BM TRADA gets medieval at Warwick Castle

BM TRADA IS PROVING that no job is too big – or too historic – with its annual safety inspection of the world’s largest wooden trebuchet.

Based on drawings from the 13th century, the timber trebuchet at historic Warwick Castle stands 18 metres high and weighs a massive 22 tonnes.
Positioned in a stunning riverside location below the south front of the castle, the trebuchet propels projectiles 25 metres into the air and sends them hurtling up to 300 metres.

The design for the castle’s machine comes from Dr Peter Vemming from The Mediaeval Centre in Nykobing, Denmark. Dr Vemming completed his first construction of the medieval trebuchet in 1989, following extensive research and preparation.

Notes and drawings from the 13th century were used as the starting point for the reconstruction and were often referred to during the long process of developing the working replica of this powerful and accurate machine.

Under Dr Vemming’s guidance and using his designs and experience the Warwick Castle trebuchet was constructed at a carpentry firm in Wiltshire – Carpenter Oak and Woodland Ltd.

The trebuchet is made primarily of oak but with the long throwing arm made of the more flexible ash, which is less prone to splitting under bending and shock loads. Every year the trebuchet, which comprises more than 300 parts held together with metal fixings, is inspected by experts from BM TRADA to ensure that it meets health and safety regulations.
“We examine the condition of the structure and make sure it is in good working order,” says BM TRADA consultant Nick Clifford. “Essentially we are monitoring for fungal decay and we advise when replacement pieces are needed.”

The trebuchet has a 12m sling arm made in two pieces and recently BM TRADA advised that one of these needed to be replaced. “We access the high level parts of the trebuchet on a cherry picker and carry out decay detection drilling to discover decay pockets which could weaken the structure and cause it to be potentially dangerous,” explains Mr Clifford.

There’s no doubt that the trebuchet has captured the public’s imagination and BM TRADA’s role in keeping it working safely is a vital part of its success.

“We first started working with BM TRADA in 2005,” said Paul Ormsby, health and safety manager at Warwick Castle. “Finding the right company to carry out the requisite safety checks on the world’s biggest trebuchet was not easy – but BM TRADA was definitely the right partner.

“We were initially impressed by the company’s knowledge of timber and subsequently the diligence and expertise that BM TRADA’s consultants bring to the job have helped us maintain a perfect safety record for the Warwick trebuchet. We certainly hope to continue the partnership in years to come.”
 
Even Nick Clifford admits it’s a pretty special job to be involved with. “The process itself is not unusual but the fact that we are working with the world’s largest trebuchet certainly adds to the excitement. We all like to go and do the work because it’s not every day you deal with a structure of this type,” he said.

• For more information visit www.bmtradagroup.com.