84 The Woodworker & Good Woodworking August 2019 http://www.getwoodworking.comFEATURE Building a giant trebuchet
FURTHER INFORMATION
Foot note:
The Compagnons du Devoir, full name
Compagnons du Devoir et du Tour de France,
is a French organisation of craftsmen and
artisans dating from the Middle ages. Their
traditional, technical education includes taking
a tour, the Tour de France, around France and
doing apprenticeships with masters. For
a young man or young woman today, the
Compagnonnage is a traditional mentoring
network through which to learn a trade
while developing character by experiencing
community life and travellingCarpenter Oak Ltd – http://www.carpenteroak.com
Warwick Castle – http://www.warwick-castle.com
Netflix – http://www.netflix.com/gbme, “that the jointing on our full-scale replica
was workable and this gave us confidence in
our carpentry for the full-scale trebuchet.”Full-scale construction of the trebuchet
The trebuchet is essentially built bottom-up,
starting with the chassis or base, then the
ladder frame, which in turn bears the two main
A-frames, followed by the axle and tread wheels.
According to Fergus, the trickiest part of the
construction is the assembly of the axle blocks
and treadmills. “The axle block is the last part
of the jigsaw, which clamps the axle in place and
there’s no means for traditional timber joinery in
this area. It’s reliant on the restraining straps and
that’s why the hand-forged restraining straps
around the axle block are critical,” he says
(photo 23).
All the ironmongery was made by the carpenter
and resident blacksmith, Graham Butler, as were
all the other hand-forged iron items including
forged metal work for strengthening timber-to-timber joints, making a traditional hand-forged
trigger arm, as well as numerous rosehead nails,
which were used throughout the build (photos
24 & 25 ).
“These were used to fix secondary components,
whereas all primary structural members were
traditionally jointed with mortise & tenons and
pegged joinery. There were some areas where
there was also wedged and dovetail joinery,”
Fergus adds.
The full-scale replica for the Netflix production
Outlaw King was a first for the Scottish team,
the Warwick trebuchet having been built in the
Wiltshire yard. The siege machine was built
and delivered in eight weeks from the day of
ordering the Scottish fir (photo 26). With the
trebuchet critical to the siege scene in the film,
the Scottish yard became the go-to firm at the
time to deliver this unique commission. As Fergus
says: “To think we were the company that got
the phone call says a lot about us. It was great
fun to work on and the guys really enjoyed it.”
Recently, the yard had another call from a
private individual who was exploring the option
of a similar war machine. With all the working
drawings and jointing details, Fergus is confident
that whether it’s for the film industry or for
an individual in the future, they have thecapabilities to build a ‘fully engineered’ trebuchet.
“Having had the opportunity to refresh the skills
and techniques learnt on the original Warwick
Castle trebuchet 14 years ago, as a team the
knowledge is here to reproduce these war
machines efficiently and with confidence –
we look forward to the next one!”26 Pre-site assembly23 Bespoke ironmongery – axle block straps24 Hand-forged restraining straps
25 Rosehead nail21 The outer axle posts also have supporting 22 Scale model of the trebuchet
diagonal struts to give cross rigidity to the structure