I worked on Minuteman III with I was in the USAF. Please post photos of your progress on this project.My next project will be a scratch built minuteman. I thought it might be interesting to build a scale silo to launch it from Has anyone done this before or have any suggestions?
Thanks
Fred
I worked on Minuteman III with I was in the USAF. Please post photos of your progress on this project.
Mario
PS
Never launch a rocket from the 11 foot deep section of a public swimming pool - especially if there is a very large woman wading in the shallow end of the same pool. Trust me on this one...
Hey Mario, I didn't know you worked in a silo. ANy details, photos or interesting bits of info would be appreciated. We had Titan II silos here in Arkansas, two of which blewup, I believe. Building a detailed silo to launch the rocket from is a great idea.
I worked on Minuteman III with I was in the USAF. Please post photos of your progress on this project.
Mario
PS
Never launch a rocket from the 11 foot deep section of a public swimming pool - especially if there is a very large woman wading in the shallow end of the same pool. Trust me on this one...
My next project will be a scratch built minuteman. I thought it might be interesting to build a scale silo to launch it from Has anyone done this before or have any suggestions?
I was thinking of a simple box pattern put in a hole then launch. detail the top maybe with a working hatch Biggest problem I see is exhaust crisping the rocket. I was wondering if a water tray would help or would it just steam said rocket?
Cheers
Fred
Oh, Fred, you are going to HAVE to launch it from a hole in the ground, now. None of this above-ground pseudo-silo business; if you are going to go to the trouble, it POSITIVELY HAS TO BE launched from underground. :bangbang:I was thinking of a simple box pattern put in a hole then launch. detail the top maybe with a working hatch Biggest problem I see is exhaust crisping the rocket. I was wondering if a water tray would help or would it just steam said rocket?
Cheers
Fred
My SS-17 and Minuteman III scratchbuilds over in the archives were designed for silo launch.
I actually launched the SS-17 from an actual in-ground silo once, though it was a test launch, not 'real'.
I used a hand post-hole digger to auger a hole about 3 feet deep in the backyard. I put concrete stepping stones on either side for 'silo doors' and pushed a launch rod down a couple inches in the clay at the bottom of the 'silo'.
For the test launch, I put a 1/2A6-2 in the rocket (designed for "D" motors) and installed the ignitor, hooked up the launch clips, and slid it down the rod into the silo. Then I launched it. It popped up out of the silo about 3 feet in the air, neatly laid over into the grass, and promptly popped it's 'chute'.
Kinda neat... I never got around to launching it 'for real' because it was about the time I started mechanic's school and got out of rocketry, and the rain collapsed the 'silo' before I could launch again.
I also made a 'revetment launcher' out of window screen stapled to a plywood square and covered with plaster of paris. This was basically a curved "mountain" like you might build for a model-railroading type layout, but portable on a plywood 2 foot-ish square, with a flat metal blast deflector under the 'launch pad' and a hole drilled for the launch rod. It looked pretty good-- flew my Alpha III off it a number of times.
I also made a plywood 'launch pad' similar to a stylized version of the ones at the Cape, with a 'flame tunnel' lined with steel on bottom, and a round hole in the top where the rocket sat over the 'flame pit' It worked pretty well and looked kinda neat. I'd even use a bit of masking tape rolled back on itself to tape a string 'umbilical' to the rocket very lightly before liftoff... still have videos of that one. I'd also load up the 'flame tunnel' with all-purpose flour so the engine jet gave a bit 'smoke cloud' at liftoff (though I wouldn't advise that anymore-- dust explosions would be bad).
I don't think I have pics of any of those anymore but the "Cape style" launcher-- if I do they're buried in my high school era junk somewhere.
Nowdays I launch everything off my clone of Dr. Zooch's "Pad 34Z" (Z for Zooch) that is detailed back in the archives and is visible in my build threads 'glamour shots' pics at the ends.
Later and good luck! OL JR
PS. I had planned to one day build a "portable silo" using a toilet flange and 4 inch PVC pipe and pipe cap from the lumberyard, centered in a plywood 'table' that could be either A) a cheap 'card table' bought cheap at a yard sale, B) set up between two sawhorses, folding chairs, or tables, or C) have four legs attached to it so it's free standing. I'd drill the bottom cap for the launch rod. Post pics!
