Since ancient times, the crossbow has been known as a very accurate and lethal long-range weapon. A crossbow is a wooden stock to which a compound or steel bow is attached.
Thanks to a special hooking mechanism, its bowstring is easily fixed, which gives the shooter the opportunity to concentrate on aiming. The special design of this weapon allows the use of even heavy arrows, which hit the target with the same accuracy as regular arrows.
History of the crossbow
The original concept of the crossbow dates back to around 400 BC. At that time, the weapon was called “gastrafet”, which could launch two-meter arrows at a distance of up to two hundred meters. Thus, the gastraphetus was a longer-range weapon than the standard bow.
The crossbow was mainly used as hunting weapon, and until the eleventh century no one considered it as effective way eliminating opponents on the battlefield. However, warriors from the Middle East, who had already appreciated the advantages of the crossbow during numerous battles for control of the lands, again popularized this weapon among Europeans.
Crossbows during the Battle of Hastings
For example, during the Battle of Hastings in the mid-eleventh century, the Normans made extensive use of crossbows against their Saxon opponents. In addition, this weapon gained considerable popularity among the crusaders.
Shooting from a crossbow did not leave Richard I the Lionheart himself indifferent. It is believed that he was excellent at handling this weapon, having personally shot dozens of people with it.
Interestingly, the king himself died from a crossbow arrow during the siege of the Chalus-Chabrol fortress.
At the end of the twelfth century, crossbows entered service with the navy and infantry. Special detachments of crossbowmen began to form, increasingly becoming important participants in battles. Some units were part of many armies and fought for money.
For example, the rebellion of the English barons at the beginning of the thirteenth century was successfully suppressed, including with the help of three hundred crossbowmen, who instantly destroyed the enemy’s mounted troops. Of course, crossbowmen were on both sides of the battle.
In the same 1215, the rebel garrison, which surrendered in Rochester, declared capitulation. According to the decree of John the Landless, all captured knights could receive their freedom for a ransom. However, this order did not apply to particularly dangerous crossbowmen, who were sent to the gallows without any exceptions.
Quite soon, detachments of crossbowmen acquired a special status as part of the defensive forces of fortresses. For example, in the garrison of Safet Castle, which was located in the Holy Land, there were about three hundred crossbowmen. Approximately the same number of crossbows (and almost 267 thousand arrows attached to them) was discovered during an inspection of weapons stocks in thirty French castles of the Capetian domain.
And in the arsenal of the Norman fortress of Passy-sur-Hère there were five large crossbows, 25 crossbows with stirrups and almost 40 crossbows, which could only be loaded with the legs.
Crossbow design
The very first models of crossbows had the simplest design: a wooden bow was attached to the stock, and the string was pulled by hand. An arrow fired from such a weapon had a modest firing range (about one hundred meters) and could only kill a warrior without armor.
A little later, participants in the Crusades learned about the designs of compound bows, as well as about the different materials for their manufacture. For example, with inside the onions were glued with special whalebone plates - they worked for compression.
The photo shows a crossbow with a compound bow
Tendons glued with outside, worked in tension. Dried fish bladders were used to make glue.
Drying of the product lasted at least one year. At the end of this process, the horns of the bow were bent in the opposite direction and had a strong tension. Stretching the bowstring of such a crossbow was a very difficult task, so mechanical devices were invented quite quickly.
At the beginning of the thirteenth century, a mechanism known as the "belt hook" appeared. To draw, the shooter had to turn the crossbow with the bow down and hook the steel hook to the central part of the bowstring. Then the shooter inserted one foot into the stirrup located in front of the weapon, straightened his body and pulled the crossbow down, applying significant effort to tighten the bowstring.
Loading a crossbow with your foot
In the fourteenth century, a new Middle Eastern type of tension hook came to Europe - the so-called “goat's leg”. It was a special rotary lever, equipped with a double fork, the end of which rested on a transverse pin on the stock of the weapon. The fork hooked the bowstring, and with the help of a lever, pulled it up to the hooking mechanism. The shooter could easily apply a force of two hundred kilograms and draw even the most lethal crossbows of those times.
Crossbow with a "goat's leg" bowstring tensioning mechanism.
By the beginning of the fifteenth century, the production of steel bows was established. By maintaining their previous dimensions, the craftsmen provided similar bows with much greater lethal force and durability. To tighten the bowstring of such a crossbow, they used a “kranekin”, i.e. removable rack and pinion gate. A belt loop secured its mechanism to the crossbow stock, and the bowstring was hooked by hooks connected to a rack. With the help of a kranekin, a crossbowman could apply a force of 1,100 kilograms. However, pulling the bowstring required about thirty turns of the handle, which sometimes took up to forty seconds.
Simultaneously with this system, a removable gate appeared, which included intermediate blocks and handles attached to the weapon stock. With the help of this gate, the crossbowman could apply a force of approximately 800 kilograms, which made it possible to spend a maximum of half a minute on cocking the weapon. However, this bulky collar was very inconvenient in battle, since it had to be constantly attached to the crossbow.
Crossbow with a "kranekin" tension mechanism.
The crossbow hook was a simple and reliable mechanism, where the bowstring was attached to the protrusion of a bronze or bone “nut”. A special cutout was usually made on the ledge, which served as a sight.
To make the bowstring, high-strength flax, hemp rope, and cord made from ox sinew or rawhide straps were used. As the bowstring gradually stretched, it was subject to regular replacement. The string also deteriorated when exposed to water, so special leather cases were used to store crossbows.
Crossbow arrows, called "bolts", were made of wood. They were up to 40 centimeters long, about one and a half centimeters thick and weighed about 70 grams.
In order to stabilize the flight path, “wings” made of wood or leather were often attached to the arrows. The tips had a petiole design and a pyramid-shaped head.
Crossbow sighting range
In the fifteenth century, the most lethal crossbow, equipped with a steel bow, could launch an arrow at a distance of up to 400 meters. Sighting range crossbow with a compound bow was about 250 meters - the same distance an arrow fired from traditional bow. However, such an arrow, firstly, was not able to hit the target at its end, and secondly, its movement along a certain trajectory could be instantly interrupted due to the wind.
The crossbow bolt pleased shooters with much more combat-ready aerodynamic parameters.
At a distance of targeted shooting at single targets (about 90 meters), a crossbow bolt successfully penetrated any enemy armor, be it chain mail, plate armor or knight's armor.
Thanks to this feature, crossbowmen were able to keep the archers of the enemy army at a sufficient distance, from which firing arrows was virtually useless.
And yet, the crossbow had one drawback over the bow - its low rate of fire. In one minute, a worthy archer could manage to fire about ten arrows, while a crossbowman during the same time managed to shoot only five times from a light crossbow or two times from a heavy one.
In addition, the crossbowman had to try to kill opponents with the first shot, otherwise during a long reload of the weapon the target could leave the affected area.
When cocking a crossbow, the shooter became an easy target for enemies, so he was often covered by a second warrior with a special shield.
MODERN CROSSBOWS - BASICS, TERMINOLOGY, CLASSIFICATION
Part 1
The popularity of this weapon is growing, that's it more people want to touch this wonderful example of human progress. After all, humanity has always strived to hit targets faster, more accurately, and from a greater distance. Some people want to touch their childhood dream, some hunt, some want to make a crossbow with their own hands, and some just like to shoot at a target. Most newcomers to the crossbow business have many questions about which crossbow to buy or make, what a “block”, “guide”, “shako”, “cable” is, how a “block” differs from a “classic” and many other questions.
