Medieval Crossbow Spanning Devices - Hook spanning belt, Windlass and Cranequin

During the Middle Ages, the crossbow was one of the most effective long-range weapons before it was gradually superseded by firearms in the course of the 15th century. It was subject to constant development over a period of several centuries. The aim was to increase the power of the weapon in order to increase the effectiveness of the projectiles used. The use of stronger bows, however, required the use of mechanical tools, the spanning devices. In the first half of the 13th century, the development of the crossbow had progressed so far that an iron stirrup attached to the bow allowed the full use of the arm muscles for the spanning process. Until then, the shooter had to fix the bow with both legs to the left and right of the crossbow stock and pull the bowstring towards the body with his arms. While it was sufficient to draw the bow with bare hands in this primitive crossbow, a draw force of 80 to 100 kilograms applied by using both arms was soon insufficient for stronger bows. Especially when the wooden bow used until then was joined by the far more powerful horn bow, composed of horn plates and sinews. With the spanning belt, which also emerged in the first half of the 13th century, it was possible to use the stronger leg muscles for drawing instead of the arm muscles. A spanning belt is made up of two parts. It consists of a fixed waist belt that holds a short strap that is usually adjustable in height. For the spanning process, the crossbow is placed vertically with its top facing the shooter. The spanning hook grips the bowstring. The shooter places the crossbow on the ground and fixes the stirrup with his foot. Now the string is pulled back until the two fingers of the nut are reached to lock the bowstring in place. From the second half of the 14th century, a hook pulley based on the pulley block principle doubled the draw force applied by the shooter. Rope and belt pulley systems came into use. In contrast to the simple spanning belt, one end of the strap is fixed directly to the crossbow stock while its other end is held by the belt. The length of the strap can be varied by means of an adjusting iron. For the spanning process, the shooter fixes the crossbow to the ground via the stirrup, kneels down and straightens up until the string reaches the nut fingers. In the Belifortis Manuscript of Conrad Kaiser, written around 1400, there is an illustration of an early windlass, which was later common especially in Western Europe. While this still had simple spanning hooks, these were subsequently fitted with pulleys and the pulley block principle was applied. For the spanning process, the windlass is attached to the rear end of the stock, the spanning ropes are unwound and the bowstring is hooked in. Then the ropes are wound up until the bowstring gets grabbed by the nut. Now the ropes are relieved and the windlass is pulled off the stock. In the first decades of the 15th century, probably the most powerful variant of spanning devices appeared, the rack or kranikin. A crankcase runs on a toothed bar, in which there are three gear wheels of different sizes. A crank drives one of the gear wheels and thus sets the rack in motion. With this ingenious system, transmission ratios of 1 to 100 and above can be realized here. For the spanning process, the kranikin is pushed onto the stock from behind. After the hooks on the rack have gripped the string of the bow, the crank is operated until the string engages in the nut. The kranikin is then released and removed from the stock. Large wooden windlasses are among the stationary spanning devices. Their first appearance probably dates back to the 13th century. For spanning, the crossbow is placed on the wooden block and fixed in the center of the bow. A hook attached to a leather strap grips the bowstring. The strap can be wound onto the shaft via two turnstiles and thus pulls the bowstring backwards. The dimensions of this windlasses allow not only hand crossbows, but also much larger and more powerful crossbows to be spanned. In a direct comparison, the time it takes for the respective ranking. First, hook spanning belt. Second, belt and pulley system. Third, pulley windlass. And fourth, kranikin. Hook spanning belts, belt and pulley systems and kranikins, which were common in the Holy Roman Empire are able to span crossbows with draw weights between 100 to about 1000 kilograms. The higher the draw weight, the longer the spanning process takes, thus reducing the shewing cadence.