CHAPTER XI.

PURCHASING WEIGHTS.

IN addition to the gear described in previous chapters for handling sails and spars, there are certain purchases specially rigged on ship-board, when required, to hoist weights in or out of the vessel, or to transport such weights from one part of the ship to another.

The support for these purchases may be-

First. The lower yard alone, supported by its lift.
Second. The lower yards, supported themselves by purchases from the mast-heads.
Third. The mast alone, as in the case of mast-head pendant tackles.
Fourth. The lower yard supported from the mast-head and by a derrick.
Fifth. The derrick alone.
Sixth. The sheers, already described under MASTING.

Hoisting in Light Articles. To hoist in an object of no great weight, such as a barrel of flour, use two single whips, one from the yard-arm, the other from the collar of the lower stay. The ends of the whips secure to a strap around the barrel, and by walking away with the yard-whip, the barrel is raised from the lighter alongside above the level of the rail; clap on to the stay whip, easing away the yard until the barrel is in line with the hatch, and strike it below by the stay-whip.

For a heavier weight use, instead of the single whips, the yard and stay water-whips, Fig. 267, Plate 35, described under TACKLES. See that the lower lift is taut, and hook the upper block of the yard so as to plumb the lighter.

It is desirable in port to keep the quarter-deck clear, therefore lead the yard-tackle forward on the same side as the weight is being raised, and the stay forward on the opposite side.

When using the “yard and stay,” to provision or water ship, it will be found very advantageous to use a small single whip, or tricing-line, to light over the lower block of the tackle, to the great saving of paint work; the coamings of hatches should be carefully protected from injury by mats or boards.

In provisioning ship with the main “yard and stay” (water-whips) the fore-topmen break out, make up and stow the stay-tackle, and the main-topmen the yard tackle.

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If both yards are to be used together, as in hoisting out boats, the main-yard will probably require bracing up, and the fore-yard bracing in. Any bracing required should be done first and then the yard topped up on the side used, if necessary, slacking the opposite lift.

After these preparations, haul taut the opposite lift first, then see that the weather lift and burtons bear an equal strain.

When the yard has been left square, or been braced forward, the burton from the opposite side is taken across forward of the mast. When a yard has been braced in, the supporting burton from the opposite side leads best abaft the topmast and between the topmast rigging and back-stays.

Hoisting in Spare Spars. Very heavy topmasts may require the use of both fore and main yard and stay tackles, but usually the main yard tackle alone will be sufficient. Fig. 377, Plate 72.

Support the main yard by both top-burtons, get an equal strain on lifts and burtons. Send down a clew jigger hooked to the main lift, and sway up and hook the upper block of the yard tackle. This block has fitted to it a strap which is rove through the thimble of the block and stopped to the back of the hook as in Fig. 2G7. The strap goes around the yard, and the hook of the block hooks into its bight.

The lower block of the yard tackle is hooked to a lashing on the balancing point of the topmast, the lashing steadied by backlashings from head and heel of the topmast. Hook the fore top-burton to a strap around the head of the topmast, and a spare burton from the main topmast head to a strap through the fid-hole, hoist the spar on board by the yard, guying it forward or aft by the top-burtons.

Hoist in other heavy spars in the same way, hoisting in

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Few ships carry anything like a full complement of spare spars. Such as they have are usually stowed between the fore and main mast.

Stowing Booms. It is impracticable in most steamers to stow the spars amidships, on account of the smoke-stacks, although room is gained in that way. If stowed in two piles, the spars on the starboard side are spare spars for the main and mizzen, and those on the port side for the fore, and spare head-booms.

Spare topmasts stow with their heads forward and always outside the boats.

If sufficiently numerous to cause confusion, spare spars should be numbered on each end, and a list taken, which will save time in finding any spar that is wanted.

The booms are lashed to span-shackles, put in the deck for the purpose. When stowed they (and the boom-boats) are protected by a tarpaulin boom-cover.

