Fireworks 101 [NA]

fgcason

En-Route
Joined
Feb 23, 2005
Messages
3,620
Location
Nomad
Display Name

Display name:
Frank Cason
In light of the upcoming holiday that usually involves lots of fireworks, I know there are at least some on the board that would enjoy this little story.

P.S. Don't try this at home unless you know what you are doing.

===========================================
About 2 weeks ago, I was looking around the Web for the BIGGEST sky rocket that I could get shipped to me via common freight carrier. I located a fireworks importer in Wisconsin who had this mondo sky rocket--biggest thing I had ever seen--called a SkyDragon. These things are 48 inches tall and are mounted on a 1/2-inch wooden dowel. Pure aerospace engineering.

I plopped down a bunch of money and had him send me two cases of these things. They arrived at the freight dock a few days ago and I had to drive the van over to pick them up. Two boxes each 2 feet by 2 feet by 4 feet in size containing 80 rockets each. The 'Class 4 Explosives' sticker on the side of each box was a real bonus. I am gonna have to save them for the scrapbook.

That night, me and the kiddos had a gen-u-ine rocket launch ceremony. I placed one of these beauties in a liter-size glass bottle and the bottle fell over. Hmmmm- this thing was waaay too big. I looked around the shop for a pipe to set it in, but realized that the only dirt I could drive the pipe into was in plain sight of my neighbor's house. I knew he was a cool guy, but I didn't want him to call the cops. You see- 'projectile-type' fireworks are totally illegal in this county. I was surprised that the Buncombe County Sheriff Department wasn't waiting for me at the loading dock when I picked these things up. Anyhow, I finally rigged a launch pad by prying up one of the driveway drain grates with a crowbar and sitting the stick into the deep pit. Looked sorta like an ICBM silo with its hardened lid slid aside.

I asked which of my three kids wanted to light the fuse, but all took a few steps back and politely declined. Chickens&(%$. Kids just aren't made the same nowadays. They fulfill their danger quotient by shooting bad guys in video games. About as far from real danger as you can get, if you ask me.

I told the little weenies to stand back as I bent to light the device with a Bic lighter.

The lady at the fireworks importer promised me that these things would NOT make any noise. I told her that they HAD to be relatively quiet so I could shoot them off in my neighborhood without causing 'undue alarm'. She said I wouldn't have any problem. I emphasized the particular legal problems I would have if there were any type of loud report at apogee. I emphasized the fact that I lived right next to a National Park and that any type of firework that was discharged or assumed to be discharged on that property would get me sent before a FEDERAL judge right before I got sent to the COUNTY judge. She again assured me I would have no problem.

That lying bi&@h.

That rocket engine had a burn time about as long as any I had EVER seen, and the ascent echoed off the surrounding trees. Diamond shock patterns extended from the back end. It kept going and going and going. When it hit apogee at about 1000 feet, the rocket disintegrated into a huge shower of silent red sparks. Pretty cool, I thought......until the shower of sparks burned out and suddenly transformed into a cloud of extremely bright and loud explosions. The kids scrambled into the back door 'Three Stooges' style (ie: where all three try to get through the same closed door at once) and left me standing in the smoking haze waiting for the cops to arrive. The dogs that live along our street were all barking their heads off at the apparition they had just witnessed in the night sky.

That ended the fireworks test for the night.

The next day, my oldest son Steven and I decided we were gonna 'neuter' one of the rockets so it wouldn't make any noise. I took him into the closet where I store the gardening tools and he saw these two huge cases of fireworks standing there. The kid went nuts. He wanted to open BOTH boxes so he could see what all 159 rockets looked like lined up next to each other. This kid has promise. I told him: "Since mom only thinks I have a few of these things lying around, maybe that wasn't such a good idea." He mulled that over for a few seconds, then gave me a real big smile in agreement.

We pulled one of the rockets out of the box and re-locked the closet door.

He and I both sat down on the driveway and proceeded to take it apart. It was a standard issue big-a$$ Chinese sky rocket. I bet they used these to kill people 500 years ago. As I sat there taking layer after layer of paper off, his brain was filling with the details of construction. Tissue, cardboard, plastic, fuses...etc. Realizing that he was mentally storing the design for some future project sorta made me shudder. All I was thinking was the fact that this thing was probably put together by a political prisoner in a hellhole somewhere who is probably gonna get 'executed' so they can sell his internal organs on the transplant market.

Probably not too far from the facts, but I managed to do a bit of explaining to him from the standpoint of aerospace engineering regarding how the thing worked. Steven is probably the only 4th grader in the U.S. who can now describe the principle of thrust using a control volume model.

