The History Of The Crossbow - back in time...

History does not exactly tell us where and when the crossbow made its way into our civilization. However there is clear evidence this weapon was used during wartime as early as the end of the 4^th century B.C. The first evidence of its use can be found with the Greeks followed by the Eurpoeans. China was also using this weapon as early as the 5^th century B.C.

The Greeks

In the Greek world the crossbow emerged during the 5^th century as a much larger version of the crossbow. It was called the gastraphetes or “belly-bow” because it was built to placed against the stomach of the archer. The manner of loading this bow resulted in more stored energy than the standard bows that were currently being used.

The gastraphetes ws improved upon. This led to the introduction of the ballista. Its use in war and against the enemies infantry resulted in very powerful bolts and larger ballistae. There was a smaller version of this crossbow called the Scorpio. This was used by snipers.

The Use of the Crossbow in Europe

Crossbows were evident in Europe during the battle of Hastings around 1500 AD. As a matter of fact, they replaced the standard longbow as the primary archer’s weapon because their use could be learned in about a week vs. the longbow which could take years to master. In addition, the crossbow released a faster and deadlier bolt than the standard bow’s arrow. It was also the favored weapon of the peasants.

Asia and the Crossbow

The first indication of crossbows in China comes from documents dated the 4^th century BC. These scripts state followers of Mozi used a crossbow catapult in the 6^th-5^th century BC. In the well known book The Art of War written by Sun Tzu, there is a description of the crossbow and its uses between 500-300 B.C..

Islam and the Crossbow

The Islamic armies adopted the use of this bow after first seeing and experiencing its effect first hand during the crusades. Muslims preferred the footstrap version of this bow during the wars in Spain.

From the Saracens, the Crusaders discovered a composite bow that had layers of different material glued together to increase the strength of the bow. The Eurpoeans adopted this idea for crossbow prods.

America and Africa

Crossbows in Africa were used for hunting and as scout weapons. Africans captured by slavers brought the knowledge of this weapon with them to America. The crossbow became popular in the south and was used extensively for hunting. The Inuit of North America also used lighter versions of the bow for hunting.

The Use of Crossbows in Modern Day

In today’s world the crossbow is used mostly for target shooting. There are still societies however that use it for hunting including Australia, Africa and America. The smaller crossbows are used for harmless blubber extraction in whales. And there are some special forces in the military who use this weapon instead of the noiser firearms.

For more great information on archery and bows, make sure to check out http://www.eaglearchery.com.

How a Crossbow Works - Educational Post

The crossbow is a combination of an archery bow and a rifle. The standard archer’s bow it uses a string to launch ammunition. However, like a rifle, it has a trigger that releases the string.

Advantages of a Crossbow

The nice feature of the crossbow when compared to other bows is there is less physical strength needed to draw the bow as compared to a traditional bow. The crossbow user can draw the string, cock it, and leave the string while taking aim. More traditional bows require the archer to hold the bow at full draw while aiming. In addition, to draw a crossbow requires the use of the archer’s buttock and thigh muscles. These muscles are much stronger than the arm and chest muscles required of a standard bow user.

Crossbow Physics

The crossbow of today is made of strong lightweight materials. The bow is simply a spring. If you compress a spring or pull a spring from either end it stores potential energy that is released as kinetic energy when the spring is released and returns to its normal shape.

The same thing happens to a crossbow. When you draw the bow, the limbs or tips move closer to the archer. When the string is let go the bow returns to its standard shape. The movement of the bow back to its original shape is what launches the projectile.

Energy Stored

The amount of energy in a bow depends on its draw weight and draw length. The draw weight is the strength needed to pull the bowstring back. The draw length is the distance between the string at rest and the string fully pulled back. A bow can hold energy equal to the draw weight times the draw length divided by two. In other words, the power of a bow depends on how much strength it takes to pull back the string of the bow and how far back you can pull it. Bow makers express this strength in terms of the bow’s energy measured in joules and the arrow’s speed in feet per second.

Factors that affect the draw weight and draw length

The size of the bow can change a bow’s power. A longbow is more powerful than a short bow. The shape of the bow affects speed of the projectile. For example, recurve bows have bows that curve away from the archer and this shortens the bracing height. As a result extra momentum is forced onto the projectile. The composition of the bow can also affect is power. A bow’s tensile strength and density determine not only the amount of energy it holds but also how quickly and exactly it can return to its original shape. Today’s bows use different materials in different parts of the bow to better serve that particular part or function of the part.

As you can see the crossbow works like a spring. As the spring is compressed, or the bowstring drawn back energy get stored as potential energy. When the trigger of the crossbow is released, like the spring, the crossbow will return to its original resting state dispensing the potential energy it stored as kinetic energy. This kinetic energy is responsible for launching the ammunition at high velocity.

For more great information on archery and bows, make sure to check out http://www.eaglearchery.com.

Everything you need to know about Crossbows!

A crossbow is a weapon primarily used by hunters. It consists of a bow placed on a stock. The purpose of the crossbow is to shoot projectiles, called bolts, at a target. There is a mechanism in the stock of the crossbow that holds the bow fully drawn. The bow is realized by pressing a trigger. In the past, the crossbow was used not only for hunting but also as a weapon in open warfare.

Crossbow Structure

The bow of the crossbow is fixed to a stick called the stock or tiller. There is a mechanism that holds the bowstring in the drawn position. The bow is also called the prod or lath and is usually made of a single piece of wood. It is very short compared to a standard bow. As a result the draw length of a crossbow is also very short. Consequently a higher draw weight is necessary to store sufficient energy to launch the projectile effectively.

Types of Crossbows

Crossbows are classified according to the acceleration system, size, energy, degree of automation and projectiles.

Straight Bow

The straight and bent prods are the simplest of the acceleration systems. These were the earliest developed of the crossbows.

Recurve Bow

The recurve crossbow is made with tips that curve away from the person firing the bow. This results in a longer draw length and better acceleration of the projectile. These bows do put more strain on the bow material and are a bit noisier when fired.

Multiple Bow

This bow has a singular manner of pulling the string using several bows. It is similar to a compound bow. Many bows are used in combination with a tackle system. This results in a faster string speed due to the effect of many bows working at once.

Compound Crossbow

With a compound crossbow the extremities are stiffer than a recurve bow resulting in more energy efficiency. However, because the limbs are too stiff to draw using a string directly attached to them, the bow has the string attached to pulleys with cables. Drawing the string causes the pulleys to rotate, which pulls the cables that bend the limbs thus storing energy. This system allows for a let-off thus lowering the full draw weight.

Ammunition

The projectiles that shoot from a crossbow are called bolts. Obviously they are shorter than arrows but can be heavier. Each variation bow has an ideal bolt weight to achieve maximum kinetic energy. The bolts usually have 3 fletches such as are seen on arrows. The bolts can attach to many difference heads depending on the use of the bow. The most common bolt is the four-sided quarrel.

Attachments for the Crossbow

Crossbows contain sights such as red dot sights or telescopic sights. They may also have multiple crosshairs due to gravitational effects over multiple distances.

Crossbows can also have quivers attached to them. Made of plastic, they hold the bolt along the side of the weapon.

Silencers can also be attached to crossbows that are rather noisy when shot. These silencers are attached to parts of the bow that vibrate quickly causing noise.

Crossbow in Modern Times

The crossbow of today is used mostly for target shooting. Hunters still use this weapon throughout the world. The crossbow, used with special projectiles, enables whale researchers to take blubber samples without harm to the whale. In the military the Special Forces use these weapons, some tipped with cyanide, in place of a loud gun.

For more great information on archery and bows, make sure to check out http://www.eaglearchery.com.