Some vessels stow spare topsail-yards in lumber-irons, or cranes on the quarters, Fig. 378, the main on the starboard side, fore on the port. To get them into the cranes from alongside, use the boats’ falls with assistance of burtons from the main and mizzen topmast heads. Support the davit heads.

To hoist a yard on board from the cranes, if in port, lower it into the water with. the boats’ falls, and hoist in inboard with the main-yard tackle. If at sea, brace in the main-yard as much as possible, use the tackles described in getting in a topmast, and ease the yard clear of the irons with tackles from the main and mizzen rigging. Have steadying lines to control the yard.

Spare spars should be protected from the weather by having all cracks chinched with cotton, and filled up with white lead, and the yards painted and covered, if in the chains, in the wake of chafes.

The spars in the chains frequently foul the mainsheet, therefore there should be no lack of timenoguys on them.

Hoisting in and out Boats. One of the-most frequent operations in hoisting heavy weights with the assistance of the lower yards, is getting in and out boom-boats with the yard-tackles, triatic-stay and stay-tackles. Fig. 379.

The Triatic-stay consists of three parts-two pendants, and span. The pendants have hooks in their upper ends, which hook to bolts in the lower caps (fore and

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Hoisting in Boom-boats. The order will be given: IN BOATS! the crew prepare for their duties as follows:

In the launch-coxswain, assisted by some of the boat’s crew to pass out oars and sails, hook purchases, &c.; or, if a steam launch, to hook on the main-yard and stay to the boiler, which is often hoisted on board first and placed in the gangway, to be afterwards hoisted in the boat when inboard.

On deck-fore and main-topmen clear away the booms for the reception of the boats.

Aloft-Forecastle-men take out their clew-jigger on fore-yard, are responsible for the fore-yard tackle, and hook the burton or burtons on the fore-yard.

Fore-topmen overhaul down their burtons, sending the falls on deck; send down fore-topsail clew-jigger for fore-triatic, and look out for fore-stay tackle.

Quarter-gunners look out for main-yard tackle, getting main clew-jigger on main-lift.

Main-topmen send down main-topsail clew-jigger for triatic-stay, overhaul down burton, and look out for mainstay tackle.

Mast-men are responsible for leading-blocks.

NOTE. A small, strap is seized on each triatic-stay pendant well below the hook. Into this becket hook the clew-jigger, and have a single hauling-line from the top to the hook of the stay pendant. The clew-jigger takes the weight of the triatic-stay and leaves enough slack to enable the pendant to be hooked readily.

The men being reported up, the officer of the deck gives the order, Lay aloft! when the men detailed will proceed to their stations. The men on the yard will receive the burtons* and clew-jiggers from the tops; when ready, give the order, Lay out! The yard-men will lay out together; secure the clew-jiggers to the lift above the burton-strap; hook the burtons; and be in readiness to secure the purchase, when swayed up to them. The men in the tops send

* Top-burtons are always kept hooked to their pendants, ready for use.

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The falls of the purchases lead thus: That of the main-yard purchase, through a snatch-block hooked in an eye-bolt in the deck by the main-fiferail, and then aft. The fore leads through one hooked by the fore-fiferail, leading aft. The fore-stay through one hooked by the fore-fiferail, and the main through one by the main; both the latter on the opposite side of the deck, leading aft.

Everything being in readiness, give the order, Man the yards!** At which the men lay in from the yards to the top. The yard purchases are manned, with a sufficient number of men at the stay purchases to take in the slack as the boat is purchased; one man in the bows and another in the stern of the boat. Now give the order, Walk away with the yards! When the boat is sufficiently high, order, Turn with the yards! Man the stays! At this, a turn is taken, with the yards, two men remaining by each to ease away as the boat comes in, while the remainder of the men man the stays.Walk away with the stays! As the boat comes in, the yard-tackles are eased off, until she is over the boat-chocks; then, Well the stays! Lower away of all! Both the yard and stay-tackles are lowered, and she is landed on the chocks, the men in the boats overhauling the purchases;

* The men on the yards look out for and report when the lift and burton are taut alike.

