If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
Need help with a rocket motor ID - no more calls, we have our winner.
"Dave Kearton" wrote in
message ... I'm currently trying to get comparision pics of the Rocketdyne LR64-NA-4 from the AQM-37. It was a fairly common engine - over 5K in service and possibly matches the size of the engine with the airframe. As Esmarelda whispered to Quasimodo "It's only a hunch, but I can't ignore it" I'm pretty sure the beast we're looking at is an LR64 variant, leastways that's close enough for me. I've sent a pic off to PWR and hopefully they'll own up to it as well. http://www.aeroconsystems.com/motors/lr64.htm Thanks to everyone for their thoughts - except for the retard on sci.space.history who told me to do my own research. I think my way was a lot more educational. -- Cheers Dave Kearton |
#2
|
|||
|
|||
Need help with a rocket motor ID
"jc" wrote in message
... Dave, Not much of a vowel but here's the stuff I got from a bud who's pretty heavy into rocketry (I am not). He didn't know what it was, specifically, but here's a bit more info you can add to the stew. One other note, Q is correct about the "SN63(4??), which is preceeded by what looks like a part #, which looks to me like it may be " ?07705" Cheers, jc "About all I can add to this discussion is that I'd agree it's probably designed for hypergols since there's no provision for ignition. Hypergols are binary propellants that use 2 liquids that spontaneously combust on contact. The only 2 I can name are furfuryl alcohol with hydrogen peroxide and the WW2 German bstoff and cstoff. That was the stuff used in the ME163 Comet rocket plane, I'm pretty sure one of the stoffs was hydrazine. That's some nasty stuff, it dissolves flesh. I've heard stories about accidental leaks and human soup. Yuck! Looking at the pictures a couple of other things strike me. Obviously there's no gimbal on the nozzle so it's not a manuvering jet. I'd guess either a seperation motor for a really big stage or possibly some kind of retro-fire thing. The other thing is the way the fluid lines wrap around the can looks like preheat to me. That either means a fuel that doesn't vaporize easily, like kerosene, or a cold soaked environment. That goes along with the idea that it's designed for vacuum. Where did the guy get it? Looks like government surplus to me. Hope my input helps." Thanks, every little bit helps. I'm currently trying to get comparision pics of the Rocketdyne LR64-NA-4 from the AQM-37. It was a fairly common engine - over 5K in service and possibly matches the size of the engine with the airframe. -- Cheers Dave Kearton |
#3
|
|||
|
|||
Need help with a rocket motor ID
"jc" wrote:
"About all I can add to this discussion is that I'd agree it's probably designed for hypergols since there's no provision for ignition. Hypergols are binary propellants that use 2 liquids that spontaneously combust on contact. The only 2 I can name are furfuryl alcohol with hydrogen peroxide and the WW2 German bstoff and cstoff. That was the stuff used in the ME163 Comet rocket plane, I'm pretty sure one of the stoffs was hydrazine. That's some nasty stuff, it dissolves flesh. I've heard stories about accidental leaks and human soup. Yuck! Manzo Zeigler's "Rocket Fighter" describes C-stoff as "thirty percent hydrazine hydrate solution in methyl alcohol" and T-stoff as "forty-eight percent concentrated hydrogen peroxide and a mixture of hydrocarbon compounds." Some brilliant and possibly pro-Ally designer placed extra fuel tanks inside the cockpit. A few years ago I listened to a lecture by a rocket engineer who had known one of the Komet's engineers. When asked about the Komet's lethality the German said "It did not kill half its pilots! It killed no more than one in three!" --Bill Thompson |
#4
|
|||
|
|||
Need help with a rocket motor ID
wrote:
I see that there was a lot of discussion I didn't read. I am glad to see that the source was tracked down. But, I am I bit surprised to see it was from Rocketdyne. "jc" wrote: "About all I can add to this discussion is that I'd agree it's probably designed for hypergols since there's no provision for ignition. It is hard to tell anything about an engine based on ignition provisions or lack of them. In "the old days" LOX/RP engines had pyrotechnic igniters (the Atlas ones were called "ROFIs". That was "Radially Outward Firing Igniters". They were a can that screwed into the injector plate. You wouldn't find them on a recovered engine. Almost everyone forgot what a "ROFI" was, and called all pyrotechnics, specifically the axially firing ones around the base of the Shuttle, to prevent hydrogen accumulation, "ROFIs".) In the early 1960s, hypergol "leads" were developed for and were used for the Atlas and all similar Rocketdyne engines. Like the H-1, F-1 and RS-27. The usual one was "TEA". Triethylaluminum. (Now, you talk about NASTY….) That was placed in a cartridge some were in the propellant lines, like the parts missing from this one. So, you wouldn't see that, either. Only LOX/Hydrogen engines usually have spark plug ignition. Hypergols are binary propellants that use 2 liquids that spontaneously combust on contact. In the early 1940s the Navy had a program to develop "RATO" headed by Bob Truax, just out of the academy at the time. They used aniline and concentrated nitric acid. That started a whole branch of rocket engine development, which are what is usually meant by "hypergols". Successive generations used fuels like hydrazine hydrate, then hydrazine (and UDMH and MMH.) The acid was "spiked" by adding nitrogen oxides, NO2/N2O4 to get WFNA and then RFNA and finally, the acid was dispensed with and the straight oxides were used. Chemically, you can think of this as starting with the "NH2-" part of the aniline and eliminating hydrocarbon bits until you get straight hydrazine "H2N=NH2" (or a few methyl groups) and combining that with the oxidizer which started as the nitrogen oxides plus water and progressively eliminating the water. One reason for the progression was availability of the chemicals involved. In the early 1940 there was no industrial production of hydrazine and hydrazine hydrate was