A heavy curved instrument, used for retaining ships in a required position. The forms of anchors, and the materials of which they are made, are various. In many parts of the East Indies the lower part of the anchor is formed of a cross of a very strong and heavy kind of wood, the extremities of which are made pointed. About the middle of each arm of the cross is inserted a long bar of the same wood, the upper ends of which converge to a point, and are secured either by ropes or an iron hoop, and the space between the bars is filled up with stones to make the anchors sink more deeply and readily. In Spain, and in the South Seas, anchors are sometimes formed of copper, but generally in Europe they are made of forged iron. Anchors may be divided into two classes - mooring anchors, and ships' anchors. Mooring anchors are those which are laid down for a permanency in docks and harbours, and are considerably heavier than ships' anchors, from which they differ in form, having sometimes but one arm, and sometimes, instead of arms, having at the extremity a heavy circular mass of iron and no stock; these latter are called mushroom anchors.
The general form of ships' anchors is shewn in the annexed figure. a is a long bar of iron, called the shank, from the lower extremity of which branch two curved arms b b in opposite directions, and forming an angle of 60° each with the shank. Upon each arm, towards the end, is laid a thick triangular piece of iron c c, termed the fluke. In the upper end of the shank is an eye, through which passes a ring d, to which the cable is attached. The stock e is composed of two strong beams of wood, embracing the shank immediately below the ring, and secured together by iron hoops and treenails; the stock stands at right angles to the plane of the arms, and serves to guide the anchor in its descent, so as to cause one of the flukes to enter the ground. Ships are generally provided with three large anchors, named the best bower, the small, and the sheet anchor; a smaller anchor, termed the stream anchor; and another, still smaller, named the kedge, which latter has generally an iron stock passing through an eye in the shank, secured thereto by a key, or forelock, which admits of its being readily displaced: its principal use is in changing the position of a ship in harbour, and in an operation termed kedging.
From the great mass of iron in large anchors (some weighing from 3 to 4 tons), the perfect forging of them becomes a matter of much difficulty; as from the great heat necessary to weld such masses, the iron is liable to become "burnt," as it is termed. Workmen also cannot always observe what is going on in the forge, where the iron is exposed to ignition from the blasts of the bellows, or to the presence of sulphur in quantity among the coals. When the welding of a large mass, like the shank of an anchor, is to be completed by the sledge hammer, the workmen are subjected to a scorching heat radiating therefrom, which renders it impossible to make a very close inspection, and the consequence frequently is, the beating up of cinders within the body of the iron. To this cause, and to burning, may be often attributed the breaking of anchors, followed too frequently by a distressing loss of lives and property. Many attempts have been made of late years to construct anchors not liable to these defects, by dividing the mass into separate parts, and by a more judicious arrangement. The following is the invention of Mr. Hawkes, a surveyor of shipping, in the Commercial- road, London.
Mr. Hawkes observes, "The anchors at present in use are made by forming the shank and flukes separately; and by the rapid action of heavy hammers, they are united or welded into each other, and the cable is fastened to a ring passed through the shank sideways. The stocks, if of wood, are let or scored over each side, and bolted and hooped over the shank of the anchor; if of iron, the eye or hole for it is formed by punching a hole through the shank of the anchor; the palms are made separately, and welded on to the flukes. The improvement consists in making one fluke and half the shank in one length, and to bend them to the form required, and then hooping the two halves together. This method of making the anchor in separate parts, admits of the forming of a groove up the middle of the shank, for a chain to pass through, and of an eye of great strength for the reception of a wooden stock, which is also made in two pieces, and passed into the shank in reverse directions; these having iron shoulders abutting against the eye, are kept immovably in that position by being braced together with an iron hoop at each end.
The construction is shown in the annexed engraving. a the cable ring; b the eye which holds the stock, made out of the whole substance of the shank, by bending each of the halves into a semicircle, in opposite directions. The anchor is shewn to be divided into two equal parts, by a line which passes down the middle of the shank, as at o o; c the wooden stock, made also in two equal parts (as before described), and firmly secured in their places by the hoops and shoulders; dddd are four strong hoops which bind the shank together; the upper one is made square, and the others circular; a portion of the shank is supposed to be removed, to ex-hibit the situation of the chain which passes up the centre, and is connected at the upper end to the cable ring, and at the lower end to the buoy ring. f, in the small separate figure, gives a transverse section of the shank of the anchor, showing it to be of an oval form, the longest diameter of which is in a line with the flukes; this figure conferring upon it great strength to withstand the powerful strains to which an anchor is frequently exposed in that direction. h h are the palms, bolted to the respective flukes, each of which is connected in one piece with a brace i i, passing in opposite directions round the shank of the anchor, thereby strengthening the flukes in a great degree, and giving a collateral support to each half of the anchor k is a strong plate of iron bolted on to the crown; l the buoy ring."