I broke my trebuchet!

The trebuchet, mightiest siege weapon of the medieval world. An awesome sight when in full flight. How could such an impressive thing have gone so wrong?

For an event we ran last summer Michael had built us a trebuchet. It was about 12 feet to the top of the swing arm. We ran a few tests on the front lawn of the Museum to see what would be best to fire from it. We found that the acceleration on the swing arm vaporised water balloons! It was like being in a very brief but heavy rain shower. We figured firing bricks was probably a bad idea, or at least one that could get us into trouble. So we settled on large baking potatoes. What could possibly go wrong?

What could go wrong is that Michael couldn’t make the event so I was left holding the baby. More precisely I was left figuring out how to rebuild the thing after it had turned into the Ikea flat pack from hell in storage. ‘Ok, so I think this bit goes…there. [Creak] or maybe here. I think.’ Eventually we managed to construct something that looked suspiciously like the trebuchet. We managed a few more test firings (don’t ask what happened to Josh’s mobile) and concluded we were all good for the big day.

On the day, everything was going swimmingly. The trebuchet was properly calibrated and firing the taters a good fifty feet through the air (mostly). The visitors pulling the rope on the release pin were getting very competitive about how far they could fire a potato. It was all great fun.

That’s when it all went horribly wrong. The first I knew about it was the creaking noise from the swingarm, followed very quickly by a loud snapping sound. Then I noticed that it was all the wrong shape and there was no sign of a potato in the sky. As I looked more closely I saw that the swing arm had done something very strange, in fact it was in two pieces, tethered to the main trebuchet falling towards the ground.

It seemed that the pouch with the potato in had caught on the rigging, the counterweight was still falling with 40kg of weight behind it but the swing arm couldn’t go anywhere. The result: it sheared clean in two! With a very loud crack it had snapped in the middle.

What on earth was I going to tell Michael who’d spent ages building it?

Easy: ‘You’ll have to build a bigger one for next year.’ And so we have.

If you'd like to join us for Fully Loaded! on 1st April it starts at 10am and goes on to 4pm. Museum admission applies and if you gift aid your entry you can visit as many times as you like for the next year.