In medieval times, sappers would dig a tunnel under a castle wall and then suspend a table top for the ceiling by ropes. Then they would load the table up with loose flour and when the dust settled they would light candles under the ropes and run like hell. When the candles burned through the ropes the table would fall and the flour would go poof and get ignited by the candles. The explosion would frequently be strong enough to collapse a section of the castle wall. But it took a lot of flour.
I have to ask: Do you have a source for that?
I'm curious for a number of reasons, not least of which is: We had flour and fire ... well, basically forever ... so this could predate gunpowder by centuries. Which ... well, which would surprise me =D
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No, I have no source for it. It’s just one of those things I learned forever ago and remembered because it was cool. Where exactly I heard/read about it didn’t stick, just the factoid. If I recall it did predate gunpowder in Europe by quite a while. I’m sure if one were to look into “sappers” it would come up in their research sooner or later.
I did look into sappers, and didn't find anything. Not that that matters - my interest is mostly because it's cool.
But then, to explode I guess the flour would have to be ground very fine. That might not have been possible too long before gunpowder, maybe 😁
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Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
Realistic or not, this sapping bit is the kind of thing I might allow at a table; something where the players are out of combat and have some time to problem solve a challenge. I'd have the player roll to see if the character remembered how to pull it off and another time or two for execution.
Speaking of improbable explosions in D&D, one time when I set a fire near some pig grease in a warehouse to help cover an escape, the DM had it end up going off like an oil tanker in an action movie. I hadn't been planning on or expecting anything like that, I was just looking for a big fire to distract people as we hustled out the front.
I did look into sappers, and didn't find anything. Not that that matters - my interest is mostly because it's cool.
But then, to explode I guess the flour would have to be ground very fine. That might not have been possible too long before gunpowder, maybe 😁
Medieval mills had an alarm for when the grinding wheels were getting too close so they could shut it down before they sparked. This implies that this was an actual danger and that they were aware of it.
I did look into sappers, and didn't find anything. Not that that matters - my interest is mostly because it's cool.
But then, to explode I guess the flour would have to be ground very fine. That might not have been possible too long before gunpowder, maybe 😁
Medieval mills had an alarm for when the grinding wheels were getting too close so they could shut it down before they sparked. This implies that this was an actual danger and that they were aware of it.
Mills about the only place it is a danger though, it would be extremely difficult to use it as a weapon because the ratio of organic dust to air has to be within a relatively narrow range to generate an explosion. The dust also has to be evenly spread in the air. Tossing a bag of flour into the air generally doesn't work because the flour doesn't disperse evenly in the air, the main body of the flour stream is too dense to ignite while the edges are too dispersed to cause the chain-reaction. However mills with their constant long-term dispersal of dust tend to have a relatively uniform low density dust content in the air which are perfect conditions for an explosion. However even then most of the time the density of dust is too low to cause an explosion (otherwise they would be exploding all the time) but the right condition occur often enough that they do happen and it is necessary to take precautions against it.
One thing to consider is that a flour explosion is the sudden release of all the calories in flour as an explosion. The main thing it did was force - the sapping example Sposta uses is an example, the fire didn't burn away the ground around it, the forceful explosion of the flour would break the ground and weaken it, and the weight of a wall would then bring it down.
I would have a flour explosion do large amounts of collateral damage - windows blown out, rooves removed, weaker walls pushed over - and knock people prone. I imagine that if you were caught in one, the heat would be intense and burn you, but it would not last long enough to kill you from the heat. If you were in leather armour and covered your head, you may walk away from it with some minor burns. So I would say a flour explosion would do:
save vs prone, can fail voluntarily
3d8 force damage, halved if you go prone (standing and taking it will come off worse than throwing yourself to the floor)
2d6 fire damage
size of the explosion will be dictated by the amount of flour.
One thing to consider is that a flour explosion is the sudden release of all the calories in flour as an explosion. The main thing it did was force - the sapping example Sposta uses is an example, the fire didn't burn away the ground around it, the forceful explosion of the flour would break the ground and weaken it, and the weight of a wall would then bring it down.
I would have a flour explosion do large amounts of collateral damage - windows blown out, rooves removed, weaker walls pushed over - and knock people prone. I imagine that if you were caught in one, the heat would be intense and burn you, but it would not last long enough to kill you from the heat. If you were in leather armour and covered your head, you may walk away from it with some minor burns. So I would say a flour explosion would do:
save vs prone, can fail voluntarily
3d8 force damage, halved if you go prone (standing and taking it will come off worse than throwing yourself to the floor)
2d6 fire damage
size of the explosion will be dictated by the amount of flour.
