Full-scale trebuchet

Design improvements and material suitability

The replacement trebuchet has the same dimensions as the original – at 18 metres tall, made from over 300 pieces of oak and weighing 22 tonnes it’s a huge structure that required careful premanufacture by our specialist team.

Senior frame designer Paul Slemmings modelled the design for the replacement trebuchet from the 2005 2D drawings to create 3D frame drawings. Some changes were made to improve it operationally, such as helping to reduce rope snagging, changing some metalwork to make it more resistant to corrosion and adding grip trips to improve safety, but nothing which affected the structure.

To ensure the new trebuchet will withstand a daily launch for many years requires specific materials to be used for different elements of it. The base and A-frame are made from green oak which we know to be strong and durable. The laminated rims of the treadwheels are made from air dried oak as this moves less than green oak and therefore maintains the geometry of the wheel as it ages. The throwing arm is made from ash which is more flexible than oak. The arm is fired twice a day, 364 days a year, so it has to take a lot of flex without snapping. Ash is however much less resilient than oak so needs to be replaced 3 or 4 times over the lifespan of the rest of the trebuchet.

Assembling the trebuchet

Our team of carpenters hand manufactured these different components at our workshop in Devon, pre-assembling them and checking their alignment and fit, before disassembling them, ready for transportation. The original trebuchet was also carefully dismantled from its riverbank location below the Castle by some of our team.

Taking a 180-mile journey by lorry up to Warwick, the trebuchet was fully assembled on the Castle’s river island over a number of weeks by our skilled team of carpenters. With our part in the project complete, Warwick Castle’s team started their testing in preparation for a new live show for visitors to the popular family attraction.

The trebuchet continues to claim the title of being the world’s largest working trebuchet. Carpenter Oak’s expertise in this specialist field of timber engineering is unrivalled and we’ve worked on some incredible projects, including for film and television.

Watch a timelapse of this amazing build!