mainly, if not exclusively produced in Germany. Likewise, nitrogen oxides were widely produced but were not handled in the pure form. All that required development. (For airplanes, RATO lost out to the army developed "JATO" solid propellant "boosters.") The only 2 I can name are furfuryl alcohol with hydrogen peroxide While Truax and the boys were doing RATO, the Germans were busy too. At the time, Germany had the world lead in chemistry and particularly in the production of hydrazine hydrate and hydrogen peroxide. They especially loved schemes that used hydrogen peroxide in some way. In the US, peroxide was always looked on with great suspicion as something infernal and demonic and eliminated as quickly as possible (One can see this sort of thing still going on. The Russians use UDMH and Peroxide but no hydrazine. That has been an on going problem with the ISS and the Russians wouldn't even talk about replacing their monoprop systems with hydrazine where as we wouldn't consider using anything else.) There are several ways that you can use peroxide. One is as a monoprop. Usually to do that, you use a catalyst and permanganates are traditional. You can either use that as a solid, impregnated into some ceramic, say. Or as a water solution. In the WW II era, the Germans had a hard time making a good solid catalyst. To get better performance, you can add use fuel with the peroxide making a biprop. One way is to use the decomposed peroxide exhaust oxygen and steam at high temperature. That works great. The other way is to use unreacted peroxide with a fuel, just as would be done with LOX. At various times, the Me163 used water solution catalyst and biprop both (one at a time). And maybe monoprop too. I always like to say that "Fuels that are not hyperbolic with peroxide are not even worth talking about (and probably don't deserve to be called "fuel")" but when say that, I have in mind the hot peroxide. With cold peroxide, furfuryl alcohol might be an ignition enhancer. But the only actual use of it that I know of was on the Nike Ajax in the "days of yore." The Nike main propellants were aniline and acid (RFNA I think.). Those are hyperbolic, but not quite as reliably as was desired, sometimes you could get a little lag which might cause a "pop." Not good. So furfuryl alcohol was used as a "hypergol lead" just as I described for TEA This was explained to my tour group (of aspiring ordnance officers) by a many-striped NCO at a Nike battery just outside DC. "They use to have this stuff, and they called it furfuryl alcohol. So, they worked on it, and worked on it, and improved it, and improved it, and now they call it 'UDMH'". I thought that was a really great explanation. and the WW2 German bstoff and cstoff. The Germans had a lot of "stoff" but "C-stoff" and "T-stoff" were the most common. That was the stuff used in the ME163 Comet rocket plane, I'm pretty sure one of the stoffs was hydrazine. Not even the Germans had hydrazine in quantity in the WW II era, but they did have the hydrate. Someone on 'sci.space' said that T-Stoff, was a mixture of 80% hydrogen peroxide plus oxyquinoline or phosphate as a stabilizer. [most of the other 20 percent would have been water. _hh] And that C-Stoff was a mixture of 57% methanol + 30% hydrazine hydrate + 13% water, with traces of either cupro-potassium cyanide or copper oxide (probably as a stabilizer). I accept those as being correct. Methanol the kind of stuff you would want as a fuel. The hydrazine hydrate would be added to provide "smooth combustion" and the water may have resulted from using the highest concentration of hydrazine hydrate that was available, or possibly it was just added as coolant. (Usually wiki is a really good place for this kind of stuff, but I didn't find the exact numbers there) That's some nasty stuff, it dissolves flesh. I've heard stories about accidental leaks and human soup. Yuck! All those things may have happened in Germany in WW II. I don't know. All I do know is that if you do the tests now, nothing like that happens. If you pour peroxide on yourself, or your buddy, even high strength stuff, it may find some catalyst in your clothing, like a dye, say. In that case, the peroxide will decompose, setting clothing (and then flesh) on fire. If you have compatible clothing, just ordinary clothing, not "space suits" usually nothing happens. Nothing. Well, maybe a little skin rash. For long-term exposure, peroxide probably has less actual data about ill effects than city air or water. One source I recall stated "not a toxin" in the usual sense. Lately I understand there has become a fad of "shooting up" peroxide, medium strength stuff, for what purpose I can't say. Not recommended by me. Hydrazine, in any strength or quantity, probably has similar effects to a gasoline spill. If it doesn't catch fire there won't be prompt effects. Read the safety manuals; there are probably more toxic warnings about gasoline than hydrazine. Rocket Research (one of the leading hydrazine thruster suppliers) had their expert search the medical literature. He found zero cases of prompt death from hydrazine exposure. Long term effects were debatable when I was involved. At one time, the main commercial use of hydrazine hydrate was for deoxidizing feed water for steam boilers. The "Stationary Engineers" that did this sort of thing were, it seemed to me, a good test case for this, as they didn't seem to be all that meticulous. One confused the beer bottle he was carrying his deoxidant in with the one he was drinking his Carlsberg out of. He not only didn't die; he didn't seem to have any long term effects. There was another guy though, who eventually did die, but only after what were said in the medical report of years of habitual careless exposure. Hydrazine (and UDMH and MMH) are often used in conjunction with N2O4 so they "get tarred with the same brush." You are not going to tell propellant handlers "be really careful with this stuff but you don't have to worry so quite as much about that stuff." N2O4 is at least 10 times as toxic for prompt effects as hydrazine. It scares the heck out of me, and I am a "rocket scientist". And everyone knows we rocket scientists don't have good sense. One thing I read said that persons exposed have this symptom and that symptom and in a couple of days they get better. And, then in a couple of more days, they die. It is hard to find people in the rocket biz that have had long term exposure to hydrazine that have not also be exposed to N2O4 so when there are stories about long term effects, you don't know which to blame. But I will take the alternative to "in a couple of more days, they die." Better chronic than prompt. I have heard all those scare stories, many times.