TNE Only: Black powder as a rocket fuel

[TheDark]

In poking through FF&S and WTH the other day, I realized the books don't allow for black powder rockets, like the Hale and Congreve or even the early Chinese rockets like the Huo Jian. So, as part of getting the collective brain trust involved, here are a couple proposed additions to the Self-Contained Thrusters table on page 70 of FF&S:

Engines
TL 2 Black Powder, Th *, MaxT 1, FC 25, FT BP, Airframe Super
TL 3 Black Powder, Th *, MaxT 2, FC 20, FT BP, Airframe Super

Fuel
TL 2 Black Powder Density 1.5, Price 7500
TL 3 Black Powder Density 2, Price 10000

The FC is loosely based on the difference between black powder's specific impulse and early solid rocket fuel specific impulse. Density is likewise roughly based on black powder's, and the price is based on WTH page 99 listing artillery charges at 5 credits per kilogram. Thrust works the same as for SF Rockets. Max Thrust numbers are wild guesses but intended to keep rockets small and less powerful than anything on the existing table.

This is very much a work in progress, so thoughts about how to improve this are welcome.

 

[Werner]

In poking through FF&S and WTH the other day, I realized the books don't allow for black powder rockets, like the Hale and Congreve or even the early Chinese rockets like the Huo Jian. So, as part of getting the collective brain trust involved, here are a couple proposed additions to the Self-Contained Thrusters table on page 70 of FF&S:

Engines
TL 2 Black Powder, Th *, MaxT 1, FC 25, FT BP, Airframe Super
TL 3 Black Powder, Th *, MaxT 2, FC 20, FT BP, Airframe Super

Fuel
TL 2 Black Powder Density 1.5, Price 7500
TL 3 Black Powder Density 2, Price 10000

The FC is loosely based on the difference between black powder's specific impulse and early solid rocket fuel specific impulse. Density is likewise roughly based on black powder's, and the price is based on WTH page 99 listing artillery charges at 5 credits per kilogram. Thrust works the same as for SF Rockets. Max Thrust numbers are wild guesses but intended to keep rockets small and less powerful than anything on the existing table.

This is very much a work in progress, so thoughts about how to improve this are welcome.

Black powder requires an oxidizer, so it won't work in space.

 

[Timerover51]

During the U.S. Civil War, the Union government was paying 25 cents per pound for gunpowder, with much of the required saltpeter being imported from India. Twenty-five cents a pound would equate to fifty-five cents a kilogram. The Dupont Powder Mill in Wilmington, Delaware was turning out 175 barrels of powder a day at 100 pounds per barrel. The Union purchased over 23 million pounds of various types of black powder during the Civil War.

That price is an order of magnitude too high.

For more information on making blackpowder rockets, you might wish to download a copy of the 1861/1862 U.S. Army Ordnance Manual from archive.org. On Project Gutenberg, you also have Congreve's book, The Details of the Rocket System.

 

[Timerover51]

Black powder requires an oxidizer, so it won't work in space.

The oxidizer in black powder is the saltpeter, which is normally around 75 percent of the mix. Black powder will function fine in a vacuum. The rest of the mixture is typically 15 percent charcoal (a limited number of trees supply good charcoal), and 10 percent sulphur.

 

[TheDark]

During the U.S. Civil War, the Union government was paying 25 cents per pound for gunpowder, with much of the required saltpeter being imported from India. Twenty-five cents a pound would equate to fifty-five cents a kilogram. The Dupont Powder Mill in Wilmington, Delaware was turning out 175 barrels of powder a day at 100 pounds per barrel. The Union purchased over 23 million pounds of various types of black powder during the Civil War.

That price is an order of magnitude too high.

The price probably doesn't match real world examples, but for the sake of providing a clear starting point for people to house rule from, I'll stick with the canon price for cannon powder from the World Tamer's Handbook.

For more information on making blackpowder rockets, you might wish to download a copy of the 1861/1862 U.S. Army Ordnance Manual from archive.org. On Project Gutenberg, you also have Congreve's book, The Details of the Rocket System.

The 1850 Ordnance Manual is also helpful. It doesn't have the details on making rockets, but it does have range tables. Britain's 1887 Treatise on Ammunition has some details on rockets, but it doesn't seem to be freely available online so I'm not certain exactly what it has.

 

[aramis]

The oxidizer in black powder is the saltpeter, which is normally around 75 percent of the mix. Black powder will function fine in a vacuum. The rest of the mixture is typically 15 percent charcoal (a limited number of trees supply good charcoal), and 10 percent sulphur.

