MASTS AND YARDS.-RUDDER.-MASTING.
Wooden Lower-masts are made of several pieces, united by dowels or coaks, and hoops.
In the United States Navy, the made masts consist of four principal pieces, each of which consists of two or more parts, scarfed together, when a whole piece, of sufficient length, cannot be obtained. These pieces are placed as in Plate 36 P. The inner corner of each piece is taken off so as to leave a square hole extending throughout the whole length of the mast, in its axis. This admits of a closer contact of the parts of the mast with each other when the hoops are set up, and does not take from the strength of the spar. This hole is one-tenth of the diameter of the mast in size.
The hoops are placed from three to three and a half feet apart from each other, and are from four and one-quarter to five inches wide, and from four-eighths to five-eighths of an itch thick, according to the class of ships the mast is made for. They must, however, be kept clear of the wedges at the partners. The scarfings of the piece must be kept clear of each other (that is, the points of junction in one piece must be as far as possible from those in another piece), and equally distributed in the mast. There is a chafing batten on the forward part of the mast, about one-fourth the diameter of the mast in width, and one-eighth in thickness.
The principal parts of a mast are the head, hounds, bibbs, neck, partners and heel.
The head, A B, Plate 36, extends from the upper extremity of the mast to the top of the hounds, and is one-sixth of the whole length of the mast, nearly.
The hounds are the shoulders produced by enlarging the diameter of the mast a few inches at the lower limit of the head.
To the sides of the hounds of the lower masts are bolted, and otherwise secured, fitted pieces of oak, of the shape shown in Plate 36, and called bibbs (B c). These, with the hounds, form the foundation for the tressle-trees. The small part of the mast, just below the bibbs, is called the neck.
Where the mast is wedged, at D, is called the partners; but a more correct definition of the term is given on page 7.
|The lower part of the mast, E, is called the heel, and the upper projection, A, the tenon.The doublings of masts are where the head of one mast doubles on the heel of the other.|
The yards, booms, and masts are usually made of yellow pine and spruce. The latter is selected for small spars.
Masts are most liable to decay at the heel, partners, and cap.
Masts are most liable to spring at the partners, tail of bibbs and hounds; bowsprits at the cap and on top between the gammoning and cap.
Tops are constructed of two thicknesses of white or yellow pine, with the rim, lubber-band and battens of white oak. The upper cross-trees are fayed down over the battens, and secured to the lower cross-trees by bolts at each end, and by four staples and toggles, so as to be readily removed when it is necessary to lift the top.
The Bowsprit is represented in full length in Plate 36. At the side the bees are shown extending from the cap to the housing, or where the octagonal form commences.
The parts marked 2 are of iron, and to them shackle the hearts for the inner, middle, and cap bob-stays.
The bowsprit cap is iron-bound. To an eye-bolt on the lower side is hooked the dolphin-striker.
Above the strap for the middle bobstay is an eye-bolt, to which hooks the whisker, 3.
Next outside is a sheave for the fore-topmast stay. An iron strap marked 1, containing a heavy, solid thimble, is for the fore-stay. There is one on each side.
Eye-bolts are represented on top of the bees, for bowline blocks, 4.
The eyes to which shackle hearts for bowsprit shrouds are not represented.
The Jib-Boom is represented in its place. The heel is cut to fit in a saddle bolted on the top of the bowsprit, and is clamped down by an iron strap; a short distance outboard is a sheave for a heel-rope.
Just inside the hounds is a sheave-hole for the jib-stay. Over the hounds fits an iron band having three shackles; one for the jib martingale stay, and one each side for the jib-guys. Immediately outside this band is a score for the foretop-gallant stay.
Lastly comes the wythe, a species of iron cap to support the flying jib-boom.
The Lower Mast has the cap on. To an eye in each end of a strap passing over the cap, shackle the chain slings for the lower yard. A back-strap about halfway down the mast-head, gives it a better lead.
The double block, hooked to an eye-bolt in the cap, is for the lower lift. The single block is the top-block for sending
|up the topmast. The chafing-batten is shown on the forward side.The tressle-trees are in place. Just below the bibbs comes the band for the patent truss, and below it the futtock-band to which shackle the futtock-shrouds.|
The Topmast has the cross-trees and cap on.