** i.e. Man the falls of the yard-tackles.
12

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Hoist in the smaller boats in the same manner, using the yard and stay-tackles.

If the boats have any water in them, it is well, when a little way up, to “avast hoisting,” and let it run out, or wash out any sand or dirt that may be in them, though a heavy boat should not remain long on the purchases.

After the boats are in (or out) give the order, Lay out! The men lay out on the lower yards, cast off the lizards, unhook the burtons, &c.; the topmen cast off the end of the stay-pendant-hands being stationed by the whips and the braces manned; give the cautionary order, Stand by to lower away together! then order, Haul taut, Square away! At this, the purchases are lowered on deck, the yards squared, the clew-jiggers taken off the lifts; the men on deck make up the purchases to be stowed away, and having given the topmen sufficient time to stow their gear, give the order, Lay down from aloft! when all the men are to leave the tops.

Winding Pendants, Fig. 381, Plate 74. In lifting the heaviest boats the upper block of the yard tackle hooks into a winding pendant. This pendant is fitted with a hook in the upper end which hooks to a bolt in the lower cap, or the pendant goes around the topmast above the cap and hooks into its own part. The other end of the pendant has a thimble for the hook of the upper yard tackle block. The bight of the pendant is hauled out to its place on the lower yard by a whip on the lower lift, and is secured to the yard by a stout lizard which traverses on the pendant. Be careful in taking the turns of the lizard around the yard and pendant to take them above the bull’s-eye of the lizard, otherwise the strain is taken by the lizard and yard-arm instead of being transferred to the lower mast-head.

To Hoist in a Launch when underway under steam, or having the wind aft. Should it become necessary to hoist in a launch when underway, when circumstances do not permit of heaving to or stopping the engines, secure the yards as usual, and haul the launch up, say on the port side, get a stout hawser from the port quarter and secure it to the stern of the launch; secure it also inboard. Get the purchases up, hook and mouse-them, and proceed to hoist her in as before directed. The only difficulty is, that with headway on the vessel, the moment the boat is freed from the resistance she meets with in moving through the water, she will surge forward with a violence in proportion to the speed

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It is well when hoisting in a heavy weight to use a preventer fore-brace leading from the bowsprit end.

On board modern ships the distance between the fore and main masts is so great, that the fore-yard tackle acts very obliquely. For this and other reasons, it would be a good plan to have derricks expressly fitted for getting the boom-boats in and out; purchasing the sheet-anchors, guns and heavy weights generally, to the great saving of the yards. These derricks may be rigged temporarily of spare spars, or fitted like the modern fish-boom for the express purpose.

On board modern iron-clads a derrick rigged similar to our fish-boom is used exclusively in hoisting in and out torpedo boats and steam launches.

Launches carried on the Rail. Many of our modern vessels carry their launches on the rail, instead of stowing them amidships between the fore and main masts.

To support these boats there are fitted two stout davits, usually of iron, together with iron cradles on which the bilge of the boat rests. The cradles are supported under their centres by shores, on which the keel takes. The ends of the cradles are hinged, and can drop down clear when the boat is being hoisted or lowered.

The davit heads are supported by chain guys, spans and topping-lifts. One end of the topping-lift is shackled to the davit-head, and the other has a large ring to fit over the head of a curved iron stanchion or “strong-back,” stepped inboard abreast of the davit. The topping-lift has a second ring a few feet out from its inner end, which is passed over the head of the strong-back when the davit is topped up for sea. Fig. 382, Plate 74. The topping-lifts are also provided with turn buckles, for use in setting up, Fig. 382 a.

To Hoist in the Launch. The davits are rigged out and the boat is hauled under them and hooked on. For heavy boats a triatic stay is got up, and the stay-tackles hooked into stout links at the davit heads and steadied taut. Walk away with the falls, and when these are nearly two blocks a hook in the breech of the upper block is hooked into a shackle on the lower block, Fig. 383. A rope rove through a hole in the bulwarks around a snatch-cleat on the cradle shore, and clamped to the inner gunwale with one of the gripe clamps, is used forward and aft to prevent the boat from swinging too far inboard as

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Now get a strain on the falls, which have been slacked off in topping up, unhook each upper block from its lower one, and place the launch in its cradle. Unreeve the easing-in lines, and use them (generally) as a part of the gripe fastenings.

