Why Modern Armies Still Use Trebuchets

SPEAKER_1 (0:00)

Picture this, it is 1521, and the Spanish conquistador, or not Cortes, is besieging the Aztec capital of Tenochtitlan. And, you know, the campaign has just been grinding on forever.

SPEAKER_2 (0:14)

Yeah, it was brutal.

SPEAKER_1 (0:15)

Totally. And he hits this massive, catastrophic logistical wall.

His army is entirely out of gunpowder.

SPEAKER_2 (0:23)

Which is a huge problem.

SPEAKER_1 (0:24)

Right. The candidates are completely useless at this point.

But Cortez, being Cortez, refuses to abandon the siege. So he decides to improvise. He actually orders his engineers to build a massive medieval trebuchet.

SPEAKER_2 (0:40)

Which, I mean, that is an incredibly bold move, because by the early 16th century, gunpowder artillery had already, you know, rendered those giant wooden siege engines basically obsolete back in Europe. Right.

SPEAKER_1 (0:52)

They were a thing of the past.

SPEAKER_2 (0:53)

Exactly. He was trying to resurrect ghosts, essentially, just to solve this very modern tactical problem he had.

SPEAKER_1 (1:01)

And it goes about as badly as you could possibly imagine.

SPEAKER_2 (1:05)

That was terrible.

SPEAKER_1 (1:06)

They spend days building this towering wooden behemoth.

They hoist up the massive counterweight. They load a huge stone into the sling, and they pull the trigger, and well, it failed spectacularly.

SPEAKER_2 (1:18)

Yeah, on the very first try.

SPEAKER_1 (1:19)

On shot number one.

The machine launches its payload straight up into the air, and gravity just brings that massive stone crashing right back down, completely obliterating the trebuchet itself. Total failure.

SPEAKER_2 (1:33)

I mean, that's got to be the ultimate humiliation for a military engineer, right?

SPEAKER_1 (1:37)

Oh, without a doubt.

SPEAKER_2 (1:38)

But that specific failure actually highlights this really profound contradiction.

SPEAKER_1 (1:43)

And that is exactly what we are exploring today. So welcome to this Deep Dive. Today, we are bringing you along as we look at the mechanics, the psychology, and really the bizarre longevity of the undisputed king of medieval siege warfare.

SPEAKER_2 (1:57)

Yeah, the trebuchet.

SPEAKER_1 (1:58)

Because despite Cortes completely failing to build a working one in the 1500s, this ancient gravity-powered wooden machine is actually, surprisingly, still being utilized in active 21st century combat zones today.

SPEAKER_2 (2:12)

It's wild to think about.

SPEAKER_1 (2:14)

It really is. Not as some museum exhibit, but as a literal improvised tool of war. So let's unpack this.

SPEAKER_2 (2:21)

Well, I think to understand why a medieval machine survives in the era of, you know, drones and microchips, you first have to separate it from the generic concept of a catapult.

SPEAKER_1 (2:30)

Right, because people lump them all together.

SPEAKER_2 (2:32)

All the time. But calling a trebuchet a catapult is like, I don't know, it's like calling a modern sniper rifle a musket.

SPEAKER_1 (2:38)

Oh, I like that comparison.

SPEAKER_2 (2:39)

Yeah. Because a trebuchet is this highly sophisticated compound machine. It dominated siege warfare for centuries, specifically because it solved the fatal engineering flaw of the tension and torsion engines that came before it.

SPEAKER_1 (2:53)

Okay, so let's break down that fatal flaw for a second. Before the trebuchet, you had these older Roman siege engines, right? Like the onager.

How exactly did those generate their power?

SPEAKER_2 (3:04)

So the onager relied on torsion.

SPEAKER_1 (3:07)

Okay.

SPEAKER_2 (3:07)

You have to imagine a massive bundle of animal sinew or really thick rope, and it's twisted impossibly tight.

SPEAKER_1 (3:14)

Like twisting a rubber band on a toy airplane.

SPEAKER_2 (3:16)

Exactly like that, but on an industrial scale. So an arm is inserted into that bundle, and when you release the trigger, that arm violently snaps upward to throw the stone.

SPEAKER_1 (3:26)

Right.

SPEAKER_2 (3:27)

But here's the problem. To stop the arm from just spinning wildly forward, it has to slam into this massive, heavily padded wooden crossbeam.

SPEAKER_1 (3:36)

So all that pent up kinetic energy doesn't just go into the rock. A huge portion of it goes directly into the machine itself.

SPEAKER_2 (3:43)

It was an absolute nightmare for engineers. Every single time an onager fired, it absorbed this massive destructive shockwave. The machines were quite literally beating themselves to death.

SPEAKER_1 (3:54)

Wow.

SPEAKER_2 (3:55)

You had to build their frames out of absurdly thick, heavy timber just so they could survive their own firing sequence.

SPEAKER_1 (4:01)

It makes me think of a baseball pitcher throwing a fastball.

Like, a good pitcher smoothly follows through, right? They let their arm and wrist flick forward naturally to release the energy.

SPEAKER_2 (4:11)

Right, exactly.

SPEAKER_1 (4:13)

But the Roman onager, he's basically like trying to hit a fastball with a baseball bat, except mid-swing, the bat strikes a solid brick wall.

SPEAKER_2 (4:21)