The forward part of the tressle-trees has a clamp. By opening this the sending up and down of the top-gallant masts is greatly facilitated. The eye-bolts under the tressle-trees are for the hanging-blocks for the head halliards.
One gin-block, for topsail-tye, is represented in its place. It should be hooked to the eye of a strap fitting over the tressle-trees and between the doublings.
In the forward part of topmast cap, are eye-bolts for the top-gallant top-block, and standing part of top-gallant mast-rope. Fitting over the topmast cap is an iron strap with a link in each end for block of topmast studding-sail halliards.
The Lower Yard has in the centre a stout iron span, to which hook the slings.
The two lower blocks are for the topsail-sheets. The two partly concealed are for the clew-garnets and hook on the forward quarter.
On the after side of the yard is nailed a chafing-batten.
Next outside is the quarter-iron for topmast studding-sail boom.
Next comes an iron burton-strap.
Outside of it is shown the eye-bolt for head-earing of the course.
On the yard-arm are the brace and lift blocks, shackled to an iron band.
Outside of all is the “pacific iron” on which fits the boom-iron.
The bending-jackstay (iron) is seen on the top of the yard.
The truss is shown in a separate figure.
The transverse section of the mast P shows the method of joining the principal pieces of which a mast is made.
The Topsail Yard, in two views, shows the jaws, tye-blocks, bending-jackstay, quarter-blocks for topgallant sheets and additional blocks, forward, for top-sail clew-lines.
Over the topmast head is frequently fitted a rectangular funnel of metal with a projecting flange at the base to receive a quarter-round piece of wood, or bolster, upon. which the eyes of the rigging rest.
Round funnels are also fitted for the top-gallant and royal mast-heads, and on them are fitted the eyes of the top-gallant and royal rigging.
Yard-Slings, Y, Plate 36, are of chain, in length twice that of their respective mast-heads; to which must be
|added half the length of the forward lower cross-tree, that being the distance the yard should hang below the top. The upper section, i.e., above the top, should be shackled together, keckled with a piece of large stuff to make it round, and neatly covered with canvas. The size of the chain necessarily depends on the weight it is required to support.They hook to the yard by the sling-hook, as represented in the plate.|
Preventer Slings for topsail yards, used when preparing for action, are made of chain and go around the mast-head.
Iron Masts. In the equipment of ships one of the modern applications of iron has been its use in constructing lower masts.
An iron lower mast is made up of plates, each bent to form an arc of a circle, usually 120 degrees, and connected at the edges and ends by through-riveted lap-joints or covering strips, the structure being usually stiffened by continuous interior T, or angle-irons.
Iron masts are commonly made of the same diameter as the wooden masts they have replaced, and for large ships are generally lighter than wooden masts of the same dimensions. The iron lower masts used in the British navy are more expensive than wooden masts of the same dimensions, and are of nearly equal weight, but the advantages gained in strength and durability are such as to outweigh the consideration of expense.
Fig. A, Plate 37, shows the section of an iron lower mast, in which there are four plates in the circumference, connected by double-riveted lap-joints, and stiffened by four continuous angle-irons worked upon the centre of each plate.
Fig. B, Plate 37, shows the angle-iron stiffeners placed so that the edge riveting shall work in as fastenings in the stiffners.
In order to stiffen masts still further, the flanges of the stiffening bars are often connected by braces or horizontal stays. These stays afford a means of climbing up inside the mast for the purpose of inspecting, cleaning and painting it. The stays are placed at intervals of from 4 to 6 feet. Fig. C, Plate 37, shows the earlier, and Fig. D the latest practice in the British service in strengthening the iron lower masts.
Figs. E and F, Plate 37, show the mode of fitting wooden trestle-trees to an iron mast. As there are no shoulders at the hounds, special provision has to be made for supporting the trestle-trees, and this is accomplished by working a plate and a ring of angle-iron around the mast, and fitting plate-knees, k k, which correspond with the bibbs usually fitted below the trestle-trees of a wooden mast. The plan E
|shows the spread of the knees and the arrangement of the plate and angle-iron below the trestle-tree.It is usual to work doubling plates upon the lower masts in the wake of the wedging decks. These plates give additional rigidity in wake of the wedges, and also prevent corrosion in the mast-plate Itself.|
Fig. G, Plate 37, shows the ordinary mode of forming the heel of an iron lower mast. The end of the mast is dosed by a circular plate fitted against and connected with the outside plating. In the centre of this plate there is a square hole, around which the angle-iron frame a is fitted, the vertical flange of the angle-iron thus forming the sides of a mortice in the heel. When in place, the mast rests on a stepping plate, upon which is riveted a rectangular box-shaped frame of iron b, and the tenon thus formed fits into the mortice in the heel of the mast.