I II or III? There are some good illustrations of a Minuteman II complex floating around on the web, a couple of the pix of which I think are mine, taken while I was with the PAO at the 321st Strat Missile Wing at Grand Forks.
We had Titan II silos here in Arkansas, two of which blewup, I believe. Building a detailed silo to launch the rocket from is a great idea.
Oh, Fred, you are going to HAVE to launch it from a hole in the ground, now. None of this above-ground pseudo-silo business; if you are going to go to the trouble, it POSITIVELY HAS TO BE launched from underground. :bangbang:
You could, I suppose, create flame trenches that vented upward to the surface next to the launch hole, but angling away from it. Isn't that how it worked with the real ones?
MarkII
I can't say that I have actually ever seen videos of any of the rockets that you mentioned being launched out of their silos, nor have I ever seen anything other than a very schematic diagram of any of their silos (and that was just for the Atlas). I was just guessing about the flame tunnels. The Soviets used them for their N-1 (which of course was launched from the surface, but the flames went into a hole in the ground and then vented back up at an angle at the surface).Minuteman was a SOLID FUEL missile, and so much more robust from an acoustics standpoint, so they were simply launched by "fire in the hole". The silo was basically a simple hole with a hard stand at the bottom that the missile sat on. Ever notice in those Minuteman launch vids, how the door opens, a HUGE flare of flame bursts straight up from the silo, and then the missile rises out of the flames, trailing licking flame and smoke before racing away, usually through a really 'cool looking' smoke ring?? That's "fire in the hole". The smoke ring is caused by the blast coming up ALL AROUND the missile as it lifts off from the silo.
The Minuteman didn't have fins, right? (But your model will need them.) I wonder how small of a span you could get away with?Another thought just occurred-- how about that cardboard 'Readi-tubes' used for concrete?? Those are bigger than PVC, cheaper, and would work just as well... (for a portable silo anyway). Gotta be big enough diameter silo for the fins on the missile to fit down it!
Later! OL JR
Try this link https://www.youtube.com/watch?v=2aHpqqhaHJ0I can't say that I have actually ever seen videos of any of the rockets that you mentioned being launched out of their silos, nor have I ever seen anything other than a very schematic diagram of any of their silos (and that was just for the Atlas). I was just guessing about the flame tunnels. The Soviets used them for their N-1 (which of course was launched from the surface, but the flames went into a hole in the ground and then vented back up at an angle at the surface).
MarkII
I saw a J-class rocket launched from a "silo" years ago, I think by the vendor RocketSilo. There may have been a photo of it in Extreme Rocketry.
At the last Plaster Blaster, a team from Arizona launched four Patriots from a scale launch container.
Only on Titan I, Titan II, and Atlas... those were liquid fuelled and the acoustics of the engines firing up and coming up to thrust, along with whatever 'detritus' in the bottom of the silo might be kicked up by the blast and puncture the fuel tanks. Remember one Titan II was punctured by a large socket wrench dropped from an upper work platform that bounced off the wall of the silo and perforated the skin of the fuel tank. If a glancing blow could perforate the missile, imagine what a stray bolt or nut or other debris in the bottom of the silo blown upward by the engine blast could do?? NASA takes some extraordinary measures to ensure their rockets don't disintegrate on the pad from the acoustics alone-- and that's OUT IN THE OPEN! Imagine the acoustics of the engine blast IN AN ENCLOSED SILO, echoing off the walls into the sides of the missile from ALL SIDES!
The bad thing about this was, the "blast tunnels" for the engine exhaust had to be cut as well, and had to have blast doors installed to protect the missile from nearby nuclear strikes-- otherwise the nuclear blast could simply funnel down the exhaust ports and demolish the missile from underneath (pressure waves rupturing the fuel tanks). This added greatly to the difficulties and expense in constructing the silos, and added a lot to their vulnerability to preemptive attack.
