as possible where curvature is greatest; hence they are most valuable checks upon the fairness of the hull, and are perhaps the most important of all lines in designing sailing ships.
From the drawing office delineation of the hull form, thus generally described, and after every means has been taken to secure fairness, off-set measurements are made, and from the sheet containing them the lines are laid off full size on the floor of the loft. In this full size delineation small inaccuracies, unavoidable in minute measurements from the small scale drawing, are eliminated, and, in the process of fairing by means of long wooden battens, a careful designer will find additional scope for the exercise of his skill and taste.
It is on the floor of the loft that some of our best designers impart a finish and character to their conceptions which are barely possible on the small scale draft plan.
From the sections so drawn, life-size on the floor of the loft, wooden moulds are, according to the custom of some designers, accurately cut, and these moulds are subsequently placed in their proper position upon the keelson of the vessel, and along this temporary skeleton long wooden battens are fastened from stem to stern. The designer can then judge by eye of the fairness of his lines. If they bulge out too much in one place, however infinitesimally, the frame mould must be proportionately reduced; if the slightest undue hollow is anywhere perceived, the batten must be wedged out, and the mould altered accordingly.
So far the outline given applies generally to yachts of any type or size, except the very smallest. Further operations are complicated and differentiated according to whether the vessel is to be built of iron, steel, or other metal, or of wood, or is to be composite that is, composed of steel frames and a wooden skin. The question as to what style of construction shall be adopted will necessarily be determined at a very early stage of the undertaking. Up to a certain size, say, roughly speaking, 40 tons, wood is the lightest and cheapest form of construction. Beyond that size, composite or steel is cheaper and lighter.
Large sailing yachts, vessels of, say, 150 tons or upwards, intended for cruising, are not infrequently constructed of steel, iron, or of some alloy of which those metals form the major constituent; and steam yachts are almost invariably built of those materials. But though steel, some of the bronze alloys, and alloys containing aluminium, have been used for the construction of racing vessels even of the largest size, they are generally built on the composite principle.
Each system has its advantages and disadvantages. Construction in wood is the best for small vessels; but for a large vessel it is not to be recommended, as it takes longer and is more costly, and, moreover, the vessel will weigh heavier than if built on any other system. Steel, metal, or composite is lighter and cheaper for good-sized vessels, and both systems possess the additional advantage, that under them considerable space is gained in the interior for cabin accommodation, owing to the small size of iron or steel frames as compared with frames made of wood. In a composite yacht of, say, 300 tons, a gain of possibly one foot in breadth would be due to this feature, while in vessels plated with steel alone the difference between the steel plate of 1-inch thickness and a wooden plank of 3 inches is also available for increasing internal breadth.
The principal disadvantages of steel and metal consist in the rapid variations of temperature due to a metal shell, and to the liability of the latter to become foul and to corrode.
Composite yachts not only possess the advantage of roomier and more comfortable interiors, but the wooden planking can be sheathed with copper, which is the best material that can be used under water as far as fouling and corroding are concerned. In large vessels, which may have to be docked to be cleaned, this is a matter of the greatest importance; in small boats, which can be easily beached, it does not so much matter, and, in point of fact, small racing vessels are never coppered. Metal sheathing, indeed, seems to be going out of fashion for even large racing yachts, as it has been found that a good anti-fouling composition, or black varnish, yields a smoother surface than copper. There are, moreover, greater facilities for scrubbing large vessels days than there were a few years years back, and a dock or slipway suitable for the purpose is available at many of the ports visited by the racing fleet in the course of the season. nowa- To follow out the growth of a vessel from inception to completion in greater detail than this would transcend the limits of a formidable book.
Suffice it to add that the vessel, if she is to be coppered, is sheathed with sheets of cold drawn metal most carefully adjusted, the deck furniture is fixed, cabin fittings, tanks, and all internal fitments are put in, and she is launched into the element in which, let us hope, she is destined to have an honourable career. The mast is stepped and stayed, the other spars are put in their places, all the running gear is rove, sails are bent, and she is ready for a trial trip.
The launch is a moment of some anxiety, not owing to the probability of accident, for that is an occurrence of exceeding rarity, but because as soon as she is in the water and her weights are on board, the accuracy of her designer's calculations is put to the test. Her designed load-waterline length is marked on the stem and on the stern post, and if no error in calculating the weights has been made, she will float exactly as designed.
It may be that she will be a little too much down by the head or by the stern; in that event weight must be shifted fore and aft of the centre of gravity. Possibly she will not come down to her marks, and lead ballast may have to be added.