A man-hole is usually cut a few feet from the lower end of an iron mast to give access to the interior and for ventilation; other openings are also made at various heights for the latter purpose.
Iron and steel have also been used in the construction of topmasts, topgallant masts and yards, but in these spars the advantages resulting from the change from wood are not so great as in the case of lower masts. The details of construction for the lighter spars do not differ greatly in principle from those described for lower masts. The plating is usually flush-jointed, and the larger spars have angle-iron, or other interior stiffeners.
Masting. In fitting out our men-of-war, advantage is taken of every facility which a navy-yard affords. The rigging is cut out by the draft furnished by the constructors, using the Equipment Book of Allowances as a guide. The masts are placed by the navy-yard sheers, and the hold stowed by regular stevedores.
When the navy-yard sheers are used, the mast is brought down from the spar-shed and placed with its head toward the ship under the sheers, or masting-derrick, the garland lashed on and the main purchase toggled, the fall being taken to the capstan, or crab, built for the purpose. Convenience determines which mast is to be taken in first. After placing one mast, the ship is hauled ahead, or dropped astern, to bring the other partners plumb under the purchase.
In the following outline of masting, the work is assumed to be done without the conveniences of a yard. The vessel, a frigate, is supposed to be lying in the stream, and her spars, &c., towed off.
Proceed to support the spar-deck for the weight it will have to sustain, by shoring it up fore and aft,* particularly
* Shores are stout pieces of timber or joist, placed under a beam and resting on a block. To give the deck above a proper support, they must be wedged up.
|those beams immediately under the places to be occupied by the sheers when getting in the masts.Sling skids outside leading from the gunwale to the channels, and from the channels to the water’s edge; block up a half-rounded spar in the hammock netting, the upper surface being well slushed, to lead the parbuckle over, and proceed.|
To Reeve the Parbuckle, Fig. 269, Plate 38. The main parbuckle consists of a hawser of a suitable size-say 5-inch-which is middled and the ends rove through the spar deck ports, a few ports apart (the distance depending on the length of the sheer legs), from out, in, leaving the bight outside. The sheer legs having been towed alongside, with their heads aft, pass the after end of the parbuckle down under the head of the first sheer leg, up over the gunwale to the opposite water-ways, where the end is snatched and led forward, having a long luff clapped on it, if found necessary. The forward end of the parbuckle is led in like manner, taking it under the heel of the sheer leg, and thence to the capstan.
The Counter Parbuckles, a a, Fig. 269, are rove in a contrary way, for easing the sheer legs inboard. They are rove through the same ports, from in, out, leaving the centre bight inboard, and the two end bights hanging down inside to catch the sheer leg when it comes over the gunwale; the ends are led down through the gun deck ports and taken around spars lashed fore and aft in the ports, having hands to attend them to ease the sheer legs down. Have a stout spar laid across the gunwale well aft to rest the heads of the sheer legs on when on board.
When ready, clap on the luff, man the bars, and “walk away.” When “high enough,” or up with the gunwale, “avast heaving,” arrange the counter parbuckles under head and heel, and set taut. Now pull up on the main, and ease away on the counter parbuckle, land the heel on the deck, the head resting on the thwartship spar placed for the purpose, roll it over, lift the heel over the capstan and get it in its proper position for forming the sheers; a spar may be placed from the gunwale to the capstan, and the sheer leg got thence to the opposite water-ways. The second sheer leg is got on board in the same manner, and placed for lashing.
NOTE. Instead of using parbuckles, the sheer legs may be got on board by means of a pair of small sheers, raked over the taffrail.
