T.
TABLING, bander, a sort of broad hem formed on the skirts and bottoms of a ship’s sails, to strengthen them in that part which is attached to the bolt-rope.
TACK, couet, a rope used to confine the foremost lower-corners of the courses and stay-sails in a fixed position, when the wind crosses the ship’s course obliquely. The same name is also given to the rope employed to pull out the lower corner of a studding-sail or driver to the extremity of its boom.
The main-sail and fore-sail of a ship are furnished with a tack on each side, which is formed of a thick rope tapering to the end, and having a knot wrought upon the largest end, by which it is firmly retained in the clue of the sail. By this means one tack is always fastened to windward, at the same time that the sheet extends the sail to leeward. See Chestree.
Tack is also applied, by analogy, to that part of any sail to which the tack is usually fastened.
A ship is said to be on the starboard or larboard tack, when she is close-hauled, with the wind upon the starboard or larboard side; and in this sense the distance which she sails in that position is considered as the length of the tack; although this is more frequently called a Board. See that article.
To Tack, virer vent devant, to change the course from one board to another, or turn the ship about from the starboard to the larboard tack, in a contrary wind. Thus the ship A, fig. 2. plate [XI]. being close-hauled on the larboard tack, and turning her prow suddenly to windward, receives the impression of the wind on her head-sails a, by which she falls off upon the line of the starboard tack a. Tacking is also used, in a more enlarged sense, to imply that manœuvre, in navigation, by which a ship makes an oblique progression to the windward, in a zigzag direction. This, however, is more usually called beating or turning to windward. See Beating and Turning.
Thus, suppose a ship A, fig. 2. plate [XI]. bound to a port B lying to windward, with the wind northerly, as expressed by the arrow. The sails a, b, c, being braced obliquely with the keel, the wind also falls upon their surfaces in an oblique direction, by which the ship is pushed to leeward, as explained in the article Lee-way. Hence, although she apparently sails W. N. W. upon the larboard tack, as expressed in the dotted line A d, and E. N. E. upon the other d f, yet if the lee-way is only one point, (and indeed it is seldom less in the smoothest water), the course will accordingly be W. by N. upon one tack, and E. by N. upon the other, as represented by the lines A e, and e g.
If the port A were directly to windward of the ship, it is evident that both tacks ought to be of equal length; or, in other words, that she ought to run the same distance upon each tack: but as the place of her destination lies obliquely to windward, she must run a greater distance upon one tack than the other; because the extremities of both boards should be equally distant from the line of her true course B A; so the larboard tack A e, crossing the course more obliquely than the other e g, will necessarily be much longer.
As the true course, or the direct distance from B to A, is only 12 leagues, it is evident, that with a favourable wind she could reach it in a few hours. On the contrary, her distance is considerably increased by the length of her boards, in a contrary wind; which, by its obliquity with her sails, operates also to retard her velocity. Thus her first board A e, on a W. by N. course, is equal to 5.7 leagues. The second tack e g is 9.2 leagues E. by N.: the third tack, parallel to A e, is 11.5: the fourth, parallel to e g, is 9.2: and the fifth, parallel to the first, 11.7 leagues. Finally, the sixth board is 4.8 leagues, parallel to the second, which brings her to the port B. By this scheme it appears that she has run more than four times the extent of the line A B, her primitive distance; and this in the most favourable circumstances of a contrary wind, viz. when the sea is smooth, and when she may carry her full topsails. For if the wind blows stronger, to render it necessary to reef the topsails, she will soon make two points of lee-way, and accordingly run east on one board, and west on the other. In this situation she will neither approach, nor recede from the place of her destination: but if the wind increases, the sea will also be enlarged; a circumstance that still farther augments the lee-way. Hence the vessel will gradually fall off from the port, in proportion to the augmentation of the wind and sea, which occasions a proportional increase of lee-way.
In order to explain the theory of tacking a ship, it may be necessary to premise a known axiom in natural philosophy, That every body will persevere in a state of rest, or of moving uniformly in a right line, unless it be compelled to change its state by forces impressed; and that the change of motion is proportional to the moving force impressed, and is made according to the right line in which that force is exerted.
By this principle it is easy to conceive how a ship is compelled to turn into any direction, by the force of the wind acting upon her sails, in horizontal lines. For the sails may be so arranged as to receive the current of air, either directly, or more or less obliquely: hence the motion communicated to the sails must of necessity conspire with that of the wind upon their surfaces. To make the ship tack, or turn round with her head to the windward, it is therefore necessary, after she has received the first impression from the helm, that the head-sails should be so disposed as to diminish the effort of the wind, in the first instant of her motion, and that the whole force of the wind should be exerted on the after-sails, which operating on the ship’s stern, carries it round like a weather-cock. But since the action of the after-sails, to turn the ship, will unavoidably cease when her head points to the windward, it then becomes necessary to use the head-sails, to prevent her from falling-off, and returning to her former situation. These are accordingly laid aback on the lee-side, to push the vessel’s fore-part towards the opposite side, till she has fallen into the line of her course thereon, and fixed her sails to conform with that situation.