The object of hooking the upper and lower fall blocks together is to prevent the boat from easing down while topping up the davits and fouling the cradle; besides, leaving only the slack of the falls to be taken through after the boat is topped up.

To Hoist out the Launch. Having rigged the purchases, &c., as before, cast off the gripes, pull up on the falls, hook the blocks together, top up by the stay purchases, shift the topping-lifts, unclamp the cradles, ease away on the stay tackles and haul on the easing-in ropes. When rigged out, get a strain on the falls, disconnect upper and lower blocks, and lower away together on the falls.

Getting in Guns on Covered Decks, Fig. 385, Plate 75. After bracing the yard over the port through which it is intended to take the guns, secure the lizard of the pendant round the yard, five or six feet outside of the ship, and hook the top burtons just outside the lizard.

Haul taut, and bring an equal strain on the burtons and lifts. Hook a rolling-tackle* on the opposite side of the yard, and bowse it well taut. Pass the end of the pendant of the gun-purchase through the thimble of the lizard; take the end up and make it fast round the topmast just above the lower cap. To the eye of the pendant, which should hang a few feet below the yard, is hooked one block of a double purchase; overhaul down the lower double block with the fall part leading from it up through a single block lashed securely on the quarter of the yard, directly over the gangway; then through a block at the mast-head and down through a leading block on deck.

An ordinary treble purchase fall, leading from the upper block, as in the figure, is more common.

Have the port lined with pine boards to keep it from being chafed. Sheet-iron will take up less room and give better protection.

Bore a hole in the deck or decks through which it is

* ROLLING TACKLE. A stout luff hooked well out on the opposite yard and to a strap around the mast below the truss, to relieve the inboard thrust. This should be used whenever the yard is topped up, in purchasing

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As each gun is mounted, unhook the purchase and garnet, take off the slings, run the carriage to its proper port, and place another for the next gun.

Taking in Guns over all. Sling the gun slightly breech heavy, to render it more manageable. If it is to be mounted on the spar deck, place the carriage in the gangway: if on the main deck, close to the main hatchway on that deck. In place of the garnet, hook the stay-purchase for lowering the gun into its carriage.

Getting out Guns through Ports. Secure the yard as in getting in guns, and sling the gun in the same manner. Hook the garnet and haul it well taut, so as to raise the breech of the gun as much as the port-sill will permit; hook or toggle the gun-purchase, and sway away. As soon as the trunnions are clear of the carriage, haul it from under the gun, ease away the garnet, and let the gun go out the port. As soon as the gun is perpendicular to the purchase, unhook the garnet and lower the gun into the lighter, or on the wharf, as the case may be. Use thwartship tackle if necessary.

If the gun is to be taken out over all, the stay tackle is to be substituted for the garnet, only it is hooked to the same end of the slings as the gun-purchase, and the lashing on the slings is to be passed around the chase of the gun, as near the trunnions as possible.

* If available, a large triangular link, secured in the cascable hole by the pin of the cascable will be convenient to hook in the garnet and thwartship tackle.

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If the guns are to be thrown overboard in shoal water where they may be subsequently recovered, they must be buoyed, and care is to be taken that each buoy-rope is of a proper length, and strong enough to weigh the gun. The best mode of securing the buoy-rope to the gun is to form a clinch, or splice an eye in the end which goes over the cascable, and take a half-hitch with the bight around the chase of the gun, and stop it with spun-yarn.*

The buoy must have sufficient buoyancy to float the rope when saturated; or in deep water, a smaller line may be used for the buoy, and attached to the rope intended for weighing the gun, that it may be hauled up when wanted.

Other Methods for getting in Guns. For taking in or hoisting out main-deck guns, no purchase that can be rigged is so handy and safe as the derrick excepting the cat.

