POLYBOLOS – Innovative Catapult of Dionysius
Catapults have been integral to siege warfare since antiquity. Though Ancient Catapults were one of the most effective weapons in siege warfare. Various types of Catapults have been used by the Greeks, Romans, and Chinese. The first catapults were early attempts to increase the range and power of a crossbow.
Polybolos was an ancient Greek repeating ballista reputedly invented by Dionysius of Alexandria, a 3rd-century BC Greek engineer at the Rhodes arsenal, and used in antiquity. Philo of Byzantium encountered and described the polybolos, a catapult that like a modern machine gun could fire again and again without a need to reload. Philo left a detailed description of the gears that powered its chain drive, the oldest known application of such a mechanism, and that placed bolt after bolt into its firing slot.
As an aside, Dionysius financed his weapons program by selling Motya’s 15,000 people into slavery. The effect of catapult technology on old ways of thinking was seen when a newfangled catapult brought over from Sicily was demonstrated for Archidamos III, King of Sparta. It is said that he lamented, “O Hercules, man’s courage is of no use anymore!” More powerful catapults were coming, and they would cause even greater wailing. The composite bow, which the Greeks adopted from the Scythian horse archers of the Ukrainian steppes, was complex and costly, laminated from layers of hardwood, horn, and animal tendon, then wrapped in leather and bound together by exotic adhesives that required long curing times. Reportedly, the best glue was made from the skin of the roof the mouth of the Volga River sturgeon. But when such a bow eventually snapped under tension, it couldn’t be repaired in the field. Clearly, something cheaper, more durable, and “soldier-proof” was needed to store energy and release it suddenly.
The polybolos was used mainly against enemy personnel, rather than against defensive structures such as walls or towers. One of the reasons contributing to this is the fact that the polybolos was able to lock on to a target. This, however, may also be a disadvantage of the weapon. An ancient writer is recorded to have complained that the polybolos was too accurate. The lack of dispersion in the shot pattern meant that using this piece of equipment to kill human units was an overkill.
A 19th-century reconstruction of a polybolos by a German engineer by the name of Erwin Schramm, for example, was reported to have been so accurate that the second bolt fired from the weapon was able to hit its target, and in the process, split the first bolt.
There is much about Greek catapults that we do not know, and may never reconstruct. The surviving evidence is limited to a handful of Byzantine copies of ancient manuscripts, some crude representations on pieces of sculpture, and a few corroded metal parts excavated by archaeologists. Today, most of what we know has been painstakingly reconstructed by classical scholars, engineers, hobbyists, legionary re-enactors, and enthusiasts who love to hurl heavy objects long distances with great force.