Indeed, the former powerful throwing weapon of ancient armies is experiencing a kind of “Renaissance” in our time, now it is available to almost everyone. Any citizen who has reached the age of 18 and has a passport can purchase a crossbow with an arc force of up to 43 kg, which has an appropriate certificate. Naturally, there are also restrictions - in our country, crossbows with a tension force of over 43 kg are considered weapons, and hunting with them is prohibited. That is, even if you have a hunting license, it’s not your destiny to hunt with a crossbow. Perhaps, after some time, something in this regard will change in our legislation, and the hunter will be able to feel what it is like to be one on one with a powerful beast, when one arrow is loaded and there is no room for error, since reloading a crossbow, even with a cocking lever, takes quite a long time. Naturally, the hunter with a crossbow bears more responsibility, since there is no opportunity to fire a second shot and finish off the wounded animal. The shot must be fired from a short distance and certainly in an area incompatible with the life of the animal.
The point of this article is not to tell where and how the crossbow (crossbow) came from, but to explain what parts a crossbow consists of, what types of crossbows there are, what accessories are used for them, types of ammunition, tensioning devices, etc.
1. Main parts of the crossbow and basic terms
A modern crossbow, of course, in its operating principle (the release of a projectile being thrown by a bowstring held by a trigger mechanism, through a trigger lever (hook), due to the stored energy of an elastic element (arc, shoulders) located across the bed) is no different from its older brother, however The design has undergone quite significant changes.
First, let's look at the main parts of the crossbow using the example of a device with the so-called “classical” layout (Fig. 1). The most noticeable difference between it and the usual old crossbow design will be the presence of separate arms instead of a solid arc. But since the vast majority of modern crossbows have such separate arms, they are actually the “classics” of our time.
Fig.1. Main parts of a crossbow.
Fig.2. Crossbow with a single guide stock
All parts of the crossbow are mounted on a single profile - a guide. There are crossbows in which all the parts are attached directly to the stock and there is no such part as such. In this case, the guide is the groove in which the arrow is placed. An example of such a crossbow is shown in Fig. 2. Please note that the crossbow shown in the last picture also has simpler, straight shoulders. The guide should not have any bends or curvature, because in essence it is the “barrel” of the crossbow. You yourself understand what shooting from a weapon with a crooked muzzle will be like. The guide, in the part along which the bowstring and arrow will move, is polished for better sliding of the projectile and less wear on the winding of the bowstring. Also, additionally use lubricant. The bowstring is rubbed with wax (beeswax or special wax for bowstrings).
As mentioned above, in most modern crossbows the arc is split, that is, in fact we have two separate arms. Firstly, it allows the arms to be raised so that they are level with the top edge of the guide without tilting, which reduces friction between the string and the guide; secondly, it allows the shoulders to be positioned more parallel to the guide; and thirdly, for ease of transportation. It is very important that both shoulders have the same characteristics in terms of geometric parameters and physical properties.
The arms are attached to the guide or directly to the stock using a block - this part, which carries a serious load, is subject to fairly stringent requirements for strength and geometry. After all, the synchronization of the work of the shoulders will depend on the accuracy of its manufacture, and the reliability and health of the shooter will depend on its strength. In general, in a crossbow, for proper operation and accurate shooting, the accuracy of the manufacturing of the mechanisms must be at a fairly high level.
Fig.3. Crossbow-pistol with a separate superstructure above the castle
The bowstring is an important and very important part of the crossbow. It must meet several requirements - be strong, light, flexible, not stretch, and hold a tug well. Mostly, modern crossbows have a bowstring made of synthetic fiber Dyneema. Fishing braid is also made from the same fibers, which, due to its large selection and availability, is one of the best materials for self-weaving bowstrings. On the bowstring, in places of friction against the guide and on the loops thrown over the ends of the arms, a winding is made, for example, from nylon thread. Such a winding is rewound as it wears out - this mainly concerns the warhead, where the bowstring wears out the most.
A trigger mechanism (SM), which is also called a lock, is mounted in the rear part of the guide. This mechanism keeps the bowstring cocked and allows it to be easily released when the trigger (lever) is pulled. It can be assembled directly into the guide or have a separate housing mounted into it. If the guide, as a separate part, is missing, then the lock cuts directly into the stock. The body of an SM crossbow in the upper part usually has a superstructure on which sighting devices or rails, such as a dovetail, Weaver or Picatinny rail, are mounted, for all kinds of optical or collimator sights. Also attached to the superstructure is an arrow clamp, which is a leaf spring that keeps the arrow from falling out in a loaded crossbow. On some crossbows, the superstructure is not part of the lock, but is attached as a separate part to the crossbow above the SM (Fig. 3). There are add-ons that can be adjusted - they change the angle of inclination, which makes it possible to adapt the crossbow sights to longer distances, because the flight of an arrow in terms of flatness (straightness) is much inferior to that of a firearm. Although, in my humble opinion, this does not make much sense, since the speed of the arrow drops quite strongly with distance, and the time it takes for it to fly, for example, 200 m, is quite long. Naturally, the lethality at such a distance is low.
Fig.4. Assembling the main parts of the crossbow
A little about the crossbow stock. In principle, there are big differences from the lodges firearms, it doesn't have it. The only thing is, due to the superstructure and highly raised sights, the butt line is located higher. The guide assembly with the remaining parts of the crossbow is attached to the stock or, as mentioned above, all parts of the crossbow are mounted on the stock itself. An example of assembling the main parts of a crossbow is shown in Fig. 4.
2. Classification of crossbows
According to state standards of the Russian Federation [Change No. 1 GOST R 51905-2002 Sports crossbows, crossbows for recreation and entertainment and shells for them. Technical requirements and safety test methods], crossbows are usually divided into:
universal sport-hunting and match crossbows, which are throwing weapons and intended for use in sport hunting, in the educational and training process and during competitions;
sports crossbows (traditional, field, etc.), not related to throwing weapons, which are sports equipment, intended for use in the educational and training process and during competitions;
crossbows for recreation and entertainment, not related to throwing weapons, which are household products intended for leisure and mass sports;
crossbows made in a homemade way(in terms of determining whether they belong to throwing weapons during forensic examinations).
The main criterion for gradation is the strength of the crossbow's arcs (Table 1).
Table 1
For the same guest there is the following classification table (Table 2). This is what concerns the legislation and standards of the Russian Federation.
Table 2
Fig.5. Sports match crossbow.
But I would like to propose a slightly different classification of modern crossbows.
Classification by purpose:
1. Sports match crossbows
2. Copies, replicas of ancient crossbows
3. Crossbows for fun and recreation
4. Hunting crossbows.
With match crossbows (Fig. 5), in general, everything is clear - this is a separate class of crossbows that are sports equipment and at the same time, according to the forensic requirements of the Russian Federation - with weapons. We will not dwell on them in detail.
Fig.6. Replica of a medieval crossbow (by "Dirty" Burdwood)
Next, in second class, are copies and replicas of ancient crossbows - combat, sporting and hunting crossbows manufactured before the 20th century. That is, these are Greek gastraphetes, and arquebuses (a crossbow with a barrel), and schnappers with balestres (crossbows that fire bullets), as well as classic crossbows, with cocking devices improved over the centuries - with a belt hook, with a “goat leg”, with an English collar, with a cranekin. Naturally, according to the same forensic requirements, most copies, especially authentic ones, will be weapons. But replicas of ancient crossbows have only external similarities with the originals, and even then, often the external differences are so significant that only to a person completely inexperienced in crossbows, such products may seem like a copy (Fig. 6). Materials for manufacturing can be any, including a variety of polymers. Such crossbows may well fit within the legal limits of 43 kg. Copies and replicas of ancient crossbows are mainly souvenirs and museum products, as well as the path of fans and re-enactors of these weapons. Although, abroad there is enough large number crossbow unions, which specialize specifically in antique crossbows, hold meetings, exhibitions and shooting competitions. But still, such crossbows are not suitable for recreational shooting, especially for spears, due to their power (again the notorious “43 kg”), the complexity of manufacturing ammunition (the shape of ancient bolts is mostly spindle-shaped), which often simply shatter into splinters upon impact o target.