But the cat-head is only available when it overlooks a port: the derrick may be rigged anywhere if a suitable spar is to be had.

* Guns taken out of a ship to lighten her when aground should be hoisted out and rafted clear, if there is any danger of bilging on them.

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Toggle for Breech-Loading Rifle-Gun, Fig. 386. To sling a breech-loading rifle-gun, the breech mechanism having been removed, place in the breech an iron-bound toggle, Fig. 386. Set up at the muzzle with an iron cross-piece, as a washer, and a screw. The toggle affords a bearing for the chain slings.

The toggle must be of wood to avoid injury to the rifling. In any case, as the guns have little preponderance, they will be nearly centre-hung by lashing the slings at the trunnions.

The heel-tackle is hooked into the eye-bolt in the end of the toggle.

Purchasing Waist Anchors. Having secured the lower yards with the lifts and both burtons, the yards being topped up, if need be, on the side used, brace in the fore and forward the main-yard, and get an equal strain on the supporting tackles, Fig. 387, Plate 76.

The purchases used are the yard-tackles with the winding pendants, the lizards of the latter regulated so that the purchase will take the anchor clear of the side, Fig. 387.

The anchor being brought alongside in a lighter with the crown aft, pass a strap around the shank just inside the ring; the anchor being stocked, lash this strap to the stock. Hook the fore purchase into this strap, and hook the main purchase to another strap passed down over the shank and under the arms, the tackle hooking into the upper bights. The forward strap should be a long one, and lashed to the stock about one-third the distance up, to keep the stock perpendicular when the anchor is raised. Use fore-and-aft tackles as necessary.

Having swayed the anchor up, rouse it in with thwartship-jiggers, place the bills in shoes, or its arm upon the gunwale, place the shores and pass the lashings, unstocking the anchor.

The anchor rests on two shores, which may be of wood resting in saucers and secured by laniards, or they are of iron, and work on hinges, Fig. 388. The shore supports the anchor, and also throws it clear of the ship’s side when let go.

To hold the anchor to the side, there are usually chain-lashings, the upper ends secured by seizings of ratline stuff; two from eye-bolts in the side below the anchor acting as jumpers to keep the anchor down, two on the shank, and one on the inboard arm to retain the anchor at the side.

In preparing to let go, the chain being bent and the

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Or transport the anchor wholly by purchases, as follows: Stock the anchor, brace the main-yard upsharp and the fore-yard in a little, use the purchases, &c., previously described in getting the anchor into place. The fore-yard hooks to a lashing around the shank inside the stock, and the main to a lashing around the crown and both arms.

When the anchor is clear of the ship’s side, ease away on the main-yard, hauling on the fore-yard tackle until the anchor hangs by the latter purchase. Then man the fore-brace and brace the yard up handsomely until the anchor is far enough forward to hook the cat; when lower, hook the cat and rouse it up to the cathead. Unhook all purchases and send them down.

You may hook the cat and fish as soon as the drift permits, and it is advisable to do so, as the latter, particularly, will be serviceable in transporting to the bows.

The fore-yard should not be braced in so far that the burtons and lift will take against the rigging, for in bracing them up again they would not bear an equal strain.

By this plan, you may transport anchors from the bows to the waist, but there is always risk attending the bracing of a yard with a heavy weight upon it, for the supports may be broken in detail, as the strain is shifted, and the yard sprung or carried away.

Moreover, in long modern ships, the distance through which the anchor must be transported requires a very great swing of the fore-yard. If this plan is adopted, good hands should be stationed to attend the burtons, and at the first indication of the slacking up of any one, to haul it taut again, and for that purpose jiggers clapped on the fall would be a material assistance.

When transporting waist anchors, the cable should be unshackled and a hawser, stout enough to weigh the anchor in case of accident, bent in its stead.