Minuteman was a SOLID FUEL missile, and so much more robust from an acoustics standpoint, so they were simply launched by "fire in the hole". The silo was basically a simple hole with a hard stand at the bottom that the missile sat on. Ever notice in those Minuteman launch vids, how the door opens, a HUGE flare of flame bursts straight up from the silo, and then the missile rises out of the flames, trailing licking flame and smoke before racing away, usually through a really 'cool looking' smoke ring?? That's "fire in the hole". The smoke ring is caused by the blast coming up ALL AROUND the missile as it lifts off from the silo.
Another thought just occurred-- how about that cardboard 'Readi-tubes' used for concrete?? Those are bigger than PVC, cheaper, and would work just as well... (for a portable silo anyway). Gotta be big enough diameter silo for the fins on the missile to fit down it!
Later! OL JR
The Minuteman didn't have fins, right? (But your model will need them.) I wonder how small of a span you could get away with?
Interesting design. Question: Was a silo ever meant to fire more than one missile in its service life? (IOW, did the USAF ever think that there would be more than one volley of missiles fired during Armageddon?)
MarkII
Try this link https://www.youtube.com/watch?v=2aHpqqhaHJ0
FWIW, the missile is actually suspended in a cage-like assembly that is adjustable so it can be precisely positioned. There are no channels to allow the fire to escape; the flames exit from the main opening just like the missile does. The missile is coated with a layer of cork to protect it from the heat until it clears the silo. The equipment in the silo has no such protection so it's a one-shot deal.
The door that you see opening weighed 90 tons when I was in the AF but it was upgraded to 120 shortly thereafter. Opening it as fast as they do is no small feat.
I didn't get out to the silos very often because I worked in the Electronics Lab. My job was to repair any of the electronic sub-systems used by the vehicle or the ground support equipment. The guidance system was very cool.
Also, Minuteman was only mostly solid propellant. The final stage, the PSRE (pronounced pisser) for "Propulsion System, Rocket Engine", used liquid fuel.
Mario
Sounds like a lot of good research and testing No problems with frying the rockets tail end in the three foot hole? PVC pipe sounds conveniant as I was just going to detail the top. I was thinking about an 18mm engine. Heres my scale data. The site has all kinds of good info on Minuteman
https://www.captainswoop.com/icbm/msls.html
Thanks for the info
Cheers
fred
I can't say that I have actually ever seen videos of any of the rockets that you mentioned being launched out of their silos, nor have I ever seen anything other than a very schematic diagram of any of their silos (and that was just for the Atlas). I was just guessing about the flame tunnels. The Soviets used them for their N-1 (which of course was launched from the surface, but the flames went into a hole in the ground and then vented back up at an angle at the surface).
MarkII
I digress a little bit. The Peace Keeper (PK) actually has a solid propellant charge that fires into a small water reservoir to create steam (steam/gas generator). There is a lip seal on the side of the PK that makes a good enough seal that the steam ejects the missile from the silo. Once clear of the silo the PK is ignited like a submarine launched missile. An advantage of this method is that the silo can be re-loaded with another PK quickly without much refurbishment. The Russians use the same idea for their solid ICBM's.
Bob
The Minuteman didn't have fins, right? (But your model will need them.) I wonder how small of a span you could get away with?
Interesting design. Question: Was a silo ever meant to fire more than one missile in its service life? (IOW, did the USAF ever think that there would be more than one volley of missiles fired during Armageddon?)
Sliding silo cover....
The air vents are visible in the foreground in this photo.
MarkII
I wonder if i will get a neat puff of smoke coming out with the rocket? Using any kind of pressure system would be cool but far beyond my capabilities i think. A neat coffin launcher for a future project would be a BOMARC in Canadian colours naturally I remeber your point about the vulnerability of silos They were talking once about dense pack defence. I think they would have got around that one by just using one big oneNope, no problems at all... maybe some "slight staining" from smoke on the plexi fins, nothing else.