Let me make a comparison - the passion for antique crossbows is akin to smoking a pipe. This is a manifestation of a certain aestheticism, listen to how such people speak about their hobby: “...to get pleasure from smoking a pipe, it takes time. This is a cigarette you can smoke while running, at work, in the toilet. Pipe is a ritual. Choose an hour or two, relax. Let the bustle leave you for a while. Slowly and carefully hammer in the tube. Relax comfortably in your favorite chair. Light it lovingly and take a mouthful of aromatic smoke. Release a puff of smoke and feel how all your problems dissolve in it. Your hand is warmed by a gentle and devoted friend, and in her beauty, in the convolutions of wood patterns and smooth lines, you will discover something new for yourself every time. Sometimes it’s harder to find such beauty and devotion in women than in pipes...” ( http://voffka.com/archives/2006/09/19/029976.html).
Let's move on to the so-called crossbows for entertainment and recreation. The majority of crossbows on the market are of this class. This includes pistol crossbows and rifle crossbows of all designs not exceeding a peak cocking force of 43 kg. Many crossbows in this group are from the following class - the hunting class, but with weakened shoulders by the standards of our country. Although with 43-kilogram shoulders, this is especially true for block crossbows, due to their design features, you can hunt small game and birds. For example, one of the record holders for arrow speed, Bowtech “Desert Stryker” (Fig. 7), was equipped for the Russian Federation with weakened arms of 43 kg.
Fig.7. Bowtech "Desert Stryker"
There are no serious design differences in hunting crossbows. The main thing is their powerful shoulders - up to 80 kg in block crossbows and up to 150 or more in classic crossbows. This allows you to send a heavy arrow with a broadhead tip (three or four bladed hunting tip) to the target with good energy. Naturally, hunting crossbows are always the most expensive and most well-equipped devices.
Classification according to the design of the power section.
1. Crossbows with classic shoulders:
a) with simple shoulders;
b) with recursive arms.
2. Block crossbows:
a) with a pulley system of 2, 4, 6 and 8 rollers;
b) with round eccentric blocks;
c) with oval eccentric blocks;
d) with binary eccentrics.
3. Crossbows with non-classical shoulder placement:
a) with reverse shoulders;
b) with a different arrangement of arms and a system of rollers (blocks).
Let's look at the above structures in order. Simple shoulders in a free state without a bowstring are a straight or slightly curved plate towards the shooter (mono-bow) or a pair of such plates (split shoulders). Most ancient crossbows had a monobow, but in modern crossbows split shoulders have become more common. An example of simple separate shoulders is a model from the Canadian company “Excalibur” for the teenage generation (Fig.. Also, such shoulders are not uncommon among home-made people due to the availability of material (springs from cars, as well as other spring elements - saws, torsion bars) and ease of manufacture An example of the author’s homemade product with shoulders made from a circular saw blade is shown in Fig. 2.
Fig.8. Crossbow Excalibur "Apex Light"
The majority of modern crossbows of the “classical” layout are equipped with recurve arms. Such shoulders differ from straight ones in that they have a characteristic and quite noticeable bend forward at the ends. In a free state, without a bowstring, the ends of such arms, as a rule, go forward further than the line of the bowstring and even further than the middle of the bow, forming an arc curved away from the shooter (Fig. 10). The degree of recursiveness can vary widely. Almost all crossbows produced by the same company “Excalibur” have such shoulders (Fig. 9, 10).
Rice. 9. Excalibur “Equinox” crossbow with recurve arms.
Rice. 10. Excalibur “VIXEN” crossbow front with arms without string.
Recursive shoulders can also be mono (Fig. 11) or split.
Fig. 11. Barnett "Commando" crossbow with a recurve mono arc.
Both simple and recursive shoulders are made with a narrowing from the root to the ends. Often both in width and thickness. This is done so that the shoulders bend when tensioned evenly along the entire length, or even a little more towards the ends, which helps to increase the efficiency of the shoulders - the weight decreases, the speed of straightening the shoulders increases.
Recursiveness helps achieve even greater efficiency. The curved ends of the arms provide additional leverage, which, as the bowstring is pulled, seems to increase the length of the arm, changing the distance from the center of rotation (from the center of the bow) to the bowstring. That is, as the resistance of the arc increases, the leverage for which we overcome this resistance also increases . Thanks to this recurve bow it draws more evenly, its force changes less throughout the entire working stroke, and with the same tension as a regular (simple) bow, a recurve bow has a much greater preload*, which makes it possible for it to push the arrow with greater force until the very end. In fact, there is a partial change in the “gear ratio” of the arc force to the string.
(*A bow with a bowstring installed, but in an uncocked state, is pre-tensioned, that is, it has a preload. The amount of preload is selected in such a way that the material from which the arms are made has a margin of safety for the required working stroke of the bowstring. That is, a compromise is found between the power of the arc and the properties of the material from which it is made. in simple words, we shorten the string - we increase the preload, which accordingly changes the power of the bow upward, but also increases the chance of its breaking with the ensuing consequences of possible injury to the shooter.)
The next stage in the development of crossbows was systems with a pulley system. The pulley is a clip with one or more round movable rollers (Fig. 12). In theory, depending on the multiplicity (number of cable branches and number of rollers) of the pulley, it is possible to reduce the string tension force from two to four times(systems with two, four, six, eight rollers) and increase the speed of the bowstring when firing by the same number of times.
Fig. 12. The principle of operation of the block and pulley. a – single block (with one cable stretched along the groove of a single pulley); b – a combination of two single blocks with a single cable covering both pulleys; c – a pair of double-groove blocks, through four paired grooves of which a single cable passes.
Also, a system with a pulley system allows you to reduce the transverse dimensions of the crossbow, since the stroke of the end of the arm in them is significantly less with the usual length of the working stroke. In practice, in addition to the advantages, there are also disadvantages of this system: losses due to friction of the cable on the rollers, friction of their axes, movement of the mass of the shoulder shackles (earrings are the roller clips at the end of the arms), non-parallelism of the cable branches (strings, which in pulley systems significant).
In Fig. 13 shows an example of how by adding a pair of rollers and the same stroke of the ends of the arms, the stroke of the bowstring increases.
Fig. 13. Comparison of a pulley system with simple arms.
Most factory-designed pulley crossbows have eight rollers (Fig. 14). Crossbows with two rollers are extremely rare (Fig. 15), as well as with six - I can only cite as an example the wonderful homemade crossbow “Lynx” from Zmeelink (Fig. 16). There are many homemade devices with four rollers (Fig. 17), and there are also factory ones (Fig. 1.
Fig. 14. Crossbow Interloper "Black Python".
Fig. 15. Crossbow from Ralph's
On factory and many homemade crossbows, the middle rollers are connected to the next pair by a rod, as in Fig. 14, 17, 18, but practice has shown that it is better to make them rigidly fixed to the guide, which allows them to be lowered below the level of the rollers at the ends of the arms without interfering with the free movement of the bowstring and the straightening of the shoulders (Fig. 16, 19).
Rice. 16. Crossbow “Lynx” from Zmeelink
Rice. 17. Crossbow from daf13
Rice. 18. Crossbow-pistol Interloper “Aspid”.
Rice. 19. Crossbow with eight rollers, the middle ones are rigidly fixed
For optimal operation of pulley systems, the arms, relative to the guide, should be located as parallel to it as possible, since the bowstring acts on the ends of the arms through rollers, which tend to bend the arms not towards the shooter, but towards each other. That is, the sharper the angle between the shoulder and the guide, the better. Of course, if the arms are placed parallel, this will significantly reduce the transverse dimensions of the crossbow, but will also increase the longitudinal ones. Therefore, here it is worth looking for the “golden mean” - and the shoulders are rarely placed at an angle less than 45 degrees to the guide. A good solution was suggested by http://forum.arbalet.info/viewtopic.php?t=2802&postdays=0&postorder=asc&start=960 igora - pseudoparallel shoulders (Fig. 19).