(Probably told some, too.) I was the program manager of some hydrazine thruster development programs for the ISS at one time. The NASA world was split between the hydrazine advocates and the O2/H2 advocates. There got to be a bit of mud flying there, and I got my share. (NASA couldn't decide between the options, or rather they did choose, several times, but the kept switching back and forth. Finally, when the Russians got involved, and were going to provide the propulsion for free, I heard no objections to their use of UDMH/N204, even from the same people that had objected t hydrazine as too toxic and too contaminating. UDMH/N2O4 is much worse on both counts.) Manzo Zeigler's "Rocket Fighter" describes C-stoff as "thirty percent hydrazine hydrate solution in methyl alcohol" and T-stoff as "forty-eight percent concentrated hydrogen peroxide and a mixture of hydrocarbon compounds." I have read that book, and everything I could find when I was proposing "cuddly" propellants to NASA about 20 years ago. Do not mix hydrocarbons with peroxide! Leave that to the terrorists who intend to be human bombs, because you are likely to be one intended or not. I have no explanation of the many descriptions of Me163 explosions. I don't think any of them sounded like they had to be "chemical yield" explosions. I think that some may have been mechanical propellant tank ruptures. (In ordnance circles, I got into this thing of distinguishing between "high order" explosions or "detonations and "low order" explosions or deflagrations. Then there are "no yield" ones, like tank ruptures. I use to rankle when people talked about auto gas tanks exploding, or example. Then I read some dictionaries. The "sufficient" definition of an "explosion" seems to be some event in which a noise was heard.) One thing that was more hazardous on the Me163 than the exotic (for then) propellants was the operational scenario. Take off, climb to combat altitude, run out of propellant, glide to a landing spot, and be stuck on the ground on the landing skids. The allied pilots quickly figured that out, and that there was little to be done about powered flight, so they just waited and followed them down and nailed them on the ground. It is a wonder that anyone had any stories about explosions, they should have all been killed. My conclusion from trying to find out what happened was that the Luffwaffe was totally negligent in keeping any useful accident reports in the WW II era, at least that I found. Some brilliant and possibly pro-Ally designer placed extra fuel tanks inside the cockpit. A few years ago I listened to a lecture by a rocket engineer who had known one of the Komet's engineers. When asked about the Komet's lethality the German said "It did not kill half its pilots! It killed no more than one in three!" I like that story. But, I don't consider it "evidence." Designers are often told that "You have t listen to what the user says, they were the ones that know what is going on. I agree that you should listen. But you should evaluate what you hear. Anyone's "eye witness account" is likely to be highly biased and frequently just imaginary. One of my "non rocket" interests armored warfare. (I had a slight professional involvement, back in the knight errant days.) In WW II, "as every school boy knows" (but I want evidence) German armor was overwhelmingly superior to US armor. And the US tankers would often tell you those stories themselves (although all eye witness accounts are prone to flip back and forth between "we were helpless" and "we got them all" modes.). I found one detailed account of an independent tank battalion written by the son of one of the unit members. It was largely based on the stories the survivors said at reunions. Man, those guys had no chance against German tanks. Period. But, the account included a description of nearly every loss of US tanks. Many, many times it is impossible to know just what the cause of a loss was. You don't know if you were hit by an opposing tank, an AT gun, or a passing asteroid. But, many of the losses did have known causes. And in many cases it was not enemy tanks, for sure. Like the guy that inadvertently drove his M-4 off a bridge and it sank in the river. Likewise, you don't always know if you really killed enemy tanks or not. Over claiming is very frequent. But, when I added it all up (which the author did not) these poor guys, who were completely overmatched, lost only something like a third of their tanks to German tanks. Yet, by their own count, they destroyed more German tanks than they lost, to all causes. A kill ratio of something like four in their own favor. The Germans, OTOH seldom admit losing any tanks to anything at all. Hey, something went with them. Part of the explanation was the resupply situation. If the ash trays in your M-4 filled up and you took it to Ordnance, they were likely to say "Well, park it over there with the rest of the scrap and take one of the backlog of unused ones parked over there." The Germans (say post d-Day in Northern France) were not getting any more tanks, so they weren't scraping any, no matter what. So, even if the hull was in one village and the turret had been blown to the next one, they still counted it as "being repaired" no matter that they had no parts or equipment to do that. The Germans were said to have about 1800 AFVs in northern France on D-Day. I have seen accounts that said that the RAF destroyed 1800 German AFVs in the Falance pocket on the last day of the collapse. I have also seen accounts that essentially buy the German version and ascribe all the losses to "envelopment." It is no wonder that people cite