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Steam Cannon

en.wikipedia.org

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Of interest is the Mythbusters episode linked in the article:

>Myth Statement: Archimedes was able to build a powerful steam cannon, using technology available at the time.

>Status: Busted

>Notes: A flash-boil-powered cannon, built even with modern materials and techniques, was barely able to push a projectile out of the barrel. A more modern pre-boiled, valve-triggered system, like those used in aircraft catapults, was able to project a cannonball a considerable distance, and required far less pressure than the MythBusters had originally projected. Also see Holman Projector which worked on a similar principle.

How can they know exactly what technology was available to Archimedes?

Have you seen the Antikythera Mecanism (https://en.m.wikipedia.org/wiki/Antikythera_mechanism)? That thing is way ahead of what we usually think the available technology was at the time.

Many of those things are "hushed up", when archaeologists find things that are against the established picture of this time it's always a "we don't know what that is, but it can't be this - because at this time this didn't existed".

e.g. look at Göbekli Tepe in turkey.

https://en.m.wikipedia.org/wiki/G%C3%B6bekli_Tepe

A 10.000-12.000 year old structure.

It doesn't seem like a matter of technology - the design as described simply doesn't work, is how I understand it. Think about it - there's a limit to how much steam, and how quickly, you can generate by introducing water to a preheated copper tube.

Continued! Steam Cannon successful at MIT!

http://web.mit.edu/2.009/www/experiments/steamCannon/Archime...

>Being frustrated with the outcome, having a visit to MIT in their schedule, and remembering last year’s Archimedes’s death ray collaboration, the MythBusters asked us to take a look. They wondered if there was a simple, plausible solution compatible with da Vinci’s vague drawing and explanation of Archimedes's steam cannon.

>The drawing has been interpreted as a direct injection concept, where water rapidly sprays into a hot breech and the resulting flash of steam launches the projectile.

>But, some back-of-the-envelope calculations suggest otherwise. A 540 °C (1000 °F) copper breech can provide a heat flux of roughly 100,000 kiloWatts per square meter to water that is in direct contact with its surface. And if water can be sprayed onto the breech in a uniform 1mm thick layer, 2,000 kiloJoules of energy per square meter of surface will produce 400 PSI steam—a pressure that would generate a reasonable projectile velocity.

[...]

>High-speed camera footage showed that the muzzle velocity was over 300 m/s (670 mph)!

>We can’t say if Archimedes did it, but this small-scale test shows that a simple, powerful steam cannon could probably have been made using technology of his era.

Very frustrating that they didn't share the actual working solution.

The most obvious would be to line the interior of the firing chamber with metal spikes or some sort of texture to increase the surface area so you have more water spray in direct contact with the hot surface at once. Also, increasing the pressure of the spray so more of it gets to the sides before the steam starts building and insulates it. It's clear the injectors need to be running at a fairly high pressure if you're going to be vaporizing half a cup of water in a few thousandths of a second.

I keep being amazed by all the purported inventions of Archimedes. And disappointed by the hubris of modern engineers who think that it should only take a handful of interns and an afternoon to reproduce what would have been at the time cutting edge military research, with a lot of ingenuity invested in it.

Someone who would invent the anti-naval claws, the sun death rays and a steam cannon would not have just one clever invention in making each work.

The solar death ray requires aiming devices and thousands of people. I find it very interesting that nowadays we can make almost perfect mirrors compared to the maybe 50% reflective bronze shields they would have had but producing a few thousands and making a few thousand people collaborate is something we have a hard time reproduce.

I’m not sure I’d call “forcing a bunch of slaves to hold up mirrors” “collaboration”.

We don't know much about Syracuse politics, but in that case, it is more likely this was done by soldiers. Syracuse garrison would have been at least a thousand troops and more probably several thousands. While waiting for the ships to land, it sounds like a good idea to try and sync them to try make the ships catch fire.

Survivorship bias towards inventors who lived to write up their experiments? I wonder how many people were killed developing these who _didn't_.

I would argue that if your invention killed you before you got a chance to write it up, it isn't a successful invention.

That too depends - was it a death ray?

https://en.wikipedia.org/wiki/List_of_inventors_killed_by_th...

Semi-related - USS Vesuvius[1] used compressed air (rather than steam) to ensure a somewhat soft launch of its artillery projectiles. This was necessitated by the use of dynamite payload - a potent & practical explosive, but somewhat sensitive to shock of normal gun firing. On the flipside, the gunshots were rather quiet, and completely free of flash or smoke.

The whole weapon system was a technological dead end.

[1] https://en.wikipedia.org/wiki/USS_Vesuvius_(1888)

Does the Chernobyl Nuclear Power Plant No. 4 nuclear reactor count as a steam cannon?

Hm, sounds like a stretch - it didn't propel any solid projectile to a substantial distance, I think? (like the Plumbbob/Pascal-B test did with a steel cap, for example - but it wasn't steam)

At least some accounts say that the first explosion blew the 1000-ton biological shield through the reactor building roof. Guess it's pretty hard to say exactly how much it threw it, since the second explosion came only seconds afterwards.

What about water heaters? I remember the mythbusters episode where they confirmed that a water heater could go through the roof of your house.

Immediately thought of this:

https://masterofmagic.fandom.com/wiki/Steam_Cannon

Here is a great retrospective if you missed out at the time:

https://www.eurogamer.net/articles/2012-04-20-retrospective-...

This other weapon from the Siege of Syracuse is great too:

https://en.wikipedia.org/wiki/Claw_of_Archimedes

This one was said to be feasible during a test by Superweapons. Although I doubt it looks like the included painting.

The painting was probably done by an artist who heard a third hand account of how it worked. A simple claw on a crane that attempted to hook onto the side of a ship and flip it doesn't seem too out of the realm of possibility, but it does require that the ship to navigate extremely close to the device. So it's only useful against invasions where the ships are attempting to disgorge soldiers onto the walls, but since that's what the Romans were doing it's in the realm of possibilities.

The way I am picturing it is that of hooks on a chain lying just below the surface that can be rushed back towards a crane, pulling any ship who crosses the line.

Looking at a map, the placement of such a line is obvious: https://en.wikipedia.org/wiki/Sicilian_Expedition#/media/Fil...

Users who liked the Steam Cannon article may also like: https://en.wikipedia.org/wiki/Potato_cannon ;)

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