It has been observed above, that the first effort to turn the ship in tacking is communicated by the helm, which is then put to the lee-side. This circumstance being announced by the pilot, or commanding-officer, who then calls out, Helm’s a-lee! the head-sails are immediately made to shiver in the wind, by casting loose their sheets, or bowlines. The pilot then calls, Up tacks and sheets! which is executed by loosening all the ropes which confine the corners of the lower sails, in order that they may be more readily shifted to the other side. When the ship has turned her head directly to windward, as in d, fig. 2. plate [XI]. the pilot gives the order to turn about the sails on the main and mizen masts, by the exclamation, Haul main-sail, haul! the bowlines and braces are then instantly cast off on one side, and as expeditiously drawn in on the other side, so as to wheel the yards about their masts: the lower corner of the main-sail is, by means of its tack, pulled down to its station at the chestree; and all the after-sails are, at the same time, adjusted to stand upon the other board. Finally, when the ship has fallen off five or six points, as h, fig. 2. plate [XI]. the pilot cries, Haul of all! or, Let go, and haul! the sails on the fore-mast are wheeled about by their braces: and as the ship has then a tendency to fall off, she is checked by the effort of the helm, which for that purpose is put hard a-lee. The fore-tack, or the lower corner of the fore-sail, being fixed in its place, the bowlines are hauled; and the other sails, which have been neglected in the hurry of tacking, are properly arranged to the wind, which exercise is called trimming the sails. See Lee-way and Sailing.
TACKLE, palan, pronounced taicle, a machine formed by the communication of a rope with an assemblage of blocks, and known in mechanics by the name of pulley.
Tackles are used in a ship to raise, remove, or secure weighty bodies; to support the masts; or to extend the sails and rigging. They are either moveable, as communicating with a runner; or fixed, as being hooked in an immoveable station; and they are more or less complicated, in proportion to the effects which they are intended to produce.
If a b d e, fig. 3. plate [XI] be a single block, upon which are suspended the weights f g, then since the nearest distance of the ropes f g, from the center of motion c, are a c equal to d c, the block will be reduced to the lever or balance a d with respect to its power: Since a c is then equal to d c, it is apparent that f g will always be in equilibrium. As no advantage therefore can be acquired, in raising a weight by an immoveable single block, it is only rendered useful by changing the direction of the moving power. This circumstance is extremely convenient to the labourers, and often absolutely necessary; particularly in raising bodies to a higher station; as from the hold to the upper decks, or from the deck to the masts or yards, &c. which would otherwise be difficult or impracticable to perform. See also the articles Block and Whip.
When a single block is moveable along with the body to which it is attached, fig. 4. plate [XI]. as the blocks of the brace-pendants, reef-tackle pendants, jiggers, &c. the momentum of the power is doubled; because it moves twice as fast as the weight, or body to which it is attached. For in the same time that any part of the rope f, moves upward from f to g, equal in length to the two equal ropes d and c, the block, and consequently the weight annexed, will be drawn through the space e h, whose length is equal to one of the ropes only.
When a tackle consists of two or more fixed and moveable blocks, wherein one rope communicates with the whole; if one end of the rope be fixed, as in fig. 5. 6. and 7. in order to proportion the weight to the resistance, the power applied must be to the weight, as one, to twice the number of sheaves in the moveable blocks: because, in the efforts of a tackle, the velocity of the moving power is, to the velocity of the rising or moving body, as twice the number of moveable sheaves to unity, as appears in fig. 5. which consists of one fixed block a, and another moveable as e. For since one rope operates on all the sheaves from g to f, the part at f, lying beyond the fixed block, and called the fall, cannot be drawn down and lengthened, unless the two parts d and c, on each side of the moveable block, be at the same time equally drawn up and shortened. Hence it is evident, that the part a f will be lengthened twice as much as either d or c is shortened, because whatever is taken from each of those parts is added to the length of a f; but the point f, to which the power is applied, descends as fast as a f is lengthened and the point e, to which the weight is fastened, ascends as fast as d or c is shortened. If therefore, a weight suspended at f, be to a weight suspended at e, as one to two, they will balance each other, as being in the reciprocal ratio of their velocities.
Whatever has been observed with regard to the tackles above mentioned, is equally applicable to all others, and is in the same manner demonstrable, viz. that the velocity with which the mechanical force moves, in raising a weight, is to the velocity wherewith the weight rises, as twice the number of moveable sheaves to unity.
A tackle wherein both the blocks are moveable, and communicate with a runner, is represented by fig. 10. plate [VIII]. That part of the tackle which is fixed to one of the blocks, &c. is called the standing part; all the rest are called running parts; and that whereon the men pull when employing the tackle, is called the fall. The application of the tackle to mechanical purposes is termed hoisting or bowssing. See those articles.
Ground Tackle. See Ground Tackle.
Tack-tackle, a small tackle used occasionally to pull down the tack of the principal sails of a ship to their respective stations. There is also a tackle of this kind constantly fixed to the tacks of the main-sail in brigs, sloops, and schooners, for the same purpose. See the French term Palan, and the phrases annexed thereto.
TAFFAREL, couronnement, the upper part of a ship’s stern, being a curved piece of wood, expressed by F F, in fig. 1. plate [X]. and usually ornamented with sculpture.
TAIL, a name given by sailors to the extremities of a hurricane, wherein the violence is considerably exhausted.
Tail-block, a small single block, having a short piece of rope attached to it, by which it may be fastened to any object at pleasure; either for convenience, or to increase the force applied to the said object, as explained in the first part of the article Tackle.
TAKING-IN, the act of brailing-up and furling the sails at sea, particularly when the wind increases. It is generally used in opposition to setting. See also Furl and Shorten.
