DESCRIPTION AND USE OF ANCHORS.
THE TWO PLATES OF ANCHORS WILL, UPON REFERENCE, CLEARLY ELUCIDATE THIS TREATISE ON ANCHOR-MAKING.
Anchors are strong crooked instruments, made of iron and wood, used at sea, in rivers, roads, harbours, &c. to retain ships and vessels from danger, or keep them in a convenient station.
The goodness of anchors is of material importance, the safety and preservation of the vessel depending greatly upon them.
An anchor is composed of a shank, two arms, two flukes, or palms, a ring, and a stock, which bear the following proportions. The length of the arm, from the inside of the throat to the bill, is the distance marked on the shank for the trend, taken from the inside of the throat; and three times that is the length of the shank from the tip of the crown; and the shank, from the tip of the crown to the centre of the ring, is the length of the iron stock: when made, the two arms, from the inside of the throat to the extremity of the bill, should form an arch of a circle containing 120 degrees.
Of anchors there are the sheet, best bower, and small bower; these do not vary in form or weight from each other, in the navy. Stream and kedge anchors are smaller, and grapnels are for boats only.
DESCRIPTION OF THE TOOLS, AND EXPLANATION OF THE TERMS, USED IN
ANVIL, a mass of iron on which the work is forged or hammered.
ARM, that part from the crown on which the palm is shut.
BILL OR PEAK, the extremities of the arms.
BLADE, that part of the arm on which the palm is shut.
BOLSTERS, cylindrical pieces of iron, with a hole through the middle, used when holes are to be punched, or opened with pins.
BOLTS, cylindrical iron pins for fastening the two parts of the stock together.
COLLAR, made of iron, forms a sling suspended by a chain to bear the anchor to and from the fire.
CROSS-BARS are round bars of iron, bent at each end, and used as levers to turn the shank of the anchor. They are from 3 to 5 feet long, and one inch and a quarter diameter.
CROWN, the lowest end of the shank, where the arms are united.
EYE. The hole at the upper-end of the shank for the ring to pass through.
HAMMERS used in making anchors are of 5 sizes, and only differ in weight and length of handle. They weigh from 26 pounds to 3 pounds, and the handles are in length from 4 feet to 1 foot: and are used as the size of the work may require.
HANCH. A sudden diminish from a larger substance to a less.
HOOPS. Straps of iron driven on the stock.
MANDRELS are circular iron instruments, forming a cone 4 feet high, on which hoops are driven to be made perfectly round.
NUTS. Two projections on the shank to secure the stock.
PALM, OR FLUKE. The broadest part of the arm of an anchor, terminating in a point to fix in the ground.
PORTER. A straight bar of iron, about 2 inches square, confined at one end to the end of the shank: it has holes punched through at the other end for the cross-bars, which act as levers in turning the shank when making.
RING. A circle of iron, in the upper-part of the shank of the anchor, to which the cable is bent.
SCARF. The place where one piece is joined to another.
SHANK. The longest part of the anchor.
SHUTTING is joining or welding one piece of iron to another.
SMALL of the anchor is that part of the shank next under the square.
SNAPE. A sudden diminish of any part.
SQUARE. The upper part of the shank.
STOCK is composed of two long pieces of oak tapering from the middle, fastened together with iron hoops and tree-nails, and fixed on the shank transversely to the arms.
Some anchors have iron stocks.
TREE-NAILS. Wooden pegs to fasten the anchor stock.
TREND, that part of the shank from which the size is taken.
THROAT, the inner-part of the arms, where they join the shank.
TWINING-IRONS, square bars, with an ess-hook at one end, which grasp the porter or the shank to turn it over.
WELDING is forging iron when intensely heated.
WELDING-HEAT is the strong heat when the iron is properest to bind.
THE PRACTICE OF ANCHOR-MAKING.
THE shank, arms, flukes or palms, and ring, are forged seperately. The shank is made of many long bars of the best tough iron, well wrought together; great care should be taken that the iron be neither too soft nor too brittle; the latter rendering it liable to break, and the former to straiten. The number of bars, sufficient to make the shank of the size designed, can only (without the bars be all of an equal size) be regulated by experience. Several parts of the anchor are governed by the
size of the trend, which is marked on the shank at the same distance from the inside of the throat as the arm measures from the inside of the throat to the extremity of the bill. The shank is rounded to the square of the upper part, and is there called the small round, being the smallest part. The two sides in the direction of the arms are flatted surfaces, about an inch less than the trend, in large anchors, and something less, in smaller ones.
The squared part is the same size as at the trend each way, and hanches into the small round, one sixth the length of the shank.
The hole, or eye, for the ring, is punched through the square part, on the flatted side, once and a half the thickness of the ring, from the upper extremity of the shank, which has its corners flatted or diamonded, on the same sides, nearly in the middle.
If the sharp edges of the hole for the ring were rounded off, it would move easier and be less liable to injury,
Between the hole for the ring and lower part of the square are two small prominences, raised across from the solid, called nuts, for securing the stock in its place. At the lower part of the shank is left a scarf, or flatted surface, with a shoulder on each side, for shutting on the arms.
In making every part of an anchor the nicest attention should be observed, as to its being smooth, fair, and even; and that the edges and angles are preserved straight in their direction, as well-made anchors should possess beauty as well as strength.
The ring, being previously forged, is put through the before-mentioned hole in the shank, and the two ends are well shut together.
