Arrow
From Wikipedia, the free encyclopedia
An arrow is a shafted projectile
that is shot with a bow. It predates recorded history and is common to most cultures.
An arrow usually consists of a shaft with an arrowhead attached to the front
end, with fletchings and a nock at the other.
History
In 2010, during an excavation at the
Sibudu Cave
in South Africa, led by Professor Lyn Wadley from the University of the Witwatersrand,
researchers discovered the earliest direct evidence of human-made arrowheads: 64,000-year-old
stone points which may have been shot from a bow. These had remnants of blood and bone, confirming their use in hunting.[1]
Size
Arrow sizes vary greatly across
cultures, ranging from eighteen inches to five feet (45 cm to
150 cm).[2]
However, most modern arrows are 75 centimetres (30 in) to 96 centimetres
(38 in); most war arrows from an English ship sunk in 1545 were 76 centimetres (30 in).[3]
Very short arrows have been used, shot through a guide attached either to the
bow (an "overdraw") or to the archer's wrist (the Turkish
"siper").[4]
These may fly farther than heavier arrows, and an enemy without suitable
equipment may find himself unable to return them.
Shaft
The shaft is the primary structural
element of the arrow, to which the other components are attached. Traditional
arrow shafts are made from lightweight wood, bamboo or reeds,
while modern shafts may be made from aluminium,
carbon fibre reinforced plastic,
or composite materials. Composite shafts are typically made from an aluminium
core wrapped with a carbon fibre outer.
The stiffness
of the shaft is known as its spine, referring to how little the shaft bends
when compressed. Hence, an arrow which bends less is said to have more spine.
In order to strike consistently, a group of arrows must be similarly spined.
"Center-shot" bows, in which the arrow passes through the central
vertical axis of the bow riser, may obtain consistent results from arrows with
a wide range of spines. However, most traditional bows are not center-shot and
the arrow has to deflect around the handle in the archer's paradox; such bows tend to give most consistent results with a
narrower range of arrow spine that allows the arrow to deflect correctly around
the bow. Higher draw-weight bows will generally require stiffer arrows, with
more spine (less flexibility) to give the correct amount of flex when shot.
GPI
rating
The weight of an arrow shaft can be
expressed in GPI (Grains Per Inch).[5]
The length of a shaft in inches multiplied by its GPI rating gives the weight of the shaft
in grains. For examle, a shaft that is 30 inches long and has a GPI
of 9.5 weighs 285 grains, or about 18.468 grams. This does not include the other
elements of a finished arrow, so a complete arrow will be heavier than the
shaft alone.
Footed
arrows
Sometimes a shaft will be made of
two different types of wood fastened together, resulting in what is known as a
footed arrow. Known by some as the finest of wood arrows,[6]
footed arrows were used both by early Europeans and Native Americans.
Footed arrows will typically consist of a short length of hardwood
near the head of the arrow, with the remainder of the shaft consisting of softwood.
By reinforcing the area most likely to break, the arrow is more likely to
survive impact, while maintaining overall flexibility and lighter weight.
Arrowhead
The arrowhead or projectile point is the primary functional part of the arrow, and plays the
largest role in determining its purpose. Some arrows may simply use a sharpened
tip of the solid shaft, but it is far more common for separate arrowheads to be
made, usually from metal, horn, or some other hard material. Arrowheads are
usually separated by function:
- Bodkin points
are short, rigid points with a small cross-section. They were made of
unhardened iron and may have been used for better or longer flight, or for
cheaper production. It has been mistakenly suggested that the bodkin came
into its own as a means of penetrating armour, but research[7]
has found no hardened bodkin points, so it is likely that it was first
designed either to extend range or as a cheaper and simpler alternative to
the broadhead. In a modern test, a direct hit from a hard steel bodkin
point penetrated Damascus chain armour.[8]
However, archery was not effective against plate armour, which became available to knights of fairly modest
means by the late 14th century.[9]
- Blunts
are unsharpened arrowheads occasionally used for types of target shooting,
for shooting at stumps or other targets of opportunity, or hunting small
game when the goal is to stun the target without penetration. Blunts are
commonly made of metal or hard rubber. They may stun, and occasionally,
the arrow shaft may penetrate the head and the target; safety is still
important with blunt arrows.
- Judo points
have spring wires extending sideways from the tip. These catch on grass
and debris to prevent the arrow from being lost in the vegetation. Used
for practice and for small game.
- Broadheads
were used for war and are still used for hunting. Medieval broadheads
could be made from steel,[7]
sometimes with hardened edges. They usually have two to four sharp blades
that cause massive bleeding in the victim. Their function is to deliver a wide
cutting edge so as to kill as quickly as possible by cleanly cutting major
blood vessels, and cause further trauma on removal. They are expensive,
damage most targets, and are usually not used for practice.
