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Topic: US Armor Trial Waivers
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All Forums : [THE MILITARY ACADEMY] : Militaria, Military Hardware & Tech Specs > US Armor Trial Waivers
| 28 MAY 2002 at 1:01am | |
GeorgeCenturion  Posts : 136 Joined: 20 APR 2002 Status : Online | There are numerous letters like these in the archives, and in almost all cases the standards were indeed waived. This is one reason the USN project monitors eventually felt they were being black mailed by the companies. The companies knew the Navy was not in a position to reject lots and thus slow an accelerated building tempo. Thus in many cases the actual quality of the armor used is very suspect. I noted many similar requests in the Iowa Class files, and I'll get those for the group the next time out. In this first case (1940) we see a plate that was slightly underweight get passed, much like the barbette armor lot did that filed to pass ballistic testing. Once again, time was the main factor, and in this case the underweight was very small. But with each exception, the requests for more grew. |
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| 28 MAY 2002 at 1:02am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | Note the "if its OK with the boss" tone. |
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| 28 MAY 2002 at 1:04am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | It seems the reminder that there was a standard didn't serve much purpose. |
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| 28 MAY 2002 at 1:06am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | the companies were asking that ballistic acceptance tests for large consignments of plates, tubing, and other armor be waived altogether based on the performance of "generally" similar lots. |
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| 28 MAY 2002 at 1:10am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | ... asked to be passed without ballistic tests. This may seem very strange in light of the known failures of some lots, but most requests were indeed granted. |
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| 28 MAY 2002 at 1:11am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | and so it went... |
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| 18 JUN 2002 at 7:08pm | |
NathanOkunCenturionPosts : 3 Joined: 23 APR 2002 Status : Online | To my knowledge, the U.S. was the ONLY nation to hold manufacturers to spec values. British specs, for instance, ALWAYS had allowed inferior plates to be bought, they merely lowered the price they would pay and bought them anyway. It was not even considered a problem at all--specs were "pulled out of the air" anyway (no laws of physics here!!) and the British understood this somewhat better than the U.S. did, though even with the hard-nosed U.S. attitude, almost all plates passed the specs (we are talking about MILLIONS of plates here!!!).
That is why you do not have as many reports of "inferior" material in most foreign (non-U.S.) documents--you can't define plates to be be inferior if you allow them to be bought anyway!! This was especially true of Krupp material, as they defined the spec and the spec was defined by what they made, round and round--ain't being a monopoly grand?
Nathan Okun Nathan Okun |
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| 18 JUN 2002 at 10:08pm | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | ... as well as the what was supposed to happen with plates that failed to meet the standards. As you know, that document was translated, along with the designated metalurgical testing procedures piece. However, one suspects these standards were not rigidly applied during wartime, although we have no documentation on this. I believe such documentation exists, and it will be tracked down over time. I doubt we shall see the hundreds of quality control documents that are available on each ship the US built, but any will be nice. We know the warship inspection reports are extremely detailed, scathing, and unforgiving. We also know faults were not accepted when they were found, and that the builders were expected to correct them -- even if the fundamental design was the problem.
We do not have many details on British test procedures, although we know plate quaility varied more during the WWI era than it did during the WWII period. I think the PRO will have documents such as these, but where to find them will be difficult. I have no idea what these documents will reveal, and I suspect the British had their own armor QC commission in action. I don't know how one can compare the relative adherance to standards in a general sense without gathering more data on specifics. I found many such examples in the US archives -- far more than I could scan. I am tempted to go back and complete the job, but that will only satisfy the US case. It does little for the Japanese, German, and British cases, let alone those of the Italians and French. But overall, I would have to say that the actual resistance of armor probably varies inversely with product demand, which will have time-lines that can be traced. Much to do here.