Or she may float below her marks, and it becomes necessary to reduce the amount of lead ballast.
These are simple operations, but they may involve serious consequences. If the ship floats too high or too low in the water, the designer has obviously miscalculated his weights. His curve of stability must be erroneous, and, to put it shortly, he has made a somewhat serious mistake. But so accurately is everything calculated out, with such marvellous precision is the exact weight of every particle of wood and metal, hemp and cotton estimated, and its effect upon the centres of gravity and stability determined beforehand, that mistakes are excessively rare, and the vessel is generally found to float within some fractions of an inch of her designed marks.
Before proceeding further with a racing vessel's career, sail making must be considered. This is a beautiful art, and well-cut, perfectly fitting sails are as necessary-if not more necessary to success in racing as perfection in design, in construction, and in balance of hull. The materials used in sail-making are flax, cotton, and ramie fibre. Flax is never used for racing sails, though, on account of its greater pliability and the comparative ease with which sails made of it can be handled, it forms the best cloth for cruising purposes. But for racing, cotton cloth is far superior, and the best possible canvas is made of long--fibred American sea island cotton; but the expense involved in its use is enormous. The quantity is very limited, and as the fibre is nearly twice as long as that of ordinary cotton, and of a beautiful silky character, it is used largely for lace-making, for which purpose the yarn fetches a high price. The market price of Sea Island cotton is three times as much as that of the best Egyptian. Sail-cloth made of the former costs double as much as that made of the latter, and the cost of a mainsail is about half as much again. As the best Egyptian cotton is scarcely inferior, it is generally employed.
The advantage of cotton over flax consists in this: cotton cloth has a closer texture than flax cloth, and consequently presents a smoother surface to the wind; the wind does not escape through it so easily as through flax cloth, but it does escape more easily off it, and its effort is therefore expended with less friction. The best sail cloth is beautiful material, and is made chiefly of Egyptian cotton. a The cotton yarn is all spun in Manchester, and the cloth woven by the well-known firm of R.
Hayward and Co., whose ancestors started the trade 100 years ago. Their business until quite recently was managed by Mr. Edward Taylor, whose forefathers made sail cloth at Coker 200 years ago from flax grown in the west of England; hence the name "Coker" sail cloth, which is a trade mark to this day. They continued in the trade from generation to generation until 1878, when Mr. Taylor became associated with the firm of Hayward and Co., and under his able superintendence, sail-cloth making became a fine art. The firm is now a limited liability company, managed by Mr. A. R. Hayward and his brother.
Ramie fibre was at one time occasionally used for racing yachts' sails, but was never very popular. The principal objection to it was that in the process of weaving small loose fibres had a way of working up, and this "hairiness" of the cloth created more wind friction than cotton. The Duc d'Abruzzi's cutter "Bona" at one time had a ramie mainsail, but it was discarded after a season's racing, and the material has now been generally superseded by brown Egyptian cotton of the best quality.
Although a great advance in sail-making has taken place during the last half century, the substitution of steam for sails has naturally stifled the scientific development of the art. Demand is small in the yachting world, and only one firm has given the very difficult subject of cutting sails the attention it deserves. Scientific men have not been encouraged to invest much time upon it, and what is known on the whole subject of the propulsion of boats by means of sails has been slowly and gradually learned by practical experience and by rule of thumb. Tradition says that the Dutch rule of thumb. Tradition says that the Dutch originally instructed the English in the art of fore and aft sail-making when Holland was in her zenith some two centuries ago; with the result that, the English proving apt scholars, the mainsails of the London smacks and coasters, Revenue cutters, and last, but not least, of the large privateers, some of them of 400 tons burden, which scoured the seas during the latter part of the eighteenth and the early part of the last century, were fairly cut, and were probably almost perfect as the loose handspun and hand-woven "BRITANNIA." as cloth of those days permitted. Early in the present century, machine-spun yarn superseded hand-spun threads, to the great benefit of sailmaking, for, although hand-spun yarn is preferable for ropes till this day, such is not the case in respect of yarn for sail cloth.
