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Sturgeon's House

STGN

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Everything posted by STGN

  1. Okay so why do you not say that to SH_MM Are these not insults?: "What I am doing - and you honestly also should start, if you actually had an interest in finding the truth - is the following:" "What you still massively fail to understand " "You on the other hand are an Abrams fanboy who doesn't bother to consider alternative interpretations, and considers newspapers more relevant than declassified documents as long as it fits your opinion. If a CIA report says "one version of the Abrams turret", a fanboy's knee-jerk reaction is: "This means that the XM774 cannot penetrate the turret". Meanwhile my first question is: Why did they write "one version of"? How does this fit along with the other sources? What is the context of this statement?"
  2. 1. No see you are trying to argue that it is imposible for the Americans to have changed their mind about what protections level even a little bit and you are just so arrogant and condecending that I love pokeing at you becasue your manners are so bad. Lets start with the turret of the original M1 Abrams, was it designed under a weight requirement of 59 tons or 60 tons? It was designed in 1976 according to Hunnicutt and I even have a picture of a model of it from 1976: So the improved FSED turret was done under the 58,9 tons weight requirement. So the 0.9 tons ballistic protection increase was added later: It even says in Hunnicutt that it was weight REALLOCATION: When the pilot tank rolls of the factory floor in 1978 its even called a 59 ton tank: So it does indicate that armor was actually added to the turret. How about the armor that is actually in the turret, the main pillar of your argument is the claim that the XM-1 had the BRL-1 armor from the 1977 trial where XM774 was able to penetrate BRL-1 at 4000 meters. However apparently you haven't read your own source: Because it is not true that the XM-1 had the specific BRL-1 armor from the 1977 fireing trials it even says so in your own source! Lets set the stage, the 1977 firing trials where done to help evaluate wheter the XM-1 should keep the 105mm or development should swith to 120mm. The BRL-1 was a hypothesised T-72 and BRL-2 was a armor that was better than the XM-1: And what was the difference between BRL-1 and BRL-2 again: Does that sound like BRL-1 was the NERA and didn't have much KE defence? So how similar was BRL-1 to the XM-1's armor, well according to MR. Stratton it is "roughly the same": So BRL-1 was infact a "representation of T72" and "roughly the same" but not the same as what was on XM-1. See this source talking about the 1977 firing trial, makes it sound like a "show trial" designed by the US Army to sell the 105mm M1 and wait with the 120mm M1. What they are saying "See the XM774 is going to be able to knock out the T-72 at incredible ranges, going for the 120mm is unessesary", "Is that actually the T-72's armor?", "That is classified sir." So we are left with a question if the BRL-1 was roughly the same how roughly are we talking? Allow me to introduce the Special Armor Infantry Fighting Vehicle(SAIFV) study. Because here we can get the numbers through the vulnerability analysis: There where several SAIFV's proposed I will be using version 1 as that is the one most closely resembling the XM-1 The turret of the SAIFV has these "mobility or firepower kill" probablities: Propablity of the 115mm WA threat was 0.2 at 1000m Probability of the 115mm DU threat was 0.23 at 3000m comming from 0.56 at 2000m so XM774 is not going to be going though the armor of an XM-1 at 4000m at the design angle. So a simple two point average analysis is that the original 1972 armor would protect against XM774 at 2500m. But by the time of the SAIFV study they where allready asking the question what would it take to increase protection? This is the answer: Here we can read that it takes 0.6 tons to give the SAIFV turret front point blank protection against XM774 from the fornt and 1.4 tons give the hull the same protection. This means that adding 0.9 tons to the turret of the XM-1 is gonna give it a considerable increase in armor protection against XM774. Now for the rest: "I use a 60 degree protection cone" This is false I used a 50 degree one for the numbers I provided. "The 350mm number is completely made up" Then why is it used on the M1A2 protection scheme (swedish trials) with the same angles as has been provided by the british XM-1 study? Supposidly the number where given at the end of the cold war when US and russia entered into at dearmament agreement. Why 325mm for M60 I don't know maybe its just a mistake that got reprinted. "M735 can penetrate 380mm of RHA" At 1524m/s? That would mean it looses 16% of its energy going just 1000m down range that seems unlikely. "You on the other hand are an Abrams fanboy who doesn't bother to consider alternative interpretations, and considers newspapers more relevant than declassified documents as long as it fits your opinion." How would you know what I have considered of other interpretations. You on the other hand have selected a study which didn't use XM-1 armor, which was suppose to study the viability of the 105mm and then you dogmatically deny any contradiction evidence. You make up stories with out evidence because you are only focusing on a narrow part of the evidence, because you apparently need it to be true that no part of the Abrams can protect against the XM774. You take the minimal protection level of the crew compartment and demand that it also be the max protection level anywhere on the tank even when we know that attacks ar not spread randomly acros that spectrum but that the front is much more likely to be hit than even at 25 degrees. And the turret is much more likely to be hit than the hull. So it makes sense to try and distribute the armor to both protect agains the minimum but also increase frontal protection as much as can be allowed. Ultimately we don't know how much wiggle room the requirements gave in the weight allocation department, if there where whishes to frontal protection etc. How is this for alternative interpretations: 1. Its one of several different ways you can weight the armor scaling between KE and CE protection 2. The different parts of the turret armor has different strength. Like maybe the Gun Shield has 400mm protection while cheeks has regular protection. 3. Turret armor was upgraded during production so the first tanks have less protection than later ones. Actual weight was over a ton above the projected one on the production line. 4. Its the proposed armor for the M1E1. 5. The CIA randomly mentions it by mistake The possiblities are plenty.