Fore and main topmasts or lower yards may be used for sheer legs; in the latter case, the yard-arms must be well strengthened, or fished and woolded, by lashing around them small spars, ormade fishes of stout oak plank, using well-stretched rope, and tautening the lashes by wedges. The lashing around the spar is termed a woolding.
|The Sheers. The sheer legs being on board, cross their heads (with the port leg uppermost if the masts are taken in on the starboard side), square the heels and spread them about two-thirds the breadth of beam at the mizzen partners, so that when spread out to their full extent, the sheer head lashings may be tautened.For sheer head lashings, take a piece of good 3 1/2 or 4-inch rope, well stretched, middle it and make one end fast to the sheer leg, near the cross; with the other end pass the requisite number of figure-of-eight turns round both spars and take a couple of half-hitches with the end around one leg. With the first end, pass a number of round turns, filling up the intervals between the figure-of-eight turns, pass frapping, or cross turns, and secure the two ends with a square knot.|
After passing the sheer head lashing, spread the heels and place them in the shoes. The shoes should be of stout oak plank, long enough to rest upon at least two of the spar deck beams. A saucer is cut out of the centre to rest the heel in, and on the forward and after side an eye-bolt is placed for lashing the heel to. There are eye-bolts in the forward and after ends, for hooking fore and aft shoe-tackles to, to aid in the transportation of the sheers. Lash the heel to the shoe temporarily. Hook the after heel tackles to straps around the heels and set them taut, and, as an additional security, when raising the sheers, shift the forward heel tackles aft.
The Main Purchase. Lash on the upper block of the main purchase, so that it will hang directly under the cross. It should be a large threefold block, strapped with two single straps and fitted with a large thimble, to hang by a lashing passing over the cross of the shear head.
The straps of the main purchase blocks should be well parcelled and marled. The lower block is double-strapped, with eyes for toggling, Fig. 235, Plate 31. Take the lower block of the main purchase to the bowsprit hole, and toggle it there with a suitable spar.
The fall should be new 5 1/4-in. Manilla rope. Begin with the standing part and reeve it fromforward, aft, through the side sheave of the upper block, beginning on the side opposite to that intended for taking in the masts; thence through the corresponding sheave in the lower block, and so on until rove full, when clove hitch it around one of the forks close to the lashing, and stop the end down to its own part. Snatch the fall in some convenient place near where the lower block has been toggled, and take it to the capstan.
If apprehensive that the upper purchase block will slue in its strap, by the greatest strain coming on one side, the fall may be rove so as to lead from the centre sheave-
|but this brings a cross in the fall, and is, therefore, objectionable.The Small Purchase, Guys, &c. The upper block of the small purchase is double, and lashes to the after fork so as to play clear of the main purchase. Lash a single block to each fork above the small purchase and reeve stout girtlines. For sheer-head guys, clove-hitch a couple of stout hawsers over the sheer head, leading two ends forward and two aft, and to each clap on a luff-upon-luff for convenience in setting up and easing off, without surging. Belly guys are put on in the same way, about one-third the distance down each leg, cleating the hitches to prevent slipping, and clapping on luffs. On each sheer leg just above the shoe, put good straps, and hook and set well taut a thwartship tackle to ease the strain on the water-ways; lastly, pass a bulwark lashing either to the bulwark, or to a stout toggle placed outside of the spar-deck ports.|
Raising the Sheers. The main purchase fall, being led to the capstan, the heels temporarily lashed to the shoes, and the forward and after shoe and heel tackles, both hooked aft, to prevent the sheers from launching forward as the strain is brought on the main purchase; the thwart-ship heel tackle set well taut, and plenty of hands to take in the slack of forward guys, and others to attend after ones, man the capstan, and heave around, catching the sheers as they rise, by the thwartship spar.
When nearly up and down, or at an angle of about eighty degrees with the spar deck, “avast heaving,” lash the heels in the shoes securely, shift the forward heel and shoe tackles, cast off the bulwark lashings, and transport the sheers to just forward of the mizzen partners (having previously wet the deck), by moving one leg at a time. The sheers should have a slight rake aft, and the main purchase hang plumb with the mast-hole. The fall may lead through a block toggled through the ward-room sky-light and thence to the capstan. When the sheers are in position, set up the after head and belly guys, leading to the quarters; and the forward ones, leading well forward; set taut the thwartship tackle, and pass the bulwark lashings, or substitute for it a good tackle-the main object of which is to prevent the opposite heel from rising when raising the mast from the water. Now overhaul down outside the main purchase and toggle to the garland on the mizzen-mast. Fig. 271, Plate 38.