There are two main types of
broadheads used by hunters: The fixed-blade and the mechanical
types. While the fixed-blade broadhead keeps its blades rigid and unmovable on
the broadhead at all times, the mechanical broadhead deploys its blades upon
contact with the target, its blades swinging out to wound the target. The
mechanical head flies better because it is more streamlined, but has less
penetration as it uses some of the kinetic energy in the arrow to deploy its
blades.[10]
- Field tips
are similar to target points and have a distinct shoulder, so that missed
outdoor shots do not become as stuck in obstacles such as tree stumps.
They are also used for shooting practice by hunters, by offering similar
flight characteristics and weights as broadheads, without getting lodged
in target materials and causing excessive damage upon removal.
- Target points
are bullet-shaped with a sharp point, designed to penetrate target butts easily without causing excessive damage to them.
- Safety arrows
are designed to be used in various forms of reenactment combat, to reduce
the risk when shot at people. These arrows may have heads that are very
wide or padded. In combination with bows of restricted draw weight and
draw length, these heads may reduce to acceptable levels the risks of
shooting arrows at suitably armoured people. The parameters will vary
depending on the specific rules being used and on the levels of risk felt
acceptable to the participants. For instance, SCA combat rules require a padded
head at least 1¼" in diameter, with bows not exceeding 28 inches
(710 mm) and 50 lb (23 kg) of draw for use against
well-armoured individuals.[11]
Arrowheads may be attached to the
shaft with a cap, a socketed tang,
or inserted into a split in the shaft and held by a process called hafting.[2]
Points attached with caps are simply slid snugly over the end of the shaft, or
may be held on with hot glue.
Split-shaft construction involves splitting the arrow shaft lengthwise,
inserting the arrowhead, and securing it using a ferrule,
sinew, or wire.[12]
Fletchings
Fletchings are found at the back of
the arrow and act as airfoils to provide a small amount of force used to stabilize the
flight of the arrow. They are designed to keep the arrow pointed in the
direction of travel by strongly damping down any tendency to pitch or yaw.
Some cultures, for example most in New Guinea,
did not use fletching on their arrows.[13]
Fletchings are traditionally made
from feathers
(often from a goose
or turkey) bound to the arrow's shaft, but are now often made of plastic
(known as "vanes"). Historically, some arrows used for the proofing of armour used copper vanes.[14]
Flight archers may use razor blades for fletching, in order to reduce air
resistance. With conventional three-feather fletching, one feather, called the
"cock" feather, is at a right angle to the nock, and is normally
nocked so that it will not contact the bow when the arrow is shot. Four-feather
fletching is usually symmetrical and there is no preferred orientation for the
nock; this makes nocking the arrow slightly easier.
Artisans who make arrows by hand are
known as "fletchers," a word related to the French word for arrow, flèche.
This is the same derivation as the verb "fletch", meaning to provide
an arrow with its feathers. Glue and/or thread are the main traditional methods
of attaching fletchings. A "fletching jig" is often used in modern
times, to hold the fletchings in exactly the right orientation on the shaft
while the glue hardens.
Whenever natural fletching is used,
the feathers on any one arrow must come from the same side of the bird. The
slight twist in natural feathers then makes the arrow rotate in flight, which
increases accuracy. Artificial helical fletchings have the same effect.
Most arrows will have three fletches, but some have four or even more.
Fletchings generally range from two to six inches (152 mm) in length;
flight arrows intended to travel the maximum possible distance typically have
very low fletching, while hunting arrows with broadheads require long and high
fletching to stabilize them against the aerodynamic effect of the head.
Fletchings may also be cut in different ways, the two most common being parabolic
(i.e. a smooth curved shape) and shield (i.e. shaped as one-half of a
very narrow shield) cut.
A flu-flu
is a form of fletching, normally made by using long sections of full length
feathers taken from a turkey, in most cases six or more sections are used
rather than the traditional three. Alternatively two long feathers can be
spiraled around the end of the arrow shaft. The extra fletching generates more
drag and slows the arrow down rapidly after a short distance, about 30 m or so[citation needed].
Flu-Flu arrows are often used for
hunting birds, or for children's archery, and can also be used to play Flu-Flu Golf.
Nocks
The nock is a notch in the rearmost
end of the arrow. It serves to keep the arrow in place on the string as the bow
is being drawn. Nocks may be simple slots cut in the back of the arrow, or
separate pieces made from wood, plastic, or horn that are then attached to the
end of the arrow. [15]
Modern nocks, and traditional Turkish nocks, are often constructed so as to
curve around the string or even pinch it slightly, so that the arrow is
unlikely to slip off. [16]
In English it is common to say "nock an arrow" or "notch an
arrow," when one readies a shot.
The wiki link on this subject can be found at: http://en.wikipedia.org/wiki/Arrow