George |
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| 18 JUN 2002 at 11:48pm | |
NathanOkunCenturionPosts : 3 Joined: 23 APR 2002 Status : Online | I have a large number of tests of German KC n/A armor made by the Germans themselves, mostly prior to WWII and the armor varies in quality over 20% plate-to-plate (some thinner plates are actually superior to plates significantly thicker. There are projectile acceptance test criteria given, also, which in some cases are obviously based on the test plates given here (some of these plates were obviously the exact plates used to develop the WWII AP projectile acceptance test values and are thus representative of the actual averages found for those thicknesses). These tests are with APC projectiles ranging from 15cm L/2.9 through 30.6cm L/4.4. The 15cm and 21cm L/2.9 and 30.5cm L/3.4 were both developed prior to WWI and were still being used to test new armor.
Similarly, the British during the 1930's and 1940's were still using the 1918 12" APC Mark VIIA (Greenboy) to test much of their armor through the end of WWII **WITH THE EXACT SAME BALLISTIC LIMITS REQUIRED IN 1919**, too, so low British armor quality (0.92 was not due to manufacturing quality, but due to using the same specs as were used in 1919 (except in some cases--very thick plates--where new projectiles were employed, which were calibrated to give the equaivalent to the old test results). British armor exceeded their specs in some cases, but many plates were way below average, hence the 15% quality spread in British WWII CA. I have the acceptance tests for the armor to be used in HMS ANSON, tested in 1939/40, and a couple of plate groups did not meet the spec and were bought at a reduced price, NOT rejected. I have the complete set of British acceptance specs for armor anf projectiles in 1940 and in 1928 and they are, where the same kind of ordnance and thickness of armor are covered, identical in every way. Improvements in British armor were by accident (the use of a thin face layer in CA), not because the spec improved, since the spec did not.
U.S. specs improved enormously over WWII materičl in every way and the U.S. Navy tests with the 12" AP Mark 15 Mod 6 "Midvale Unbreakable" projectiles, which were invulnerable to U.S., British, and German KC-type armors at the end of WWI at normal incidence were being destroyed when they hit U.S. WWII Class "A" armor. British and German armor also improved, but not as much in basic steel quality--U.S. face-hardened armor suffered from a spec that required projectiles to be heavily damaged on impact (not a part of either British or German specs) and this ended up requiring a very thick face to obtain due to the superiority of U.S. AP projectiles (they could go through armor up to 1.4 caliber thick at 30° obliquity in intact condition or up to 1.0-caliber thick at 40° in an intact condition--both regular spec tests and both at just above the complete-penetration ballistic limit, which were simply IMPOSSIBLE for any foreign projectiles to do, ever!). This thick face caused the heavy, BB-thickness armor to have less total resistance (lower ballistic limit) if the projectile was not damaged (but did not hurt cruiser-thickness armor), and U.S. projectiles proved by the end of WWII that the continual improvements in projectile quality (they were up to Revision "J" in their test spec by the end of WWII) rendered them essentially invulnerable to such damage--the requirement was thus a mistake that was counterproductive against large projectiles.
I have plenty of tests, including the tests by the British and U.S. after WWII, of Krupp armor. One KC n/A plate was so bad that the U.S. NPG testers didn't even bother to lower the striking velocity enough in the standard U.S. 14" AP Mark 16 projectile tests at 30° to find out how bad it was, but it was matched by some of the poor plates in those German Krupp KC n/A armor tests, though most KC n/A plates were in the 0.925-1.0 range, averaging 0.96, which is the same result obtained from British tests of 32cm KC n/A plates taken from TIRPITZ and gives results close to G.Kdos. 100 when the projectiles are similarly calibrated. That is why I use 0.96 as the post-1930 KC n/A plate quality in my FACEHARD program, though this is with a LARGE "grain of salt."
You cannot excuse the problems by saying they were "wartime" problems, since many were evident and chronic during the 1930's, well before WWII. The Krupp WWII projectile specs in Germany were established well before WWII and were actually exactly the same as in WWI (before, actually)--roughly half-caliber plate at 30° and 500 m/sec intact ("Heil") and roughly one-caliber plate at normal and 500 m/sec (also "Heil"). Krupp APC L/4.4 projectiles actually exceeded this requirement significantly, especially the 20.3cm and 38cm sizes, but this was not because they had to, while the earlier APC L/3.7 design (28cm Pocket BB gun and 15cm light cruiser/BB secondary gun) barely passed. Carefully study the KC n/A penetration curves in G.Kdos. 100 and you will find that my FACEHARD program tracks them rather well (as well as possible using the formulae that I use, which are not the same as the Krupp formulae), so I know what I am talking about here.