The Derrick. It may occur that the angle of the sheers with the deck, before raising, is so small that the main purchase will not be effective, in which case it will be necessary to start them up with a derrick, as follows:
A small stout spar (say a stump top-gallant mast) is
|placed between the cross of the sheer-forks, where it is retained by a loose lashing. Hook a stout tackle from the head of this spar to the sheers, and attach two other (canting and heel) jiggers together with head-guys, as in Fig. 272, Plate 39. With these, get it erect, slushing the spar and the forks at their points of contact. Now, with the assistance of the tackle, the head of the sheers can be elevated to a considerable degree, and the main purchase made to act, at an angle sufficiently great, to raise the sheers without further difficulty.Getting in the Lower Masts. The mizzen mast is taken in first, because the breadth of beam is less aft, and the sheers, as they are transported forward spread the heels and tauten the sheer head lashings; and for the reason, that getting in the foremast last, the sheers may be better secured and raked for getting in the bowsprit.|
The Garland, Fig. 273, if used, should be of good four-inch rope, made selvagee fashion, marling it with small stuff. It is lashed on the forward side of the mast about six-tenths from the tenon, so that the mast will hang a little heel heavy. The distance from the heel must in any event be such that the garland may not take in the partners before the heel is landed. The garland lashing is passed as in Fig. 273. After passing enough turns, dog the ends down the forward part of the mast and seize them together. The garland should be lashed on before the mast is put in the water, not only for the greater convenience, but the subsequent wetting tautens the lashings very considerably. If the small purchase is used-as in getting in the main and foremasts, its garland is placed on the mast as far above the main garland, as the small purchase block is lashed on above the main. If practicable, the lower purchase blocks are lashed to the mast and the garlands dispensed with.
To take in the Mizzen-Mast, Fig. 271. Tow the mizzen-mast alongside with the head aft. Having overhauled down the main purchase abaft, shove the two eyes of the lower block strap through the garland and toggle it, using a small lashing to guard against slipping.
Man the capstan and “heave around,” observing that the skids and mats, or whatever has been placed to protect the ship’s side from chafing, are properly adjusted. When the mast-head is up with the gunwale, “avast heaving,” lash a couple of stout single blocks to the tenon, one on each side, and reeve girtlines, taking the precaution to knot the ends together to prevent unreeving. Put a couple of good straps around the mast, just above the futtock band, for pendant tackles, and bend the canting girtline, from the sheer-head to the mast, just below the bibbs; sway up again until high enough; ease the heel inboard by a jigger, coming up the belly guy, which must be set up again. Pull up on the canting line and point the mast fair for stepping,
|wipe the heel dry, and white-lead the tenon and mortise, have hands on the gun-deck to keep the mast on the right slue, and carpenters on the berth-deck to attend at the step, lower away and step the mast. Sway up three pendant tackles and hook them to the straps about the masthead-the two at the side set up in the channels, and one fore-and-aft to act as a stay; set taut the tackles and wedge the mast temporarily. When nearly stepped, a stout strap and heaver may be used to get the mast on the right slue.Come up the purchases and take off the garlands. Cast off the bulwark lashing, man the guys, shoe and heel tackles, and transport the sheers, one leg at a time, observing to wet the decks and come up the thwartship tackle in the wake of obstructions; get them a little forward of the main partners, rake and secure them as before.|
If the sheers are high enough or can be made available by spanning the fork above the sheer-head lashing, send up the tressle-trees, &c., of each mast, before transporting them to take in the rest.
Take the main and foremast in, in the same manner, with the additional use of the small purchase.
Should the sheers prove too short, the fork above the lashing may be spanned by a stout rope and the upper block of the small purchase lashed to the span. If the garland takes in the partners before the mast is stepped, the heel may be rested on blocks, or stout planks, the mast steadied by the guys and the garland shifted higher. Should the sheer-legs be found too slender and to complain, a spar may be lashed across from one to the other, in the wake of the guys.
When both purchases are employed in getting in heavy masts, a good plan, and one which obviates the necessity of heavers on the heel, is to lash the garlands, a little on each side, and not in the same right line with the axis of the mast. Then, by slacking one purchase and holding on the other, it may be slued at pleasure. The position of the small garland should be at the distance of its purchase block, from that of the large one, on the sheers, above the main, so that the falls cannot come two blocks except at the same time.