TALLYING, border, a phrase used by the common sailors, implying the act of pulling aft the sheets, or lower corners of the main-sail and fore-sail.
TAR, a sort of liquid gum, of a blackish hue, which distils from pines or fir-trees, either naturally or by incision; and being prepared by boiling, is used to pay the sides of ships and boats, and their rigging, in order to preserve them from the effects of the weather, by which they would otherwise soon become cracked, split, or rotten.
Tar is also a figurative expression for a sailor of any kind.
Tar-pawling, prélart, a broad piece of canvas well daubed with tar, and used to cover the hatchways of a ship at sea, to prevent the penetration of the rain, or sea-water, which may occasionally rush over the decks. See Battens.
TARTAN, (tartana, Ital.) a small coasting vessel navigated in the Mediterranean sea, and having only one mast and a bowsprit, the principal sail, which is extremely large, being extended by a lateen-yard. See Vessel.
TAUGHT, roide, (dicht, Dutch) the state of being extended or stretched out. It is usually applied to a rope or sail, in opposition to slack.
TAUNT, foit, an epithet used, in the sea-language, to signify high or tall. It is peculiarly expressed of the masts when they are of an extraordinary length, as square is applied to the yards on the same occasion.
TENDER, patache, a small vessel employed in the King’s service, on various occasions; as, to receive volunteers and impressed men, and convey them to a distant place; to attend on ships of war or squadrons; and to carry intelligence or orders from one place to another, &c.
TENDING, the movement by which a ship turns or swings round her anchor in a tide-way, at the beginning of the flood or ebb. Thus, if the flood sets northerly, it is evident that the ship, unless when moored head and stern, will fall into the line of the current, turning her head to the southward. But as the reflux will for the same reason set to the southward, the ship will of necessity turn about at the change of the tide, and carry her head to the northward; and the transition from one situation to the other is called tending or swinging.
TENON, the end of a piece of timber cut smaller to enter into a mortise.
THIMBLE, cosse, a sort of iron ring, whose outer surface is hollowed throughout its whole circumference, in order to contain, in the channel or cavity, a rope which is spliced about it, and by which it may be hung in any particular station. See plate [XII]. fig. 1. It is used to guide the direction of some running rope, which passes through it, from one place to another. See Span.
THOLES, (tholet, Fr.) certain small pins driven perpendicularly into the upper edge of a boat, as expressed by e, fig. 1, plate [III]. In the exercise of rowing, the oar is contained between the two tholes, in the space which is called the row-lock. Sometimes there is only one pin to each oar, as in the boats navigated on the Mediterranean sea. In that case the oar is hung upon the pin by means of a strop; and indeed this method is much more ancient than the former. See the article Rowing.
THROAT, a name given to the inner end of a gaff, or to that part which is next to the mast. It is opposed to peek, which implies the outer extremity of the said gaff, or that part of it which extends the sail behind. Hence the ropes employed to hoist up, and lower a gaff, being applied to those parts of it, are called the throat and peek haliards. See Haliards.
THUS! the order by which the pilot directs the helmsman to keep the ship in her present situation when sailing with a scant wind; so that she may not approach too near the direction of the wind, and thereby shiver her sails, nor fall to leeward, and run farther out of her course. See Steering.
THWART, banc, the seat or bench of a boat whereon the rowers sit to manage the oars.
Thwart-ships, across the ship. See the article Athwart.
TIDE, marée, (tyd, Sax.) a regular periodical current of the water, setting alternately in a flux and reflux, produced by the influence of the moon.
If the ocean were equally deep in every place, the ebbing and flowing of the tide would be universally regular and equal; but the shallowness of the water in many places, and the streightness of the channels, by which the tides may be considerably interrupted in some parts, and propagated in others, occasion a great diversity in their force and quantity. Hence, without an exact knowledge of all the circumstances of the several places where they happen to run, as of the position of the land, the breadth and depth of channels; it is impossible to account for this diversity.
The theory of the tides is concisely described by a great author, in these words: “That motion of the water called tides is a rising and falling of the sea: the cause of this is the attraction of the moon, whereby the part of water in the great ocean which is nearest the moon, being most strongly attracted, is raised higher than the rest; and the part opposite to it being least attracted, is also higher than the rest; and these two opposite elevations of the surface of the water in the great ocean, following the motion of the moon from est to west, and striking against the large coasts of the continents, from thence rebounds back again, and so makes floods and ebbs in narrows, seas, and rivers.” Locke.
With regard to the relative force of the tide on a ship floating therein, it is already explained in the article Current.
TIER, batterie, a name given to the range of cannon mounted on one side of a ship’s deck. See the articles Deck and Cannon.
Tier of the cable, is a range of the fakes or windings of the cable, which are laid within one another in an horizontal position, so as that the last becomes the innermost. See Coiling.
Cable-Tier is the hollow space in the middle of a cable, when it is coiled.
TIGHT, (dicht, Dutch) the quality whereby a vessel resists the penetration of any fluid, whether compressing its surface, or contained within it. Hence a ship is said to be tight, when her planks are so compact and solid as to prevent the entrance of the water in which she is immersed: and a cask is called tight, when the staves are so close that none of the liquid contained therein can issue through or between them. In both senses it is opposed to leaky, which see.
TILLER, timon, or barre de gouvernail, the bar or lever employed to turn the rudder in steering. See the article Helm.
