Traction Trebuchet
Vlachernai's Traction Trebuchet
by Stephen Francis Wyley
In 1997 I and members of the Vlachernai Garrison of the New Varangian Guard Inc. attempted to ready a trebuchet for a dual display with the counterpoise trebuchet of the Grey Company. Sadly, we did not complete the project in time, however the chance to play with Grey Company's engine only enspired us more. The following is an on going report on the results and conclusions drawn from the operation of Vlachernai's traction trebuchet.
Vlachernai's traction trebuchet is based on the attacking trebuchet found in the Chronicle of Petrus de Eboli showing the forces of Emperor Henry IV (1190-97) laying siege to Naples. Biblioteca Nacional, Madrid, Codice Griego Matritense de Skylitzes, f.151b. Note that there is a smaller version a top the besiege castle's tower.
I would like to take this opportunity to the construction crews (especially John Sultana, Budd Weston and Bryan Evans Jones) and the teams of pullers whom have made it all happen. And a special thankyou to Russell Miner and John Southall of the Grey Company for all their helpful advice and encouragement.
Stephen Francis Wyley
Picture of original replica plans.
Dimensions
First toss at Dubh Linn's Feast, Modenwarre, Victoria, 1998.
Preparing to loose Vlachernai's Traction Trebuchet (Version 1.)
The pivot bar and sling in action.
Left: The resultant spilt in the pivot support beam caused by inferior materials being used and the stress placed on the whole pivot support section by the sling beam coming into contact with main structural beam. Damage also occured to the join between the sling beam and the support struts of the sling beam itself.
Three tosses were achieved using a missile only weighing about 100 grams before the engine completely broke down;
Toss 1 = 25 metres forwards.
Toss 2 = 0 metres (at pullers feet)
Toss 3 = -1 metre (behind trebuchet)
Conclusions arising from the exercise;
1. Use heavier missile.
2. Use stronger materials for pivot support section.
3. Make pivot support section taller to enable better use of pullers.
4. Pullers must pull in unison to gain full power.
Display at the 1999 Australasian Medieval Conference (Bacchus Marsh).
Sven standing in front of Vlachernai's Traction Trebuchet (Version 2.).
Sorting out the rope before loosing of the trebuchet.
Notice the addition height and strength of the pivot support section.
The first two tosses using a 500 gram missile failed to work because the sling was too bulky and the sling too thick (and new). Thanks to Russel Miners (Grey Co.) for the use of his staff sling sling we were able to continue.
Two tossers occured the results of which were that the missiles were flung in a high arc to a distance of over 70 to 80 metres.
Sadly one of the support struts of the sling beam came adrift and the display was cut short.
Thanks to Kate Bugden for the photographs.
Conclusions arising from the exercise;
1. The stresses on the sling beam support structure needs to be addressed.
2. More unbreakable missiles need to improvised.
Further experiments of planned and I will post the results and photographs here as they come to hand.
Links.
Some links to other trebuchet-related sites
Pictures of other period traction trebuchets
Bibliography.
Bradbury, J., The Medieval Siege, Great Britain, 1992.
Cockerel, S., Old Testament Miniatures, London, 1969.
Erbstösser, M., Trans. C.S.V. Salt, The Crusades, German Democratic Republic, 1978.
Koch, H.W., Medieval Warfare, London, 1978.
Nicolle, D., Medieval Warfare Source Book, Volume 1; Warfare in the Western Christendom, London, 1995.
Warner, P., Sieges in the Middle Ages, London 1968.