  3. I appreciate the good push back MM, make me go back and check my logic and arguments I haven't been doing this for years. In doing so I was able to recall how I made the measurements, I was conflating a few things but I will explain that later(another post). First I have to repeat, because you apparently missed that I am not a hard core beliver in the Abrams having XM774 protection but I think its a possibility that the turret had it. If you go back to my first post I even say that I lean towards XM774 but I am not sure. However you have strawmaned me a bit talking about "my essential claim" etc. 1.Now you say it is wrong to consider the slope of the turret and you give great examples of why protection over a narrow front is possible. Remember US consider XM1 armor equivalent to 175mm(350/2) sloped at 60 degrees. Putting this on the both the right and left turret front we have to as you said multiply by a factor depending on the slope of the armor when shooting from the front. For the left side this factor is 1.22 and on the right side that is a factor 1.12 Left: 175 x 1.22 = 213.5 x 2: 427mm equivalent Right: 175 x 1.12 = 196 x 2: 394mm equivalent Your argument shows well how 400mm protection is a reasonable possibility head on, and for narrow cone of XM774 at 1000 meters. 2. No that is a quote, if you are allowed to make inferances and judgements based on referances why am I not? Also why are you trying to read my mind and make all sorts of negative judgements, what you achieve is just that you are arguing with your own projection of me. See you get to call 15" a generic figure and claim that it doesn't mean anything, yet somehow its exactly the same number as XM774 penetration. 3. But we do agree that 400mm is directly stated right? Again you get to make all sorts of excuses and explanations, but I am blinded by my need to have protection against XM774, right? 4. Now seeing as you love to ascribe all sorts of motivation to me, I can't help but notice that you seem to think that is somehow an argument, in this discussion, that the CIA keept underestimating Russian capabilities, you seem to have a rather negative attitude towards the US, could that cloud your view of the facts and lead you to draw wrong conclusions? 5. Cool argument bro, one thing though, that drawing and the proposals for turret redesign was made in 1976 not 1978 read Hunnicutt again. The turret redesign was made prior to Chrysler being selected as the winner. Conclusion: Your approach seems very negative and so overconfident you don't even notice that you prove yourself wrong, post erroneous information and freely attribute all sorts of negative assertions about my beliefs, you are calling me corrupt while you tell all sorts of stories, any info that doesn't go your way can be thrown away. So get a grip.
  4. 1. I wasn't clear enough, I don't scale of plate thickness rather the outside dimensions, and by doing that I am able to get the proper plate thickness. I am surpriced you can't, but I have disagree with you blanked statement that you can't get any accurate information off the drawings. Sure its not blueprint quality, but for our purposes its much better than nothing and we are within a cm of accuracy. 2. First, even if the turret only provides protection against XM579 out to 25 degrees then due to the angle of the armor its going to be providing protection against XM774 just over a narrower cone, Read SAIFV again and look at the angular protection of the side armor against XM774. You don't need many degrees between XM579 and XM774. Here is the quote from NYT 23-03-1978: "The XM‐l guns will fire a kinetic energy round that Army experts say travels at about a mile a second and can penetrate 15 inches of armor. But not, they add, the new armor.". The same CIA report that states 400-750 also states: "Should the Soviets archive the same muzzle velocity in the RAPIRA-2 125mm smoothbore AT gun as they do with T-64/T-72 main gun, they will be able to penetrate 350mm og RHA at 2,100M. In other words, USAARMC is also increasingly concerned about KE warhead composition (WA, DU), and development of a hypervelocity antitank system which may become a threat to the M1 system, especially at shorter ranges." So they don't think that the soviets are clearly over matching them yet but it is getting closer. And they are concerned about the soviets developing a DU round. This indicates, to me at least, that the Abrams has better protection than 350mm from the front turret. We also know that the CIA discovers in the late 70ties that they had underestimated the capabilities of the T64/T72 and that the superiority of the Abrams they had estimated back in 1972 was not going to be realized. At the same time the Abrams gains in weight, in 1978 0.9 tons are added to the tank in form of ballistic protection finally pushing the tank to 60 tons, 2 tons over the original 58 requirement. Source: "Transportability in the defense department. By Zycher and Morton. 1992" So we do actually have evidence that the Americans added to the armor protection before production commenced, and that in 1982 they where only worrying. I appreciate your time and information! Though trying to say that the CIA report is really just talking about the M1E1 I find really doubtful, given that the CE protection is only 750. My suspicion is that when they decided on the armor of the M1A1 their major concern was not KE weapons rather it was CE, you can read in one of their reports on the Russian tanks that they estimate that the Russians will soon develop a missile capable of overmatching 750mm steel. Thats why they add 200mm to the turret front to protect against CE.
