Can gunpower be used as a rocket propellant?

Factual Questions
21
      • As I remember, it was always the nozzles we couldn’t make right. The paper tubes we could make, but the nozzles of the Estes engines was this sort-of clay stuff, and we tried to duplicate them with different modeling clays… -but if the nozzle isn’t perfectly concentric, the rocket only lifted off a foot or so and then did tight sommersaults.

  • You could use either black powder or smokeless powder as propellant, ideally you’d want to add some charcoal to it to slow its burn rate down. The recipes for black powder and propellant are very similar, the propellant only has more charcoal IIRC*. And yea, the stuff might blow up on you. If you tried it.

  • When I was a wee lad, there was a set of Collier’s encyclopedias from the 19060’s in the house. If you looked up “fireworks” in them, it gave instructions for making fireworks. If you looked up “explosives”, it didn’t give recipes, but for a dozen or so major types it gave a list of ingredients and a general overview of how they were mixed.
    ~
22

We solved this by making the rocket motors out of large bamboo sections; the nozzle was just a small hole drilled through the woody node; the node at the other end was cut off and the propellant (which had been crystallised onto a sheet of blotting paper, then tightly rolled, but I’m still not going to mention the recipe) was loaded through the open top end, which was then plugged with a dowel, glued and bound.
About half of the rockets so constructed blew up violently, sending dangerous razor-sharp splinters of bamboo in every direction, but those that worked, worked incredibly well - they were launched in daylight, but disappeared completely out of sight and we never saw them come down.

23

How comes nobody told me about all these neat tricks with match heads, black powder and homemade explosives when I was a kid? :mad:

24

We were afraid you’d poke an eye out.

25

Hmm…and probably rightly so…

26

The OP is, of course, describing a cannon. Mangetout, too, was describing a poorly made cannon.

I’m licensed by the Commonwealth of Massachusetts to fire cannons. AFAIK we one of only two states that require a license.

The most important things about putting black powder in a tube are the construction of the tube and the granulation of the powder.

A cannon, be it cast iron, bronze, whatever, is thicker at the breech to better withstand the force created by the rapidly burning powder. In Massachusetts, new bronze or cast iron cannons are required to have an inner sleeve of SEAMLESS 1/4 inch stainless steel. Older guns, like the original Mexican War 24 pounders I fire must be tested for microscopic cracks that could cause the barrel to shatter.

Black powder comes in a number of granulations from very fine FFFFG for pistols and priming to coarse FFG musket powder, and even coarser FG and Cannon Grade powders. The finer the powder the more powerful the force.

Usually 3 to 4 ounces of FG or Cannon Grade powder is allowed for each inch of bore diameter. If you loaded that much FFFFG into the gun, it could mean death to your crew and any bystanders.

When our crew fire cannons with a six-inch bores for ceremonial purposes at a seacoast fort, we fire with 18 ounces of powder, and no packing or projectile. It’s a blank charge. We get an impressive boom that can be heard miles away.

These very same guns could fire a 24-pound iron ball a mile or more (with a larger powder charge.)

This is not something to try at home without training, but it’s what was used in times of war for hundreds of years.

The test for a license in MA requires knowledge of gunpowder handling, storage, transportation, proper procedure for making the charge, the entire gun firing drill, the procedure for dealing with misfires, the “clear zone” for spectators, etc.

Fireworks operators take an even tougher test covering a lot more rules and regulations.

27

I guess I’m more interested in propelling something across a parking lot. Heres what I am thinking.

In the movie Dawn of the Dead (2004), the stranded people are witness to a single, stranded man across the mall parking lot. They then attempt some incredibly daring stunt to rescue him.

I had the idea "What if they shot some kind of rocket across the parking lot. They could attach a steel line, have him chimmy across, boom. He’d be safe.

What I was wondering, how easily could you build a rocket that would shoot a minimum 1500 feet. I thought that gunpowder might do the trick.

Does that help anyone?

28

Told you it was a rocket! :smiley:

29

It is intended for a rocket, but I’m not opposed to vigilante milita cannons :smiley:

30

I recommend The Big Bang: A History of Explosives by G.I. Brown. It is predominantly about gunpowder and an interesting historical read.

Few points about gunpowder - firstly, a loose mixture of the ingredients isn’t gunpowder, it’s “green meal” and its burn rate is pathetic. True gunpowder involves a degree of mechanical processing, and that step is dangerous! Historically, powder mills had blast walls and a weak wall to direct the inevitable “explosions” in a safe direction.

Secondly, gunpowder burns very hot, is very spark and flame sensitive, and is moderately friction sensitive. In a lot of ways it’s more antsy than many detonating explosives. Be sensible. Don’t take it lightly. A big heap may self-confine enough to puff up a fireball, and discussions about whether that’s a real explosion or not won’t bring your eyes back.

For somewhat lower-risk pyrotechnic fun, check out the film can cannon and the matchstick rocket on this siteL

http://scitoys.com/

31

for your zombie problem solving, you’d be better off with a cannon. It’ll take several tries to hit the target, and it is much easier to fine-tune the targeting on a cannon/mortar than on a homemade rock.

plus, hitting the top of a building from a kilometer away will be eaier with a parabolic arch than with rocket propelled line.

32

When PVC tubing explodes the semi molten schrapnel leaves wicked scars. :frowning:

When it worked it was spectacular, when it failed, whoo boy.

33

The Coast Guard’s used both cannon, Lyle Guns, and rockets for line throwing. I haven’t found a decent ref on the rockets, but some of the cites in this extensive bibliography seem to imply that rockets ended up being the preferred method of projection:

34

man you guys are so helpful. I’m glad no one even made fun of me for thinking that a safety line would have been their best bet.

35

Hahaha, everybody point and laugh!

36

My mother taught me how to place an explosive to take down a wall*, but my uncle never got around to teaching me how to make explosives.

While I know the theory, have recipes etc. now, being a father and such makes experimenting with explosives rather prohibited.
*Mom also taught me how to shoot, and how to do time in jail without getting shived. Mom’s an interesting woman.

37

Gunpowder was the only rocket propellant for the first centuries after the Chinese invented the things.

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The book “From the Earth to the Moon” by Jules Verne in 1865 described a gunpowder-fired cannon that shoots a manned capsule to the moon. His 900 foot cannon contained 200 foot of explosives. Sunk vertically in the ground, it fired a 9 ft. diameter capsule whose walls were supposedly a foot thick.

Though many facts won’t support this (especially the g-forces involved at firing), he did get several things right: prediction of weightlessness, inventing retro-rockets to slow the descent to the moon, etc. And all this about a century early!

The book is available for free online from Project Gutenberg. www.gutenberg.org/

39

Well my first thought was that if they’ve got a cannon they could just blast away at the zombies from the comfort of their rooftop.

Yeah, I’ve seen the movie. Just sayin’.

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no no, cannoning the zombies wouldn’t work. Unless you can set a cannon to only get head shots :smiley: