Underwater rocket launch

[John Anderson]

I cannot recall the thread but someone was wondering about launching a rocket from a scale boomer and some said "Estes" and water don't mix.
WRONG!
Back in high school myself and Joesph Padavano and our Physics teacher built and launched several Estes C series powered rockets froma pad sitting in 5 feet of water.
Heres the things to do to have a succesful submerged estes launch FOLLOW EXACTLY.
USE ONLY a C-6-3 or B-14- 3 delay ENGINE! no more no less
By the way I see no reason why a two stager wouldn't work we just never got around to it.
1) Build a tumble recovery type Estes rocket using waterproof Epoxy. But make sure the fit between nose cap and body is SNUG but not overly so. Just enough so you can pick the rocket loaded withan engine up by the nose without it sperating no more no less.
2) Paint you rocket normaly
3) Dip finished rocket WITHOUT ENGINE and with nose cone seperate in liquid parafin likewise the nose cone. RUB down the Rocket to remove excess cooled parafin. Fit the nose cone back inplace letting it shave the excess Parfin in the join area so it fits snuggly again. Carefully remove the cooled parafin from the engine holder until engine fits correctly.
4) With a fine brush carefully coat the engine case with parafin then agian rub it down till it fits the engine holder. You only need a very lite coating! DO NOT coat the ejection charge plug! Take a cotton swab and carefully insert it in the engine nozzle opening and agine with the fine brush lightly coat the engine nozzle with Parafin. DO NOT GET PARAFIN INSIDE THE NOZZLE OPENING. This completes pre load.
5) At launch site Insert nose cone into body and lightly cover the join seam with a thin layer of Vaseline.
6) Tape a piece of lite weight masking tape over the Ejection charge plug. after it is in place give it a lite coat of vaseline. Insert engine in rocket.
7) place the igniter in nozzle as normal and using plasticine clay cap the nozzle opening just enough to coverthe hole and area you protected with the swap while parafining it.
8) place rocket in launch tube or pad hook leads to igniters and submerge.
9) FIRE! You will get maybe 50 feet or so in altitude froma depth of 4 feet using a standard launch rod.
10) Here is the tricky part! The rocket needs to be recovered VERY quickly and the engine removed before the engine case swells from water inside it. Like three minutes tops! So before doing this consider the rocket a one shot deal.

Now if you are doing a launch from a sub some things need considering HEAT!!!!!! mainly. I personaly would build the launch tube as follows. Using an aluminum tube with a wax plug that can melt at the tube bottom when the engine lites. This will do two things vent the exhaust into the water on normal launch and also act as a vent if the rocket hung in the tube. The top muzzle door would need a seal to keep the tube dry while shut. A piece of sharan wrap held witha rubber band cana ct as a secondery seal just like the real thing. Just prior to firing a puff of compressed air blows the seal off and clear of the tube. Then fire away. The tube can be made witha removable inner linner that holds the rocket and then it would be easy to connect the wires to the rocket outside the confines of a tube in a hull. This "cartridge" would be setup so that as it slipped in place it would make conntact with the igniton cricut wirung intrnal to the sub itself sort of like how a battery makes contact. A saftery interlock could be made that keeps power awy from the tube as long as the outer muzzle is shut in cruise position.
John

[coolsub101]

maybe not, i wor k with estes rockets. these things take a good second plus to fire after you push the button, plus it uses a lotta power. you probably could only use an a motor, since the lighting charge is about as powerful on a rockets, and they fire faster. b's can send a shel 400 feet, but in most cases, a motors can send a small shell higher than that, plus, if you wanted to launch a b motor, you would need the hatch to blow between when the button is pressed, plus, it may not be very stabll launching. use a capsule with guidance fins under the engine, and a shot of air to send it out the hole, air, not co2, and you could launch from lower than 4 feet. it may also help if you create a nosecone with a very sharp tip, amd small find portruding from the halfway mark. a three fin system will work best, though a simpler 4 fin sy stem could work too. also, painting the missile orange, and cutting holes in the rocket pod just above the engine will help keep it from being lost, and keep it on a straight path skyward.

[Aeroengineer1]

I too have made a rocket that fired form under water. We actually used A motors and fired it as a torpedo. Very cool!!! We launched it about 10 times. We had a fishing line with a swivel attached to one of the fins.