TILT, tendelet, (tyld, Sax.) a small canopy or awning of canvas, or other cloth, extended over the stern-sheets of a boat, and supported by small pillars, or broad laths of flexible wood incurvated into arches. It is used to cover the passengers from the rain or sunshine. See Boat.
TIMBERS, couples, the ribs of a ship, or the incurvated pieces of wood, branching outward from the keel in a vertical direction, so as to give strength, figure, and solidity to the whole fabric.
It has been observed in the article Naval Architecture, that one timber is composed of several pieces united into one frame, which is accordingly called a frame of timbers by the artificers. These different pieces are exhibited in plate [I]. Pieces of the Hull, by U, V, and W. The head of the lower piece, called the floor-timber, being cut square, to join the heel of the next above it. To support the connection of the timber in that place, another assemblage of pieces are formed, and joined in the same manner; so that when both the sets are fastened together, the joinings in one set will be nearly opposite to the middle of the pieces in the other. Hence it is evident, that the mould which serves for the lowest piece will conform to the under part of the corresponding piece above it: and thus the mould, appropriated to every division of a timber, will determine, or answer to the figure of the next adjoining thereto.
The timbers whose areas or planes are perpendicular to the keel, are called square timbers; and those which are placed obliquely on the keel, as at the extremities of a ship, are called cant-timbers. The foremost of those pieces on the ship’s bow, are called the knuckle-timbers; and the hindmost on the quarter are called the fashion-pieces.
The outlines, or bends of the principal timbers of the ship are geometrically delineated in the plane of projection, plate [I]. as also in plate [IV]. fig. 11. and plate [X]. fig. 2.: and their particular stations in the ship’s length are represented in the horizontal plane, and that of the elevation, plate [I]. In order to give a more comprehensive idea of their figures and dimensions, we have exhibited a perspective view of the carcase of a small vessel, in plate [XII]. fig. 2. consisting only of the keel A, the stern-post B, the stem C, the transoms K L M, and the ribbands F F.
Timber and room, or room and space, is the alliance betwixt the moulding edge of two adjoining timbers, which must always contain the breadth of two timbers; and sometimes two or three inches between them. It must be observed, that one mould serves for two timbers; the fore side of the one being supposed to unite with the after side of the other, and so make only one line; which is actually the case in all the frames, which in some ships are every third, and in others every fourth timber. The frames are first put up, and fastened to the ribbands, and afterwards the others are put up, which are called fitting-timbers. Murray’s ship-building.
TIMONEER, (timonier, Fr.) the helmsman, or person who manages the helm to direct the ship’s course. See the article Steering.
In a ship of war the quarter-masters and timoneers are usually chosen by the master, to cun and steer the ship; as also, to stow the provisions in the hold, coil the cables, regulate the watch, &c. See Quarter-master.
TOGETHER! accord, the order given to the men in the exercises of heaving, rowing, holding, &c. to act all in concert, or at the same instant.
TOGGEL, cabillot, a small wooden pin, about five or six inches in length, and usually tapering from the middle towards the extremities. It is used to fix transversely in the lower part of a tackle, in which it serves as an hook whereby to attach the tackle to a strop, slings, or any body whereon the effort of the tackle is to be employed.
There are also toggels of another kind, employed to fasten the top-gallant sheets to the span, which is knotted round the cap at the top-mast-head. For as the lifts of the topsail-yard are out of use when the topsail is hoisted, they are always converted into top-gallant sheets, to render the rigging at the mast-heads as light and simple as possible. Before the topsail-yards can be lowered so as to be sustained by their lifts, it therefore becomes necessary to transfer that part of the lift to the top-mast-head, that so the whole weight of the yard may be sustained by its mast-head, and no part thereof by the top-gallant-yard, which would otherwise be the case. This is performed by fixing the double part, or bight of the lift, within the eye of the span above mentioned, and inserting the toggel through the former, so as to confine it to the latter, which operation is amongst sailors called putting the sheets in the beckets.
TOMPION, (tampon, Fr.) a sort of bung or cork used to stop the mouth of a cannon. At sea this is carefully encircled with tallow or putty, to prevent the penetration of the water into the bore, whereby the powder contained in the chamber might be damaged or rendered incapable of service.
TONNAGE. See the article Burthen.
TOP, hune, a sort of platform, surrounding the lower mast-head, from which it projects on all sides like a scaffold.
The principal intention of the top is to extend the top-mast shrouds, so as to form a greater angle with the mast, and thereby give additional support to the latter. It is sustained by certain timbers fixed across the hounds or shoulders of the mast, and called the tressel-trees and cross-trees, the former of which are expressed by k, fig. 1. plate [VI]. and the latter by l, l, fig. 2. The plan of the top is represented in fig. 6. where g g represents the holes through which the top-mast shrouds communicate with those of the lower mast, as explained in the article Shroud.
Besides the use above mentioned, the top is otherwise extremely convenient to contain the materials necessary for extending the small sails, and for fixing or repairing the rigging and machinery, with more facility and expedition. In ships of war it is used as a kind of redoubt, and is accordingly fortified for attack or defence, being furnished with swivels, musketry, and other fire-arms; and guarded by a thick fence of corded hammocs. Finally, it is employed as a place for looking out, either in the day or night.