Rice. 19. Pseudoparallel shoulders, by igora
As the author himself described it: “The essence of the proposed 2nd method is to make the shoulders of an ordinary one-piece monobow work just as parallel to the stock (which is what all manufacturers strive for) while remaining a regular arc and even without bending at all. Along the way, it increases gear ratio the chain hoist used. Moreover, for example, in the figure, the chain hoist in the 2nd version will give a gear ratio approximately like that of an 8-roller, but in reality only two of them are added. Well (and most importantly!) the direction of the forces applied to the shoulder will be corrected). The biggest problem I see is the long string, but not longer than the 8-roller.”
The shoulders of pulley crossbows are made short and rigid, often without narrowing in width and thickness, because the stroke of the end of the shoulder in these systems is small, and the force that the shoulders must create is several times higher than in “classical” systems. The material of the factory shoulders is unidirectional fiberglass. Homemade, most often - springs from cars,
The pulley transfers force from the shoulders to the string through a certain gear ratio (which usually reduces the force and increases the stroke). But since this gear ratio is constant, then as the bending increases, the force on the arc increases in the same way on the bowstring. To get rid of this, and to further improve the shooting qualities of crossbows, so-called blocks appeared. They allow you to transfer force from the shoulders to the bowstring with a variable gear ratio, thereby ensuring that, regardless of the degree of bending of the arc and the force on it, the desired force is always on the bowstring. Some of the simplest blocks are round eccentric blocks. This is a more complex system compared to a pulley system - each block consists of two rollers secured together, the axis on which it rotates is offset from the center (Fig. 20). Two strings - one, of two parts, connecting power rollers blocks and opposite ends of the arms is called a power or technical bowstring (blue with a yellow fork in the figure), and the second is a combat or high-speed bowstring, which directly accelerates the arrow (white with a red winding, Fig. 21).
Fig.20. Round eccentric blocks (the hole for the axle is highlighted)
Rice. 21. System with round eccentric blocks
The layout and reeving of bowstrings in systems with round eccentric blocks is shown in Fig. 22. Also, the ends of the power strings can be attached not to the rollers at the ends of the block axes (Fig. 21), but by means of a transition piece under the block, attached to the axle (Fig. 23).
Due to the fact that the power string does not extend much lower than the speed string, it became necessary to lower it somewhat so that it does not interfere with the lower feathering of the arrow. Therefore, all crossbows with eccentrics have a characteristic slot for a power bowstring, with a guide part running inside it along with two slots for the left and right power bowstrings (Fig. 22).
Fig.22a. Location of blocks, string and pressing part (top view)
Fig.22b. Location of blocks, string and pressing part (bottom view)
Another feature of the eccentrics is that at the end of the tension, the operation of the block provides the so-called reset - a sharp decrease in the tension force. Therefore, in such crossbows, the tension force is measured by the peak force, and not by bringing the bowstring to the lock, as with simple and recurve arcs or in pulley systems.
Rice. 23. Barnett “Lightning” crossbow with round eccentrics.
The next stage in the development of crossbows was the use of oval eccentrics instead of round blocks (Fig. 24). The shape of these blocks only resembles an oval, but in fact it is more complex. The fact is that in such blocks, the force on the bowstring is controlled not only by simply shifting the axis of the block, but also by changing the very shape of the rollers that form the block. This allows you to create absolutely any desired force on the bowstring throughout its entire working stroke. A small illustration of the operation of an oval eccentric (Fig. 25 (by Andrey 74)) shows how the gear ratio between the power and speed parts of the block changes during its unwinding.
By combining the shapes and sizes of the power and speed parts of the block, as well as their relationship with each other, you can select the optimal characteristics of force, speed and stroke of the bowstring for specific shoulders. Examples of crossbows with oval eccentrics in Fig. 26, 27, 28.
Rice. 24. Oval eccentric blocks
Rice. 25. Illustration of the operation of an oval eccentric (author andrey 74)
Fig.26. Ten Point "Phantom"
Rice. 27. Darton “Serpent”
Rice. 28. Crossbow Parker “SAFARI CLASSIC”
On some models of crossbows with oval eccentrics, the blocks are installed in the opposite direction and the bowstring lies on the side opposite to the shooter - these are the so-called “mirror blocks” (Fig. 29). In this case, the crossbow becomes somewhat more compact in the longitudinal direction than with the usual arrangement of eccentrics.
Rice. 29. Parker “Cyclone” crossbow
Recently, there has been a tendency to increase blocks almost to the size of archers. Due to rewinding more bowstrings from blocks, we get a larger stroke of the bowstring, which means that the transverse dimensions of crossbows can be further reduced. Despite the fact that with such large eccentrics, the stroke of the crossbow string approached 45 cm! Sammy prominent representatives The new generation of crossbows and record holders for arrow speed are the PSE “TAC-15” (Fig. 30) and Bowtech “Stryker” (Fig. 32) crossbows. Both crossbows are unique in their own way.
Let's take a closer look at the TAC-15. Due to its huge eccentrics, the width from axis to axis of the blocks in the uncocked state is 42.5 cm, and in the cocked state - 29.8 cm. And the stroke of the bowstring is a record for a crossbow - 45 cm! With a peak force of 77.2 kg, it is capable of sending a 425 grain (26.44 g) arrow at a speed of 125.6 m/s. IN given time– this is an absolute record for crossbows. The kinetic energy developed in this case is up to 217 J, sufficient for hunting any large animal. The crossbow is also unusual in that the back of the crossbow is from an AR-15 (M16) automatic rifle - as you know, this rifle has a modular design (Fig. 31). Therefore, any weapon based on the M16 can be easily converted into a crossbow. The TAC-15 has a built-in winch-type cocking device. One more point - the arrow of this crossbow does not lie on the guide, but, like a bow, rests with its leading edge on the shelf. And the arrows recommended by the manufacturer also have a record length for crossbows - 26.25 inches (~66.7 cm)!
Rice. 30. Crossbow PSE “TAC-15”.
Rice. 31. AR-15 rifle
Rice. 32. Crossbow Bowtech "Stryker"
The Bowtech "Stryker" crossbow has slightly more modest characteristics, it launches a 425 grain arrow at a speed of 123.4 m/s, while having kinetic energy at 210 J. Its width from axis to axis of the block in an untensioned state is 69.2 cm, and in a tense state - 61.6 cm, the peak tension force is 79.45 kg with a bowstring stroke of 432 mm. But the Stryker has one feature - binary eccentrics, which places it in the next subclass of compound crossbows.
What are the differences between binary eccentrics and ordinary oval ones? Let's try to figure it out. All compound crossbows have one bad feature - the center of their bowstring (arrow stop) can shift to the left or right side due to the fact that each rotates independently, as a result of which shooting accuracy decreases. In binary systems, the blocks have an additional third pulley, onto which the other end of the power string on the right or left side is wound, due to which synchronization occurs (Fig. 33. (author igora)). In Fig. 34 shows an example of a binary eccentric of a compound bow for clarity.
Rice. 33. Illustration of the operation of binary eccentrics from igora
Rice. 34. Binary eccentric compound bow
Even the brilliant Leonardo da Vinci came up with a design for crossbows with reverse arms (Fig. 35), and only recently did crossbows of this design begin to be mass-produced. The first sign was the Armcross "LeoPro" crossbow, created by Russian designers (Fig. 36). The main advantages of such crossbows are: compactness (reduced longitudinal and transverse dimensions), better weight distribution, reduced shot recoil, because when shooting, the shoulders do not move away from the shooter, but as if to each other and a little “into the shoulder.” In Fig. 37 you can see how compact the LeoPro is. Among the disadvantages of a crossbow, we can highlight the sharp angle of tension of the bowstring (Fig. 3, due to which it is convenient to cock the crossbow only using a cocking device, and also, purely hypothetically, it can be assumed that the shoulders, which are too close to the shooter’s face, can break injure.
