The first Trebuchet type machines were developed by the Chinese in 500 BC. These machines underwent considerable improvements over the centuries and it was only in the 13th Century that the Trebuchet on display at Warwick castle was perfected.
It is basically a giant catapult which fired extremely heavy objects at or over castle walls. At first their use was restricted to breaking the walls of fortresses and castles. Once the walls were breached, soldiers could gain entry and attack the occupants. But some armies used the Trebuchet for much more sinister purposes! Pigs or horses which had died a week or two before were often catapulted over the castle walls. The carcass would then plummet to the ground and splatter walls and people with rotting flesh. Aside from the revulsion this caused to the occupants, the rotting flesh would quickly spread disease.
This particular use of the Trebuchet would be reserved for the latter part of a siege when water was scarce. Without water the occupants could not clean off the rotting flesh. Lack of water in a siege also increased the effectiveness of catapulting burning tar balls into the interior of a castle. Without water to put out the fires, a
castle interior made largely from wood quickly burnt to the ground.
The Trebuchet at Warwick Castle is constructed mainly of oak wood which has immense strength. The arm however is made of ash which is not as strong but has the ability to bend slightly under tension. This bending increases the catapult effect significantly when the Trebuchet is fired.
The fire rate of a Trebuchet of this type is about one shot every 15 minutes. At a typical siege (if ever there was such a thing!) there would be around 10
to 20 Trebuchets and between them, they would be firing maybe three different types of objects.