The frame of the top is either close-planked like a platform, or open like a grating. The former kind, which is exhibited in fig. 6. plate [VI]. is generally stronger and more convenient; but the latter is much better in tempestuous weather, as presenting a smaller surface to the wind when the ship leans over to one side, and by consequence being less exposed to its efforts.
In all ships of war, and in the largest merchantmen, the top is fenced on the aft-side by a rail of about three feet high, stretching across, and supported by stanchions, between which a netting is usually constructed, as appears by fig. 2. plate [VI]. The outside of this netting is generally covered with red bayze or red painted canvas, which is extended from the rail down to the edge of the top, and called the top-armour. By this name it seems to have been considered as a sort of blind, behind which the men may conceal themselves from the aims of the enemy’s fire-arms in time of action, whilst they are charging their own muskets, carabines, or swivels.
The dimensions of tops in the royal navy are as follow. The breadth of the top athwart-ships, q q, fig. 6. is one third of the length of its corresponding top-mast. The length of all tops, from the foremost to the after edge p p, is equal to three fourths of their breadth athwart; and the square hole in the middle is five inches to a foot of those dimensions. The tressel-trees and cross-trees extend nearly to the edge of the tops. See those articles.
Top-block. See Block and Mast.
Top-chain. See the article Chain.
Top-lanthorn, fanal de hune, a large lanthorn placed in the after part of the top, in any ship where an admiral or commodore is personally aboard. It is supported on each side by iron braces r, as expressed in fig. 3. plate [VI].
Top-mast, mât de hune, the second division of a mast; or that part which stands between the upper and lower pieces. See the article Mast.
Top-rope, guinderesse, a rope employed to sway-up a top-mast or top-gallant mast, in order to fix it in its place; or to lower it in tempestuous weather, or when it is no longer necessary. The rope used on this occasion for the top-masts is, on account of their great weight, furnished with an assemblage of pullies, at its lower end, called the top-tackle, to hoist or lower the mast with greater facility. The whole of this is particularly explained in the article Mast, and the plate therein referred to.
Top-sails, certain large sails extended across the top-masts, by the top-sail-yard above, and by the yard attached to the lower mast beneath; being fastened to the former by robands, and to the latter by means of two great blocks fixed on its extremities, through which the topsail-sheets are inserted, passing from thence to two other blocks fixed on the inner part of the yard close by the mast: and from these latter the sheets lead downwards to the deck, where they may be slackened or extended at pleasure. See the article Sail. N. B. The top-gallant sails are expanded above the topsail-yard, in the same manner as the latter are extended above the lower yard.
The several parts of the machinery by which the top-sails are managed, as the bowlines, braces, haliards, lifts, and sheets, being copiously defined in their proper places, it would be superfluous to repeat their explanations.
TOPPING, apiquer, the act of pulling one of the extremities of a yard higher than the other, by slackening one of the lifts, and pulling upon the opposite one, so as to place the yard at a greater or lesser obliquity with the mast.
Topping-lift, balancine de gui, a large and strong tackle, employed to suspend or top the outer end of a gaff, or of the boom of a main-sail and fore-sail; such as are used in brigs, sloops, or schooners. See Square.
TORNADO, travade, a violent squall or gust of wind rising suddenly from the shore, and afterwards veering round the compass like a hurricane. These are very frequent on the coasts of Guinea and South Barbary. See Wind.
TOUCHING, the state of a ship’s sails when they first begin to shiver, with their edges in the direction of the wind. It is either occasioned by a sudden alteration of the ship’s course, or by a change of the wind, in which it blows more obliquely along the surface of the sails, instead of falling into their cavities from behind, according to its usual direction. See Full and by.
Touching-at, implies the circumstance of stopping, or anchoring occasionally, at some intermediate port, in the course of a voyage.
To TOW, remorquer, (teon, teohan, Sax.) to draw a ship forward in the water, by means of a rope attached to another vessel or boat, which advances by the effort of rowing or sailing.
Towing is either practised when a ship is disabled, and rendered incapable of carrying sail at sea; or when her sails are not fixed upon the masts, as in a harbour: or when they are deprived of their force of action by a cessation of the wind.
When a ship of war is dismasted, or otherwise disabled from carrying sail at sea, she is usually towed by a cable reaching from her bow to another ship a-head. In a harbour towing is practised by one or more boats, wherein all the force of the oars are exerted to make her advance.
Tow-line, a small hauser generally used to remove a ship from one part of an harbour or road to another, by means of anchors, capsterns, &c. as explained in the article Warping. It is also employed occasionally to moor a small vessel in a harbour, conveniently sheltered from the wind and sea.
Tow-rope, a name given to any cable or other rope used in the exercise of towing.
TRACING-LINE, martinet, a small cord generally passing through a block or thimble, and used to hoist up any object to a higher station, in order to render it less inconvenient. Such are the tracing-lines of the awnings, and those of the yard-tackles, which, by hanging down in a cavity or bight, would be aukward and incommodious.
TRACK of a ship. See the article Wake.
TRACKING, the act of pulling any vessel or floating body along the stream of a canal or river, by means of a rope extending from the vessel, &c. to the adjacent shore, and drawn along the banks of the river, by men or horses. Whence,
TRACK-SCOUT, a vessel employed to carry goods or passengers up and down the rivers or canals in Holland, and the countries bordering on the Baltic sea. It is usually tracked by a horse, who trots along the margin to a limited distance, after which he is relieved by another.