Rice. 35. Schemes by Leonardo da Vinci
Rice. 36. Crossbow Armcross "LeoPro"
Rice. 37. Crossbow Armcross "LeoPro" with a specially designed unloading vest
Rice. 38. Cocking the Armcross "LeoPro" crossbow using a tensioner (shown below to the right)
Rice. 39. Crossbow Horton “Recon 175”
Another crossbow with reverse arms is produced by the Horton company - “Recon 175” (Fig. 39). Please note that both of the most famous crossbows with reverse arms have round eccentrics, which does not prevent them from showing very good performance - the initial arrow speed reaches 99 m/s.
It is not advisable to make such crossbows with a classical layout, that is, without blocks, since the shoulders will “run away” in the direction opposite to the tension and the efficiency, relative to crossbows with a classically located arc, will be much lower.
Recently, another player has appeared in the camp of crossbows with reverse arms - “Scorpyd” (Fig. 40). According to new trends, its blocks are binary and have large sizes. The stated initial speed of the arrow is 425 feet per second, which corresponds to 129.5 m/s! The stroke of the bowstring of this compact crossbow reaches a record 52 cm!
Rice. 40. Crossbow “Scorpyd” SLP
Among homemade products there are also crossbows of a similar design. Almost all have a similar “LeoPro” design, but mostly with a pulley system with two or four rollers (Fig. 41, 42, 43).
Fig.41. Crossbow from OLEKS
Fig.42. Crossbow from sa1982
Rice. 43. Crossbow from Frank
So, it’s time to touch on the last type of crossbow with a non-classical arrangement of shoulders - this is a crossbow that was released by the Swiss company Swiss Crossbow Makers - “Twinbow II” (Fig. 44). This crossbow is unusual not only in the location and operation of the shoulders, but also in its unique cocking device (Fig. 45). With compact dimensions (length 875 mm, width 420 mm) and a bowstring stroke of only 197 mm, it has very good power - with a tension of 180 kg, arrow speed of up to 113 m/s and energy of 145 J! When the bowstring is tensioned, the arms become almost parallel; both ends of each arm work through a roller system. As a result, the recoil when shooting from such a powerful crossbow is practically not felt.
Fig.44. Crossbow “Twinbow II”
Fig.45. Cocking the Twinbow II crossbow
There are several homemade crossbows, made according to the “Twinbow II” scheme. The gunsmith111 crossbow (Fig. 46) uses a twin system without a cocking lever. But on shushai crossbows the main feature of the Swiss is implemented - cocking with a lever (Fig. 47 and 4.
Rice. 46. Crossbow from gunsmith111
Rice. 47. Crossbow “Twilight” from shushai
Rice. 48. Crossbow “Cyclone” from shushai
PART 2
3. Triggers of modern crossbows.
As mentioned above, the trigger mechanism (lock) of a crossbow can be an integral part of the design of the guide (stock) or can be mounted in a separate housing. The latter are found much more often both among crossbow manufacturers and among home-made people, due to the ease of installation of ready-made trigger mechanism(SM) to any place.
With all the variety of modern crossbow triggers, locks can be divided into three main types:
a) with a lower hook (nut, cracker) (Fig. 49a);
b) with an upper hook (Fig. 49b).
c) with a fixed hook (pin lock) (Fig. 49c)
A) 
b)
Rice. 49. Triggers with lower (a) and upper (b) hook
Attention: when using materials from this article, a link to the site, as well as an indication of the author of the article MANDATORY!
In Europe, starting around the 11th century. and for 500 years the crossbow was an extremely widespread weapon. It (in the easel version) was used mainly to protect various objects, such as castles and ships. Hand crossbows were widely used in field battles. In addition, the crossbow played a significant role in understanding the properties of various materials (since during its manufacture it was necessary to take into account the action of many forces) and the laws of movement in the air (after all, the crossbow arrow had to have certain flight qualities). Leonardo da Vinci repeatedly turned to the study of the principles underlying crossbow shooting.
The craftsmen who made bows, crossbows and arrows did not know mathematics or the laws of mechanics. Nevertheless, tests of samples of old arrows carried out at Purdue University showed that these craftsmen managed to achieve high aerodynamic qualities.
At first glance, the crossbow does not seem complicated. Its arc, as a rule, was strengthened in front, across a wooden or metal machine - the stock. A special device held the bowstring stretched to the limit and released it. The direction of flight of a short crossbow arrow was set either by a groove cut into the top of the stock into which the arrow was placed, or by two stops that secured it in front and behind. If the arc was very elastic, then to tighten the bowstring, a special device was installed on the stock; sometimes it was removable and carried along with a crossbow.
The design of a crossbow has two advantages over a conventional bow. Firstly, on average, a crossbow shoots further, and the shooter armed with it in a duel with an archer remains out of reach of the enemy. Secondly, the design of the stock, sight and trigger greatly facilitated handling of the weapon; it did not require special training from the shooter. The hook teeth, which held and released the drawn string and arrow, are one of the earliest attempts to mechanize some of the functions of the human hand.
The only thing in which a crossbow was inferior to a bow was its speed of fire (not entirely true, there is one more parameter in which a bow is superior to a crossbow - price. A bow is much cheaper to produce, of course this applies to ordinary weapons). Therefore use it as military weapons It was possible only if there was a shield, behind which the warrior took cover while reloading. It is for this reason that the crossbow was mainly a common type
weapons of fortress garrisons, siege detachments and ship crews.
Classic medieval crossbow with composite bow from South Tyrol 1475.
The crossbow was invented long before it became widespread. There are two versions regarding the invention of this weapon. According to one, it is believed that the crossbow first appeared in Greece, according to another - in China. Around 400 BC. e. The Greeks invented a throwing machine (catapult) for throwing stones and arrows. Its appearance was explained by the desire to create a weapon more powerful than a bow. Initially, some catapults, similar in principle to a crossbow, apparently did not exceed it in size.
The version of the origin of the crossbow in China is supported by archaeological finds of bronze triggers dating back to 200 BC. e. Although evidence of the first appearance of the crossbow in Greece is earlier, written Chinese sources mention the use of this weapon in battles in 341 BC. e. According to other data, the reliability of which is more difficult to establish, the crossbow was known in China one century earlier.
Archaeological finds indicate that the crossbow was used in Europe throughout the entire period from the ancient era to the 11th-16th centuries, when it became most widespread. It can be assumed that its widespread use before the 11th century. There were two obstacles. One of them is that arming troops with crossbows was much more expensive than with bows. Another reason is the small number of castles in that period; Castles began to play a historically important role only after the conquest of England by the Normans (1066).
With the increasing role of castles, the crossbow became an indispensable weapon used in feudal feuds, which were not without violent battles. Fortifications in the pre-Norman period were usually very simple and served mainly as shelters for the people living nearby. Therefore, it was necessary to keep weapons behind the fortress walls to repel the attacks of the conquerors. The Normans exercised power in the conquered territories with the help of small, heavily armed military units. Castles served them to hide from the indigenous inhabitants and repel attacks by other armed groups. The firing range of the crossbow contributed to the reliable protection of these shelters.
Over the centuries after the appearance of the first crossbows, attempts were made repeatedly to improve these weapons. One of the methods may have been borrowed from the Arabs. Arabic hand bows belonged to the type called composite, or complex.
Their design fully corresponds to this name, since they were made from various materials. A composite bow has distinct advantages over a bow made from a single piece of wood, since the latter has limited elasticity due to the natural properties of the material. When an archer pulls the bowstring, the arc of the bow on the outer side (away from the archer) experiences tension, and on the inner side it experiences compression. If the tension is excessive, the wood fibers of the arc begin to deform and permanent “wrinkles” appear on its inner side. Usually the onion was kept in bent state, and exceeding a certain maximum tension could cause it to break.