phenomenal kill ratios. Take your pick. On the Me163 I have seen a lot of German accounts of them spontaneously exploding, but I don't recall one single one of a loss to enemy action. There are many stories by the allies of blasting Me163s on the ground, but of course, they wouldn't have known about spontaneous explosions. Another possible explanation is structural failure, or materials compatibility problems. I have never found a real explanation of how the Me163 worked, but it had to be a pressure fed system. I have never seen or heard of a peroxide pump. That means there were large pressurized tanks, which probably were not all that conservatively designed. A bit of a bump on landing and the tank pops, spraying residual propellant, peroxide or alcohol/hydrazine about. And, what were those tanks made of. There was only one material that would be considered a "structural material that was available to the Germans in WW II that was peroxide. Pure (and therefore dead soft) aluminum. Well, that is not consistent with having a flying pressurized tank, so the material was incompatible. Usually that means that it sits around for a shorter or longer period of time, depending on how incompatible the material is. Then the peroxide starts to decompose a bit; temperature goes up a bit. Vicious circle ensues. Boom. But that is not usually really "peroxide explosion" either. Just a tank overpressure ("Not to worry, there was no nuclear yield".) And, what were the seals and all the other bits made of. I was once reading a report on the X-1 which was very like an American Lox Me163 and at about the same time. There was something about an explosion and a fire. The report said they weren't sure what happened, but they though it might have involved a seal. (I think maybe it was in a check valve and lit off when the valve closure slammed on it.) They then started to discuss what sort of special, proprietary LEATHER (!) the seal was made of. I quit reading. All I can say is, old war stories may be interesting. I have told a few myself. But, one has to interpret them in light of other stuff, like facts. --Bill Thompson Henry H. |
#5
|
|||
|
|||
Need help with a rocket motor ID
|
#6
|
|||
|
|||
Need help with a rocket motor ID
|
#7
|
|||
|
|||
Need help with a rocket motor ID
Henry_H@Q_wrote:
I see that there was a lot of discussion I didn't read. I am glad to see that the source was tracked down. But, I am I bit surprised to see it was from Rocketdyne. It looks like someone issued specs that said, basically, "make it reliable and simple, and don't worry too much about the weight." (For airplanes, RATO lost out to the army developed "JATO" solid propellant "boosters.") I can see why. RATO could be throttled and restarted, but I think the only application anyone saw for that was in seaplane take-offs. JATO looks a lot less maintenance-intense than RATO (see attached picture). T-Stoff, was a mixture of 80% hydrogen peroxide plus oxyquinoline or phosphate as a stabilizer. [most of the other 20 percent would have been water. _hh] And that C-Stoff was a mixture of 57% methanol + 30% hydrazine hydrate + 13% water, with traces of either cupro-potassium cyanide or copper oxide (probably as a stabilizer). I accept those as being correct. Methanol the kind of stuff you would want as a fuel. The hydrazine hydrate would be added to provide "smooth combustion" and the water may have resulted from using the highest concentration of hydrazine hydrate that was available, or possibly it was just added as coolant. (Usually wiki is a really good place for this kind of stuff, but I didn't find the exact numbers there) Those are the same figures in Sutton's "Rocket Propulsion Elements." I figure that Mano Zeigler gave different numbers in "Rocket Fighter" due to conditions in Axisland--with the Allies bombing their plants and supply lines, they may have had to settle for anything that could flow through the lines and burn. It is hard to find people in the rocket biz that have had long term exposure to hydrazine that have not also be exposed to N2O4 so when there are stories about long term effects, you don't know which to blame. But I will take the alternative to "in a couple of more days, they die." Better chronic than prompt. As I recall, Vance Brand passed out from exposure to dumped fuels during the Apollo-18/ASTP descent, and the crew was taken to the hospital afterward. They didn't seem to suffer any long-term effects. (In ordnance circles, I got into this thing of distinguishing between "high order" explosions or "detonations" and "low order" explosions or deflagrations. Then there are "no yield" ones, like tank ruptures. I use to rankle when people talked about auto gas tanks exploding, or example. Then I read some dictionaries. The "sufficient" definition of an "explosion" seems to be some event in which a noise was heard.) I know people who think that a proper footnote is anything with an asterisk. (Sorry, but citing a newspaper gossip column isn't quite the same as citing, say, a trial transcript.) One thing that was more hazardous on the Me163 than the exotic (for then) propellants was the operational scenario. Take off, climb to combat altitude, run out of propellant, glide to a landing spot, and be stuck on the ground on the landing skids. The allied pilots quickly figured that out, and that there was little to be done about powered flight, so they just waited and followed them down and nailed them on the ground. It is a wonder that anyone had any stories about explosions, they should have all been killed. My conclusion from trying to find out what happened was that the Luffwaffe was totally negligent in keeping any useful accident reports in the WW II era, at least that I found. That was a typical condition in the Reich. And, given how hard it was to find self-confessed Nazis after the war, the condition persisted. Albert Speer's "Inside the Third Reich" is a classic example. Designers are often told that "You have to listen to what the user says, they were the ones that know what is going on. I agree that you should listen. But you should evaluate what you hear. Anyone's "eye witness account" is likely to be highly biased and frequently