Ready…Aim…Fire!

Trebuchets — giant, gravity-powered catapults — are said to have revolutionized siege warfare eight centuries ago, but did these war machines really bring down castle walls? More than 50 craftsmen were assembled in Scotland by NOVA to build a replica and find out. The episode on trebuchets will air on PBS on February 1 as part of a miniseries on experimental archaeology.

One of the trebuchets they constructed was mostly the brainchild of Col. W. Wayne Neel, who teaches mechanical engineering at the Virginia Military Institute. With limited help from old drawings, and using his own intuition, Neel began by crafting meticulous working scale-model trebuchets, which propelled small foil-wrapped packages of butter across restaurant rooms with astounding violence.

A medieval craft village sprang up at the Loch Ness site, and every effort was made to produce trebuchets exactly as they would have been made but applying modern safety standards. Watching the proceedings was Hew Kennedy, a Shropshire landowner who, a decade ago, had built his own machine at the top of a sloping farm field, then began startling his neighbors by hurling drums of flaming gasoline, upright and grand pianos, dead farm animals, even a one-ton car.

At Loch Ness, a second trebuchet with a different design was built under the direction of Renaud Beffeyte, a French master carpenter and the world's only full-time trebuchet maker. Author Evan Handingham participated in the heroic efforts to produce these machines and brings us to the moment of truth when they are fired.