LEGION XXIV BALLISTA PAGE
GREEK "PALINTONE" TORSION-POWERED STONE THROWING SIEGE BALLISTA
Updated December 27, 2009
A Greek "Palintone" type Ballista Catapult Engine being prepared for firing during PENNSIC WAR XXIX, near New Castle, PA. Darius Architectus (Kurt A. Suleski), the crew commander and builder of this engine, as well as the smaller Legion XXIV machine, stands at left surveying the "field of fire"; as Gaius Licinius Marcellus (Daniel Collins - center) and Gallio Velius Marsallas (George Metz) operate the winch levers that will "cock" the weapon for discharge. This machine is a meticulously researched, museum quality recreation of a medium size Greek Ballista Siege Catapult and is capable of throwing a three pound concrete ball more than 200 yards! The balls are visible at the base of the machine. The term "Palintone" (stretched-back) refers to the skeins and vertical stanchions being staggered within the head-frame of the machine. This permits the arms to travel in a greater arc than in a "Euthytone" (stretched-straight) type of weapon, where the skeins and stanchions are in a straight line side to side within the head-frame. See our Catapulta Page for the Legion's "Euthytone" style Engine of Terror.
More information is available from the builder, Kurt Suleski (Darius Architectus) at
Knight's Armoury firstname.lastname@example.org
Note how the staggered stanchions of the Palintone head-frame allows for a greater angle of arm pull-back from the "at rest" position and then more distance of forward travel when discharged. The Euthytone arrangement is generally found on the smaller arrow/bolt shooting "Scorpion" catapulta "shield-piercer" machines. Also note that the heals of the arms impact upon the inner stanchions when discharged and remain there when "at-rest" and do not contact the outer stanchions at any time. The outer stanchions are generally notched on the rear edges to allow clearance for the arms to travel a little further upon discharge. Diagram by George Metz - Legion XXIV
The original concept and design for this type of catapult came from the Greeks. This machine is similar to the ballista siege engines later used by the Romans. The Roman engines differed from the Greek machines in having a ratchet wheel and pawl at the capstan winch (carchesium) instead of the long toothed racks on the sides of the ladder beam (scapus climacidos). Also, some of the structural members comprising the torsion head on the Roman engines had a different appearance. The weapon is powered by two horizontal cross-bow like arms, which are inserted into two vertical and tightly wound "skein" springs of braided nylon rope contained in the rectangular frame structure. The Romans used skein springs made from gut or hemp. This replica originally employed gut/hemp skeins; but after some difficulties, braided nylon was substituted. There is no record of the Romans having used metal springs in their torsion powered catapulta.
The smallest stone-throwing torsion "Palitones" ballista engine mentioned by the Greeks threw a stone weighing 10 minae, equal to 9.6 pounds. Such a machine would have been about 16 feet long overall. Practical size limitations for portability dictated that Kurt Suleski's machine be constructed as a 3/4 size replica about 12 feet long. It is not a toy! . . . But, a powerful weapon requiring skill and prudent care to be operated safely.
The term catapult comes from the Greek word "Katapeltes" "shield piecer" (kata = through, pelta = small shield"). A Roman Legion probably employed 10 of the larger stone throwing "Ballista" engines, as above, one for each Cohort, while one smaller "Catapulta" arrow bolt shooter would be assigned to each of the Legion's 59 Centuries. One Contubernium (squad of eight men) of each Century would be assigned responsibility for the emplacement and maintenance of the catapulta engine. The so-called "Scorpion" catapulta was a smaller two-man portable torsion-powered arrow shooter. It is believed that Auxiliary units did not have catapultae assigned to them.
Interpretation of a large siege ballista from the book "Weapons" by Edwin Tunis, 1954.
The Ballista-Catapulta was powered by two horizontal cross-bow like arms, which were inserted into two vertical and tightly wound "skein" springs composed of leather or sinew or hemp or combination of these materials contained in a rectangular frame structure making up the head or principle part of the weapon. The arms were drawn rearward to further twist the skeins and thus gain the torsion power to cast a projectile. There is no evidence that the Romans ever used metal springs in their torsion powered weapons.
Ballistae were rather high-maintenance devices and were vulnerable to having their leather or sinew or hemp skeins get wet or even damp, which would cause them to slacken and lose tension, rendering the engine useless. Also, these machines required a skilled crew to tighten the skeins and keep the weapon adjusted and ready for deployment. This was difficult enough in peaceful conditions, not to mention during the heat of battle, so the death or injury of a critical crew member could compromise the effectiveness of the weapon.
Catapulta Ready for Discharge with the legionary in cold weather clothing and, at Right, Catapulta / Ballista trigger detail showing cocking pawl, both from "Weapons" by Edwin Tunis, 1954.
Isometric plans from "Build Your Own Greek Seige Engine" by Kurt Suleski
On the left, is a rear isometric view showing the ballista ready for discharge. The launching slide, carrying the trigger release, has been drawn back by the windless. This action has also drawn back the torsion arms, twisting them to the rear, against the resistance of the skeins, thus creating the power to launch the projectile.
On the right, is a close-up isometric view showing the projectile ball in firing position, just in front of the trigger release. This view looks forward along the launching trough that the projectile will follow much like a rifle barrel.
Detail photos of the Palitone Ballista. A close-up of the trigger mechanism is at lower right, showing a three pound ball in the launching sling. The trigger pawl is engaging the sling loop. The trigger is released by yanking the horizontal bar out from under the tail of the trigger pawl. To the left of the trigger is one of two "cocking" pawls; which engages the ratchet bars on either side of the ladder beam; which comprises the "tail" of the machine. The weapon is aimed by lifting the ladder beam and visually pointing it toward the target area.
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