just imaginary. That's what I was taught when getting my degrees in hysteria, er, history. My favorite example has to do with the "Nuts!" event at Bastogne. There are several accounts of exactly what was said; the accounts come from people who were there--and they don't match up. (Although the military historian SLA Marshall claims that the Germans did, indeed, get the "Nuts!" message. Marshall interrogated Manteuffel and his staff after the war. At one session Manteuffel kept blaming his mistakes on his staff. At last one of his subordinates leaned forward, waggled a finger in Manteuffel's face and shouted "Nuts! Nuts!") And, what were the seals and all the other bits made of. I was once reading a report on the X-1 which was very like an American Lox Me163 and at about the same time. There was something about an explosion and a fire. The report said they weren't sure what happened, but they though it might have involved a seal. (I think maybe it was in a check valve and lit off when the valve closure slammed on it.) They then started to discuss what sort of special, proprietary LEATHER (!) the seal was made of. I quit reading. The Ulmer leather gaskets, which if memory serves were treated with tricresyl phosphate. The accounts I've read said that the treated gaskets didn't react with the liquid oxygen--but in the presence of lox, the gaskets became *very* sensitive to mechanical shock, making them "slightly" explosive. I think the losses of the X-1A, X-1D and second X-2 were blamed on that. --Bill Thompson |
#8
|
|||
|
|||
Need help with a rocket motor ID
On Sun, 04 Feb 2007 03:40:31 GMT, "William R Thompson"
wrote: Henry_H@Q_wrote: I see that there was a lot of discussion I didn't read. I am glad to see that the source was tracked down. But, I am I bit surprised to see it was from Rocketdyne. It looks like someone issued specs that said, basically, "make it reliable and simple, and don't worry too much about the weight." As I said, it doesn't look like it goes to far "up the stack". I though about it being an "airplane" but I couldn't imagine which one. But, it looks better, "all dressed up." (For airplanes, RATO lost out to the army developed "JATO" solid propellant "boosters.") I can see why. RATO could be throttled and restarted, but I think the only application anyone saw for that was in seaplane take-offs. JATO looks a lot less maintenance-intense than RATO (see attached picture). Hey, looks simple to me! I have done my tour on both the liquid and solid fronts. Both have advantages, both have problems. I will take the liquid problems any day. But, I am in the minority it seems. I think it turns out that rockets are much to expensive for general use whether they are liguid or solid. I meant to say that although Truax didn't have the right answer for airplanes, that work lead drrectly on to the whole world of hypergols in the US, many, many vehicles and engine/motors. T-Stoff, was a mixture of 80% hydrogen peroxide plus oxyquinoline or phosphate as a stabilizer. [most of the other 20 percent would have been water. _hh] And that C-Stoff was a mixture of 57% methanol + 30% hydrazine hydrate + 13% water, with traces of either cupro-potassium cyanide or copper oxide (probably as a stabilizer). I accept those as being correct. Methanol the kind of stuff you would want as a fuel. The hydrazine hydrate would be added to provide "smooth combustion" and the water may have resulted from using the highest concentration of hydrazine hydrate that was available, or possibly it was just added as coolant. (Usually wiki is a really good place for this kind of stuff, but I didn't find the exact numbers there) Those are the same figures in Sutton's "Rocket Propulsion Elements." I figure that Mano Zeigler gave different numbers in "Rocket Fighter" due to conditions in Axisland--with the Allies bombing their plants and supply lines, they may have had to settle for anything that could flow through the lines and burn. If I remember the book, and I am pretty sure I do, it was sort of a "quick and dirty" account based on very limited sources. I think I first read it myself only a couple of years after the war, so it has been around a while. A lot of documentation dhowed up later that the author didn't have then. It is hard to find people in the rocket biz that have had long term exposure to hydrazine that have not also be exposed to N2O4 so when there are stories about long term effects, you don't know which to blame. But I will take the alternative to "in a couple of more days, they die." Better chronic than prompt. As I recall, Vance Brand passed out from exposure to dumped fuels during the Apollo-18/ASTP descent, and the crew was taken to the hospital afterward. They didn't seem to suffer any long-term effects. I remember somethign about tat, but I don't even know as much as you said. (In ordnance circles, I got into this thing of distinguishing between "high order" explosions or "detonations" and "low order" explosions or deflagrations. Then there are "no yield" ones, like tank ruptures. I use to rankle when people talked about auto gas tanks exploding, or example. Then I read some dictionaries. The "sufficient" definition of an "explosion" seems to be some event in which a noise was heard.) I know people who think that a proper footnote is anything with an asterisk. (Sorry, but citing a newspaper gossip column isn't quite the same as citing, say, a trial transcript.) One thing that was more hazardous on the Me163 than the exotic (for then) propellants was the operational scenario. Take off, climb to combat altitude, run out of propellant, glide to a landing spot, and be stuck on the ground on the landing skids. The allied pilots quickly figured that out, and that there was little to be done about powered flight, so they just waited and followed them down and nailed them on the ground. It is a wonder that anyone had any stories about explosions, they should have all been killed. My conclusion from trying to find out what happened was that the Luffwaffe was totally negligent in keeping any useful accident reports in the WW II era, at least that I found. That was a typical condition in the Reich. And, given how hard it was