I am working on a story that happens in a dystopian world where the only source of energy is Coal.

I wanted to know whether it is possible to break a dam by pressurizing Dam walls with coal GAS

Thank you in advance for your help.


closed as unclear what you're asking by Liam Morris, Measure of despare., Gryphon, Cyn, L.Dutch May 19 at 16:02

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    $\begingroup$ This is among the best options to destroy a dam. en.m.wikipedia.org/wiki/Bouncing_bomb $\endgroup$ – TheDyingOfLight May 19 at 9:10
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    $\begingroup$ Which dam? How is it built? Where is it built? What are its conditions? Without these info it is hard to answer your question. $\endgroup$ – L.Dutch May 19 at 9:11
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    $\begingroup$ If the only source of energy is coal, there are no dams. Water behind a dam is a source of energy. $\endgroup$ – Mike Scott May 19 at 9:12
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    $\begingroup$ @MikeScott, beavers build dams. But have no clue what a turbine is. $\endgroup$ – L.Dutch May 19 at 9:57
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    $\begingroup$ Please edit your question with important details, including (a) what real-world dam can we use as an example of the dam you want to destroy? (b) What approx. year represents the tech level of your world? (c) What are the conditions limiting delivery (defenses, timing, etc.)? $\endgroup$ – JBH May 19 at 13:45

The problem with explosives generally is confinement. People are fairly fragile. Overpressure of a few psi tends to leave them in poor condition to do much. Buildings take much higher pressures. Concrete structures even more.

The bouncing bombs used on the dams on the Ruhr during WWII were designed to sink just short of the dam and explode some distance below the surface. The water provided both containment of the explosive, and transfer of the energy to the face of the dam.

To use gas as your explosive material you have to compress it to a density approaching that of a solid. Call is 15 to 30,000 psi, if the gas laws apply. In actual fact they don't. You are well above the critical pressure, so the volume doesn't decrease nearly as fast as the pressure increases. I would NOT want to try mixing coal gas and oxygen and pressurizing it to 30,000 psi. (Probably want to do it in a double container that had a separator, then trigger it with a stick of dynamite)

But if you can make dynamite, you can make more conventional explosives.

In your world you need to come up with a plausible reason why there is no developed hydro power. Water wheels and wind powered mills were in use long before coal was harnessed. Coal was much higher energy density than wind, and good water wheel sites aren't common. But many dams are multipurpose: Power and irrigation. You need a good reason why the power aspect isn't being used.


Instead of coal gas, why not look into coal dust?

Coal dust (and in fact any finely ground flammable, flour being an obvious example) has a much larger surface area exposed to the air, so it can oxidise (burn) very very quickly, otherwise known as exploding.

This principle is actually used in modern munitions, where highly combustible fuels are aerosolised and mixed with air. The air gives the oxygen, the fuel gives the fuel, and because they’re very evenly mixed the whole thing goes boom very impressively.

One major advantage to this kind of weapon is that it tends to create low velocity but very large atmospheric shockwaves. Coal dust explosions have brought down mines and solid stone fuel stores. Hell, even flour dust explosions wee responsible for utterly annihilating heavy stone windmills.

Dust explosions won’t do much to harder construction materials, but if your dam is made of anything shy of reinforced concrete a suitably positioned explosion will turn the air around the dam into a battering ram, crack the dam, and from there it’s physics.

So: Finely grind a hell of a lot of coal into a dust. Disperse it by flying over and powdering the area or using some mechanical contrivance to fling the dust into the air right next to the dam, then ignite. Aim to get a nice, homogeneous cloud right next to the base of the dam for maximum boom.

Make sure to use safety lanterns and soft shoes when producing/deploying the bomb. We don’t want premature ignition, and the air itself will be a bomb waiting to go off.

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    $\begingroup$ "disperse it by flying over..." in your coal-fired bombers, of course. $\endgroup$ – Starfish Prime May 19 at 11:19
  • $\begingroup$ @StarfishPrime: Of course! Coal oil powered helium zeppelins, anyone? $\endgroup$ – Joe Bloggs May 19 at 11:54
  • $\begingroup$ The problem is that you aren't going to do much damage to a dam with an explosive (short of a nuke) detonated above the surface. $\endgroup$ – jamesqf May 19 at 17:09
  • $\begingroup$ @jamesqf: Depends on the exact size and structure of the dam. Even small cracks can (in the right place or in a poorly designed dam) cause huge problems, and another benefit of this kind of bomb is that the explosion wavefront pushes the fuel/air mixture into tunnels/cracks prior to combustion, so if there are any currently unused culverts or rooms for equipment/personnel this will basically turn them from small weak points into very big ones in short order. If this dam is just a huge concrete wall to divert a river, then I agree with you, but I’m assuming it’s more interesting than that. :-) $\endgroup$ – Joe Bloggs May 19 at 18:58

The short answer -- that is feasible, but impractical to pump a gas till pressure is high enough to crack the dam. Do you want to use gas pressure alone? Pump gas between the dam and the river floor? The gas will also leak before sufficient pressure is achieved.

You can, though, use coal gas as you originally intended but extra pressure may be achieved by using a gas tank this way: Fill a gas tank with sufficient pressure, with a MIX of coal gas and oxygen, add a spark generator with a battery + remote-control or a long wire. (Depending on whatever technology there is). Sink the tank near a weakness point and ignite the gas.

The gas tank will blow-up because there is oxygen mixed with the fuel. This ignition will be more devastating than gas pressure alone. Underwater explosions have a greater impact, so the tank must be dropped into the water behind the dam. See wikipedia's article "Underwater explosions".


Launch Coal gas fueled rockets at the face of the dams. Hypervelocity weapons with penetrator tips could crack the dam, weakening it, then the water pressure destroys the time.

Just like liquid fueled rockets, the coal gas would be liquified and combined with an oxidizer like liquid oxygen, hydrogen peroxide, etc to produce powerful engines.

And, you’d need a guidance system and vector-able thrust.

You’d launch the weapon towards the dam, but it would need to steer itself so it attacked the dam wall from a right angle to the sloped walls surface.

Once the weapon was heading the right direction, the engines would kicked in to high gear and accelerate right towards the time.

The penetrator tip would be as massive as your rocket could lift shaped to minimize ricochets. It might be like 3 prongs (like two fingers and thumb on one hand) or might be chisel shaped. The penetrator is intended to induce a shearing shockwave into the dam at its base. Once it is cracked and weakened, water pressure will do the rest.

An attack might be a single huge weapon or a barge of multiple smaller ones.


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