When, in dismasting, a mast is jammed in the step, a gentle roll given to the ship will start it.
To get in the Bowsprit, Fig. 276 A, Plate 40. Transport the sheers as far forward as the bows will permit; send a hand to the sheer head, bend a girtline to the small purchase block and light it up; unlash and shift it to the forward side of the sheer head. Pass a strap around the foremast head, to which hook the double block of a large tackle; the other block take aft and set well taut. Lash a couple of large blocks to the foremast head; middle a hawser
|and clove-hitch it around the sheer head, reeve the ends through the blocks at the foremast head, lead them aft and set them up; take aft the forward head-guys, which, with the after ones, are to be set up, and the forward belly guys to the cat-head; hook the after-shoe and heel-tackles forward and set them taut. Rake the sheers over the bows so that the main purchase will clear the billet-head.The bowsprit is towed under the bows, with the head forward, the cap on, and the main garland lashed on a little over one-third its length out from the heel, or so that it will hang head heavy. The small garland, lash on just inside of the cap. Have guys or whips from eye-bolts in the cap to the cat-heads, and an eye-bolt in the heel for the bedding tackle which leads from the bitts on the gun-deck out through the bowsprit partners.|
In getting in a bowsprit in modern vessels, the thrust of the heel, owing to the necessary lead of the purchases may be so great as to push the heel inboard too soon, before it is pointed fair for placing. To diminish the thrust and get the spar on the right slue use a fore-and-aft outrigger (stunsail yard) with one end against the neck of the strap on the lower purchase block, and the other controlled by two heel tackles.
Sway away on the main and small purchases, steadying the spar by the guys. When the heel is high enough, hook the bedding tackle. Wipe the tenon dry, and white-lead it and the mortise. Keep fast the small purchase; ease away on the main and bowse on the bedding-tackle and cat-head guys, and get the bowsprit in its place. Come up the purchases and guys, and unlash the garlands.
The bowsprit rests on the stem head, between the knight-heads, and steps in the bowsprit partners-on the gun-deck in a frigate and on the spar-deck in a sloop-of-war. It comes inboard about one-third its length. If the cap was not on, it may be shipped by means of a small pair of sheers, stepped on the bees.
If, by taking the forward head guys well aft, and setting them up, the support is found sufficient, the hawser at the sheer head may be dispensed with.
To Dismantle the Sheers. Proceed now to dismantle the sheers. Take the after heel tackles aft, come up the bulwark lashing, and rouse the heels aft, easing away the forward heel tackles, the head guys and the hawser, and lower away until the sheer heads rest on the knight-heads; strip the sheer legs, cast off the sheer head lashing and get each leg aft in the gangway; unreeve the hawser from the foremast-head and send down the single blocks. Put straps on the ends of the sheer legs and hook the fore and main pendant tackles to them, having the opposite tackles set well taut. Hook to the same straps, jiggers leading in from the channels. Pull up on the
|tackles, rouse out by the jiggers and lower the sheer leg overboard, taking care to have skids in the proper places to prevent chafe, or the spars taking against the dead-eyes in the channels. Or, the sheer-legs may be got down by lashing their heads separately to the lower mast, casting off the cross lashing and lowering them by means of the pendant tackles.In masting or dismasting with one’s own resources, it is necessary to measure the lengths for slinging the masts very accurately, so as to make sure of carrying the heel clear of the upper deck, and yet avoid, if possible, top-heaviness. When the spars are short for the work (as in the case of the topmasts of a high ship), the masts must be slung so low as to make top-heaviness unavoidable. In going out, when the heel of the mast is near the upper-deck partners, tackles are put on above from each side of the upper-deck, and one strong and long one, led from below through the lower mast holes, is lashed to the heel, and well cleated each way. The tackles are tautened until, the heel being clear of the partners, they are eased away, and the mast lowered head foremast overboard, Fig. 274.|
In coming in, the mast is slung above the balancing point and hoisted with an extra tackle alongside the sheers; the purchases are then lashed low enough down, and the heel is confined to the side by the turns of a greased hawser passed through the ports; or, in a merchant ship, through the ballast-hole. When the heel is nearly up to the highest bight, deck-tackles are lashed on from all sides, which are cleated in their place. These are tautened as the mast rises, and guy the heel, when high enough, into the mast-hole.