About thirty years later, weaving machinery was introduced and gradually took the place of the old hand looms, and the make of sail cloth was thereby very much improved. In this, as in other trades, the employment of expensive machinery brought about the gradual extinction of small men, and nowadays the yacht sail cloth business is practically confined to four firms in the south of England. Up to comparatively recent times, loose-footed sails were used; they were cut with a considerable hollow in them, and flax was exclusively employed in their manufacture. It was not until the form and body of yachts had been greatly improved that the value of flat sails and the superiority of cotton over flax was demonstrated. Flax was good enough for the full-bottomed, iron ballasted yachts of early days, as was shown when flat sails were tried and proved to be of no advantage whatever. Then came the year 1851, and the revolution in yacht designing caused by the success of the "America."
Great importance was attached to her flat cotton sails, and it was thought that her close windedness was due to that cause alone. Such, however, was not really the case; her fine performance was due principally to her beautiful model, fine lines and small displacement, factors which ensure that a vessel possessing them will hold a better wind than a full-bottomed beamy boat of large displacement. The "America's" sails undoubtedly suited her model, but they did not suit the British yachts of that day equally well, as was very soon discovered by experiment. Flat sails did little to increase their speed, and until improved models were introduced the advantages of flat sails were not made apparent. Cotton sail cloth was introduced about this time, but although tried for a year or two it was found useless in making full- "VALKYRIE II." bottomed boats go any faster, and it was abandoned. a The object of the sail-maker is to obtain a material possessing great strength, little elasticity, uniformity of stretch, close texture, and smooth surface, from which the wind frees itself with the least possible friction. Sail cloth makers and sail makers busied themselves for years in pursuing these requirements, and progressed faster than did designers and builders of yachts, for it was not until the advent of the "Alarm," "Gloriana," "Flying Cloud," "Galatea," and "Shark," that laced-footed and flat mainsails came into use. The year 1863 saw a lot of famous schooners, among them the "Aline," "Albertine," "Egeria," "Pantomime," and "Witchcraft," all vastly improved in model, and therefore capable of standing their sheets being pulled in; and once a yacht will allow of that, flat sails can be used with great advantage. Flat sails accordingly became the rule and not the exception; but flax cloth was still used, for the yachting world was not yet educated up to cotton. In 1868 appeared the beautiful 400-ton schooner "Sappho," from America, canvased with cotton. She was a lovely model, but had neither power nor ballast to stand up to her cloth, and she made a sorry show in a race round the Isle of Wight against such boats the "Cambria," "Aline," "Oimara," and "Condor." Completely remodelled and rebuilt in as 1870 by Bob Fish, one of the smartest men in America at designing and sailing boats, she sailed three matches against the Cambria." As Sappho" measured 400 tons, and "Cambria" only 200 tons, and as no time allowance was given, the former had naturally by far the best of it. She won easily, and her success set the fashion in cotton cloth.
The following year Mr. Ashbury built the "Livonia." She was canvased with cotton, and the sails did well. But the boat was not a great success, and in consequence cotton cloth again dropped out of use for some years, and was not tried again till the year 1887, when the "Thistle " had all her sails made of that material. East India cotton was, however, used instead of Egyptian, and the cloth did not come up to expectation. The next boats to use cotton were Yarana," "Valkyrie," "Deerhound," and "Iverna," and all the succeeding racing yachts, including "Britannia," "Satanita," "Calluna," "Valkyrie II." and "III.," were canvased with cotton cloth. 66 The mainsails of "Valkyrie II." and "III." were both made of Sea Island cotton, but the latter was also given a white Egyptian cotton sail, which was used for the Cup races, as it was considered a better sail than the one made of Sea Island cotton.
It is no compliment, but a universally recognised truism, to say that the best sails in the world are made by Messrs. Lapthorn and Ratsey.
George R. Ratsey, born in 1769, served his apprenticeship at East Cowes, and in 1790 set up on his own account in that town. In those days hundreds of merchant ships called at Cowes for orders, and Mr. Ratsey's business was principally concerned with them.
But he also made sails for His Majesty's Navy, as in those stirring times, when fleets were constantly fitting out at Portsmouth, a good deal of sail-making was given out to private firms. He made the sails for the "Waterwitch" brig, owned by Lord Belfast, to which allusion has already been made.
Mr. Ratsey subsequently retired in favour of his son, by whom the Cowes business was carried on very successfully until the year 1880, when he retired, and his sons entered into partnership with Mr. Edwin Lapthorn.
James Lapthorn served his apprenticeship at Kingsbridge, near Salcombe, and then went to London, where he managed a large sail-making business. In 1825 he migrated to Gosport, and started sail-making on his own account, and in the course of time was joined by his two sons, James and Edwin, who carried on the business most successfully for many years. James Lapthorn died in 1868, and his son James in 1869, and the business was conducted subsequently by his surviving son, Edwin, until he entered into partnership, as already mentioned, with Messrs.
