Anchor
ANCHOR (from the Greek agkura, which Vossius considers
is from ogke, a crook or hook), an instrument of iron
or other heavy material used for holding ships or boats in
any locality required, and preventing them from drifting by
winds, tides, currents or other causes. This is done by the
anchor, after it is let go from the ship by means of the cable,
fixing itself in the ground and there holding the vessel fast.
The word "anchor" is also used figuratively for anything which
gives security, or for any ornament or appendage which takes
the same form. Owing to a vessel's safety depending upon the
anchor, it is obviously an appliance of great importance, and
too much care cannot be expended on its manufacture and proper
construction. The most ancient anchors consisted of large
stones, baskets full of stones, sacks filled with sand, or
logs of wood loaded with lead. Of this kind were the anchors
of the ancient Greeks, which, according to Apollonius Rhodius
and Stephen of Byzantium, were formed of stone; and Athenaeus
states that they were sometimes made of wood. Such anchors
held the vessel merely by their weight and by the friction
along the bottom. Iron was afterwards introduced for the
construction of anchors, and an improvement was made by
forming them with teeth or "flukes" to fasten themselves
into the bottom; whence the words odontes and dentes
are frequently taken for anchors in the Greek and Latin
poets. The invention of the teeth is ascribed by Pliny to
the Tuscans; but Pausanias gives the credit to Midas, king of
Phrygia. Originally there was only one fluke or tooth, whence
anchors were called eterostomoi; but a second was added,
according to Pliny, by Eupalamus, or, according to Strabo,
by Anacharsis, the Scythian philosopher. The anchors with
two teeth were called amfiboloi or amfistomoi, and
from ancient monuments appear to have resembled generally
those used in modern days, except that the stock is absent
from them all. Every ship had several anchors; the largest,
FIG. 1.--Rodger's Anchor.
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FIG. 2.--lmproved Martin Anchor.
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corresponding to our sheet anchor, was only used in extreme danger,
and was hence peculiarly termed iera or sacra, whence the
proverb sacram anchoram solvere, as flying to the last refuge.
Until the beginning of the 19th century anchors were of
imperfect manufacture, the means of effecting good and efficient
welding being absent and the iron poor, whilst the arms,
being straight, generally parted at the crown, when weighing
from good holding-ground. A clerk in Plymouth Yard, named
Pering, in the early part of that century (1813) introduced
curved arms; and after 1852 the Admiralty anchor, under the
direction of the Board, was supplied to H.M. ships, followed
by Lieutenant (afterwards Captain) Rodger's anchor (fig.
1). This marked a great departure from the form of previous
anchors. The arms, de, df were formed in one piece, and were
pivoted at the crown d on a bolt passing through the forked
shank ab. The points or pees e, f, to the palms g were
blunt. This anchor had an excellent reputation amongst
nautical men of that period, and by the committee on anchors,
appointed by the admiralty in 1852, it was placed second
only to the anchor of Trotman. Later came the self-canting
anchor, which, passing through successive improvements,
became the improved Martin anchor (fig. 2) made of forged
iron. A projection in the centre of the arms works in a recess
at the hub of the shank: the vacancies outside the shank are
filled by blocks bolted through on each side, and are flush
with the side plates, which keep the flukes in position.
FIG. 3.--Improved Martin-Adelphi Anchor.
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The introduction of cast steel in 1894 led to the improved
Martin-Adelphi pattern (fig. 3), in which the crown and arms
are cast in one, and, with the stock, are made of cast steel,
the shank remaining of forged iron. A projection in the crown
works in a recess (right, fig. 3), and is secured in its place
by a forged steel pin, fitted with a nut and washer, which
passes through the crown and the heel of the shank. All the
above anchors were provided with a stock (fig. 1, hk), the
use of which is to "cant" the anchor. If it falls on the
ground, resting on one arm and one stock, when a strain is
brought on the cable, the stock cants the anchor, causing the
arms to lie at a downward angle to the holding ground; and the
pees enter and bury themselves below the surface of the soil.
To stow a stocked anchor on the forecastle, it is hove up close
to the forefoot, and by means of a ground chain (secured to a
balancing or gravity band on the anchor), which is joined to a
catting chain rove through a cat davit, the anchor is hove up
horizontally and placed on its bed, where it is secured by
chains passing over a rod fitted with a lever for "letting
go." The cat davit is hinged at its base, and can be laid flat
on the deck for right ahead fire or when at sea. Ground and
catting chains have been superseded in some ships by a wire
pendant and cat hook; the anchor is then hove close up to the
hawse-pipe. To avoid cutting away a portion of the forecastle,
in the Cressy, Terrible and Diadem classes of
the British navy, the anchors, secured by chains, are stowed
a-cock-bill, outside the ship, with their crowns resting on
iron shoes secured to the ship's side and the flukes fore and
aft. A difficulty is experienced in stowing the anchors when
the ship is pitching or rolling heavily. Fig. 4 illustrates
an anchor with cat davit or anchor crane used in the P.
and O. Company's steamers (India class, 8000 tons);
for sea the anchor is stowed on board by the anchor crane.