Since you seem to indicate that an explosion like this probably wouldn't kill a person (or were you only saying that they wouldn't die from the heat?), I'd say your damage is way over-tuned. A commoner only has 4 hp, and would thus die essentially automatically if caught in the blast. I guess if this were a mill explosion or the sapping example provided that would be reasonable, but seems excessive for just about any other situation.
One thing to consider is that a flour explosion is the sudden release of all the calories in flour as an explosion. The main thing it did was force - the sapping example Sposta uses is an example, the fire didn't burn away the ground around it, the forceful explosion of the flour would break the ground and weaken it, and the weight of a wall would then bring it down.
I would have a flour explosion do large amounts of collateral damage - windows blown out, rooves removed, weaker walls pushed over - and knock people prone. I imagine that if you were caught in one, the heat would be intense and burn you, but it would not last long enough to kill you from the heat. If you were in leather armour and covered your head, you may walk away from it with some minor burns. So I would say a flour explosion would do:
save vs prone, can fail voluntarily
3d8 force damage, halved if you go prone (standing and taking it will come off worse than throwing yourself to the floor)
2d6 fire damage
size of the explosion will be dictated by the amount of flour.
Since you seem to indicate that an explosion like this probably wouldn't kill a person (or were you only saying that they wouldn't die from the heat?), I'd say your damage is way over-tuned. A commoner only has 4 hp, and would thus die essentially automatically if caught in the blast. I guess if this were a mill explosion or the sapping example provided that would be reasonable, but seems excessive for just about any other situation.
Fair point.
Probably go for 1d6 fire damage and then 2d6 force, halved if prone.
Reasonable chance to kill a commoner but underwhelming against monsters.
Powder explosions, like methane gas explosions are essentially thermobaric explosions - that is they use up all the oxygen in the area in the explosion and then blast the remaining nitrogen outward at supersonic speeds giving the force blast. This is then followed by a return blast as the air around refills the volume of the blast - also at supersonic speeds. So you get at least 4 different effects - the heat of the burn, the suffocation of the burn and vacuum, the force of the outward blast and the force of the return stroke. That sapping explosions doesn’t just crack the earth it lifts it cracking the wall then settles into the blast emptied space collapsing the now broken wall.
Also (scientifically) known as the quadruple ouchie.
I do feel it might be wise to put modern fuel-air bombs at one end of the spectrum, and some flour on a table at the other. For one thing, a table full of flour would have a rather limited source of oxygen to consume for the explosion.
I've no idea how much difference that makes, I'm neither a phycisist or a demolitionist. I just feel ... maybe flour doesn't get quite as much bang for the buck as ... I dunno, magnesium, ignited not by a candle but by some super reactive explosive compound.
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Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
Also (scientifically) known as the quadruple ouchie.
I do feel it might be wise to put modern fuel-air bombs at one end of the spectrum, and some flour on a table at the other. For one thing, a table full of flour would have a rather limited source of oxygen to consume for the explosion.
I've no idea how much difference that makes, I'm neither a phycisist or a demolitionist. I just feel ... maybe flour doesn't get quite as much bang for the buck as ... I dunno, magnesium, ignited not by a candle but by some super reactive explosive compound.
I do feel it might be wise to put modern fuel-air bombs at one end of the spectrum, and some flour on a table at the other. For one thing, a table full of flour would have a rather limited source of oxygen to consume for the explosion.
I've no idea how much difference that makes, I'm neither a phycisist or a demolitionist. I just feel ... maybe flour doesn't get quite as much bang for the buck as ... I dunno, magnesium, ignited not by a candle but by some super reactive explosive compound.
Flour on a table will struggle to even burn. Substances that are actually explosive will typically create their own oxygen as they're consumed. Dust explosions are a different animal entirely, almost anything combustible suspended in the air in the appropriate concentration will result in an explosion.
Flower or sugar on a table doesn’t burn well because it is mostly not exposed to the air or an ignition source. It’s piled n itself so only the outer does can burn so it burns slowly inward like an ice cube melting. the problem comes when it’s finely ground AND well distributed dust in the air. Now the entire volume is exposed to the air and the ignition runs through it essentially instantaneously. Using sugar ( the most basic carb) as an example: C6H12O6 + 6O2 = 6CO2+6H2O; we go from a dispersed powder +6 molecules of air to 12 molecules of very hot gas in less than 1/25,000 of a second ( high explosives by definition burn at rates >25,000 ft/sec) 1 unit of sugar turns into 6 units of gas and heats another 6 units to at least 350 F burning the insides of your lungs in the process. The addition of 6 units of gas calls for an extra 134.4 liters of space for each mole of sugar plus the expansion of the gas from STP to 350 F. Hence the big shock waves. The gas goes rushing out, then collapses back and reverberates as it settles down. Burning n the table slowly releases the same volume but over enough time for the air to adjust nonexplosively. yes many modern high explosives carry their own oxygen in the form of nitrates but in the case of dispersed micro flammables it is not needed.