Ratsey in 1880.
The firm of Lapthorn and Ratseys carry on business at Cowes, Gosport, Gourock, Southampton, and New York, and there can be no doubt that the combination of talent and experience derived by this amalgamation has been very beneficial to the art of sail-making. Of late years immense strides have been made in the art of sail-cutting, and the difficulty in setting sails properly and keeping them in their places has been proportionately decreased. Fiveand-twenty years ago racing yachts were started from an anchor, with all their sails down, and it was a very difficult business, especially if there was any weight of wind, to set properly the canvas of a 100-ton cutter in those days. In fact, with much wind the mainsail could never be got to set all day. Hemp stays and gear were also stretching all the time, and even if the sails were properly set at starting, a pull here and there was constantly required to keep them in their place. Nowadays, with perfectly cut sails, and with wire gear and rigging, which practically has no stretch, a sailing master's difficulties in respect to setting his canvas are much diminished. The sail-maker always sends printed instructions with the sails, and the skipper has not very much more to do than to carry them out. Some care, of course, must be taken with a new mainsail, although it is not nearly so easily damaged as is generally supposed.
Pcpular opinion is that a sail may be spoilt irretrievably if it gets wet, or if it is reefed before it has become thoroughly stretched. It is certainly better to avoid reefing it if possible before it is stretched into shape, but far from wetting spoiling a sail, we believe it does it good, provided, of course, that it gets thoroughly dry afterwards.
The difference between a well-cut and a badly cut sail, though plain enough in practice, is due to such small and almost imperceptible causes, that it is not easy to account for the fact that one firm have succeeded in acquiring a practically complete monopoly of sail-making for racing yachts, especially as the superiority of their productions is not due to any patent process, or secret of trade. Excellence led up to monopoly, and monopoly has conduced to excellence.
Severe competition would inevitably have produced depreciation of quality in the material used, and the primary consideration in sail-making is that the sail-cloth shall be AI; it is no more possible to make a good fitting sail from inferior stuff than it is to make a good fitting pair of trousers out of shoddy. There are many small points in sail-making, individually of apparently but small importance, that go to make a good sail, and it is the combination of all these small items that ensures the success of the whole. If all sails were square sails, the difficulties in the way of sail-making would be comparatively small, and an ordinary skilled mechanic would be able to turn out as good work as any one else. But in respect of fore and aft sails, the case is very different. The cloths of such sails are all more or less cut on the gore, and one of the chief arts in cutting the gore is to allow for its stretching, so as to counteract the stretch of the sail, and thereby prevent the sail getting out of shape.
Another very important point to be considered in sail-making is the relative stretch of the cloth and the rope. This must be exactly calculated. allowed for, and adjusted, for if the rope is too tight, the sail will be baggy, and on the other hand if it is too slack, the cloth will be stretched out of shape or burst.
The constant and undivided attention of intelligent and talented men for some three generations directed to these and similar practical matters connected with sail-making, together with the fact that, owing to absence of competition, nothing but the very best material has been employed by them, no doubt explains the fact that, as is universally admitted, the work of no sail-maker in any country can compare with that turned out by Messrs. Ratseys and Lapthorn.
The following plan illustrates the most approved and up-to-date method of cutting the cloths of sails. Jibs, foresails, and topsails certainly stand much better cut according to this method, owing to the fact that, the after-leeches and foots being cut square with the cloth, the stretch is reduced to a minimum. Formerly the cloths of the mainsail were put in parallel to the leech, but nowadays such sails are almost invariably cross cut" for racing purposes in order to reduce the wind friction on the seams. This method was introduced by Messrs. Ratsey and Lapthorn in 1899, and proved so successful that it has been almost universally adopted for racing yachts' mainsails. The idea is not, however, altogether new, as the present Mr. Ratsey's father made similar sails as far back as 1852, but yachtsmen did not take to them, and it is quite possible that they were not cut as they are now.
The propulsion of boats to windward and the trimming of sails is a most interesting subject.
History does not record the name of the astonished boat or ship sailor who first discovered that by trimming the yard of his square sail, and hauling in a little of his sheet, he could manage, DIAGRAM SHOWING HOW THE CLOTHS ARE PUT INTO A RACING YACHT'S SAILS. by going about, gradually to work his way dead against the wind; but there can be no doubt that the first steps towards beating to windward were made by accident, and that from sailing before the wind it was found out little by little that it was possible to work gradually against it. Though all that we know about windward sailing has been originally derived from practical experience, the theory and science is well worthy of consideration.