  5. 1. Oh great because you don't realize that you can actually test out an hypothesis about size and volume using 3d. Things have to fit together you know. 2.Great, yes. And yes I did make that, based on what I knew at the time. If you are going to be pointing out that it is not 100% right, then I already know that as I have updated my knowledge since then. 3. I did, what is the point here? 4. Yes I have. 5. I never said "everything is wrong" I said it is "mostly wrong", sure you got the outside right, however you put alot of numbers on the inside, we already know the outside of the tank, its the inside that is the interesting part. 6. Maybe you should be looking at the mirror to answer the question who is protecting their beliefs. 7. Right even as I went through all the logic of my argument you can't see anything. 8. I never said all your pics are shit. That is something you have chosen to read into it. I specifically criticized the composition and LOS of your drawing of the Abrams left side turret armor.
  6. 1. Oh wow you got internal measurement from photogrammetry, you must be a genius. 2. Can you see the images I posted or is there some magic spell called 105mm that completely changes the design of the turret, you do know that the turret was designed for the option to be upgraded, right? 3. Yeah we all know that the worst source for information is official drawings. But I look forward to your photogrammetry of the inside of the armor. 4. Yeah put your fingers in your ears and yell lalalalal, because there is no corrolation between armor dimensions and protection level I guess. 5. And? there you have the source which you have just confimed is in line with your photogrammetry. 6. Which holy war? You mean that I argue, that in order to achieve the desired protection level the armor has to be thicker than what you "guessed", so as I am arguing that the armor is less effective than what you want it to be, and I am waging a holy war? 7. You obviously don't know what an argument is, because you are the one just posting a picture putting on values with out having any evidence or logic behind it.
  7. 1. I agree that the images in their original state are a bit skewed. However when you apply the correct external dimension and internal(center of gun rotor) you get the same values that Gaijin measured on the outside of plate thickness. they also correspond to other measurements on the outside of the tank like distance between front of front plate and weld line of the hull array. Plus you get the same LOS when you measure on SAIFV drawings and the British computer drawings. So I think they are actually pretty accurate. 2. I have to clarify I think the front turret can withstand the xm774 not the hull. You are quit right I have read the report many times. 3. Maybe the steel equivalent values are "irrelevant" however my point was that when you are designing after a specific threat once you have an armor that can defeat it then you can just apply it, and when you calculate the numbers you find that the steel LOS is similar for arears that is suppose to defeat the same threat. 4. The 400mm number from CIA seems to be obviously based on the XM774 also there is a difference in how the Germans measure armor and how the Americans measure armor. I don't recall reading the DM23 400mm claim at what angle was the steel, it penetrated? 5. You are quit right about all these documents, however its the turret front we are interested in here not overall protection.
  8. Maybe you should read what I wrote before you get defensive. The internal structure of all productions Abrams models is the same, that is why you can turn a M1 into a M1A2C using the same original turret, you just replace necessary external parts. That is why I posted the image of the internal structure from US army documents. I was starting with arguments if you bothered to read them. My guess was how to approach it which I have to admit failed. First argument: Gaijins 19,5" figure is wrong because it measures from the wrong point. Second argument: The frontal turret armor of the Abrams is adjustable, it is not like the front hull armor with a solid monolithic plate of armor in the back, rather it is more like the bustle armor, you bolt armor plates to a "thin" back plate. Third argument: The frontal hull armor has a LOS of 650mm. You can get that from SAIFV, UK gov docs, from CIA drawings if you scale them to the tanks dimensions. Fourth argument: Protection level of front hull was the same for the Turret. Therefore using M1 armor technology we need 650mm LOS on turret to achive same protection at the apropriate angle, 25 or 30 degrees angular Fifth argument: Giving 650mm LOS to 25-30 angular on left side gives ~800mm frontal LOS, applying that ~800mm LOS to the right side lines up with the rest of the turret structure, GPS well etc. If your didn't get it the reason I mentioned the protection level was to emphasize that LOS is not just random but integral to the armor protection level. Then I gave you my measurements of the CIA drawings of the SA. Which is base on the same images you posted though in a bit better resolution, here is a taste: And that is the source of the estimates. And why I found that steel LOS was very similar on parts that had same armor specifications. I have also made 3d models though its many years ago now: That "productions stages" drawing looks very much like its from a model kit, not actual turret. Just look at the rotor, that is not how the M1 rotor housing looks. But talking about sources: Maybe I am out of the loop but which source talks about 4" armor?