In a compound bow outer surface The arch is attached to a material that can withstand greater tension than wood. This additional layer takes on the load and reduces the deformation of wood fibers. The most commonly used material was animal tendons, especially the ligamentum nuchae, a large elastic knot that runs along the spine and over the shoulders of most mammals. Tests have shown that such material, if properly processed, can withstand tension of up to 20 kg/sq. mm. This is about four times more than the most suitable tree can support.
For the inside of the bow, they used a material that works better in compression than wood. The Turks used bull horn for these purposes, the permissible compression force of which is about 13 kg/sq. mm. (Wood can withstand compressive loads four times less.) The unusually high awareness of archery craftsmen about the properties of various materials can also be judged by the kind of glues they used in the manufacture of bows. The glue made from the palate of the Volga sturgeon was considered the best. The variety of unusual materials used in archery suggests that many design solutions were achieved experimentally.
Italian crossbow from the 16th century, with a steel bow. Pull the bowstring into a firing position on such a “monster”
It was impossible to do it manually; special devices were used for this, which will be discussed below.
Crossbows with compound bows were common in the Middle Ages, including the Renaissance. They were lighter than crossbows with a steel bow, which began to be manufactured at the beginning of the 15th century; with the same bowstring tension, they shot further and were more reliable (there is most likely a mistranslation here: the steel arc was clearly more powerful than the composite one). The action of compound arcs interested Leonardo da Vinci. His manuscripts indicate that he used them to study the behavior of various materials under load.
The advent of the steel bow in the Middle Ages was the zenith in the development of crossbow design. In terms of its parameters, it could be second only to a crossbow made of fiberglass and other modern materials. Steel arcs had a flexibility that no organic material had previously been able to provide. The Victorian sportsman Ralph Payne-Gallwey, who wrote a treatise on the crossbow, tested a large military crossbow with a string tension of 550 kg, sending an 85 gram arrow to a distance of 420 m. E. Harmuth, an expert on the history of crossbows, claims that there were arcs with twice the tension. However, in the Middle Ages, the most common crossbows were those with a draw weight of less than 45 kg. Even with special lightweight arrows they shot no further than 275 m.
With the achievement of higher tensions, steel arches no longer benefit in efficiency. Increasing the mass of the arc limited its ability to impart greater acceleration to the arrow. Because of the difficulty of obtaining large-sized steel ingots, crossbow bows were typically fused from many pieces of metal. Each fusion point reduced the reliability of the crossbow: at any moment the arc in this place could break.
More powerful crossbows required reliable triggers. It should be noted that the trigger mechanisms used by the Europeans, which usually consisted of a rotating tooth and a simple lever release, were inferior to the Chinese ones, which had an intermediate lever that allowed the shot to be fired with a short and light pull on the trigger lever. At the beginning of the 16th century. in Germany, multi-lever triggers of a more advanced design began to be used. It is interesting that a little earlier Leonardo da Vinci came up with the same design of the trigger mechanism and proved its advantages by calculation.
Swiss crossbow with a composite bow. Around 1470. In the inset at the top left is a section of the arc of this crossbow. At the bottom there are horn plates, which turn out orange in the photo. The surface of the plates is covered with notches, thanks to which they fit perfectly together. It is not known what kind of glue was used to connect the horn parts, but in general the technology was very successful, since the crossbow was symmetrical, balanced and capable of withstanding heavy loads. The “back” of the crossbow arc is made of tendons, the outside of the horns was covered with parchment, birch bark or, as here, thick paper with a pattern.
The crossbow arrow also changed over time. Before tracing its evolution, let us consider the forces acting on a bow arrow. When shooting from a conventional bow, the arrow at the moment of aiming should be located between the center of the archer's chest and the fingers of his outstretched hand. The relative position of these two points determines the direction of flight of the arrow after the bowstring is released.
The forces acting on the arrow when it is released, however, do not exactly coincide with the line of sight. The released bowstring pushes the butt of the arrow towards the center of the bow rather than to the side. Therefore, in order for the arrow not to deviate from the given direction, it must bend slightly at the moment of launch.
The required arrow flexibility for a traditional bow places a limit on the amount of energy imparted to it. For example, it was found that an arrow designed for a bow with a tension of up to 9 kg, when shot from a crossbow with a tension of 38 kg, can bend so much that its shaft breaks.
In this regard, in the ancient era, when crossbows and catapults began to be used, arrows of a new design were invented. Due to the fact that the surface of the crossbow stock ensured that the direction of movement of the bowstring coincided with the initial direction of flight of the arrow, and a special guiding device made it possible to hold it in a certain position without using hands, it became possible to make crossbow arrows shorter and less elastic. This in turn made them easier to store and carry.
The design of arrows that appeared at that time can be judged by two main types that have survived to this day. One type of arrow is half the length of a regular bow arrow. It flares sharply towards the rear end and has several vanes, or fletchings, that are too small to stabilize the arrow in flight. The end part of the boom is captured by the hooking teeth.
Other types of arrows do not have blades. Their metal front is a third of their length, and the wooden shaft is reduced to a minimum. These arrows also have a shape that flares towards the tail. Their total length is less than 15 cm.
The design features of these arrows indicate that the craftsmen Ancient Rome, who first invented them, were familiar with the flight qualities of bodies of various shapes. Today we understand that the fletching, which prevents the arrow from rotating in flight, is the main reason for its braking. Reducing its size would increase the range of the arrow, provided that it does not turn to the side, which would further slow down its flight. This can be avoided by sharpening the shaft, that is, making it narrower at the front than at the back. If an arrow with such a shaft begins to turn to the side, then the air pressure on the wider back will be higher than the front one; Due to this, the direction of flight of the arrow is leveled.
It can also be assumed that the shaft has a center of pressure (the equilibrium point of all aerodynamic forces acting on it) located behind the center of gravity. On a cylindrical arrow without fletching, this point will be located approximately in the middle of the shaft. With an expanding boom, the center of pressure moves toward the rear. Since the center of pressure is located behind the center of gravity, the stability of an arrow with a flared shaft is higher than with a cylindrical one, and due to the absence of feathers, its drag is less.
The expanding shaft also contributes to a more uniform distribution of air mass pressure on its surface. Using the terminology of modern aerodynamics, we can say that the boundary layer is less susceptible to destruction. Reducing the length of the boom also improves its flight characteristics, since with increasing length the turbulence of the air flow parallel to the cylindrical surface increases, absorbing more energy.
ANOTHER factor that affects the effectiveness of flared shaft arrows is fletch design. To hold the bolt with the gripping teeth of the trigger mechanism, a special recess was made in its plumage. Like the flared shape of the shaft, the presence of a notch helps air flow more evenly around the arrow, reducing energy-absorbing turbulence behind it.
In the early Middle Ages, the craftsmen who made bows and crossbows were not familiar with the laws of air movement and the forces that arise on the surface of bodies when they move in the air. Concepts such as air flow and drag did not appear until the time of Leonardo da Vinci. There is no doubt that crossbow arrows were created mainly by trial and error. Probably, their creators were guided by the desire to achieve maximum flight range and greatest impact force.
Nevertheless, the design of crossbow arrows is perfect. Wind tunnel tests we conducted at the Purdue University Aerodynamics Laboratory confirm this. A regular arrow was tested for combat bow, which were used in the Middle Ages, a crossbow arrow belonging to the same period and two types of catapult arrows. The results obtained should be interpreted with some caution, since the sizes of the objects under study, especially the smallest ones, approached the sensitivity threshold of the measuring equipment. But even under these extreme experimental conditions, it was possible to obtain very interesting data. Firstly, the smallest arrow, which was completely preserved, except for minor damage to the tail, judging by the data obtained, stably maintained its position at all permissible flight angles.
