Catapults
are siege engines using an arm to hurl a projectile a great
distance. Any machine that hurls an object can be considered
a catapult, but the term is generally understood to mean medieval
siege weapons.
The
name is derived from the Greek ?ata (against) and ßa??e??
(to hurl (a missile)). Originally, "catapult" referred
to a stone-thrower, while "ballista" referred to
a dart-thrower, but the two terms swapped meaning sometime
in the fourth century AD.
 Catapults
were usually assembled at the site of a siege, and an army
carried few or no pieces of it with them because wood was
easily available on site. Catapults can be classified according
to the physical concept used to store and release the energy
required to propel the projectile.
Types
Catapults can be classified according to the physical concept
used to store and release the energy required to propel the
projectile.
Catapult
 The
first catapult distinct from hand-held launchers (bows, crossbows,
slings etc.) was the Greek gastrophetes, a crossbow so large
it was braced against the abdomen rather than being held in
the hand, hence the nickname belly-bow. The next step from
this was a larger form a crossbow mounted on a stand, including
early versions of the oxybeles (Greek for bolt shooter) and
the ballista (the Roman version of the oxybeles). The arbalette
à tour was a medieval version of the stand-mounted
crossbow. These catapults are tensional, in that the energy
is stored as tension and compression of the bow. Although
similar to a crossbow, a sling on the end of the rope meant
these weapons could be used for firing all sorts of projectiles,
from rocks to pots of Greek fire.
Subsequently,
torsional catapults were developed; those with two torsion
powered arms, the later versions of the ballista and oxybeles,
and those with one torsion powered arm, the onager, known
in medieval times as the mangonel. The bottom end of the throwing
arm of the onager and the inner ends of both ballista arms
are inserted into rope or fibers that are twisted, providing
a torsional store of energy.
 Torsional
ballistas were operationally equivalent to their tensional
cousins, except the torsional energy store gave greater power.
Onagers have an arm with a bucket, cup, or most often a sling
to hold the projectile at one end.
Finally,
the last type of catapult is a trebuchet, which used gravity
or traction rather than tension or torsion to propel the throwing
arm. A falling counterweight, or the effort of the one or
more operators, pull down the bottom end of the arm and the
projectile is thrown from a sling attached to a rope hanging
from the top end of the arm, essentially like a sling attached
to a giant see-saw. The counterweight was usually much heavier
than the projectile. More modern trebuchets often replace
the counterweight with industrial springs to create tension.
History
French troops using a catapult to throw hand grenades during
World War I.
Improvised catapult made out of leaf spring during the Warsaw
Uprising for launching of Molotov cocktails.In Europe, the
first catapults appeared in later Greek times around 400 BC-300
BC [citations needed]. According to Roman engineer Heron of
Alexandria, the first types derived from by the earlier gastraphetes
("Belly shooter"), constisting in camposite bow
mounted trasversely on a stock. Biton attributes the creation
of the first crewed catapult to one Zopyrus from Taranto,
in soutern Italy.
Early
adopters of the catapult design were Dionysius of Syracuse
(who called it katapeltikon) and Onomarchus of Phocis. Katapaltai
are mentioned in the Siegecraft (Poliorketika) treatise of
Aeneas Tacticus, from around 350 BC. It is probable that standard
torsion-powered catapults entered in common use in Greek world
and Macedon only around 330 BC. Alexander the Great introduced
the idea of using them to provide cover on the battlefield
in addition to using them during sieges. Projectiles included
both arrows and (later) stones.
Romans
started to use catapults probably as booty from their wars
against Syracuse, Macedon, Sparta and Aetolia (3rd-2nd century
BC). Standard use of artillery (ballista and onager) is attested
only from the time of Julius Casear, however.
In the
Medieval times, when the trebuchet was introduced a relatively
short time before the advent of gunpowder, the catapult became
basically obsolete. Cannons soon replaced catapults as the
standard siege weapon in Europe in the 14th century.
During
medieval times, catapults and related siege machines were
the first weapons used for biological warfare. The carcasses
of diseased animals and those who had perished from the Black
Death or other diseases were loaded onto the catapult and
then thrown over the castle's walls to infect those barricaded
inside. There have even been recorded instances of beehives
being catapulted over castle walls.
The last
large-scale military use of catapults was during the trench
warfare of World War I. During the early stages of the war,
catapults were used to throw hand grenades across no man's
land into enemy trenches.
At the
present, in England, trebuchets are sometimes used by thrill-seekers
as human catapults to experience being catapulted through
the air. There has been at least one fatality, when the participant
failed to land onto the safety net.
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