  9. This is mostly wrong dimensionally and conceptually. Where to start... I am guessing that you are basing your drawing on Gaijin's measurements of the Minnesota Abrams combined with the CIA drawing of the hull front armor? First of all I am sure they got the front armor volume wrong because they thought they measured from the edge of the internal armor plate sticking out through the underside of the turret on the right side. However this is a miss conception we can easily see this in images from the underside during production. What they are actually measuring from is the "armor floor plate" the plate that carries the armor, that is why we don't see any weld lines and it is curved rather than sharply angled like two welded RHA plates would be: This points to another misconception about the Abrams front turret armor rear plate, that it is monolithic. However it is not a straight copy an past of the hull front armor, rather it is a mix of front and bustle armor. The Abrams is rather similar to the Leo2 in this regard. A "thin" back plate to maximize the adjustability of the armor protection. Here the similarity ends, because to this back plate bolts can be fastened enabling you to mount the number of armor plates needed to reach the desired protection level. So how can we estimate the LOS of the Abrams turret front? Well we go back to the front hull and fist we get the right dimensions from that. Now I happen to have the exterior dimensions of the Abrams, but we could scale of the dimension that Gaijin have provided us of 22" from front to start of back plate. And in the end up with a Armor LOS of ~650mm which is a damn coincidence cause that is also the LOS of Leopard 2 hull armor(and turret I estimate). So now we know the minimal LOS needed with Abrams armor to meet the armor requirements of 322mm+ KE/ 636mm+ HEAT. Given that the turret had to meet at least this same requirement we can just add ~650mm LOS to the side of the left turret cheek at the correct angel. Here I am unsure whether they went with 25 or 30 degrees but it actually don't make much difference, what you end up with is a ~800mm frontal LOS with either. But now we know the frontal LOS which by the way is roughly in the middle range of the Gun Shield LOS of 710-855mm. This gives us a minimal LOS of ~570mm rather than ~500mm on the left cheek. And we can use that to estimate the right side armor LOS. The right side of the turret have a shallower sweep but houses all the most important equipment of the tank so it makes sense to copy the frontal LOS rather than the 25-30 degree LOS to achieve a uniform protection from the front. Now if you put all that in to a 3d Program you will see that everything starts matching up really nice with photos, GPS housing, real dimensions and the ones we find in CIA documents and Army technical papers. Scaling the array composition we of cause also have to take offset in the numbers we can find in official documents and the CIA drawings. When you scale the armor drawings you find that they have similar amounts of steel LOS at the appropriate angles. The Gun Shield has a 6" back plate(part of the rotor) a ~1,3" LOS plate(probably not steel), 12,5" deep Special Armor(SA) array and a 1,6" plate angled at 33 degree obliquity giving 2" LOS The Hull front has a 5,8 LOS backplate(110mm plate) ~12" deep SA array and a 1,3" plate at 49 degree obliquity giving ~1,65" LOS. Hull side is pretty similar despite missing SA. We know that the hull front could defeat the XM579E4 APFSDS(at 1470 m/s) but not the XM774 APFSDS XM579E4 could penetrate 161mm RHA at 60 degree obliquity (322mm LOS) XM774 could penetrate 189mm RHA at 60 degree obliquity (378mm LOS) BTW (322+378)/2 = 350 , probably where the 350mm figure stems from. And now we have to decide how to interpret the given information. The Army tells us in New York Times, march, 1978 that the Abrams can not be penetrated by its own round, which is capable of penetrating 15"(380mm, XM774) of armor. CIA documents tells us that one version of the Abrams turret has 400mm-KE 750mm-CE protection UK tells us 25 degree XM579E4 protection is principal others say 30 degree 350mm protection. How I read this is that the steel LOS of Gunshield with SA LOS of hull is likely how the front cheeks are armored. However it might just be similar to the hull in composition. Turret side armor over the crew compartment looks different but is really just the hull armor scaled to 65 degree obliquity. Instead of the 3 SA tri plates being angled relative to the outer plate they are lying parallelly to the plate. The rear plate being ~2,49" thick LOS at 25 degree angular is ~150mm(~5,9") with the outer plate being 19mm that is ~45mm(1,8") LOS. My estimation of side LOS is 400mm rather than Gaijin's 381mm, I think they missed the fact that the roof plate is recessed down into the interior side plate. Turret bustle has thicker LOS of about 441mm and while it has probably bad KE protection head on it will likely provide better protection than the front armor at 25-30 degrees angular.
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