Secondly, a comparative analysis of the drag-to-weight ratio for all four types of arrows showed that the bow arrow was significantly inferior in its flight qualities to the other three. The mass of an arrow can be thought of as a measure of its ability to store kinetic energy. If all these arrows were launched at the same speed, then the mass of each of them would determine the energy reserve of the arrow at the initial moment. The rate of energy consumption depends on the drag. A low drag-to-weight ratio means the arrow is likely to have a long range.
For bow arrows this ratio is approximately twice that of crossbow arrows. It can be assumed that if medieval and earlier craftsmen had managed to overcome design limitations in creating arrows for bows, they could have developed a more optimal design. The existing design of the arrow corresponded so well to the materials available at that time that its geometry was not improved during the period while the bow was considered the main weapon.
ALL THESE improvements were dictated by the urgent need for crossbows. Often in peacetime, garrisons were stationed on the territory of castles, consisting mainly of shooters armed with crossbows. At well-defended outposts, such as the English port of Calais (on the northern coast of France), there were 53 thousand crossbow arrows in reserve. The owners of these castles usually purchased arrows in large quantities - 10-20 thousand pieces each. It is estimated that over the 70 years from 1223 to 1293, one family in England produced 1 million crossbow arrows.
Based on these facts, we can say that mass production began long before the industrial revolution. This can be confirmed by the simple device used at that time from two fastened wooden blocks, forming something similar to a vice: an arrow blank was inserted into the recesses in the wooden blocks for subsequent processing. To make the tail blades, metal plates with grooves were used into which blanks were inserted. This device made it possible to obtain the required dimensions and symmetrical shape of the blades.
Another device was a planing machine, which was probably intended both for turning the arrow shaft and for cutting grooves into which the feather blades were inserted. Rods from wooden blanks of small diameter were not easy to produce on primitive lathes of that time, since the blanks were bent when processed with a cutting tool. In a planing machine, a metal cutting tool was fixed in a wooden block with two clamps on opposite sides.
The block moved along the clamping device, which firmly held the arrow blank. The cutting tool removed chips until the block reached the surface of the clamping device. In this way, automatic control of the thickness of the cut layer and cutting direction was achieved. As a result, the arrows were almost the same size.
The crossbow was replaced by a firearm. The popularity of the ancient crossbow began to decline. However, they continued to be used in naval battles. The reason was that the crossbow did not have a fuse, and it was safe for the shooter, unlike firearms, which at first often hit the shooter himself. In addition, the bulwark on the ship served as good cover, behind which one could safely reload a crossbow. Heavier crossbows continued to be used in whaling. Firearms gradually replaced the crossbow in hunting on land.
The exception was crossbows, which fired stones or bullets. This type of weapon was used in hunting small game until the 19th century. The fact that these crossbows, which fired shot or bullets, had much in common with firearms indicates the mutual influence of the two types of weapons in the process of their evolution. Such elements of firearms as the stock, the trigger, which requires a slight pressure, and the sighting device, were borrowed from crossbows, and primarily from sports ones. Such crossbows have not yet gone out of use.
Appearance in the 20th century. fiberglass materials led to the creation of a new generation of composite crossbows. Glass fibers are not inferior in properties to natural veins, and their cellular structure is as strong as a bull's horn. Although the crossbow still lags behind the bow in many ways in the revival of archery, it also has many adherents. A modern crossbow shooter has at his disposal a “weapon” that is much more advanced than what it was in the Middle Ages.
ENGLISH CROSSBOW. Its wooden stock shows the date of manufacture - 1617. The ivory plate with inlay indicates that this crossbow was a hunting one; a military crossbow would hardly have such artistic decoration. To tension the crossbow string, a force exceeding one hundred kilograms was required, so the crossbowman used a special mechanism with a gear drive. The crossbow stock has a socket that was probably intended for this mechanism. The bowstring is shown in a taut state. In this position, it was held by hooking teeth, which released it when the trigger, located at the bottom of the stock, was pressed. A short 30.5 cm long arrow fired from a crossbow flew a distance of about 400 m. The crossbow's arc was attached to the stock using a ring and a harness. The drawing was made from a crossbow from the collection of the US Military Academy Museum at West Point (New York).
THREE CROSSBALLETS are depicted in a painting by an Italian artist of the 15th century. Antonio del Pollaiolo "St. Sebastian". One shooter takes aim with a crossbow, the other two draw the string using a crossbow "stirrup", since tensioning the string required a lot of force. The painting is kept in the National Gallery in London.
FRENCH COMBAT CROSSBOW XIV century. and two arrows for it from the collection of the US Military Academy Museum at West Point (New York). It was impossible to tighten the bowstring of such a crossbow manually, so a collar was installed at the rear end of the machine, or stock. The stock has a length of 101 cm, the width of the crossbow arc is 107 cm, and the length of the arrows is approximately 38 cm.
A CROSSBOW consists of a curved bow, a bowstring, a hook tooth (to which the bowstring clung) and a trigger lever. When the lever was pressed, the tooth released the bowstring and the arrow flew out of the crossbow. The stop fixed the position of the tension mechanism, with the help of which the bowstring was retracted back. The design of the tension mechanism is one of the earliest examples of the use of gearing.
THE ARROW PARADOX partly explains why short arrows were used when shooting crossbows. The paradox is demonstrated for the case when the shooter uses an arrow from a conventional bow. When aiming (1), the arrow is positioned on one side of the bow. The sight line runs along the arrow. However, when the archer releases the arrow (2), the force exerted by the string causes the tail of the arrow to move towards the center of the bow. In order for the arrow to maintain its direction towards the target, it must bend in flight (3). During the first few meters of flight, the arrow vibrates, but eventually its position stabilizes (4). The need for flexibility in a bow arrow limits the amount of energy that can be imparted to it. In contrast, a crossbow arrow must be shorter and stiffer, since the crossbow imparts significant energy to it. Such arrows also had better aerodynamic properties.
TRIGGER MECHANISMS of crossbows had different designs. In China 2000 years ago, a mechanism (a) was used with a tooth to engage the bowstring, which was mounted on the same axis as the trigger. A curved intermediate lever connected both parts, due to which the release was carried out with a light and short press. The direction of movement of the bowstring during descent is shown on the right. In the West, trigger mechanisms were first used in catapults (b). In these mechanisms, when the bowstring was released, the tooth did not fall, but rose. In medieval Europe, the most common mechanism was the escapement wheel (c); its position was fixed by a simple release lever, which hooked into a recess at the bottom of the wheel. When such a lever was pressed, the crossbow could move from its aiming position. Over time, all designs of trigger mechanisms began to use an intermediate lever to facilitate the descent.
TYPES OF ARROWS for bows and crossbows: regular arrow for a combat longbow (a); an arrow used by the Romans (b) for a catapult, similar to a crossbow; a typical arrow for a medieval crossbow (c) and two varieties of arrows for a catapult of another smaller Roman type (d). Below the images of the arrows is their view from the tail and the view from the tip.
Wind tunnel test results for the five types of arrows shown in the top picture. The tests were carried out with the participation of the author of the article at the Aerospace Research Laboratory of Purdue University. In calculations performed by W. Hickam, it was assumed that the initial speed of each arrow was 80 m/s. Although longbow arrows were unlikely to have such a speed, the accepted value was convenient for comparative analysis.
The story about crossbows and crossbowmen would probably not be complete without a review of pavez - specific shields for crossbow shooters.
What is a paveza - PAVEZA (pavez, pavise, pavise, paveze) is a type of shield widely used by infantry in the 14th-16th centuries. The shield was rectangular in shape, the lower part could have an oval shape. The paveza was often equipped with a stop; sometimes spikes were made on the lower edge, which were stuck into the ground. Usually, a vertical protrusion (from the inside - a gutter) passed through the middle of the shield to strengthen the structure. The width of the pavese ranged from 40 to 70 cm, height - 1-1.5 m. The shield was made of light wood and covered with fabric or leather. Pavezes often painted emblems with heraldic or religious content.
One of the most famous paveuses is the pavese from the Cluny Museum (Paris). Mid 15th century, David and Goliath painted.
