Elenco Catapult - Manual (Page 11)

9
Springald on a Swivel Mounting
Bowed Springald
Double Onager
Da Vinci’s drawing of an existing device, the framed torsion
weapon, is called a Springald. The inward-facing bow arms
are clearly drawn, as are the torsion bundles that power the
device. This machine is a bolt thrower, and the tip of the bolt
can be seen projecting forward of the frame at the right.
Leonardo has modified the arms and bundles to show two modest bundles holding a
square structure connected to four arms in a cross. Da Vinci may have determined
that four arms would allow more tension to be applied to the bundles.
Da Vinci explored the idea of making a new version of an
existing torsion-powered device by mounting the twisted rope
bundles on bow-like springs. This machine appears to be an
attempt to take the Springald concept of the frame-mounted
torsion weapon with inward-facing arms, and adapt it to use
powerful springs to create the same motion. In this rendition, the projectile is a ball
(perhaps a gunpowder grenade, perhaps a stone) and it rests on a narrow track on the
top of the frame.
This machine is similar to the bowed Springald, but here Da Vinci takes the concept
even further, making the bows larger and using their tips rather than the middle of each
bow. He also modified the fitting the system with two throwing arms rather than a
bowstring. One arm is fitted with a sling, the other appears to have a rock set on a flat
rest rather than a sling. As with the other double-projectile machines, the hurled objects
can be expected to have quite different ranges, with the one in the sling going significantly
further.
Springald on a Swivel Mounting
Bowed Springald