Da Vinci’s Giant Crossbow Visualized

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One of many Da Vinci’s Military Inventions

I will come back to Da Vinci because there is much to choose from. He had great ideas but they were often unfeasible at the time.


This is a story about a giant military machine. Let’s see how big this thing really is and how it is supposed to work.

This drawing of the crossbow is the only thing that Da Vinci left behind for us. Any research comes out only from this picture anyway. Therefore, I decided not to look for any information initially and remain unaffected until I finish my own study and form my own opinion.

Da Vincis Giant Crossbow original drawing.
Original Da Vinci’s Drawing


A little bit of history. The drawing is a part of ”Codex Atlanticus” and is one of many inventions that Da Vinci never built up. The historians believe that the goal was to gain the favour of Ludovico Sforza, and as with Da Vinci’s tank, nobody really expected this battle machine would be ever built.

Dimensions and Weight

Da vinci's giant crossbow - dimensions -poster
Da Vinci’s giant crossbow – dimensions -poster

Based on the figure on the original Da Vinci picture, I believe that dimensions are approximately 24,5 m – length of the shoulder, and 22 m – length of the body.

It is easy to calculate the volume of anything in the 3D world. Blender showed me that the volume of the wooden parts is 38m3 and 1,6m3 of the iron parts. Therefore, we can suppose that the weight of the wooden parts is almost 20 tons and the weight of the iron parts is 13 tons. Of course, there must have been using different kinds of wood but this is beyond my knowledge. I think it is enough to know to create an idea of what the weight of this thing was. As you can see, not a little.

How Does It Work?

Let’s take a closer look at each section.


The most important part of the crossbow. While I was working on the 3D model, I realised that this could not work on such a scale. Wood is not a rubber. You can bend it, but you cannot squeeze it. Then I noticed that the inner side is made up of several smaller parts, probably separated from each other by gaps. Everything started to make sense. This is to prevent the string holder from sliding and at the same time to use the advantage of the flexibility of the rope.

Da Vincis Giant Crossbow design flaw.
The beams close to each other sliding out the string holder.
Da Vincis Giant Crossbow design flaw solution
The gaps between the beams prevent the string holder from sliding out.


The charging mechanism is simple. The problem is that such a wooden coil would have had the high friction even if it had been made very precisely and had been sufficiently lubricated. The charging would have taken 10 minutes and would have been tedious for the operator, which does not make this battle machine very efficient.

Da Vinci's Crossbow cocking mechanism
Da Vinci’s Crossbow cocking mechanism


Da Vinci suggested two ways to release the string. Either with a hammer blow or with a lever. I would certainly choose a hammer.

Da Vinci's Crossbow triggers
Da Vinci’s Crossbow triggers


Notice the inclination of the wheels in the original picture. Such talented artists and skilled inventors like Da Vinci certainly did not draw it like this only as a coincidence together with a very weird construction. It will definitely be a way to change the angle of the shot. In my opinion, Da Vinci relied on wheel spikes to help keep the wheels at the right angle. Such a chassis would not have worked according to Da Vinci’s ideas in the real world. The weight would have also been a problem. A much more complex mechanism should have been produced, perhaps similar to today’s car axles.

Da Vinci's Crossbow - sideview
Da Vinci’s Crossbow – side view


I remember a document, in which a group of experts made a prototype. I cannot find it now, but if I remember correctly, they fired to the distance of 4-5 meters.

So would it work? No. But it is a nice piece of military technology history. Isn’t it?

This is one of many Da Vinci Inventions. You can find a post about Da Vinci’s fighting vehicle design flaw here.

Here you can download Da Vinci’s crossbow high-resolution wallpapers or posters ready for print. You will also find here 3D models of metal prints for download.

Da vinci's giant crossbow - patent art blackboard

Da Vinci’s Giant Crossbow Blackboard Landscape

Da vinci's giant crossbow - patent art sephia paper

Da Vinci’s Giant Crossbow Sephia Paper Landscape

Download military wallpapers and other military images in patent art or 3D artwork. For a large high-quality military poster about military history and military technology please check one of the stores.

To allow walking you have to click on the image, even if the cursor is not visible.

WASD = move, Mouse = look, Space = jump, Esc = exit

Works fine on PC, just need to add controls for touch screens and polish the design.

I’ve spent some time on the solution and it’s beyond my knowledge. Therefore, I decided to focus on creating new interesting posts and artworks, instead of devoting more time to this.
If you know how to do it and you are willing to help me, I will not be the only one who will be grateful to you. Definitely, all visitors will.