Pavesa of a Swiss crossbowman with the depiction of the coat of arms of the city of Bern - a bear.
Late 14th century. Kept in the historical museum of Bern.
Depending on the method of use, there were hand-held and standing paveses (the latter were often used by crossbowmen due to the long time it took to reload weapons during the siege of castles and cities). The hand paveses were quadrangular, often tapering downwards. They were used by both infantry and knightly cavalry. Pavezes were widely used by the Hussites during the Hussite Wars.
It is traditionally believed that the name of the shield comes from the Italian city of Pavia, where it was invented in the 13th century. It is also noted that the classic infantry version of the paveza took shape during the Hussite Wars.
Unusual Belgian (Flemish) pavese of the 15th century, with a loophole for firing in the center
shield and two spikes for driving into the ground, from the collection of the Brussels Historical Museum.
Later researchers came to the conclusion that the paveza could have entered Western Europe through the Baltic crusaders, who borrowed this type of shield from the local Baltic population. The lands of Rus' (XII century) or the Lithuanian-Mazovian region (XIII century) are called the place where paveza originated. At the turn of the 13th-14th centuries, the Pavezes spread to Mazovia, the lands under the rule of the Teutonic Order, Western Rus' and, probably, the rest of Poland. Belarusian archaeologist Nikolai Plavinsky notes that around the 14th century, the distribution area of the paveza covered the entire Baltic-Polish-Russian region
A lot of these shields have survived (oddly enough, much more than contemporary crossbows), so the review can be endless.
The strength and convenience of shields of this type quickly led to their widespread use by the knightly class and ordinary warriors (not crossbowmen) throughout Western Europe. Naturally, mostly in the manual version.
The age of the paveza ended with the spread of handguns.
Like many centuries ago, the design of the crossbow remains virtually unchanged
Compound Bow with separated shoulders
Fiberglass and aluminum are ideal materials for crossbow arrows and bolts. Often the bolts have a threaded insert on the front end of the shaft, which allows you to change the tip from a sporting one to a hunting one and vice versa. A hunting point is most often equipped with three or more steel blades
1.Castle
The lock secures the crossbow string in the cocked state. The principle of its operation is based in one form or another on a design invented by the ancient Chinese: when cocked, the bowstring snaps a “nut” onto a spring-loaded trigger. Subsequently, this design was continuously modernized, became more complex, and acquired adjustments, fuses, and additional parts to facilitate descent. Even an electronic trigger mechanism is not uncommon on expensive sports models.
Unlike a firearm trigger, in which a lot of force is not required to hold the “striker”, the parts of a crossbow lock bear all the power of its shoulders, so high-strength steel is most often used for their manufacture, and less often titanium or composite materials. Although some “craftsmen” try to make locks from aluminum, they do not last long and, as a rule, apart from injuries, they do not bring other joys to their owners.
2.Box
The stock is the basis of the crossbow. It is the design and materials of the stock that determine the convenience, comfort and appearance the entire crossbow. For a hunter, the stock will be light and flexible, for an athlete it will be long and heavy, with numerous adjustments, in the gift version it will be expensive and beautiful, with carvings and inlays, and for children it will be small and safe, pistol-type. The most suitable material is wood or glued veneer. Plastic is not welcome. But not any tree is suitable for creating a stock; it is best to use walnut, oak, mahogany, that is, strong and tough types of wood for these purposes.
3. Shoulders (arches)
The arms of a crossbow are the elastic elements of a bow that store the human mechanical energy produced during the draw for the subsequent shot. The shoulders are attached directly to the stock; on powerful crossbows - to the stock through a metal block (5). Crossbow bow designs are divided into traditional and compound bows.
In turn, the shoulders can be straight or curved (recursive), have a monolithic or separate design.
The traditional design is a regular bow as we understand it, the ends of which are tied with a string. In the block design, blocks (round or eccentric) are fixed at the ends of the arms, through which the bowstring is passed. Due to these blocks, the process of cocking a crossbow is significantly simplified, while the power of the shot remains the same.
The most common materials for the production of shoulders are reinforced fiberglass, carbon fiber reinforced plastic, and duralumin. Previously, when materials were tight, old springs from Moskvich were used as a blank for the bow. Not only was such a crossbow incredibly heavy and massive, it was dangerous, since the steel tended to burst at the most inopportune moment, scattering sharp fragments into different sides. Therefore, subsequently they began to put a protective bandage on such bows, and then they completely abandoned this material.
4. Stirrup
The crossbow stirrup is designed to facilitate the cocking process. The stirrup can be loop-shaped or T-shaped. In both cases, the shooter’s legs hold the crossbow by the stirrup while the string is tensioned.
5. Block
The block is the second most important component of a crossbow after the lock. This element plays a connecting role between the shoulders and the rest of the crossbow structure. It is the block that bears the entire load of the arcs in their pure form. It is the block that must withstand enormous loads during a shot. It is on the block that all the energy of the so-called “reverse recoil” occurs, when the arrow has already flown out, and the shoulders continue to straighten further at enormous speed. That's why so much attention is paid to the block. Typically, high-strength steel is used for the block; on expensive crossbows, titanium is used. Although I sometimes met crazy would-be designers who put an aluminum profile block on their 80-kilogram crossbows. And then they wondered why, after a dozen shots, she was turning inside out.
6. Bowstring
The string of modern crossbows is a thread folded several times, followed by braiding of the rubbing parts. The best choice for a bowstring is a strong and low-stretch thread, such as Dacron, Dacron, aramid thread (commonly known as Kevlar) or a foreign analogue of Fast-Fligh. On powerful crossbows, as well as on the auxiliary bowstrings of compound crossbows, a steel cable is used.
7. Guide
The crossbow's guide, as the name suggests, is designed to hold the arrow and guide it towards the target. In medieval crossbows, the groove was made either directly in the stock, or in the form of a bone plate with a groove. On the simplest modern crossbows, a plastic guide is glued directly on top of the stock. On more “advanced” ones, the guide plate is made of a material that has sufficient anti-friction properties so that the arrow moves along it easily and evenly, and the bowstring wears out as slowly as possible. In systems with high tension forces, it is even recommended to use oil to lubricate the guide. Such a guide is fixedly attached to the body of the crossbow, or two guide plates are used, located at some distance from each other. As for the distance between the guides (groove), its dimensions depend on the diameter of the arrows used, as well as the height of the tail. As a rule, the width of the groove (with chamfers removed) should be such that the axis of the arrow intersects the center of the bowstring, which in turn should lie (without vertical force) on the upper surface of the stock and move parallel to it when fired.
8. Sighting device
Due to the steep trajectory of the arrow, the installation and design of crossbow sights has its own characteristics. The sights used are divided into three categories: open, diopter and optical.
Below we will look at each of them separately, along with the design features in more detail.
Open. This design is a development of the idea of a bow sight. The fixed rear sight is complemented by a console mounted next to the bow, on which a set (three to five pieces) of horizontal front sights (each can be adjusted horizontally and vertically) for different shooting distances (the so-called “comb”) is attached. When aiming, the shooter selects the desired height of the front sight depending on the shooting distance.
Dioptric. Basically, these sights are installed on sports crossbows and are identical in design to sights for bullet sports. All the differences are only in the front sight: it has wide range adjustments and can be equipped with a leveling level to control the “blockage” of the weapon. In addition, it is usually possible to tilt the diopter itself and its front sight in order to eliminate the ellipse of the front sight if they do not match in height. On the other hand, there is a tendency to move away from the firearms ideology of aiming. Nowadays they prefer to carry out all micrometric adjustments on the front sight, while the diopter itself remains stationary.
Optical. Existing designs for bullet weapons are quite suitable for installation on crossbows. You just need to remember that the mount has a bevel towards the target of about one or two degrees.
The material was prepared with the assistance of the Interloper crossbow center