Stockless anchors have been extensively used in the British
mercantile marine and in some foreign navies. In 1903 they
FIG. 5.--Hall's Improved
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FIG. 6.--W. L.
Byer's Stockless Anchor. Stockless Anchor.
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were adopted generally for the British navy, after extensive
anchor trials, begun in 1885. Their advantages are:--handiness
combined with a saving of time and labour; absence of davits,
anchor-beds and other gear, with a resulting reduction in
weight; and a clear forecastle for "right ahead" gun fire
or for working ship. On the other hand a larger hawse-pipe is
required, and there appears to be a consensus of opinion that
a stockless anchor when "let go" does not hold so quickly
as a stocked one, is more uncertain in its action over uneven
ground, and is more liable to "come home", (drag). The
stockless anchors principally in use in the British navy are
Hall's improved, Byer's, and Wasteneys Smith's. In Hall's
improved (fig. 5) the arms and crown of cast steel are in one
piece, and the shank of forged steel passes up through an
aperture in the crown to which it is secured by two cross
bolts. Two trunnions or lugs are forged to the lower end of the
shank. In Byer's plan (fig. 6) the flukes and crown consist
of a steel-casting secured to a forged shank by a through bolt
of mild steel, the axis of which is parallel to the points
of the flukes; one end of the bolt has a head, but the other
is screwed and fitted with a phosphor bronze nut to allow the
bolt to be withdrawn for examination. A palm is cast on each
side of the crown to trip the flukes when the anchor is on the
ground, and for bringing them snug against the ship's side when
weighing. Wasteneys Smith's anchor (fig. 7) is composed of
Fig. 7.--Wasteneys Smith's Stockless anchor.
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three main parts, the shank and crown which form one forging,
and the two flukes or arms which are separate castings. A bolt
passes through the crown of the anchor, connecting the flukes
to it; to prevent the flukes working off the connecting through
bolt, two smaller bolts pass through the flukes at right angles
to the through bolt and are recessed half their diameter into it.
Fig. 8 represents the starboard bow of H.M.S. New Zealand.
FIG. 8.--Starboard Bow of H.M.S. New Zealand.
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(16,350 tons) with lower and sheet (spare) anchors stowed.
To let go a stockless anchor (fig. 9) the cable or capstan
holder C is unscrewed, and in practice it is found desirable
to knock off the bottle screw-slip A, allowing the weight
of the anchor to be taken by the inner slip A' (Blake's
stopper). Stern, stream and kedge anchors are usually
stowed with special davits. A portable anchor suitable for
small yachts is the invention of Mr Louis Moore; the shank
passes through the crown of the anchor like the handle of
a pickaxe and the stock over the head of the shank. At
the end of the stock are loose pawls. There are no keys or
bolts, and the only fastening is for the cable. The anchor
takes to pieces readily and stows snugly. In 1890 Colonel
Bucknill also invented a portable anchor for small yachts.
Iron buoy-sinkers (fig. 10), as used by the London Trinity
House Corporation, weigh from 8 to 40 cwt.; the specified
weight is cast on them in large raised figures, and the
cast and wrought irons used are of special quality, of which
samples are previously submitted to the engineer-in-chief.
The anchors supplied to ships of the British navy are reqaired
FIG. 9.--Forecastle of H.M.S. New Zealand. A.
Bottle or screw-slip. B. Deck or navel pices. A'. Slip
or Blake's stopper. F. Fairleads for wire hawsers. D.
Bitts. H. Hawse-pipes. C. Cable or Capstan-holders. S.
Stopper-bolts. C'. Centre line capstan. R. Rollers.
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to withstand a certain tensile strain, expressed in tons,
proportionate to their weights in cwts. New anchors are
supplied by contractors, but repairs are made in H.M. dockyards,
a record of its repairs being stamped on each anchor. In
the Anchors and Cables Act 1899 a list is given of authorized
testing-establishments, with their distinctive marks and
charges, and testing- houses for foreign-owned vessels are
Fig. 10.--Iron Buoy- Sinker.
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enumerated in Table 22 of Lloyd's Register of British and
Foreign Shipping. Cast-steel anchors, in addition to the
statutory tests, are subjected to percussive, hammering and
bending tests, and are stamped "annealed steel". (J. W. D.)
Updated 1996-04-25 by
Lars Bruzelius
Sjöhistoriska Samfundet |
The Maritime History Virtual Archives.
Copyright © 1996 Lars Bruzelius.