Adam

[coolsub101]

plus, if you plan on launching in a submarine, you'll need a strong launch base. a b motor can cut chunks from a cement coated launch plate at liftoff. it would damage the wire that carries the electrical charge, and cause a short. in other words, if you wanna launch a rocket from a sub, get a second small battery, make multiple tubes, and a timing mechanism so the rockets launch 2 by 2, abd most importantly, a pump in the tube, since flooded tubes can offset weight. then you could launch rockets from estes from a sub. water doesn't mix with estes rockets, since water dissolves the engines!!!

[coolsub101]

that sounds like fun, but does the delay charge ever blow the torpedo up
?

[Aeroengineer1]

No, but it did soften the hot glue that we used to mount the plastic nose cone to the plastic fin assy. We were only in 7th grade, so our engineering skills were not the best, but it worked. It went about 20' under water, then broached, then went back in for another 20'. The backfire kicked the motor out. We had fun.

[John Anderson]

maybe not, i wor k with estes rockets. these things take a good second plus to fire after you push the button, plus it uses a lotta power. you probably could only use an a motor, since the lighting charge is about as powerful on a rockets, and they fire faster. b's can send a shel 400 feet, but in most cases, a motors can send a small shell higher than that, plus, if you wanted to launch a b motor, you would need the hatch to blow between when the button is pressed, plus, it may not be very stabll launching. use a capsule with guidance fins under the engine, and a shot of air to send it out the hole, air, not co2, and you could launch from lower than 4 feet. it may also help if you create a nosecone with a very sharp tip, amd small find portruding from the halfway mark. a three fin system will work best, though a simpler 4 fin sy stem could work too. also, painting the missile orange, and cutting holes in the rocket pod just above the engine will help keep it from being lost, and keep it on a straight path skyward.

Cool if you read my post all the way through you would realize i had done the launch several times. The drag of the water 600 times that of air signifcantly cuts out altitude gained.
As far as a B blowing chunks out of concrete???? Wet maybe but cured???a D and F sure
I was heavily into Rockets for nearly twenty years flying everything from the tiny alpha to Super Scale Sprint ABM's I even Had a ten engine D class Dragon boost glider.
As Far as the delay with estes igniters yeah they are junk. we used what was called flash bulb ignition you soldered Photflash bulbs together and taped a Centarui solar igniter on the bulb and hot taped that in place worked everytime ZERO delay in lighting the candle. What also works to minimize bad lite offs is to use piano wire as the igniter and a few grains of Hercules red dot pistol powder. Very fast light off.
If you had further reead the post it details how to waterproof the engine.
Again this worked 100% on the multiple launches I did.
Nose cones a blunt parabolic cone of moderate curve works best for the water launch a sharp cone bird tended to cant over from cavatation on launch. And is also the best shape for the transition from water to air as porven by the Polaris and Posideon/ Trident class birds.
We found fin number really didn't matter albiet SHAPE did low drag parabolics gave best altitude after launch. Why cut holes in your body tube????/ It's sealed if you follow the step by step.
The speculation I made was in how to fire it froma launcher in a boat. As far as wires getting melted explain how my clips and leads lasted for over 100 launches each?
Power requirements are actually very low 3 volts in the pocket launcher system. Nearly all the boats her run on at least 5 cells 6 volts and up. My own Stingray is a ten cell boat.
As far as contact details go I'm sure the folks here could figure out a way better arangement. Such as strips on the outside of the body that contact a strip in the tube.
The air bubble I speculated on was to give a scale look no more no less.
The system you drew out os overly complex and would require a set of relays to sequence in order. A lot of our hulls just do not have the room.
ther eis a rule set down by the great Kelly johnson KISS Keep It Simple and Stupid.
And the maxum "An over complex design is the sign of a poor designer."

[coolsub101]

i launch model rockets quite a bit, and the "concrete" pad they give gets gaps in it only a fraction of a mm, but a tube could be worse..

[coolsub101]

you cut a hole in the body tube so the delay charge doesn't harm the rocket itself with heat.

[John Anderson]

So how do you deploy your recovery sytem or do you just let it auger in like a dart? Very unsafe doing that.