This has been demonstrated by several youtubers.
Cody's Lab is the one I most remember... he's done a couple. I can only easily google one up from him.

https://www.youtube.com/watch?v=_yQBEoJyolM&ab_channel=Cody'sLab
https://www.youtube.com/watch?v=nhDw-2jKXNo&ab_channel=ExplosiveScience
https://www.youtube.com/watch?v=Ijm0aUNHFPk&ab_channel=WarpedPerceptionX

 

[Timerover51]

The price probably doesn't match real world examples, but for the sake of providing a clear starting point for people to house rule from, I'll stick with the canon price for cannon powder from the World Tamer's Handbook.

I am not sure what you mean by "real world examples" as that is a Real World Example from a time when black powder was in very wide use. If you mean the price of black powder today, it is going to be quite a bit higher, as the quantity produced is much lower that millions of pounds a year.

Per the report of the Chief of Ordnance for the Fiscal Year ending on June 30, 1882, the Ordnance Department sold to Dupont on July 6, 1881 77,700 pounds of serviceable cannon powder for 12 cents a pound, presumably surplus from the Civil War purchases.

On July 13, 1881, the Ordnance Department sold to Dupont 1,200 pounds of unserviceable cannon powder for eight cents a pound.

On November 14, 1881, the Ordnance Department sold to Dupont 192,400 pounds of cannon powder for 10.5 cents per pound.

These were also the prices of black powder being sold to other companies as well.

On July 7, 1881 the Ordnance Department sold to Dupont 100.000 pounds of serviceable musket powder for 14 cents a pound. These sales alone equal 370,100 pounds of cannon powder, viewed as surplus by the government. Do you want a screen shot of the full sale list posted?

Edit Note: The 1895 Montgomery Ward Spring and Summer Catalogue lists Dupont selling 25 pound kegs of black powder for $3.25 a keg. That is 13 cents a pound per 25 pound keg.

Edit Note 2: The following quote comes from the book, America's Munitions 1917-1918 by Benedict Crowell, Assistant Secretary of War, Director of Munitions, published by the Government Printing Office in 1919, reporting on U.S. military production for the Army in World War One. It can be found on both Project Gutenberg and archive.org.

Black powder of all grades for military purposes was being produced at the rate of 840,000 pounds a month, at a cost of 25 cents a pound, at the time the armistice was signed. At that time there was on hand 6,850,000 pounds of black powder.

 

[whartung]

That price is an order of magnitude too high.

How much is it in inflation adjusted 1980 dollars?

And, here's a riddle, what kind of power would you from the SRBs on the Space Shuttle if they were black powder? Would they be safe at that scale?

Out of curiosity, were the SRBs the largest solid fuel rockets made?

 

[Diveguy]

In poking through FF&S and WTH the other day, I realized the books don't allow for black powder rockets, like the Hale and Congreve or even the early Chinese rockets like the Huo Jian. So, as part of getting the collective brain trust involved, here are a couple proposed additions to the Self-Contained Thrusters table on page 70 of FF&S:

Engines
TL 2 Black Powder, Th *, MaxT 1, FC 25, FT BP, Airframe Super
TL 3 Black Powder, Th *, MaxT 2, FC 20, FT BP, Airframe Super

Fuel
TL 2 Black Powder Density 1.5, Price 7500
TL 3 Black Powder Density 2, Price 10000

The FC is loosely based on the difference between black powder's specific impulse and early solid rocket fuel specific impulse. Density is likewise roughly based on black powder's, and the price is based on WTH page 99 listing artillery charges at 5 credits per kilogram. Thrust works the same as for SF Rockets. Max Thrust numbers are wild guesses but intended to keep rockets small and less powerful than anything on the existing table.

This is very much a work in progress, so thoughts about how to improve this are welcome.

Is the intent to model in-atmosphere surface to surface/air type rockets? Or is this a thought of something capable of escape velocities (NOT reasonable with black powder given the burn characteristics).

 

[TheDark]

How much is it in inflation adjusted 1980 dollars?

And, here's a riddle, what kind of power would you from the SRBs on the Space Shuttle if they were black powder? Would they be safe at that scale?

Out of curiosity, were the SRBs the largest solid fuel rockets made?

Black powder STS SRBs would definitely not be safe. The likelihood of a crack somewhere in the fuel causing unpredictable ignition characteristics would be too high.