But before discussing why a vessel can be propelled almost against the wind, by the wind acting on her sails, the difference between true and apparent wind must be understood. The true wind is of course the direction of the wind as it strikes a stationary object; apparent wind is the direction of the wind as it strikes the sails, as it is indicated by the vane at the masthead of a ship in motion, and it is constantly changing according to the velocity of the motion of the ship.
As a craft close-hauled moves forward maintaining a certain angle between the plane of the sail and the direction of the true wind, she obviously draws the wind ahead, and lessens the angle between the plane of the sail and the direction of the apparent wind, in a degree dependent on her speed. Hence it is that, under equal conditions of wind and of weatherly qualities, a boat progressing at the rate of five miles an hour will hold a better wind-that is to say, will sail closer to the true wind than one moving at the rate of ten miles an hour. The difference in the angles between the true and the apparent wind will be much less in the former than in the latter case.
It is this difference between the true and the apparent wind, and not, as is generally supposed, the action of tide under the lee bow, that makes a boat hold so good a wind when sailing against a foul tide. Imagine a cutter close-hauled going at the rate of five miles an hour through the water, stem on against a five mile an hour current; she will be stationary as far as the wind is concerned.
She will feel the true wind, because the ship being stationary the true and apparent winds will coincide, and she will point, say, within three points of the wind.
Suppose the tide to turn, and to run with the same velocity in the opposite direction. The craft will then be travelling at the rate of ten miles an hour in reference to the wind, and the apparent wind which she feels will be drawn about two points ahead; in other words, the ship will break off two points, and will point within five instead of three points of the true direction of the wind.
In treating of the action of wind on sails in propelling a boat to windward, the apparent wind only has to be considered. The effect of air in motion upon a sail set at any angle to its direction is to create an excess of pressure upon the side of the sail exposed to the wind and a diminution of pressure on the other side, and the result is a force acting at right angles to the plane of the sail. If, therefore, in the case of a ship, a sail were in the same plane as the keel, the force of the wind would be exerted in a direction forming an angle of 90 degrees with the keel, and, independently of shape, would drive the vessel in the same direction-that is to say, sideways.
But sails are always trimmed at some angle exceeding, say, IO degrees to the line of keel; and, therefore, the force of the wind is exerted upon the body to be moved at an angle of less than 90 degrees, and that body will have a tendency to move forward. As an example, a truck on rails, equally free to move forwards or backwards, will, with the sail properly trimmed, move forward within about four points or 45 degrees of the wind. A sail being fixed on a body equally free to move in any direction, the body will move in the same line as the direction of the wind-force; in other words, at right angles to the plane of the sail. If the body is not equally free to move in all directions, the direction of motion will be correspondingly_modified towards the line of least resistance. In the case of a ship, the line of least resistance is a prolongation of the line of the keel forward. If the resistance fore and aft be equal, and the wind is right aft, it will blow a vessel straight forward; if the wind is right ahead, it will blow her straight backward.
If the wind strike the vessel at any angle sufficiently large to fill the sails, the course of the vessel will be in a corresponding angle determined by the relative proportions of fore and aft to lateral resistance.
So much for the effect of wind on a ship, on the assumption that the force of wind upon the hull, spars, and rigging, the friction of wind on the canvas, and the effect of curvature of the sail, are eliminated. But taking these factors into consideration, the result for a vessel sailing close hauled is that the various forces of the wind may be reduced to one resultant force acting in a direction nearly perpendicular to the plane of the sail; the angle between the direction of this single effective force and the apparent wind will be somewhat greater than a right angle.
But a vessel is not moving freely in the water; she is affected by fore and aft and lateral resistance, and the effect of the latter is much greater than the effect of the former. These resistances are also reducible to one resultant force, the direction of which forms an angle of something more than 90 degrees with the path of the vessel through the water. These two forces, the one forming an angle of over 90 degrees with the direction of the apparent wind, and the other forming an angle of over 90 degrees with the direction of the path of the ship through the water, are the only two external forces acting upon the craft; consequently, assuming that the vessel ve is travelling steadily, they must be equal and opposite, their directions being in the same straight line. Hence it follows that the angle between the direction of the apparent wind and the path of the ship through the water, or her course made good, is equal to the sum of the excesses over 90 degrees of the angles formed by the two forces above mentioned.