to find self-confessed Nazis after the war, the condition persisted. Albert Speer's "Inside the Third Reich" is a classic example. You have to be careful about testimony of participants. You have to be ten times more careful when they are under duress. And, being a POW after having lost a war is a LOT of duress. But there are all to many examples of people thinking up stories and then feeding them to people just like that to get them to play them back. The worst one I think of off hand was some guy who was on the interrogation team of the Japanese Navy participants in PH. His own personal theory was that the Japanese should have left the ships alone and gone for the oil tanks. So he asked that question over and over again until all the Japanese got the answer right. There was a similar deal about the pre war demands, whch are totally unclear as to whether they mean "China" or IndoChina" or both. Some different guy (I guess he was different) got all sorts of people to say it would have been entirely different, "If they had only known" what we said. The Japanese were unusually eager to cooperate, be everyone is eager in those circumstances. Designers are often told that "You have to listen to what the user says, they were the ones that know what is going on. I agree that you should listen. But you should evaluate what you hear. Anyone's "eye witness account" is likely to be highly biased and frequently just imaginary. That's what I was taught when getting my degrees in hysteria, er, history. My favorite example has to do with the "Nuts!" event at Bastogne. There are several accounts of exactly what was said; the accounts come from people who were there--and they don't match up. I have read many of those accounts. And there are very different versions of what General McAuliffe initally said. Some say it was profane, othere say that people heard what they wanted to hear, and that McAuliffe never used profanity and that is exactly what he would have said. "It is very true, and if it is not, it should be." Some stories are so well known and are so much a paart of what happened they are as important as "facts." But, there is another aspect of the "Nuts" story. In about 1950 the National Archives put togetner an exibition on a train and it toured the country. It had really "heavy weight" stuff on it. Including the Constitution and the Declaration of Independnce, the originals (I think!). Hard to imagine doing that now. I toured the train. I was there. I SAW the piece of paper that McAuliffe wrote it on. Just like the Germans to file that away. SO, although there can be debate about what he SAID, I KNOW what he wrote, because I saw it. However, I can't find any discussionof anyone else knowing that. (Although the military historian SLA Marshall claims that the Germans did, indeed, get the "Nuts!" message. Marshall interrogated Manteuffel and his staff after the war. At one session Manteuffel kept blaming his mistakes on his staff. At last one of his subordinates leaned forward, waggled a finger in Manteuffel's face and shouted "Nuts! Nuts!") Another sub plot to that story that I have seen in one account was that there was some junior officere there who was an English language expert. He thought up the idea of the surrender demand. And wrote it and got permission to deliver it. But, when he got the answer, he didn't know what it meant. The officer who escorted him back to the German lines explained it in terms the German understood. He may have used any of the expressins that have been suggested. It was also said that when they parted, the German made a last plea "you must accept or many people will die." the escort was said to have said "this is war and that is what it is all about. Many will die and they won't all be on our side." Now, that is a REAL fairy tale. And, what were the seals and all the other bits made of. I was once reading a report on the X-1 which was very like an American Lox Me163 and at about the same time. There was something about an explosion and a fire. The report said they weren't sure what happened, but they though it might have involved a seal. (I think maybe it was in a check valve and lit off when the valve closure slammed on it.) They then started to discuss what sort of special, proprietary LEATHER (!) the seal was made of. I quit reading. The Ulmer leather gaskets, which if memory serves were treated with tricresyl phosphate. The accounts I've read said that the treated gaskets didn't react with the liquid oxygen--but in the presence of lox, the gaskets became *very* sensitive to mechanical shock, making them "slightly" explosive. I think the losses of the X-1A, X-1D and second X-2 were blamed on that. I have though about that a lot. The correct process for making leather LOX compatable doesn't leave ANY leather in the leather. Or as I told a guy once "Send me that (polyethelyne bottle) to be LOX cleaned and I will send you back an empty bag with a tag on it." In those days, I gather, they hadn't come up with impact testing. And such events were how they got the idea. In one sense, most things are "compatible" with LOX, as there is no "attack' in the absece of impact. RP won't react with LOX until you hit or subect it to an ignition source. That is what makes it so dangerous, you can get an accumulationt that will blow the back end of the vehicle into the next county. "Static" compatibility is meaningless for LOX. "Low order" reactions to impact are also pretty meaningless since even a small pop can do a lot of damage, including possibly stuff like igniting some surrounding stuff, like aluminum valve housings, say. It is somewhat hard to see how anything could have been done wiht any useful oxidizer, LOX, peroxide, N2O4 or whatever, untel Teflon came along. But they did do lots of stuff. Even Teflon has a lot of problems. (but is compatable.) Henry H. --Bill Thompson |
#9
|
|||
|
|||
Need help with a rocket motor ID
On Sun, 04 Feb 2007 03:40:31 GMT, "William R Thompson"