The SRBs are not the largest SFRs made. They have a thrust of 2.8 million pounds and a burn time of 127 seconds. Aerojet built a trio of experimental solid rocket motors. The goal was to see if a single solid rocket could replace the first stage of a Saturn I. The first two fired with 3.5 million pounds of thrust for two minutes, and the third was set for a higher thrust of 5.4 million pounds with a shorter burn time.

Is the intent to model in-atmosphere surface to surface/air type rockets? Or is this a thought of something capable of escape velocities (NOT reasonable with black powder given the burn characteristics).

Honestly, I was just trying to fill a gap in FF&S. I don't see a use for it beyond primitive artillery rockets or signal flares, but maybe some additional use cases would exist on non-Earth-like planets.

 

[Timerover51]

How much is it in inflation adjusted 1980 dollars?

The inflation factor from the time period I am quoting prices from, circa 1860 to around 1900 is 10. However, the original poster does not seem to be looking at what the price would be at a Tech Level roughly equal to today, but a Tech Level in Traveller: The New Era comparable to much earlier Tech Levels. I have no idea what the Tech Level for a period from 1860 to circa 1900, which is Tech Level 4 in Classic, would be.

And, here's a riddle, what kind of power would you from the SRBs on the Space Shuttle if they were black powder? Would they be safe at that scale?

Out of curiosity, were the SRBs the largest solid fuel rockets made?

If you could safely build a black powder rocket that big and with the same mass ratio, you would get about 1/3 the thrust and about 1/3 the velocity change. Far more likely would be them being the world's largest ever firecracker.

 

[TheDark]

The inflation factor from the time period I am quoting prices from, circa 1860 to around 1900 is 10. However, the original poster does not seem to be looking at what the price would be at a Tech Level roughly equal to today, but a Tech Level in Traveller: The New Era comparable to much earlier Tech Levels. I have no idea what the Tech Level for a period from 1860 to circa 1900, which is Tech Level 4 in Classic, would be.

I am not looking at what the price would be for any Tech Level. As I tried to explain previously, I am using the price from the World Tamer's Handbook. Historical prices may be interesting, but are irrelevant for my purpose.

 

[Timerover51]

I am not looking at what the price would be for any Tech Level. As I tried to explain previously, I am using the price from the World Tamer's Handbook. Historical prices may be interesting, but are irrelevant for my purpose.

I guess given my background as an historian and former Army supply officer, I naver view historical data as irrelevant. If the data in a role-playing game manual conflicts with actual data, the actual data wins out, unless the author of the manual was using say, prices of equipment, as a mean of relieving the players of all of the loot thay had collected.

 

[Werner]

The oxidizer in black powder is the saltpeter, which is normally around 75 percent of the mix. Black powder will function fine in a vacuum. The rest of the mixture is typically 15 percent charcoal (a limited number of trees supply good charcoal), and 10 percent sulphur.

I remember the saying, "keep your powder dry." Apparently keeping black powder dry was important to the musketeer. Most soldiers in the gunpowder age took pains not to dunk their firearms in water or to get their powder horns wet, apparently wet gunpowder didn't work very well or at all.

 

[whulorigan]

I remember the saying, "keep your powder dry." Apparently keeping black powder dry was important to the musketeer. Most soldiers in the gunpowder age took pains not to dunk their firearms in water or to get their powder horns wet, apparently wet gunpowder didn't work very well or at all.

As a 17th Century Living History re-enactor, I can tell you with authority that damp blackpowder (even blackpowder on a humid day) routinely causes misfires/hangfires, or makes firing completely impossible (to say nothing of it being actually wet).

Matchlocks are more reliable in humid conditions than firelocks, simply because a matchlock does not have a metal frizzen on which condensation can accumulate, extinguishing any potential spark. (Hot smoldering match going directly into powder is much more reliable in such cases, though it can still suffer from the powder "gumming-up" with humidity, however, just like with a firelock).

A firelock will not fire reliably (or at all) in humidity or rain of any amount, whereas I can usually fairly reliably fire my matchlock in a light rain or drizzle.


BTW, this thread may also prove to be of some interest: English Civil War Small Arms for TL 2 worlds .

 

[Enoki]

Black powder as a rocket propellant has several poor qualities. Unlike smokeless powder or nitrocellulose that has mostly replaced it, it is consumed essentially all at once making it an explosive versus a very energetic, fast burning material. It also has a rather low specific impulse by weight so it doesn't provide as much thrust as other fuels would.