TRADE-WINDS, certain regular winds blowing within or near the tropics, and being either periodical or perpetual. Thus, in the Indian ocean, they blow alternately from different points of the compass, during a limited season; and, in the Atlantic ocean, continue almost without intermission in the same direction. They are accordingly called trade-winds, from their great utility in navigation and commerce. See Monsoon and Wind.
TRAIN. See the articles Cannon and Fire-ship.
TRANSOMS, barres d’arcasse, (transenna, Lat.) certain beams or timbers extended across the stern-post of a ship, to fortify her after-part, and give it the figure most suitable to the service for which she is calculated.
Transoms are here defined beams or timbers, because they partake equally of the form and purpose of those pieces. Thus the deck-transom is the aftmost or hindmost beam of the lower deck, whereon all the deck-planks are rabetted: and all the transoms are fixed athwart the stern-post, in the same manner as the floor-timbers are laid upon the keel. As the floor-timbers also, with regard to their general form and arrangement, have a rising, by which, the bottom becomes narrower as it ascends towards the extremities; so the arms of the transoms, being gradually closer in proportion to their distance from the wing-transom downwards, give a similar figure to that part of the ship, which accordingly becomes extremely narrow, from the counter towards the keel; and this general figure or curve is called the flight of the transoms.
Although these pieces are therefore extremely different in their figures, according to the extent of the angles formed by their branches or horns, each of them has nevertheless a double curve, which is partly vertical, and partly horizontal, with regard to its situation in the ship. The former of these is called, by the artificers, the round-up, and the latter the round-aft.
As the transoms fill up the whole space comprehended between the head of the stern-post above, and the aftmost floor-timbers below, it is necessary to distinguish them by particular names. Thus the highest is called the wing-transom: the next, the deck-transom; and afterwards follow the first, second, and third transoms; together with the intermediate ones, as represented in fig. 1. plate [X]. and described in the explanation thereof.
The vertical direction of the arms or angles of the transoms, with regard to the ship’s length, are expressed in the plane of Elevation; and their horizontal curves are also delineated on the plane of Projection; both of which are represented under those terms in plate [I]. and described in the general explanation of the planes in the article Naval Architecture.
The highest transoms are connected to the ship’s quarter by knees, which are bolted to those pieces, and to the after-timbers. See the article Sleepers.
TRANSPORT. See the article Ship.
TRANSPORTING, the act of removing a ship from one place to another, by the help of anchors and ropes. See Warping.
TRAVELLER, racambeau, a sort of thimble, whose diameter is much longer, in proportion to the breadth of its surface, than the common ones, fig. 3. plate [XII]. It is furnished with a tail formed of a piece of rope, about three feet in length, one end of which encircles the ring, to which it is spliced. These machines are principally intended to facilitate the hoisting or lowering of the top-gallant-yards at sea: for which purpose two of them are fixed on each back-stay, whereon they slide upwards and downwards, like the ring of a curtain upon its rod: being thus attached to the extremities of the top-gallant-yard, they prevent it from swinging backwards and forwards, by the agitation of the ship, whilst the yard is hoisting or lowering at sea.
TRAVERSE, in navigation, implies a compound course, or an assemblage of various courses, lying at different angles with the meridian. Thus fig. 2. plate [XI]. exhibits the traverses formed by a ship, when making an oblique progression against the direction of the wind, as explained in the article Tacking.
The true course and distance resulting from this diversity of courses is discovered by collecting the difference of latitude and departure of each course, and reducing the whole into one departure and one difference of latitude, according to the known rules of trigonometry. This reduction will immediately ascertain the base and perpendicular; or, in other words, will give the difference of latitude and departure to discover the course and distance. See Navigation.
Traverse-board, a thin circular piece of board, marked with all the points of the compass, and having eight holes bored in each, and eight small pegs hanging from the center of the board. It is used to determine the different courses run by a ship during the period of the watch; and to ascertain the distance of each course. This implement is particularly useful in light and variable winds, at which time the helmsman marks the course every half hour, by fixing a peg in that point of the compass whereon the ship had advanced. Thus, if the wind is northerly at the beginning of the watch, the ship, being close-hauled on the larboard tack, will steer W. N. W. If, after the first half hour, the wind changes to N. by W. the ship will fall off to W. by N. both of these courses are marked by the helmsman upon the traverse-board, by putting in one peg for every half hour on which she steers the same course; as, one peg into W. N. W. and two pegs into W. by N. if she sails an hour on the latter course; and so on. The lee-way and variation of the compass are afterwards allowed by the pilot, on summing up the whole.
TREE-NAILS, gournables, certain long cylindrical wooden pins, employed to connect the planks of a ship’s side and bottom to the corresponding timbers.
The tree-nails are justly esteemed superior to spike-nails or bolts, which are liable to rust, and loosen, as well as to rot the timber; but it is necessary that the oak of which they are formed should be solid, close, and replete with gum, to prevent them from breaking and rotting in the ship’s frame. They ought also to be well dried, so as to fill their holes when they are swelled with moisture. They have usually one inch in thickness to 100 feet in the vessel’s length; so that the tree-nails of a ship of 100 feet long, are one inch in diameter; and one inch and a half for a ship of 150 feet.
TRESTLE-TREES, tesseaux, two strong bars of timber fixed horizontally on the opposite sides of the lower mast-head, to support the frame of the top, and the weight of the top-mast. See Mast and Top.
