Trebuchet
From DT Online
Introduction
Medieval weaponry included a large number of Catapults such as the Mangonel, Onager, the Ballista, and the Trebuchet which was brought over to Europe in the 4th century AD.
The Trebuchet was a large machine, about 30m high consisting of a long beam attached by an axle suspended high above the ground by a strong frame and base.
The long beam was Winched down and the Sling loaded with a large stone typically, but could be almost anything. When released, the Counterweight would cause the arm quickly to swing upwards and the long Sling also to rotate and release the load at the end of the movement. This combined motion would impart considerable speed on to the Sling and an average load of 50-100kg could be hurled 300m or more - (see the DT Online article on Velocity Ratio)
Two types of Trebuchet were used. Counterweight Trebuchets had either a weight fixed to the short arm of the beam or a Traction Trebuchet had weights loaded into a basket hanging from it and, in addition, troops would pull it down with ropes to assist and/or control the release.
They were used mainly to throw stones, fire pots and even rotting corpses over the fortifications to cause destruction and create chaos inside the walls.
Stripwood Model Trebuchet
Model Trebuchet can be made using Stripwood Technology techniques with card and 8mm x 8mm square timber. Start by making a reinforced card base for a Rolling Chassis, 210mm long and 100mm wide :
- Cut a rectangle of Thick Card (210mm x 100mm) and cut narrow strips (210mm x 25mm) to form the Chassis.
- Hold strips of timber in a small Clamp-on Vice and cut to length of 210mm using a Junior Hacksaw - these will be used to stiffen the Chassis.
- If the Trebuchet is to be put on a wheeled chassis, clothes pegs can be used as wheel bearings (see the DT Online article Rolling Chassis for other ways to make the Trebuchet mobile).
- Reinforce two card plates, 150mm x 50mm, and pivot them together with a third plate 75mm x 30mm using dowel and PVC tube spacers as shown.
- Mount the assembled plates to the centre of the card Chassis with the 210mm lengths of Stripwood to form the main hinged support for the throwing arm.
Safety Point! Use a Cutting Mat and a metal Safety Ruler when using a knife to cut card
- Cut a piece of Stripwood about 300mm long to make the throwing arm and fix a paper clip to one end - either tape or bind with cotton and glue.
- Ensure half the paper clip is over-hanging the end of the throwing arm so that it can be bent to an angle which releases the Sling.
- Make the Sling from a strip of cloth and use cotton or twine to tie one end to the throwing arm and the other to a keyring which is hooked over the paper clip.
- A Fixed Counterweight can be added to a model Trebuchet by sliding over the front end of the throwing arm a 50mm length of 50mm diameter card tube and packing it with Plasticine.
- Similary, a Hanging Counterweight can be added by pivoting the Plasticine filled card tube on the end of the throwing arm (e.g. thread a short length of Dowel through holes punched near the top of the tube and into card triangles glued to the end of the throwing arm as shown - use short pieces of PVC tubing to hold everything in place).
- It may be necessary to angle the sides of the card tube to allow it to swing freely.
Safety Point! Use table tennis balls, squash balls or wooden beads as ammunition for example - NEVER use anything sharp or heavy
Model Trebuchets compared with an Onager
Activity: Find out about Roman Siege Equipment (e.g. Vinea, Pluteus, Mantelet, Testudo, Musculus, Helepolis, Turris, Corvus, Ballista, Onager, Mangonel, Trebuchet, Aries (Battering Ram) and construct a working model or models using Stripwood Technology.
Safety Point! Take great care with hot glue guns and all hot-melt glues. The melted glue can stick to the skin and cause severe burns.
