A Trebuchet is a deadly siege weapon that hurls an object by using a counterweight.
A trebuchet is a medieval siege weapon. A machine that knocks down walls. It is also a magazine that does much the same thing with contemporary art. This page is about how a trebuchet works and why Trebuchet works for us.
How a trebuchet works: the mechanics
A trebuchet is not quite a catapult, though there are similarities. Both launch missiles, and both were built to attack stationary fortifications. But where a classical catapult stores energy in a twisted rope or a bent limb, a trebuchet takes its power from gravity. Heavy counterweights are cranked up, held, and on release drive a pivoting beam. The beam swings and passes its energy to a sling, which travels further and faster, opens at the top of its arc, and looses the projectile toward whatever is deemed worthy of destruction.
Three key features define a trebuchet, and each one is geared to optimise leverage.
1. Gravity is the engine. Raise a counterweight of mass M through height h and you store energy equal to Mgh. Drop it, and the beam pivots on a raised axle like a first-class lever, trading a slow fall for a fast swing (AAAS 2019; Denny 2005). The earlier traction trebuchet does the same with a crew hauling ropes instead of a weight (Chevedden et al. 1995). Efficient, too:
- 70 to 80 per cent of the stored energy reaches the projectile in idealised designs.
- Optimised reconstructions model past 90 per cent (Siano 2001; Horsdal, Johansen & Rasmussen 2025).
2. The long arm multiplies speed. The throwing arm runs several times longer than the counterweight arm, so its tip sweeps a wider arc in the same time and moves much faster than the weight falls.
- Optimal ratio of long arm to short arm: about 3.75 to 1 (Siano 2001).
- Practical machines: four to six to one.
- Fulcrum reaction during a shot: roughly three times the counterweight’s weight (Horsdal, Johansen & Rasmussen 2025).
3. The sling multiplies it again. Fixed to the arm’s tip, the sling acts as a second lever, extending the arm at the decisive moment. A sling near the length of the throwing arm adds roughly half as much range again (Siano 2001).
Release is a matter of tuning, only partly automatic. A loop of the sling sits over a fixed pin, and the angle of that pin sets the instant it slips free. Most builders aim to loose the payload near 45 degrees, the optimal angle for range in a vacuum. Air resistance pulls that a little lower in practice (Denny 2005; Siano 2001).
Each feature can be tuned and adjusted endlessly, which is exactly what draws today’s enthusiasts in. At peak, the power delivered to the projectile tops 800 kilowatts in the last milliseconds before release, enough for a medieval trebuchet to hurl a 90-kilogram stone close to 300 metres (Chevedden et al. 1995; Horsdal, Johansen & Rasmussen 2025).
Trebuchet magazine
Trebuchet is also a critical art publication. We cover contemporary art through interviews, reviews and long-form critical writing. We came into being through a desire to give contemporary art criticism a proper platform.
Many of us came from commercial media or from the academy, and the thrill of Trebuchet is to write from neither. We are not beholden to financial interest, and we are not bound by academic process, yet we want the reach of the first and the insight of the second. We hold to a simple belief: smart fun creates joy.
Why Trebuchet?
As a metaphor, the machine, the method and purpose has a lot to say. A trebuchet uses gravity to amplify action. We want our writing to do the same: to understand art’s processes, histories and trajectory on a heavy level, then use that weight to amplify and accelerate art’s evolution. Our gravity is a visceral feeling as much as an intellectual rigour. We love theory, and the constellations of art-speak. But how often does it make us feel the work more? Too often it just convinces us that our own feelings should be understood in someone else’s terms. Or worse, that art is a moral badge rather than a route into uncharted perception.
Then there’s leverage. New art, new masters. We want to raise their profile and feed something other than the recursive cycle of previous financial successes the art world so often runs on. Reach is the point. Use the weight you have gathered to throw a name further than the market would on its own.
There’s an elegance to how a trebuchet holds its balance while staying true to its aim. Ideally. With plenty of reflexive caveats, and constant adjustment for context. That is the work, and the fun: negotiating the details, the caveats, the context, all to increase the range of Art. Trebuchet is a metaphor and a meta aim. We aim to hit our targets. The real trick is knowing how contemporary art hits theirs.
Trebuchet is a contemporary art magazine: biannual in print, near-daily online. About Trebuchet. Read the criticism.
References
American Association for the Advancement of Science 2019, Trebuchets and their modern use, AAAS, viewed 14 August 2026, aaas.org.
Chevedden, PE, Eigenbrod, L, Foley, V & Soedel, W 1995, ‘The trebuchet’, Scientific American, vol. 273, no. 1, pp. 66-71.
Denny, M 2005, ‘Siege engine dynamics’, European Journal of Physics, vol. 26, no. 4, pp. 561-577, doi:10.1088/0143-0807/26/4/002.
Horsdal, E, Johansen, FD & Rasmussen, J 2025, The swinging counterweight trebuchet: experiments on inner movement and ranges, arXiv preprint 2502.19442, viewed 14 August 2026, arxiv.org.
Siano, DB 2001, Trebuchet mechanics, technical report, viewed 14 August 2026.
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The aim of art is to represent not the outward appearance of things, but their inward significance. – Aristotle