TRIM, manege du navire, (trimman, Sax. to build) implies, in general, the state or disposition by which a ship is best calculated for the several purposes of navigation.
Thus the trim of the hold denotes the most convenient and proper arrangement of the various materials contained therein, relatively to the ships motion or stability at sea. The trim of the masts and sails is also their most apposite situation, with regard to the construction of the ship, and the effort of the wind upon her sails.
As the stowage of the hold, or the disposition of the several articles of the cargo, considerably affects the ship’s motion and stability, it will be necessary to give a general idea of the action of a heavy body upon the fluid that supports it, and the re-action of the fluid on the floating body.
The whole weight of any body, then, may be considered as united in its center of gravity; so that, if it were suspended by a line fastened to this center, the line would hang in a perpendicular position, as directed through the center of gravity to the center of the earth. A body which floats in a fluid is not, however, supported by its center of gravity, but by the compression of the surrounding filaments of water: and each of these, being considered as infinitely small, will act upon a very minute portion of the surface of the floating body, with regard to the specific gravity, and conform to a principle applicable to all fluids, in proportion to the height of these filaments, viz. That the weight of a column of any fluid will be in proportion to the specific gravity of the fluid and the height of the column multiplied by its base.
But as heavy bodies endeavour, by their gravity, to approach the center of the earth, in a vertical line passing through their centers; so the pressure of fluids endeavours to carry bodies in a vertical, tending from the center of the earth towards their surface, and passing through the center of gravity of the submerged part, which forces them towards the surface. So, in any submerged body at rest, these two opposite forces coincide in the same vertical, acting in a direction quite contrary to each other. Bouguer’s Traité du navire.
From this theory it results, that the stability or trim of a ship chiefly depends upon her construction, as considering the bottom to be homogeneous. This, however, can only happen when her cargo consists of the same materials throughout, as with corn, salt, or any species stowed in bulk, and when her hold is entirely filled. For if the ship has not sufficient breadth to resist the effort of the wind upon her sails; or if she is built too high, or too sharp in the floor, her center of gravity will be too high, and she will be very crank, i. e. apt to overturn.
But as the stiffness of a ship, or quality to carry sail without danger of overturning, depends very much on the stowage of the hold, the center of gravity may thereby be considerably lowered, by which her stability will be increased in proportion. It is a general maxim amongst mariners, that a ship will not carry sufficient sail till she is laden so deep that the surface of the water may glance on her extreme breadth amidships. She must therefore have a great deal of weight, as ballast, &c. to bring her to this situation, which is called a good sailing trim.
Several circumstances are also to be particularly considered with regard to the quality, weight, and stowage of the ballast. The center of gravity being placed too high, will render the ship incapable of carrying a sufficient quantity of sail; and by having it too low, she will be in danger of rolling away her masts. When it is placed too far forward, the ship will pitch, and labour heavily; and when too far aft, she will occasionally be exposed to the dangerous circumstance of a pooping sea. These extremes being carefully avoided, it remains to proportion the contents of every part of the hold to its capacity, and to place the lightest materials uppermost. See Stowage.
Trim, when applied to the sails, denotes the general arrangement which is best calculated to accelerate the ship’s course, according to the direction of the wind. See the article Sailing.
If the ship were always to sail before the wind, it would be a very simple operation to trim the sails; because nothing else could be required than to dispose them so as to receive the greatest possible effort of the wind, which is evidently performed by arranging them at right angles with its direction. But, when the current of wind acts more directly upon the ship’s side, it necessarily falls more obliquely on the surface of the sails, so as to diminish their effort to push the ship forward; and to augment their tendency to make her incline to one side. Hence we may conclude, that an increase of the wind, when accompanied with a variation unfavourable to the ship’s course, will by no means augment her velocity; because the force previously employed to push her forward, will afterwards operate to overturn her; and because this impression renders it necessary to reduce the quantity of sail; the effort of which is farther diminished by the obliquity of the action of the wind upon its surface.
By this theory it appears, that the effect of the wind to advance the ship decreases in proportion to its obliquity with any sail upon which it operates.
The mechanical disposition of the sails, according to every direction of the wind upon their surfaces, is copiously described in the articles Close-hauled, Large, Sailing, and Tacking.
Trim, when expressed of the masts, denotes their position with regard to the ship and to each other. Thus, in the latter sense, they should neither be too near nor too far apart; and, in the former, they should not be too far forward or aft; and, according to the situation or quality which communicates a greater velocity to the vessel, they should either be upright, or inclining aft, or forward.
Trim the boat. See Boat, and the phrases succeeding it.
Sharp-Trimmed, the situation of a ship’s sails in a scant wind.
TRIMONEER, a barbarous corruption of Timoneer. See that article.
TRIP, a cant phrase, implying an outward-bound voyage, particularly in the coasting navigation. It also denotes a single board in plying to windward.
TRIPPING, the movement by which an anchor is loosened from the bottom by its cable or buoy-ropes. See Atrip.
TROUGH, a name given to the hollow, or interval between two high waves, which resembles a broad and deep trench perpetually fluctuating. As the setting of the sea is always produced by the wind, it is evident that the waves, and consequently the trough or hollow space between them, will be at right angles with the direction of the wind. Hence a ship rolls heaviest when she lies in the trough of the sea.
TROWSERS, a sort of loose breeches of canvas worn by common sailors.
TRUCK, a piece of wood, which is either conical, cylindrical, spherical, or spheroidical.
