One year ago today I posted the first project on Ropes and Poles- a small trebuchet (you can get the SketchUp model here).
This week I received photographs of two trebuchets built by Scout troops. The first is built by 9th Irene Scout troop from Pretoria. This trebuchet has a throwing arm around 10m long, and a counterweight (made from barrels filled with water) of about 50kg. It throws projectiles 60m and was built at Cornwall Hill College's Carnival. You can see more photos and some videos at the Troop website.
The second trebuchet is from Montevideo in Uruguay. The 45th Scout Group 'Juan de Cordoba' won the 'Bauen' pioneering competition with this 3m trebuchet that throws a basketball 120m (that's more than the length of a football field). There are some photos of the construction here,they are worth taking a look at- this trebuchet won the 'best trebuchet' prize and also had the best distance and won a 'best technique' award (apparently this design is based on the 3m trebuchet I posted here- if so it is a great improvement, the best we managed is around 30 metres)
Many people who visit Ropes and Poles have searched for 'trebuchet sling' and the best way I can recommend to understand how a sling works is to watch a trebuchet in action- like this video from 'Juan de Cordoba' Troop's trebuchet:
William Gurstelle was also written a a good book on catapults, trebuchets and other siege weapons)