wrote: Henry_H@Q_wrote: I see that there was a lot of discussion I didn't read. I am glad to see that the source was tracked down. But, I am I bit surprised to see it was from Rocketdyne. It looks like someone issued specs that said, basically, "make it reliable and simple, and don't worry too much about the weight." As I said, it doesn't look like it goes to far "up the stack". I though about it being an "airplane" but I couldn't imagine which one. But, it looks better, "all dressed up." (For airplanes, RATO lost out to the army developed "JATO" solid propellant "boosters.") I can see why. RATO could be throttled and restarted, but I think the only application anyone saw for that was in seaplane take-offs. JATO looks a lot less maintenance-intense than RATO (see attached picture). Hey, looks simple to me! I have done my tour on both the liquid and solid fronts. Both have advantages, both have problems. I will take the liquid problems any day. But, I am in the minority it seems. I think it turns out that rockets are much to expensive for general use whether they are liguid or solid. I meant to say that although Truax didn't have the right answer for airplanes, that work lead drrectly on to the whole world of hypergols in the US, many, many vehicles and engine/motors. T-Stoff, was a mixture of 80% hydrogen peroxide plus oxyquinoline or phosphate as a stabilizer. [most of the other 20 percent would have been water. _hh] And that C-Stoff was a mixture of 57% methanol + 30% hydrazine hydrate + 13% water, with traces of either cupro-potassium cyanide or copper oxide (probably as a stabilizer). I accept those as being correct. Methanol the kind of stuff you would want as a fuel. The hydrazine hydrate would be added to provide "smooth combustion" and the water may have resulted from using the highest concentration of hydrazine hydrate that was available, or possibly it was just added as coolant. (Usually wiki is a really good place for this kind of stuff, but I didn't find the exact numbers there) Those are the same figures in Sutton's "Rocket Propulsion Elements." I figure that Mano Zeigler gave different numbers in "Rocket Fighter" due to conditions in Axisland--with the Allies bombing their plants and supply lines, they may have had to settle for anything that could flow through the lines and burn. If I remember the book, and I am pretty sure I do, it was sort of a "quick and dirty" account based on very limited sources. I think I first read it myself only a couple of years after the war, so it has been around a while. A lot of documentation dhowed up later that the author didn't have then. It is hard to find people in the rocket biz that have had long term exposure to hydrazine that have not also be exposed to N2O4 so when there are stories about long term effects, you don't know which to blame. But I will take the alternative to "in a couple of more days, they die." Better chronic than prompt. As I recall, Vance Brand passed out from exposure to dumped fuels during the Apollo-18/ASTP descent, and the crew was taken to the hospital afterward. They didn't seem to suffer any long-term effects. I remember somethign about tat, but I don't even know as much as you said. (In ordnance circles, I got into this thing of distinguishing between "high order" explosions or "detonations" and "low order" explosions or deflagrations. Then there are "no yield" ones, like tank ruptures. I use to rankle when people talked about auto gas tanks exploding, or example. Then I read some dictionaries. The "sufficient" definition of an "explosion" seems to be some event in which a noise was heard.) I know people who think that a proper footnote is anything with an asterisk. (Sorry, but citing a newspaper gossip column isn't quite the same as citing, say, a trial transcript.) One thing that was more hazardous on the Me163 than the exotic (for then) propellants was the operational scenario. Take off, climb to combat altitude, run out of propellant, glide to a landing spot, and be stuck on the ground on the landing skids. The allied pilots quickly figured that out, and that there was little to be done about powered flight, so they just waited and followed them down and nailed them on the ground. It is a wonder that anyone had any stories about explosions, they should have all been killed. My conclusion from trying to find out what happened was that the Luffwaffe was totally negligent in keeping any useful accident reports in the WW II era, at least that I found. That was a typical condition in the Reich. And, given how hard it was to find self-confessed Nazis after the war, the condition persisted. Albert Speer's "Inside the Third Reich" is a classic example. You have to be careful about testimony of participants. You have to be ten times more careful when they are under duress. And, being a POW after having lost a war is a LOT of duress. But there are all to many examples of people thinking up stories and then feeding them to people just like that to get them to play them back. The worst one I think of off hand was some guy who was on the interrogation team of the Japanese Navy participants in PH. His own personal theory was that the Japanese should have left the ships alone and gone for the oil tanks. So he asked that question over and over again until all the Japanese got the answer right. There was a similar deal about the pre war demands, whch are totally unclear as to whether they mean "China" or IndoChina" or both. Some different guy (I guess he was different) got all sorts of people to say it would have been entirely different, "If they had only known" what we said. The Japanese were unusually eager to cooperate, be everyone is eager in those circumstances. Designers are often told that "You have to listen to what the user says, they were the ones that know what is going on. I agree that you should listen. But you should evaluate what you hear. Anyone's "eye witness account" is likely to be highly biased and frequently just imaginary. That's what I was taught when getting my degrees in hysteria, er, history. My favorite example has to do with the "Nuts!" event at Bastogne. There are several accounts of exactly what was said; the accounts come from people who were there--and they don't match up. I have read many of those accounts. And there are very different versions of what General McAuliffe initally said. Some say it was profane, othere say that