To transport a Waist Anchor inboard. Having previously secured the lower yards, hoist the anchor inboard with the fore and main-yard tackles, and transport it forward along the deck, the deck being wetted down and mats placed under the anchor and ball of the stock. If the vessel has a flush spar-deck, the anchor is dragged far enough forward to hook on the hoisting-out tackles immediately. But should the vessel have a topgallant forecastle,

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Mast-head. Pendant Tackles, Fig. 390. These are purchases, double or treble, the upper block lashed to a pendant from the topmast-head. A top pendant may be used to form the pendant, taking a turn with it around the topmast-head, securing the ends together, and lashing the upper block into the bight.

A mast-head pendant tackle is guyed clear of the top by a guy from forward or aft, as the case may be, usually secured to the pendant just above the upper block.

These purchases are very useful in hoisting heavy articles out of the fore or main hold, or in any case when the purchase is required immediately over the fore-and-aft line. They could be used in place of the stay-tackles in purchasing boats, should there be no triatic-stay.

Transporting Spare Anchors, Fig. 390, Plate 77. The anchor intended to be stowed in the fore hatch is hoisted on board, crown up and unstocked, by means of the fore-yard and mast-head pendant tackle, the latter being abaft the mast. Should the anchor stow in the main hatch and forward of the main-mast, use the main-yard and a mast-head pendant tackle at the main, and forward of the mast. Use, in addition to the purchases, fore-and-aft and thwartship tackles as necessary, and a guy on the ring of the anchor in getting it into place. The anchor stows up and down, and on modern vessels usually on the forward side of the fore hatch.

In transporting this anchor to the bows from the fore hatch, hook the mast-head pendant tackle to a stout strap around the crown, and a tackle leading aft on the lower deck is hooked to the shank of the anchor to guy it clear as it goes up. Cast off the lashings, sway up, and as the crown comes above the upper deck use the fore pendant tackle, hooked into a strap around the shank near the place for the stock, in getting the anchor forward of the mast. Having stocked it, transport it over the bows by means of the purchase on the fore-yard and fish, as in the case previously described of transporting anchors inboard. When high enough, and clear of the side, lower away to the water’s edge, hook

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Shoring up a Lower Yard. Fig. 391, Plate 78. To get in a very heavy weight, lower the main-yard some distance below its slings, housing it over athwartships so that the truss arms will be clear of the mast and on the side nearest to the weight, which rigs the yard out further on that side. Top up the yard on the side used and lash it to the mast, having first passed old canvas in wake of the lashings. Use rolling tackles on the opposite yard-arm, and hook both top burtons in wake of the purchase on the upper yard-arm, Fig. 391. If the jeer-blocks are needed to form the purchase used, hang the yard by pendant tackles from the lower pendants.

Get the spare main-topmast up and place its heel in a shoe in the water-way under the yard. Shore up the deck underneath and lash the head of the topmast with a cross-lashing to the after side of the yard. Use a spare gaff at about half the height of the topmast from the deck as a shore, the jaws lashed to the derrick and the peak to the mast. Reeve a topping-lift from where the topmast-head is lashed at the yard, to a block lashed above the lower cap. The topmast should be further supported by head guys forward and aft, which are omitted in the figure.

The upper block of the yard purchase is lashed to the lower yard and topmast with a long lashing. Both purchase blocks treble, or at least one of them fourfold, if such blocks are available.

The stay purchase consists of a double pendant from the lower mast-head, supporting a treble purchase. With falls, &c., of the following dimensions, a vessel sparred as heavily as the Trenton could safely raise a 10-inch rifle gun: yard purchase, 8-inch falls; stay purchases: two parts of pendant, 10-inch; falls, 8-inch; topping-lift, five parts of 6-inch.

A hawser rove from forward through a top-block at the fore cap may be secured to the eye of the stay pendant so as to haul the stay purchase forward to plumb the hatchway if the weight is to be struck below. If the weight is a gun to be placed on the gun-deck, sling it breech heavy. Fig. 391.