U.S. Navy WWII armor was the only one REQUIRED to be better than WWI armor by having specs with hard floors (even 2% low ballistic tests or 1.24% low thicknesses had to get special permission to pass--British and German testers would have not even blinked when passing such plates (as with ANSON's armor), sometimes with lower cost/per plate, and would never have even thought about getting permission from the head of their BuOrd equivalents to do so). That is why U.S. armor and ordnance continually improved through WWII and by 1945, U.S. late-model light and heavy cruisers had the best APC projectiles in the world (significantly better than they were in 1941, good as they had been then) and U.S. Class "A" armor was 2.5% better, on the average, than it was in 1941.
By the way, those new turret roof and grating plates for the old battleships were there because of the threat of aircraft bombs after the AIRZONA, TENNESSEE, and WEST VIRGINIA had major bomb damage. The turret roofs in two turrets, one in each of the latter ships, were holed WITHOUT PENETRATING THE ARMOR!! The plates were shingled (partially overlapped) to resist a highly oblique hit from a gun projectile from the front and the Japanese Type 99 Number 80 Mark 5 16.1" AP bombs hit from the rear, dented the plate hit, tearing the rivets holding the top of the plate hit to the bottom of the plate further forward where they overlapped, and were then able to pass through te resultant mouth-shaped gap (the bombs were both heavily damaged in the process, but still able to burn out the turrets). The new turret roofs were installed to bring their armor up to WWII design standards against all threats, not because of any deficiency in the armor quality.
The uptake gratings in WWI were merely criss-crossed nickel-steel bars in layers to deflect highly-oblique projectile impacts on the funnel uptake openings in the "protective decks" of these WWI-era and pre-WWI-era ships. This was entirely inadequate against bombs, so again modern solid VERY thick armor plate "gratings" with many holes drilled in them were installed in their place to resist bombs. For example, YAMATO had the same kind of gratings, made of 38cm-thick Molybdenum Non-Cemented deck armor with many holes, that was equal to about 6" of solid MNC deck armor.
By calling such things "suspect" you show that you do not understand the subject (again). You have to know why something is done and then you can criticize it compared to what should have been done in its place, if it comes up short. Thus, you have to know what "better" could possibly be to say something is not the "best." Please learn this before making comments about relative quality, good or bad.
Nathan Okun Nathan Okun |
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| 19 JUN 2002 at 12:47am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | Nathan:
I thought that you would have learned more than to put bombast before decorum, but that doesn't seem to be your style. Furthermore, please don't lecture me about what I do or do not know -- for you are hardly fit to judge others. Should I question you about your accademic credentials, as in what degree you earned from what university? I don't think you want to play that game Nathan, and especialy with someone who has been around the accademy for nearly his entire adult life.
So let us stick to the facts. You say you have many tests that say X, Y, and Z, and I am calling upon you to give us the actual texts in their entirety. Don't give us your interpretations or distilations or partial reports, but the actual primary source literature in all its glory. This is what we do here. You failed to do so with GK 100 when you were given a chance, and it was up to a person whom you did share the data with to give the results to this group. Furthermore, I believe you have been rather selective in your use of data on occasion, but let us not dwell on the negative.
As for my excusing problems by manufacturers, where did you come up with that? ALL armor makers are capable of making mistakes when pressured, and its is you who appear to be trying to excuse US failings by pointing out the failures of others. And even here, you are simply wrong on the facts. Indeed, US QC problems run into the 1948 era, and I have the material to prove it. It will be posted here for everyone to read. I don't have to make claims -- for the data tell the tale. And it is a story that differs profoundly from your claims. For example, the reports of US researchers disagree with your published assessments about the effects of delaminations. The reports of US researchers differ form your published assessments concerning US quality consistancy. And you know I could site numerous other examples wherein you have been rather... creative with the facts.