I don't know how much the damp clay earth cooled the exhaust, but I doubt it was a whole lot, relatively speaking. The exhaust gases from our engines cool fairly decently just by expansion and mixing with ambient air, which the silo would be full of. By the time the exhaust flame streams out, hits the deflector (heating it up and cooling the gases), spreads out across the deflector, and starts curving back up again, it's had a LOT of mixing and time to cool, much like an ejection baffle. So long as your rocket isn't sitting 1/2 inch above the silo 'floor' and has more than 1/2 inch of clearnance all the way around (which would be necessary for the fin span I would think) it should be fine. If in doubt, give yourself a little greater 'depth' to the silo actually below the rocket, to give a greater air volume below the rocket for the exhaust to mix with, and a little more 'time/distance' for the exhaust gases to travel before they start back up around the rocket.
I only had a few grainy pictures to go by from Bill Gunston books we had in our high school library back when I built mine-- so I had to 'scale from photographs'... get one measurement you know (diameter from the text is a good one, or overall length) and then using dividers and an drafting scale, measure out every point in the picture, then plug the measurements into a 'scaling factor' derived from the ratio of the pic measurement of length or diameter to the real thing. Of course this doesn't account for perspective, so there is some error in this method, especially on shots where the rocket is not precisely 90 degrees to the camera. Small image size also reduces the "fidelity" of the data, since the greater the 'scaling ratio', the more 'unsure' the measurements are (more uncertainty) Close up photos, however, usually suffer more from perspective changes, especially on long tall objects like rockets... the camera *might* be close to perpendicular to the bottom third of the rocket, but the upper 2/3 might be at a significant angle (30-40-50 degrees or more) to the camera and that introduces SIGNIFICANT perspective errors, especially in length measurements. Diameters are less affected, but they DO develop errors due to perspective effects... (railroad tracks coming together in the distance though they are parallel).
Much MUCH easier scaling from drawings...
Good luck! OL JR
PS. That reminds me of one of the other methods that was employed by the Atlas missile-- COFFIN LAUNCHERS! These were steel and concrete structures with steel doors on top for a roof, in which the missile was stored horizontally in a cradle. To launch, the missile doors were opened, then the missile was stood upright, the cradle retracted, and the missile was fuelled and launched. VERY susceptible to attack, and even if the missile were still secure in it's coffin launcher, the coffins weren't particularly 'hardened' against nuclear attack. Still would be a cool looking effect for a MR launch.
Later Atlas's and Titan I's were put in underground silos, with elevators to raise them to the surface for fuelling and launch. Still vulnerable during the long time they were being fuelled and readied for launch. At least one Titan I was 'hot fired' successfully from the bottom of the silo, since all the liquid fuelled missiles had exhaust ducts to the surface (again, which were vulnerable to attack).
Most Russian missiles up until say 20 years ago or so were primarily liquid fuelled, storable hypergolic liquid fuels, like Titan II, so they could sit 'instantly ready' in the silos like solids, but still were more finicky and fragile than solids like Minuteman and SS-13 Savage (Russia's first solid ICBM). Even their SLBM sub missiles were liquid fuelled for a long time, but there was a significant safety and performance "push" to develop solid fuel missiles for subs. All the new Russian ICBM's (Topol M, Bulava, etc.) are solid fuelled (as are China's ICBM's and SLBM's, and India's IRBM's) Interestingly enough, Russia, China, and India are also foregoing silo basing, instead switching to land-mobile transporter/erector/launcher setups, or railroad based launchers (India, though even those are being phased out from what I've read-- India NEVER fielded a silo based missile). Silos are now considered too vulnerable.
Russian missiles were generally 'cold launched' from the silos, using a gas-generator system and a launcher 'plug' quite similar to a piston launcher or an ejection piston in MR. The missile sat on this 'plug' and when it was fired, the gas generator blew the missile up out of the silo; once clear, the plug launcher seperated from the missile, and was propelled to one side by laterally facing (solid?) rockets, as the main liquid engines on the missile itself fired up. This acted much like a piston launcher and actually extended the range or throw weight of the missile, as well as protecting the silo from the engine blast, allowing for easier reloading. Much the same systems are used aboard submarines-- the missiles are actually 'blown' out of the submarine by compressed air, and the rocket engine is ignited only after it has cleared the surface.
THAT would a cool setup! JR
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