The Derrick. We have so far dealt chiefly with the lower yards in describing purchases, but the derrick possesses advantages which render it superior to a yard in some respects, for lifting heavy weights. The derrick transfers the weight to the deck, which can be well supported by shores from below. It removes all anxiety for

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Recently the U.S.S. New Hampshire was towed from Norfolk to the Training Station at Newport, R.I., to be fitted up at that place. She had her topmasts fidded, lower and topmast rigging set up. The other spars, davits, &c., were on deck in an unfinished condition, all the iron-work for the yards, such as truss and sling bands, shoulder bands, and burton straps, being stowed below. The vessel carried on her spar deck fourteen boats, two being launches of the largest size, some stowed bottom up. In addition, there were two ten thousand pound anchors on deck, one in each gangway. It was required to hoist out the boats and to place the anchors on a lighter for transportation to the shore.

The boats were taken in hand first. The main-yard being the largest spar available, was rigged as a derrick. It was about 75 feet long, the size for a vessel of the Portsmouth class, the ship being much undersparred.

The lower yard-arm was stepped in a shoe close to the water-way, abreast of the main-mast. Fig. 392, Plate 79.

At the upper end, about the place for the burton strap, was lashed the upper block of a treble purchase, 6-inch fall. At the same point were hooked into suitable straps two topping-lifts, the upper one being the top burton of the side, the lower one a pendant tackle hooked into a strap around the lower mast, just above the trestle-trees-block underneath the top.

A burton from under the yard-arm, close to the purchase block, led outside to a toggle in a lower gun-deck port, acting as a jumper. An outrigger for this jumper would be needed in a vessel with less beam.

There were, in addition, forward and after guys from the fore and mizzen chains to the place for the upper purchase block. The deck was shored up under the heel of the derrick. Neither belly guys nor fishes for the lower yardarm were required, although their positions are indicated in the figure. The derrick, until rigged, lay across the rail, and was raised into position by means of the mast-head pendant tackle; topped up by the topping-lifts when the lower yard-arm was clear of the rail, the heel carried into place by heel tackles. The derrick purchase took the place

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The boat being upright was slung with a span for hoisting out, as in Fig. 394, the span for the launches being four turns of 5-inch manilla, fitted so as to render and take an equal strain. Particular attention was given to the belly lashing passed around the middle of the boat, it being made to bear an equal strain with the span. Plank spreaders were placed inside the boat between the gunwales in wake of the belly lashing. The span passed under the fore-foot and counter, with back lashings, as in the figure.

In hoisting out, the mast-head and derrick purchases were lashed to the span, the boat lifted by the mast-head purchase and swayed out and lowered by the derrick purchase.

In using the same tackles to get out the sheet anchors, both were lashed to the shank of the anchor at its balancing point, the lashing being steadied by stout back lashings from the ring and crown. Fig. 395.

The purchases described would have readily lifted 11-inch guns for a ship’s battery; had it been required.

An Upright Derrick. To land the above mentioned anchors from the lighter, an upright derrick was rigged on shore. It consisted of a spar 20 feet long and about 8 inches in diameter. The heel rested on the ground, the head being supported by four guys placed as nearly as possible at equal angles, and some 50 feet from the heel of the spar. The spar was raised by jiggers on two of these guys, the other two being anchored off in the water, to get them at the required angles. The derrick being upright with one (double) block of the purchase lashed to its head, the lighter was hauled in close to the shore and the lower block of the purchase lashed inside the balancing point of the first anchor, in order to drag rather than lift. The purchase fall led from the upper block through a leading block lashed to the heel of the derrick. The anchor was raised by the purchase just clear of the lighter and was allowed to slide on skids to a point some 15 feet from the base of the

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A Practical Method of Ascertaining the Stress on Derricks. In the figure, divide any part, a c, of the supporting line of the weight, W, into a convenient scale representing the weight suspended, (in this case 5 tons).

From a draw a b parallel to the tie rod, and from c draw c b parallel to the jib, cutting a b at b. The tension on the tie rod will be given by a b, referred to the scale a c, and the thrust on the jib will be represented by b c referred to the same scale.

Scales for the measurement of strains on any derrick formed of spars on shipboard may be constructed as in the foregoing case. Attention must be given to the relative positions of the derrick and supports which may vary from the above.