The rocket was pretty simple. It had a very large booster engine topped with a warhead that contained the red sparkly things that exploded. Removing the warhead was as simple as giving a quick twist, and I assumed the neutered rocket would fly higher without the payload. I was correct. Steven and I did a daylight 'stealth' test and were able to add about 50% to the altitude attained the previous night. We decided to modify four more rockets and put them aside in the closet for easy access. When this was done, Steven had a jar full of stuff that came out of the warheads including: 12 fuses about 3-inches long each, some paper, 4 plastic nosecones and a big handfull of these little black balls about the size of 12-gauge buckshot that turned out to be the 'red sparkly popper things'. It appeared that the outer layer was a simple gunpowder coating designed to quickly burn off as red shower of sparks. I surmised that the inner core had some kind of magnesium thermite that gave off an intense white light and a loud bang. Pretty cool if you ask me. Lots of energy packed into one teeny little ball.

I didn't want to see the popper thingies go to waste, so I told Steven we were gonna put them in a hole in the ground and set them off. He gave me another big smile.

It's amazing how kids think alike...even when separated by 30 years.

As I was digging a shallow hole with my hand, Steven asked if it would be alright to put an army man next to these things so that "When they go off, it would look like he was getting shot with a maching gun". Dang....exactly what I was thinking. I agreed and he ran off to his room to dig something out of the mess. He returned in about 3 seconds, out of breath and holding a cheap plastic imitation of Robert E. Lee on horseback and a Civil War cannon. I pointed out that they didn't have true machine guns in the Civil War, but we would overlook this for the purpose of the demonstration. He handed me the action figure and I placed it and the cannon next to a rather large pile of black beads from which a few of the fuses extended.

I figured that three inches of fuse would take 2 seconds to burn, so I had at least that amount of time to stand up and take a few steps back. I neglected to recount the night before.....when the warhead ignited IMMEDIATELY upon reaching apogee. Tricky Chinese. They had installed extremely fast-burning fuse in these things and that fact totally escaped me.

I squatted next to Robert Lee and gave a short eulogy. Steven laughed. I took the trusty Bic lighter and placed it next to the fuse. One flick got the lighter going and THIS IMAGE IS ONE I WILL REMEMBER FOR A LONG TIME. My hand holding a lighter next to a pile of explosives.

There is usually a short but noticeable mental pause that occurs immediately before something bad or really stupid happens. It is where that little voice in your head says: "You dumba$$."

The fuse burn time was in the 1/1000ths of a second range. The pile of little popper thingy's immediately ignited into a tremendously brilliant ball of fire. All I could think was ..."...th....th.....thermite..." Unfortunately, when they are viewed at ground level, these little popper thingies become REALLY BIG POPPER THINGIES and have a tendency to jump up to 15-feet in every direction from their point of ignition. I instantaneously became engulfed in a ball of fire that sounded a lot like being in a half-done bag of Orville Reddenbacher's popcorn.

It was all over about as fast as I could snap my fingers.

After the smoke cleared, Steven started laughing his rear end off. That meant I was still in one piece. Steven does not laugh at dismembered limbs. He said I jumped about 10-feet, an action that I do not remember. I checked my clothes for burn marks, and found none. He checked my back to make sure it was not on fire. No combustion there. The driveway was peppered with black holes where the concrete had been scarred from these things.

A close one. Another REAL close one. My mind ran the tapes again to re-hash what it had seen. All I remembered was being inside something akin to a 30-foot diameter........flaming dandelion. Whew.

We examined Ol' Robert E. at ground-zero.

Instead of a machine-gun peppering, he got nuked. He and the horse he rode in on.......and his cannon too. One side was untouched, but the other side was arc-welded. Real warfare. Steven examined it real quiet-like and then started laughing again.

I assume he will remember the finer points of the lesson as he grows older. When I now speak of 'almost being burned beyond recognition' he will have a slightly better understanding of what I mean. I hope that this vivid image tempers the knowledge he now has regarding rocket construction. Oh well. After all, if your dad isn't gonna teach you how to get your rear blown off, who will?

===================================
 
Frank that is hilarious. Nothing unreasonable in the entire story. Seems like a normal afternoon of fun to me. :D
 
Reminds me of when at 17 I went up to my dad "We're gonna make some nitro glycerin (to blow up 10 acres worth of tree stumps), any adice?", "Don't do it", "Well, we're gonna anyway","Mix the acids very slowly and have lots of salt and ice. If you see anything start to boil, run as fast as you can because it's gonna blow". On batch 20 something, he was proven right.
 
Henning said:
Reminds me of when at 17 I went up to my dad "We're gonna make some nitro glycerin (to blow up 10 acres worth of tree stumps), any adice?", "Don't do it", "Well, we're gonna anyway","Mix the acids very slowly and have lots of salt and ice. If you see anything start to boil, run as fast as you can because it's gonna blow". On batch 20 something, he was proven right.