Gust of wind, even a small air elemental. You need to get the flour up into the air, keep it up and then ignite it - preferably with your party out of the area of effect. Simply leaving a lit torch in the room while the spell or elemental swirls the dust is probably enough as the cloud will explode when the concentration hits the right point.
As for ancient mills. They used stone mill "stones" and didn't start using steel mills until the early 1900's. No need for any explosive alarms. All wood and stone. My little city still has a working water powered grain mill.
And as for magnesium. Well that brings back a few memories from high school. The local police got to know our gang of friends pretty well.
As for ancient mills. They used stone mill "stones" and didn't start using steel mills until the early 1900's. No need for any explosive alarms. All wood and stone. My little city still has a working water powered grain mill.
And as for magnesium. Well that brings back a few memories from high school. The local police got to know our gang of friends pretty well.
Stone still causes sparks when it hits itself at high speeds. Mills would have alarm bells that would ring when the stones got too close to each other (generally when they ran out of stuff to grind). This gave the miller a very short window to stop them before they contacted each other and potentially ignited any dust that may have been in the air.
The original DuPont gunpowder works are on display in Delaware and used bronze bowls and wooden pestles and rails to mix and grind the powder - in open faced huts along the river so if something blew it did so fairly harmlessly. They did have one silo blow fairly spectacularly at one point.
Flour on a table will struggle to even burn. Substances that are actually explosive will typically create their own oxygen as they're consumed. Dust explosions are a different animal entirely, almost anything combustible suspended in the air in the appropriate concentration will result in an explosion.
Yea. Thanks. The table is a reference to an earlier post, and I'm well aware of how explosives work. What I'm saying is, going by common sense alone, it seems unlikely flour would ever work particularly well for sapping. Common sense is commonly wrong, so I'm willing to be convinced otherwise, but remain at this point doubtful.
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Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
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I have to ask: Do you have a source for that?
I'm curious for a number of reasons, not least of which is: We had flour and fire ... well, basically forever ... so this could predate gunpowder by centuries. Which ... well, which would surprise me =D
Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
No, I have no source for it. It’s just one of those things I learned forever ago and remembered because it was cool. Where exactly I heard/read about it didn’t stick, just the factoid. If I recall it did predate gunpowder in Europe by quite a while. I’m sure if one were to look into “sappers” it would come up in their research sooner or later.
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I did look into sappers, and didn't find anything. Not that that matters - my interest is mostly because it's cool.
But then, to explode I guess the flour would have to be ground very fine. That might not have been possible too long before gunpowder, maybe 😁
Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
Realistic or not, this sapping bit is the kind of thing I might allow at a table; something where the players are out of combat and have some time to problem solve a challenge. I'd have the player roll to see if the character remembered how to pull it off and another time or two for execution.
Speaking of improbable explosions in D&D, one time when I set a fire near some pig grease in a warehouse to help cover an escape, the DM had it end up going off like an oil tanker in an action movie. I hadn't been planning on or expecting anything like that, I was just looking for a big fire to distract people as we hustled out the front.
Medieval mills had an alarm for when the grinding wheels were getting too close so they could shut it down before they sparked. This implies that this was an actual danger and that they were aware of it.
Mills about the only place it is a danger though, it would be extremely difficult to use it as a weapon because the ratio of organic dust to air has to be within a relatively narrow range to generate an explosion. The dust also has to be evenly spread in the air. Tossing a bag of flour into the air generally doesn't work because the flour doesn't disperse evenly in the air, the main body of the flour stream is too dense to ignite while the edges are too dispersed to cause the chain-reaction. However mills with their constant long-term dispersal of dust tend to have a relatively uniform low density dust content in the air which are perfect conditions for an explosion. However even then most of the time the density of dust is too low to cause an explosion (otherwise they would be exploding all the time) but the right condition occur often enough that they do happen and it is necessary to take precautions against it.
One thing to consider is that a flour explosion is the sudden release of all the calories in flour as an explosion. The main thing it did was force - the sapping example Sposta uses is an example, the fire didn't burn away the ground around it, the forceful explosion of the flour would break the ground and weaken it, and the weight of a wall would then bring it down.
I would have a flour explosion do large amounts of collateral damage - windows blown out, rooves removed, weaker walls pushed over - and knock people prone. I imagine that if you were caught in one, the heat would be intense and burn you, but it would not last long enough to kill you from the heat. If you were in leather armour and covered your head, you may walk away from it with some minor burns. So I would say a flour explosion would do:
size of the explosion will be dictated by the amount of flour.
