Siege engines must use Period principles of operation such as
rope torsion bundles, counterweights, flexing arms, etc. Period
appearance is not an absolute necessity, although (at the whim
of the Siege Marshal, judge, whatever) it may be considered for
the purpose of breaking a tie or some such reason.
They may not employ tension or compression devices (such as bungie
cords, elastic bands, coil springs) nor compressed or explosive
gasses for their power source.
It is permitted to use some modern equivalents of period materials
and parts, such as woodscrews (vs. pegs), pop-rivets, rubber pads,
modern glues, nylon, aluminum, fibreglass (vs. horn), and plastic.
The maximum size for engines shall be 18 inches in height, width,
and length while in the cocked state, not including any trigger
lanyard that allows the operator to fire it from a distance. "Length"
is defined as the dimension parallel to the flight path of the
ammunition, so you may not tilt or turn the engine at an angle
to fit inside the imaginary box and thereby gain extra length.
Once the trigger is operated, part(s) of the engine (eg. throwing
arm, sling) may move beyond the 18" size limit, but shall
not actually detach and leave the engine.
Due to the small scale of the engines they may be cocked by hand
(although a working winch or windlass would contribute to the
period appearance), but must be fired using a trigger lanyard
while the operator stands to one side of the engine.
The operator may not touch the engine (excepting the trigger lanyard)
to fire it. The trigger lanyard itself may not be the means of
powering the engine, ie. the operator may not be the "energy
storage system", such as used in traction engines.
More than one engine may be submitted, provided they are of different
types (eg. ballista vs. trebuchet, or onager).
This is primarily a test of accuracy. The target(s) will be something
along the lines of a large panel tilted at an angle, with circular
target zones plus a few high-value spot target zones. The target
may be anywhere from 10 to 30 feet away from the engines - we're
not sure, it depends on the overall performance level of the engines
entered. You will be allowed five attempts for a given distance,
with the opportunity to make adjustments between shots. The exact
scoring system will be announced at the event.|
The engine may be placed on a table or on the floor. Again, due
to the small scale and mass of the engines, the operator may use
tape to anchor the engine to the floor or tabletop and prevent
it from sliding around during firing. Any tape used shall be included
in the size limit.
The ceiling is believed to be about 15 feet high. The ammunition
will be a medium-density irregularly-shaped object with a mass
of 20 grams. It is approximately 2" by 1.5" by 1",
but may be manipulated and tied to form a more spherical shape.
Siege Engines
A very good site on (mostly) ballistas, by Darius Architectus.
http://www.stormthewalls.dhs.org/Siege/siege.htm
and
http://198.144.2.125/Siege/Blueprints.htm
Ripcord's Trebuchet Stuff
an excellent collection of references and tutorials about trebuchets,
particularly on designing, building, and tuning small-scale models
on a budget.
http://www.ripcord.ws/
Ron Toms "How to Build a Catapult"
the links page on Ron's site. -
http://www.trebuchet.com/plans.html
Overview of siege engines
http://www.catapults.info/
Ron Toms's kits:
http://www.catapultkits.com/
Larger than permitted for the competition, but do inspect the
photos for some construction ideas. (Note: Do not use a design
similar to what he calls the "Scorpion" models - they
use bungie cords. The object that he calls a "Petraria",
while it is merely a fantasy of post-Period artists, does qualify
because it uses technology that
was possible in Period)
SiegeEngine.com
the home of Team Tormentum. Check out the "Engines of War"
section for photos of their engines, and the "Engineering"
section for photos and tips on building specific parts, such as
a torsion bundle for an onager.
http://www.siege-engine.com/
"Dictionairy [sic] of Siege Engines"
Many useful terms and names of different types of siege engines
and their components.
http://members.lycos.nl/onager/dictionairy.html
E mail me: hew *at* northernelectric.ca
"Cum catapultae proscribeantur tum soli proscripti catapultas
habeant."
