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TheDark April 12th, 2021 05:21 PM

Black powder as a rocket fuel
 
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 April 12th, 2021 06:07 PM

Quote:

Originally Posted by TheDark (Post 623969)
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 April 12th, 2021 06:11 PM

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 April 12th, 2021 06:18 PM

Quote:

Originally Posted by Werner (Post 623971)
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 April 12th, 2021 09:13 PM

Quote:

Originally Posted by Timerover51 (Post 623972)
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.

Quote:

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 April 13th, 2021 12:51 AM

Quote:

Originally Posted by Timerover51 (Post 623974)
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=_yQB...el=Cody%27sLab
https://www.youtube.com/watch?v=nhDw...plosiveScience
https://www.youtube.com/watch?v=Ijm0...pedPerceptionX

Timerover51 April 13th, 2021 01:53 AM

Quote:

Originally Posted by TheDark (Post 623982)
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.

Quote:

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 April 13th, 2021 04:49 PM

Quote:

Originally Posted by Timerover51 (Post 623972)
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 April 13th, 2021 07:49 PM

Quote:

Originally Posted by TheDark (Post 623969)
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 April 13th, 2021 09:11 PM

Quote:

Originally Posted by whartung (Post 624007)
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.


Quote:

Originally Posted by Diveguy (Post 624013)
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.


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