people heard what they wanted to hear, and that McAuliffe never used profanity and that is exactly what he would have said. "It is very true, and if it is not, it should be." Some stories are so well known and are so much a paart of what happened they are as important as "facts." But, there is another aspect of the "Nuts" story. In about 1950 the National Archives put togetner an exibition on a train and it toured the country. It had really "heavy weight" stuff on it. Including the Constitution and the Declaration of Independnce, the originals (I think!). Hard to imagine doing that now. I toured the train. I was there. I SAW the piece of paper that McAuliffe wrote it on. Just like the Germans to file that away. SO, although there can be debate about what he SAID, I KNOW what he wrote, because I saw it. However, I can't find any discussionof anyone else knowing that. (Although the military historian SLA Marshall claims that the Germans did, indeed, get the "Nuts!" message. Marshall interrogated Manteuffel and his staff after the war. At one session Manteuffel kept blaming his mistakes on his staff. At last one of his subordinates leaned forward, waggled a finger in Manteuffel's face and shouted "Nuts! Nuts!") Another sub plot to that story that I have seen in one account was that there was some junior officere there who was an English language expert. He thought up the idea of the surrender demand. And wrote it and got permission to deliver it. But, when he got the answer, he didn't know what it meant. The officer who escorted him back to the German lines explained it in terms the German understood. He may have used any of the expressins that have been suggested. It was also said that when they parted, the German made a last plea "you must accept or many people will die." the escort was said to have said "this is war and that is what it is all about. Many will die and they won't all be on our side." Now, that is a REAL fairy tale. And, what were the seals and all the other bits made of. I was once reading a report on the X-1 which was very like an American Lox Me163 and at about the same time. There was something about an explosion and a fire. The report said they weren't sure what happened, but they though it might have involved a seal. (I think maybe it was in a check valve and lit off when the valve closure slammed on it.) They then started to discuss what sort of special, proprietary LEATHER (!) the seal was made of. I quit reading. The Ulmer leather gaskets, which if memory serves were treated with tricresyl phosphate. The accounts I've read said that the treated gaskets didn't react with the liquid oxygen--but in the presence of lox, the gaskets became *very* sensitive to mechanical shock, making them "slightly" explosive. I think the losses of the X-1A, X-1D and second X-2 were blamed on that. I have though about that a lot. The correct process for making leather LOX compatable doesn't leave ANY leather in the leather. Or as I told a guy once "Send me that (polyethelyne bottle) to be LOX cleaned and I will send you back an empty bag with a tag on it." In those days, I gather, they hadn't come up with impact testing. And such events were how they got the idea. In one sense, most things are "compatible" with LOX, as there is no "attack' in the absece of impact. RP won't react with LOX until you hit or subect it to an ignition source. That is what makes it so dangerous, you can get an accumulationt that will blow the back end of the vehicle into the next county. "Static" compatibility is meaningless for LOX. "Low order" reactions to impact are also pretty meaningless since even a small pop can do a lot of damage, including possibly stuff like igniting some surrounding stuff, like aluminum valve housings, say. It is somewhat hard to see how anything could have been done wiht any useful oxidizer, LOX, peroxide, N2O4 or whatever, untel Teflon came along. But they did do lots of stuff. Even Teflon has a lot of problems. (but is compatable.) Henry H. --Bill Thompson |
#10
|
|||
|
|||
Need help with a rocket motor ID
On Sun, 04 Feb 2007 03:40:31 GMT, "William R Thompson"
wrote: [snip] That's what I was taught when getting my degrees in hysteria, er, history. My favorite example has to do with the "Nuts!" event at Bastogne. There are several accounts of exactly what was said; the accounts come from people who were there--and they don't match up. After my first reply to this message I did some Googleing. I still can't find any mention of the "Nuts" document. However, I did find this on wiki: ***************** The 1947-1949 Freedom Train was proposed by Attorney General Tom C. Clark as a way to reawaken Americans to their taken-for-granted principles of liberty in the post-war years. The idea soon got the approval of President Harry S. Truman and everything else fell into place. Top Marines were selected to attend to the train and its famous documents. The Marine contingent was led by Col. Robert F. Scott. The train carried the original versions of the United States Constitution, Declaration of Independence and the Bill of Rights on its tour of more than 300 cities in all 48 states. As Alaska and Hawaii didn't gain statehood until 1959, this train toured all of the US States that existed at the time. ***************** I saw it when it stopped in Atlanta, Ga. on Jan. 2, 1948/ I am very sceptical of authority in reference sources, I certainly don't think the EB is very authorative. "Trust everyone, but cut the cards, anyway." But, as a friend use to say "Even a blind pig finds some nuts." There are a LOT of nuts on wiki. Various kinds. No matter what you know, you don't know that you know everything until you check wiki. Henry H. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Mooney Rocket | Al | Owning | 7 | September 1st 06 07:31 PM |
FS: Harmon Rocket II | Rob S. | Piloting | 0 | March 4th 06 11:50 PM |
Rocket Man.... | Gary Emerson | Soaring | 2 | November 5th 05 04:49 AM |
WW-II rocket motor on E-bay - opinions ? | BeepBeep | Naval Aviation | 32 | August 11th 05 03:29 PM |
TWO EXTREMELY RARE ROCKET BOOKS ON EBAY - INCREDIBLE ROCKET HISTORY! | TruthReigns | Military Aviation | 0 | July 10th 04 11:54 AM |