In handling a bowsprit with your own resources use the jibboom and spare topmast for sheer legs; or, if the fore-topmast is sent on deck, it may be used as one of the legs. The sheer head may be supported by the foretop pendants thus: Each pendant is taken through its top block at the lower mast head, thence through a top block on the upper side of each sheer head in wake of the lashing, and made fast at the foremast-head. The after ends of the pendants have the top tackles clapped on to them, led from as far aft as possible. Take the usual precautions in shoring the decks, etc. Bring the inner purchase as close in to the heel of the bowsprit as the housing permits, and the outer purchase well inside the cap. Use the spar above described to counteract the thrust in coming in. The position of the purchase blocks on the bowsprit is determined by the length of the sheer legs, which in this case would be comparatively short. The bowsprit might have to come up athwartships, when suspended, to clear the billet head. This slueing is effected by the tackle from one of the catheads; the tackle
|from the opposite cathead will slue the spar fore and aft again when above the billet head, the heel tackle being previously hooked to assist in placing the bowsprit.A long topgallant forecastle will make it difficult to handle the bowsprit with improvised sheers alone, as they are too short to get sufficient cant and make the main purchase clear the billet head. In that case the sheers may be assisted by a topmast used as a derrick. Fig. 276 B, Plate 40, shows such a derrick, the sheers being represented as formed of two lower yards, fished.|
Vessels with long topgallant forecastles such as the “Omaha”, and class, are likely to have comparatively light head booms and short bowsprits. In such cases a topmast alone, used as a derrick, might suffice to get in the bowsprit.
A neat performance in the history of Masting on one’s own resources was in the case of an English line-of-battle ship, which, having lost her own mainmast, helped herself in one operation to that of a captured frigate. Sheers were formed of the main-topmasts, whose heads were supported by guys set up to the fore-topmasts, which were rigged out through the main deck ports on the off-side. A derrick was made of the main yard, which was secured at its lower quarter to the sheer leg on the working side, the pressure at this point being relieved by an athwart-ship spar, thrusting outward, by means of a tackle led across the deck. The purchase on the upper arm of the derrick took the mast out, the frigate was dropped astern, the mast lowered until the sheer purchase “looked” well up and down, when that tackle brought it in. Fig. 275, Plate 39.
Besides carrying duplicates of some of the important spars, vessels of war are supplied with iron fishes of various sizes. With these and the heavy planking, &c., furnished in the outfit, there is a large amount of material available for effecting repairs to the spars and masts when necessary, or for rigging jury masts and yards.
Fig. 277, Plate 41, represents the ordinary form of rudder of men-of-war. Around the pintles, A A A, the wood is removed so as to allow the rudder to ship on the gudgeons, C C C. In all but the topmost space the wood is removed so as to leave a vacant place, as shown in the figure, but by the topmost pintle the wood is cut square, as seen in the figure at d. This is in order to admit a small piece of oak under the upper pintle after the rudder has been shipped. This piece of oak is called awood lock (d), and is intended to prevent the rudder from unshipping. Under the second
|gudgeon a strong cleat is sometimes placed, on which the pintle partly rests. This relieves the gudgeons of much strain.To Ship the Rudder.-First Method. Bring the rudder under the stern, hung to a scow. Bore a hole through a beam over the rudder case (i.e., the hole in the stern into which the rudder head is inserted), and drive an eye-bolt up; put a washer on and key it. In Fig. 280, a represents the key, bthe washer, d the beam, F the eyebolt and E a top block. Bore a hole through the rudder head, if one is not there already, and drive an eye-bolt through and key it in the hole for the tiller. Then reeve a pendant through the top block, take it down through the rudder case and hitch it to the eye-bolt in the head of the rudder. To the thimble in the other end of the pendant hook a deck tackle. Take a hawser and make an overhand knot near the middle, reeve the hawser through the hole in the rudder H, Fig. 277, and on the side of the rudder opposite to where the overhand knot brings up make a marlinespike hitch, through which shove a toggle; make a laniard fast to this toggle long enough to reach the deck. Take the ends of the hawser forward to each gangway to act as guys; sway up, guy the rudder fair, so that the pintles are fair for entering the gudgeons, then lower away, fit the wood-lock and bolt it. Come up the purchase, unreeve the guys (hauling the toggle out by the laniard, jerking the hitch adrift and hauling the hawser through on the side of the knot), ship the tiller, reeve the wheel ropes, shackle the rudder chains, and stop up the pendants.|
The tiller of a sailing vessel is shipped in a mortise in the rudder-head. Two pieces of iron, a a, Fig. 281, are put on each side of the mortise before the rudder is shipped. The pieces of iron are prevented from coming out by the two shoulders, b b. The ends, c c, of these pieces, are put through holes in the small vertical projections, d d, and are set up with nuts, e e. These pieces, called flanges or dogs, prevent the tiller from unshipping.