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Since you seem to indicate that an explosion like this probably wouldn't kill a person (or were you only saying that they wouldn't die from the heat?), I'd say your damage is way over-tuned. A commoner only has 4 hp, and would thus die essentially automatically if caught in the blast. I guess if this were a mill explosion or the sapping example provided that would be reasonable, but seems excessive for just about any other situation.
Fair point.
Probably go for 1d6 fire damage and then 2d6 force, halved if prone.
Reasonable chance to kill a commoner but underwhelming against monsters.
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Powder explosions, like methane gas explosions are essentially thermobaric explosions - that is they use up all the oxygen in the area in the explosion and then blast the remaining nitrogen outward at supersonic speeds giving the force blast. This is then followed by a return blast as the air around refills the volume of the blast - also at supersonic speeds. So you get at least 4 different effects - the heat of the burn, the suffocation of the burn and vacuum, the force of the outward blast and the force of the return stroke. That sapping explosions doesn’t just crack the earth it lifts it cracking the wall then settles into the blast emptied space collapsing the now broken wall.
Wisea$$ DM and Player since 1979.
Also (scientifically) known as the quadruple ouchie.
I do feel it might be wise to put modern fuel-air bombs at one end of the spectrum, and some flour on a table at the other. For one thing, a table full of flour would have a rather limited source of oxygen to consume for the explosion.
I've no idea how much difference that makes, I'm neither a phycisist or a demolitionist. I just feel ... maybe flour doesn't get quite as much bang for the buck as ... I dunno, magnesium, ignited not by a candle but by some super reactive explosive compound.
Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.
Even a small breach is a breach.
Creating Epic Boons on DDB
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Content Troubleshooting
Flour on a table will struggle to even burn. Substances that are actually explosive will typically create their own oxygen as they're consumed. Dust explosions are a different animal entirely, almost anything combustible suspended in the air in the appropriate concentration will result in an explosion.
Flower or sugar on a table doesn’t burn well because it is mostly not exposed to the air or an ignition source. It’s piled n itself so only the outer does can burn so it burns slowly inward like an ice cube melting. the problem comes when it’s finely ground AND well distributed dust in the air. Now the entire volume is exposed to the air and the ignition runs through it essentially instantaneously. Using sugar ( the most basic carb) as an example: C6H12O6 + 6O2 = 6CO2+6H2O; we go from a dispersed powder +6 molecules of air to 12 molecules of very hot gas in less than 1/25,000 of a second ( high explosives by definition burn at rates >25,000 ft/sec) 1 unit of sugar turns into 6 units of gas and heats another 6 units to at least 350 F burning the insides of your lungs in the process. The addition of 6 units of gas calls for an extra 134.4 liters of space for each mole of sugar plus the expansion of the gas from STP to 350 F. Hence the big shock waves. The gas goes rushing out, then collapses back and reverberates as it settles down. Burning n the table slowly releases the same volume but over enough time for the air to adjust nonexplosively.
yes many modern high explosives carry their own oxygen in the form of nitrates but in the case of dispersed micro flammables it is not needed.
Wisea$$ DM and Player since 1979.
It occurs to me that Gust of Wind would be a fairly effective means of getting flour into the air in an enclosed space.
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"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
Gust of wind, even a small air elemental. You need to get the flour up into the air, keep it up and then ignite it - preferably with your party out of the area of effect. Simply leaving a lit torch in the room while the spell or elemental swirls the dust is probably enough as the cloud will explode when the concentration hits the right point.
Wisea$$ DM and Player since 1979.
As for ancient mills.
They used stone mill "stones" and didn't start using steel mills until the early 1900's.
No need for any explosive alarms. All wood and stone.
My little city still has a working water powered grain mill.
And as for magnesium. Well that brings back a few memories from high school. The local police got to know our gang of friends pretty well.
Stone still causes sparks when it hits itself at high speeds. Mills would have alarm bells that would ring when the stones got too close to each other (generally when they ran out of stuff to grind). This gave the miller a very short window to stop them before they contacted each other and potentially ignited any dust that may have been in the air.
The original DuPont gunpowder works are on display in Delaware and used bronze bowls and wooden pestles and rails to mix and grind the powder - in open faced huts along the river so if something blew it did so fairly harmlessly. They did have one silo blow fairly spectacularly at one point.
Wisea$$ DM and Player since 1979.
Yea. Thanks. The table is a reference to an earlier post, and I'm well aware of how explosives work. What I'm saying is, going by common sense alone, it seems unlikely flour would ever work particularly well for sapping. Common sense is commonly wrong, so I'm willing to be convinced otherwise, but remain at this point doubtful.
Blanket disclaimer: I only ever state opinion. But I can sound terribly dogmatic - so if you feel I'm trying to tell you what to think, I'm really not, I swear. I'm telling you what I think, that's all.