Henning, you seem to have done it all, and amazingly survived to tell. Most people, I'd throw down on 'em, run up the BS flag. Your bona fides have been adequately vetted, though, so you must be the luckiest SOB around.

So.

Tell the Nitro story, and spare no details.
 
I loved the story. Reminded me of my childhood, my Dad, and how truly LOUD July 4th used to be (and not all professional fireworks displays).
 
If you google "fireworks Skydragon" you'll see that this story dates from at least 1999. From what i can see it was first forwarded around the University of Virginia. Forwarded, meaning it might not even have originated then.

Funny how great writing survives long after the original author is lost to net history.
 
I had my own share off experience with explosives in my mid teens.

I was in Caracas, Venezuela at the time. (For those of you who don't know, it's the capital, huge city, 5 million at least, skyscrapers galore, I lived in the 24th floor) I didn't have enough money for fancy rockets so I had to come up with creative alternatives.

The most popular type of fireworks were this little tubes, just a bit bigger than a cigarette, which gave a very, very loud explosion sound. Extremely simple, a small cardboard cylinder filled with gunpowder, with a fuse on one end and a plug on the other.

Well they were very fun, and illigal, but everyone bought them. The cool thing was the explosion would resonate in the city between nearby buildings. One time I had a little demonstration of the speed of sound; I was on the phone with a friend whole lived one block away, when one of these fireworks (called fosforitos in spanish) went off and I heard it first through the phone, and less than a second later heard it in person.

Well anyways, later on I started experimenting with these things. I found out if you cut out the end with the plug on one of these things, and then lit it, it would a very bright flash, with no sound (that's when I learned the loud sound came from the gunpowder being confined, and the tighter the packaging the louder the sound. That's when I got the idea to make my first home made device.

I cut open 10 fosforitos, and put their gunpowder inside a matchbox. On one of the sides of the box I made a small hole where I stuck half of a fosforito, the end with the fuse. I used some tape, wrapped all sides of the matchbox and took it to a location to set it off. I hadn't used enough packaging, so the result was a very wimpy explosion, and a lot of smoke. I went back to the drawing board and this type I repeated the previous steps, but this time used layers and layers of cartboard, and then very thick tape to wrap it all in. At the time I went to try it out with a friend, less than a block away from my music conservatory (bad idea). That thing was the loudest thing I had heard, ever. I had my fingers in my ears, but I felt the explosion through my body. It was all fun until I almost got expelled from the conservatory.

Needless to say I built another one and took it to a female's friend appartment. She lived in the 13th floor. I went in a room with another friend (who was asking me to throw it, even agains't my hostes's will). So I did, although not onto the street but out a windo looking into some parking lots and whatnot. I lit it and threw it as hard as I could. A few seconds later, wow, another MASSIVE explosion. Again, there was lot of ressonance from the buildings. Of course I got kicked out of the appartment by my friend... (she just didn't know how to have fun). On my way out I see the police talking to a person about a possible gas line explosion... ummm .... I got out of there as fast as I could. Oh so much fun, that was the last time I ever messed around with that stuff.

Disclaimer: Never do anything similar to what I did, it was stupid, and could have blown myself up...
 
Tomahawk,

You need to hook up with Ben Myers of this board and AOPA. He's a fine cellist, college music professor and good guy.
 
SCCutler said:
Henning, you seem to have done it all, and amazingly survived to tell. Most people, I'd throw down on 'em, run up the BS flag. Your bona fides have been adequately vetted, though, so you must be the luckiest SOB around.

So.

Tell the Nitro story, and spare no details.

Not really a major story. My friends granpa had some land west of St. Louis, several hundred acres mixed hardwoods and cleared. Well he had another 10 acres felled for lumber and we were assigned the task of clearing the stumps. After a day with chainsaws, shovels and a tractor,(the equipment supplied to us) we made some quick calculations and figured it woud take us about 6 years to finish the project. So we decided to blow the stumps apart. I was making it in small batches because and filling his granpas old cigar tubes. We'de ignite by topping the tube with an M-60 firecracker that we'd put longer fuses in. Just chainsaw around at the surface roots, drill a hole in the stump with a long auger bit, place charge and ignite. Simple and quick. We were working out of an old rickety shed behind the barn when I was pouring in the sulfuric acid and it started to boil. I yelled "Run" which was the agreed upon signal to do just that. Nitro 1, Shed 0. We were done in a month. His grandpa was amazed, told us he never expected us to finish, he just wanted to teach us what "Hard Work" was really about for the summer and then have a crew with equipment come in the next spring and have it cleared. "By the ways boys, what happened to the shed?", "Uuhhhhh, we kinda blew it up", "Oh well, it was about to fall down anyway...".
 
Back
Top