The arms are made of shorter bars than the shank; but as good in quality, and as well put together; they are rounded and flatted on the different sides, to resemble the shank; and are the same size as the shank at the throat and small round. The rounding part is continued to the palm, which is nearly in the middle of the arm; from thence it is made with a square tapering to the bill on the flatted side; and, on the inner rounded side, is made a square seat for shutting on the palm, that the palm, when shut on, should project its thickness at the base or inner part, the outer part making a straight surface with the peek or bill. The back or outer side of the arm is made straight from the rounded part, or hanch, to the snape; and there kept to half the substance of the inner part. The snape resembles the bill of a duck, and is one-third the breadth of the palm in length.
The thickness of the ring to be half the diameter of the small round.
The diameter of the ring, thickness included, reaches from the hole in the upper part of the shank to the hanch of the small round.
The inner part of the arm is mostly made straight, from the bill to the throat: it is thought stronger for having a small angle in its length inclining to the shank.
Shanks taper in their length, one inch and a half in small anchors, to three inches in large, keeping their proper size at the trend; and three quarters of an inch to two inches the flatted way.
The arm in its length inclines to the shank, and forms a small angle, the touch or point thereof being in the middle. The throat-end of the arm is scarfed, or flatted, to answer the scarf in the shank, to which the two arms are united (after the palms are shut on) in the firmest manner possible, and it is elevated above the horizontal plane, or inclined to the shank, that each arm may spread at the peek or bill. The length of the arm, from the inside of the throat to the extremity of its bill, is then taken, and that length from the inside of the throat is set upon the shank, and called the trend; from the trend to the bill forms an angle of about 60 degrees.
The palms, or flukes, are two thick plates of iron, made of various pieces, well wrought together, in the form of an isosceles triangle; one inch and a half to one inch and a quarter longer than the
breadth of the base, and curve about as much in their sides. The base or lower part, to be straight: the inner flat surface curves a little in the breadth, but is straight lengthways: the palms, being finished thus far, are lastly shut firmly on to the inner side of the arm, in the seat before mentioned, the base inclining inwards.
The stock is composed of two long beams of oak, strongly bolted and treenailed together, and secured with four strong iron hoops, two on each side of the middle, and one near each end. It is fixed on the upper end of the shank, transversely with the flukes or palms; and the nuts are set into the middle of the stock.
The length of the stock is the length of the shank and half the diameter of the ring. The depth and thickness in the middle is as many inches as the stock is feet in length.
The ends to be kept square, half the depth or thickness in the middle. The upper-side next the ring is always kept straight, as is the lower-side half the depth on each side the middle; and thence it tapers to each end in the above proportion. It is necessary to leave an opening in the middle of one inch and a half, between the two pieces, that the hoops may be driven nearer the middle, in case the stock should shrink.
The making of anchors is a most laborious employ, and has been much facilitated by the invention of two machines, called, the hercules and the monkey, of which see the forms in the plate.
The HERCULES is used for setting straight the shank, welding the palms to the arms, and the arms to the shank, of large anchors. It consists of a weight of about 400 lb. faced with steel, and a long iron shank. It is suspended perpendicularly over the work by a rope encircling a small iron wheel fixed in a mortise cut in the beam.
It performs its duty by being drawn up about seven feet high, by men at the tails of the rope; and, encreasing in weight by the velocity of its fall, it is found to produce more effect than the most powerful exertions with the hammer and strength of man. That the weight may fall on the spot required, a long iron rod, with a hook, is occasionally fixed to the shank above the weight, for the workman to direct the stroke.
The MONKEY is a machine for setting the arms, &c. It consists of a weight of about 200 lb. sometimes faced with steel, and a long iron shank suspended by an iron chain to a crane, hanging horizontally against the side of the work, and it is used by being drawn back and thrust forward by the workmen.
KEDGES, or small anchors, are made in proportion to the large anchors; their stocks were formerly of iron but are now mostly of wood. If iron, they are to be the same in length as if wood, and two thirds of the trend in diameter in the middle. Near the middle of the stock is a shoulder that bears against the hole on one side the square of the shank, with a forelock-hole in the stock, on the other side the square of the shank, for a forelock to go through, to confine the stock in its place: it is tapered from the middle each way, and, when put through the shank, one end is bent, to prevent its falling out, and to keep it close, when brought to the side of the shank, for less stowage.
GRAPNEL, or GRAPPLING, is like a small anchor, with four or five flukes, or claws, used in small vessels or boats to ride at.
FIRE-GRAPNELS resemble the former, are from eighteen to twenty pounds weight, and have strong barbed claws, with a chain to the ring. They are used by fire-ships.
CREEPER is like a small anchor, with four hooks, or claws, used in recovering any thing from the bottom of rivers, &c.
SHEER HOOKS are of iron, with two prongs, like a fork, and four hooks at the other end, used at the extremities of the yards of fire-ships to entangle the enemy's rigging, &c.
Boat grapnels are in weight from 112 pounds to 36 pounds. Fire and chain grapnels weigh about 70 pounds, and bear the same proportion with the hand and chain; grapnels and creepers are made of wrought-iron, and shaped agreeably to the plate. The shanks are round, and have an eye wrought in the upper-end, to receive the ring, the ring being put through, and the ends firmly shut together. The shank is left longer than the nett length above, for weldiug on the claws. Flukes are shut on the extremities of the claws of boat-grapnels, and barbs are made from the solid of fire-grapnels. The claws are welded on to the lower-part of the shank, and spread from the same, at the end, one-third the length of the shank, in boat-grapnels; three-fourths in fire-grapnels; and half the length of the shank in creepers.
On the importation of anchor-stocks, imported in British ships, there is payable a duty of 2s. 3d. each, drawback 2s. 1d. imported in foreign ships 2s. 4d. each, drawback 2s, 1d.