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Article #1: Boat anchors

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An anchor is a heavy object, often made the shank which would roll the anchor
out of metal, that is used to attach a over so the point would penetrate the
ship to the bottom of a body of water at bottom, was developed and within a single
a specific point. There are two primary century became the standard anchor type.
classes of anchors—temporary and In the East, however, another model of
permanent. A permanent anchor is often anchor had been known for some time which
called a mooring, and is rarely moved; it also used a stock, but with the stock
is quite possible the vessel cannot hoist located at the crown along with the arm.
it aboard but must hire a service to move This successful model is still built
or maintain it. A temporary anchor is today in virtually unchanged form. It
usually carried by the vessel, and also informed such modern designs as the
hoisted aboard whenever the vessel is US Navy's stockless Mark IV and the
under way; it is what most non-sailors fluke-style anchor.
mean when they refer to an anchor. A sea A modern temporary anchor usually
anchor is a related device used when the consists of a central bar called the
water depth makes using a mooring or shank, and an armature with some form of
temporary anchor impractical. The hole flat surface (fluke or palm) to grip the
through which an anchor rope passes is bottom and a point to assist penetration
known as a hawsepip. of the bottom; the position at which the
An anchor works by resisting the movement armature is attached to the shank is
force of the vessel which is attached to called the crown, and the shank is
it. There are two primary ways to do this usually fitted with a ring or shackle to
— via sheer mass, and by "hooking" into attach it to the cable. There are many
the seabed. It may seem logical to think variations and additions to these basic
wind and currents are the largest forces elements—for example, the whole class
an anchor must overcome, but actually the of anchors which include a stock such as
vertical movement of waves develop the the fisherman and fluke anchors.
largest loads, and modern anchors are The range of designs is wide, but there
designed to use a combination of are actually trends in designs for modern
technique and shape to resist all these anchors which allow them to be classed as
forces. hook, plow, and fluke types, depending on
The earliest anchors were probably rocks the method by which they set.
and many rock anchors have been found Hook designs use a relatively small fluke
dating from at least the Bronze Age. Many surface on a heavy, narrow arm to
modern moorings still rely on a large penetrate deeply into problematic bottoms
rock as the primary element of their such as rocky, heavy kelp or eel grass,
design. It simply works. However, using coral, or hard sand. Two of the more
pure mass to resist the forces of a storm common versions of this design are the
only works well as a permanent mooring; fisherman and the grapnel.
trying to move a large enough rock to Plow designs are reminiscent of the
another bay is nearly impossible. antique farm plow, and are designed to
A simple anchor using a pair of wood arms bury themselves in the bottom as force is
under a rock mass is a primitive anchor applied to them, and are considered good
which is still in use today. The wood in most bottom conditions from soft mud
arms are pointed to penetrate the bottom, to rock. North sea designs are actually a
and the mass will overcome normal variation of a plow in how they work;
movement forces. Together they comprise they bury into the bottom using their
what may have been the first successful shape.
attempts to hook into the seabed and use Fluke designs use large fluke surfaces to
the strength there to prevent a vessel develop very large resistance to loads
from moving. Almost all future anchor once they dig into the seabed. Although
developments combine these two they have less ability to penetrate and
elements—a penetrating point and a are designed to reset rather than turn,
reasonable mass. their light weight makes them very
In the western world the vast majority of popular.
anchors worked on the concept of the In the past 20 years or so, many new
grappling hook—multiple points on arms anchor designs have appeared. Driven by
such that at least one will be aimed the popularity of private pleasure boats,
toward the bottom. Suddenly the concept these anchors are usually designed for
of the stock, a bar placed perpendicular small to medium sized vessels, and are
to the hooking arm at the other end of usually not appropriate for large ships.






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