The band, f f f f, around the rudder-head, is of iron.
Second Method. The rudder for sailing and screw ships differs in the construction of the head; that for the latter being often shaped to receive an iron yoke, Fig. 278. Should there be no beam wherein to place the eye-bolt for the top-block, a pair of sheers, or a stout spar, lashed across the rail over the rudder-hole, may be substituted.
An improved method of securing the rudder chains, is to shackle them to the eye in the extremity of a stout iron bar projecting from the rudder as at B, Fig. 277.
During the Exploring Expedition, the rudder-head of the “Vincennes” becoming so much decayed that the tiller was useless, stout pieces of oak were bolted to the rudder on either side, so as to project similar to B. These “out-
|riggers” were connected, by means of luffs, to spars lashed on the quarters, and the vessel steered in that way.|
Since the introduction of the screw-propeller and very long ships, the effort has been made to increase the water surface of the rudder with a view to an improvement in steering. The objection to some of these inventions is that the great increase of resistance brings too much strain upon the rudder-head and tiller, rendering the former liable to be twisted off. Still, where the draft is light in comparison to the length, an increase in the breadth of the rudder, over the old pattern, is indispensable.
The most successful design, so far, and one in which the difficulty just stated is overcome, seems to be the pattern known as the equipoise rudder, Fig. 279, Plate 41. In that figure, C E represents the after portion of the keel, D the screw, and A B the rudder, made of iron and working at one-third its breadth, on an iron spindle, or after-stern post c. Now, if the helm be put a-starboard, for example, then A C, two-thirds of the entire breadth, present the desired surface to the action of the water, but the strain on the tiller is diminished by the one-third, B C, which acts in conjunction with it, by the water acting on the surface from B to C.
A rudder, unprovided with the usual pintles and gudgeons, whether it be equipoise or of the ordinary type, must be fitted with some arrangement for taking its weight inboard, the spindle at the heel being merely intended to steady it.
One method of taking the weight of the rudder inboard is shown in Fig. 283, Plate 42.
The four aftermost vertical frames support a horizontal platform, O O, and a circular forging, Q, is secured to the platform, forming a table whose upper surface is beveled, as shown in the figure.
The diameter of the rudder-head is reduced so as to-receive upon it a forging, S, and to leave a shoulder above and below that forging. By means of this shoulder the weight of the rudder is transmitted by S to friction rollers underneath it, on a band, R, Fig. 282, so that the working of the rudder is rendered easy.
The after part of the forging S may be formed in such a manner as to overlap the forward edge of a locking plate, V, where, by means of a locking pin, W, the rudder can be fixed at any desired angle.
It has been found that the great area of an equipoise rudder, while adding to the maneuvering power of a vessel under steam, tends to destroy her way when tacking, causes
|her to miss stays, &c. Equipoise rudders have, therefore, been designed where the fore part may be locked in its amidship position, leaving the after part alone to act in steering the ship when under sail.Back-Chains. It is frequently necessary for steamers to back against the helm, but in doing so the strain brought on the rudder and its fitments is immense.|
Tug-boats guard against such accidents by using back-chains. These are chain pendants which attach to the after-part of the rudder and to some point under the counter, one each side, and of such a length as to give ample support to the rudder when backing with the helm hard over.
Instead of these chain pendants, many tugs and small steam craft have chocks bolted to the rudder-post on each side, and of such shape as to limit the motion of the rudder to an angle of 45° in either direction.