The result is that past a certain point more isn't better. That is, black powder as a propellant is consumed in an instant rather than giving sustained thrust over several seconds or longer. That means the rocket receives a specific impulse on launch then coasts thereafter.

This, in turn, means that a black powder rocket has a limited range based on that initial velocity and its weight and aerodynamic shape.

There are some pages available for amateur black powder rocketry that might be useful as a starting point for determining flight distances, etc.

https://www.insanerocketry.com/blackpowder.html
http://rocketrycalculator.com/rocke...Edvvg6sinR4RsRdaYqCu-NCaeITNmweYF7-AXHHZftliK

Of course, these are for small motors. Something larger would require a casting of the powder to allow for proper ignition rather than just packing the rocket with it.

In a Traveller setting, I'd think a crude rocket fuel would more likely be something like rubber dissolved in a solvent with quick lime added then cast into motor form. Asphalt (tar) would be another alternative. Changing the quick lime to ammonium nitrate would be even better. These could be manufactured at very low tech levels as easily--and more safely--than black powder.

 

[Grav_Moped]

Black powder as a rocket propellant has several poor qualities. Unlike smokeless powder or nitrocellulose that has mostly replaced it, it is consumed essentially all at once making it an explosive versus a very energetic, fast burning material. It also has a rather low specific impulse by weight so it doesn't provide as much thrust as other fuels would.

The result is that past a certain point more isn't better. That is, black powder as a propellant is consumed in an instant rather than giving sustained thrust over several seconds or longer. That means the rocket receives a specific impulse on launch then coasts thereafter.

This, in turn, means that a black powder rocket has a limited range based on that initial velocity and its weight and aerodynamic shape.

There are some pages available for amateur black powder rocketry that might be useful as a starting point for determining flight distances, etc.

https://www.insanerocketry.com/blackpowder.html
http://rocketrycalculator.com/rocke...Edvvg6sinR4RsRdaYqCu-NCaeITNmweYF7-AXHHZftliK

Of course, these are for small motors. Something larger would require a casting of the powder to allow for proper ignition rather than just packing the rocket with it.

In a Traveller setting, I'd think a crude rocket fuel would more likely be something like rubber dissolved in a solvent with quick lime added then cast into motor form. Asphalt (tar) would be another alternative. Changing the quick lime to ammonium nitrate would be even better. These could be manufactured at very low tech levels as easily--and more safely--than black powder.

If the power output is effectively a detonation, do it in stages (or rather, a series of impulses). Sort of like a very-low-tech, very-inefficient Orion-drive rocket. Pretty sure I read a novel built around that idea once.

But, yeah, you can do better for rocket propellant even at the same tech level.

 

[Werner]

If the power output is effectively a detonation, do it in stages (or rather, a series of impulses). Sort of like a very-low-tech, very-inefficient Orion-drive rocket. Pretty sure I read a novel built around that idea once.

But, yeah, you can do better for rocket propellant even at the same tech level.

Black powder can be used in fire crackers and as noise makers to scare horses. Not so good as spaceship propellants, also solid fuel rockets can't be throttled, there are no fuel pumps, just a tube packed with powder, you ignite it and you burn the whole thing.

 

[MThompson016]

It is possible to build a solid propellant rocket that can be throttled. US8336287B1 is a patent on designing a solid propellant system that shuts down in flight and can be restarted. It's a relatively new technology, and stops combustion when the pressure in the stage gets too high.

Additionally, pulsed rocket motors exist. This places a barrier between cast sections, allowing for either commanded or planned ignition of sections in a stage.

Finally, it could be planned to vary the thrust of a stage based on the grain geometry. Many solid propellant motors have star shapes cut through the propellant grain to ensure level thrust and a quicker burn, but it could be designed to start with one (circular bore) and burn into a star.

 

[TheDark]

Black powder burn times aren't quite instantaneous, at least not for the compressed mixtures used for TL 3 rocketry. The Hale used a launcher with a resisting disk that used a weight on a pendulum to hold the rocket until a specific level of thrust was achieved. That adjusted the range without changing the launch angle by having the rocket burn propellant while held back. Total burn time was 10 seconds, and the counterweight could be set to hold the rocket up to 8 seconds. They were quite slow - only about 300 ft/s, so I may have to play around with the numbers to get the right balance between thrust, fuel consumption, and total weight.