But this forum is not intended to be a place of personal invective, and your doubting someone's credentials when you are presented with studies that work against your claims is not the way to go about any debate. If you have studies, present them in depth and detail -- without leaving anything at all out. If all you have are unsubstantiated claims, invective, and insults, then perhaps you'll find a more receptive audience in a less scholarly group. The ball is in your court, and I'd advise you to play nice.
George |
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| 19 JUN 2002 at 7:17am | |
NeilSCenturionPosts : 3 Joined: 20 APR 2002 Status : Online | This from A-7a 3025. |
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| 19 JUN 2002 at 1:30pm | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | A claim was made regarding British testing methods, and now we see some primary source documentation about how the testing was actually conducted that offers important details about an incentive program that was inherent in the proof trial procedures. We read of ranges wherein acceptance is deemed suitable, with penalties being paid for being on the downside of those ranges. I suspect this procedure may be more efficatious than simply passing lots without performing any ballistic trials on them at all. That is to abandon QC altogether -- and can result in the fitting of plates that are so delaminated as to resemble "ant farms."
George |
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| 19 JUN 2002 at 2:52pm | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | ... most British plates exceeded acceptance standards. In fact, I believe it was Nathan that delivered this view. If this is the case, I am at a bit of a loss to understand what the angst is concerning the variability in British armor trials.
George |
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| 24 JUN 2002 at 8:44pm | |
TrentHCenturionPosts : 1 Joined: 22 APR 2002 Status : Online | While this was still an email list, a rather large British document was sent out that contained the results of various proof testing of shells and armor. The document included the results of information gathered from cooperation with American ordnance examinations of British material at Aberdeen. Unfortunately, I do not remember the exact reference to this document, and I do not have it with me at the moment.
Although the document does not say so explicitly, it is very evident that one of the things the British hoped to gain from the exchange of knowledge was an improvement in their testing and acceptance procedures so as to decrease the level of variation in the performance of their shells and armor.
One of the facts brought out by the document is that where the British placed emphasis on the skill of individuals in their testing procedures, the Americans placed far more emphasis on scientific formula and calculation. This is echoed by the document posted by Neil which indicates that the British placed great responsibility in the hands of the proof officer. The American system does not appear to have relied so heavily on individual observation and judgment, allowing it to achieve a higher level of consistency.
It may be therefore that there are a large number of documents detailing "inferior" US armor plates available, not because the manufacturing procedures were flawed, but because the US system of testing and acceptance was sophisticated enough to allow this level of detail to be recorded and reported on, making it easier to evaluate the progress of the industry. |
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| 25 JUN 2002 at 12:06am | |
GeorgeCenturionPosts : 136 Joined: 20 APR 2002 Status : Online | ... acceptance criteria, one notes a variety fo methods were used by all countries. For example, the Germans took core samples from different planes, and the Italians made multiple metal analysis throughout the melt and charge process. Some countries fired at different parts of the target plates during ballistic tests, while others did not. These factors are just as important as an adherance to formulae. Indeed, the application of most of formulaic methods were incorrect in detail, and some of the traditional metal tests failed to predict ballistic behavior.
In terms of relative testing merrits, sample size and consistancy of testing methods are both key variables. And when one eschews testing large lots based on the performance of similar material, then sample size as a function of material produced goes way down for the type of armor in question. This is hardly ever a good thing from a QC and statistical reliability perspective. I suspect other nations also did this given the demands caused by war. The degree to which none-testing was a problem for various nations remains to be determined. We know this procedure exisited in the USN and we also know plates that failed acceptance trials were still used. The extent of this problem remains unclear, although given the ample correspondance on its existance and even a Congressional investigation -- one cannot say it was an uncommon event. As usual, there remains much to do, and I assure you that there are abundant records in the archive that remain untapped.
George |
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