Thus the trucks fixed on the spindle of a mast-head, and which are otherwise called acorns, are in the form of a cone: and those which are employed as wheels to the gun-carriages are cylinders. The trucks of the parrels assume the figure of a globe; and, lastly, those of the flag-staffs resemble an oblate spheroid. See the articles Acorn, Cannon, Parrel, and Flag-staff.
Trucks of the shrouds are nearly similar to those of the parrels: they are fastened to the shrouds about twelve or fourteen feet above the deck, the hole in the middle being placed perpendicularly to contain some rope which passes through it. The intention of these is to guide the sailors to the particular rope, which might otherwise be easily mistaken for some other of the same size, especially in the night.
Speaking-TRUMPET, trompette marine, a trumpet of brass or tin used at sea, to propagate the voice to a great distance, or to convey the orders from one part of the ship to another, in tempestuous weather, &c. when they cannot otherwise be distinctly heard by the persons to whom they are directed.
Fire-TRUNK. See the article Fire-ship.
TRUNNIONS, tourillons, the two knobs or arms which project from the opposite sides of a piece of artillery, and serve to support it in the carriage. See Cannon and Mortar.
TRUSS, (trousse, Fr.) a machine employed to pull a yard home to its respective mast, and retain it firmly in that position.
As the truss is generally used instead of a parrel, it is rarely employed, except in flying top-gallant-sails, which are never furnished with parrels. It is no other than a ring or traveller, which encircles the mast, and has a rope fastened to its after-part, leading downward to the top or decks; by means of which the truss may be straitened or slackened at pleasure. The haliards of the top-gallant-sail being passed through this ring; and the sail being hoisted up to its utmost extent; it is evident, that the yard will be drawn close to the mast, by pulling down the truss close to the upper part of the sail. For, without the truss, the sail and its yard would be blown from the mast, so as to swing about, by the action of the wind, and the rocking of the vessel; unless the yard were hoisted close up to the pulley wherein the haliards run; which seldom is the case in flying top-gallant-sails, because they are usually much shallower than those which are fixed or standing.
Truss-parrel. See Parrel.
TRYING, à la cape, the situation in which a ship lies nearly in the trough or hollow of the sea in a tempest, particularly when it blows contrary to her course.
In trying, as well as in scudding, the sails are always reduced in proportion to the increase of the storm. Thus, in the former state, a ship may lie by the wind under a whole main-sail, a whole fore-sail, or a whole mizen; or under any of those sails, when diminished by the reef or balance. As the least possible quantity of sail used in scudding are the goose-wings of the foresail; so in trying, the smallest portion is generally the mizen-staysail or main-staysail: and in either state, if the storm is excessive, she may lie with all the sails furled, or, according to the sea-phrase, under bare poles.
The intent of spreading a sail at this time is to keep the ship more steddy, and, by pressing her side down in the water, to prevent her from rolling violently; and also to turn her bow towards the direction of the wind, so that the shock of the waves may fall more obliquely on her flank, than when she lies along the trough of the sea. While she remains in this situation, the helm is fastened close to the lee-side, or, in the sea-language, hard a-lee, to prevent her as much as possible from falling-off. But as the ship is not then kept in equilibrio by the effort of her sails, which at other times counterbalance each other at the head and stern, she is moved by a slow but continual vibration, which turns her head alternately to windward and to leeward, forming an angle of three or four points in the interval. That part where she stops, in approaching the direction of the wind, is called her coming-to, and the contrary excess of the angle to leeward is termed her falling-off.
Thus, suppose the wind northerly, and a ship trying with her starboard side to windward: if, in turning her head towards the source of the wind, she arrives at N. W. ½ N. or N. 39° W. and then declines to the leeward as far W. ½ S. or S. 84° W, the former will be called her coming-to, and the latter her falling-off. In this position she advances very little according to the line of her length, but is driven considerably to leeward, as described in the articles Drift and Lee-way.
TUCK, a name given to that part of the ship where the ends of the bottom-planks are collected together immediately under the stern or counter.
When this part, instead of being incurvated, and forming a convex surface, assumes the shape of a vertical or oblique plane, it is said to be square, as represented in fig. 8. plate [IX]. A square tuck is accordingly terminated above by the wing-transom, and below and on each side by the fashion-pieces.
TUMBLING-HOME, encabanement, that part of a ship’s side which falls inward above the extreme breadth, so as to make the ship gradually narrower from the lower deck upwards. This angle is represented in general throughout all the timbers in the plane of projection, plate [I]. It is also more particularly expressed by Q T in the Midship-frame, plate [VII]. where it is evident, that the ship grows narrower from Q towards T. N. B. In all our old sea-books, this narrowing of a ship from the extreme breadth upwards is called housing-in. See Upper-work.
TURNING-to-windward, chicaner le vent, that operation in sailing wherein a ship endeavours to make a progress against the direction of the wind, by a compound course, inclined to the place of her destination. This method of navigation is otherwise called plying. See also Beating and Tacking.
TYE, itague, a sort of runner or thick rope, used to transmit the effort of a tackle to any yard or gaff, which extends the upper part of a sail.
The tye is either passed through a block fixed to the mast-head, and afterwards through another block moveable upon the yard or gaff intended to be hoisted; or the end of it is simply fastened to the said yard or gaff, after communicating with the block at the mast-head. See also the article Jears.