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Subject: USS Iowa and the USS Wisconsin bite the dust
Heorot    12/29/2005 3:43:24 PM
A sad day but apparently a boost to the DD(X). http://www.washingtonpost.com/wp-dyn/content/article/2005/12/20/AR2005122001445.html
 
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fitz    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 11:39:43 AM
"Apparently the people that really want the BBs around are the Marines." The Marines have expressed no such opinion. The only people who really want them back are a very small group of hobbyists with a fetish for battleships who formed an organization called the United States Naval Fire Support Organization. In spite of the name, the only goal of this group is to reinstate the Iowa class battleships and kill EVERY OTHER NAVY PROGRAM for providing fire support. They claim to speak for the Marines, but so far as I can tell no member of USNFSA is a former or current Marine and none have any experience whatsoever in fire support issues (which shows). Several of them are, however very well connected which gives them the access to pester Congress and the GAO about the status of the Iowa's from time to time.
 
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AlbanyRifles    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 11:40:00 AM
As for amphibs....same argument. If the Amrines are attacking a shore which requires this much fire support to take, then they are attacking in the wrong place. With the availability of PGMs available to both the airwing and the projected DDX there is no need for 16 inch shellfire.
 
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Arbalest    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 3:18:35 PM
Fitz ? a quick review of "Breyer" reveals that the Roma had only 1 significantly thick armored deck (varying 100-162mm), the Iowa had 2 (127+19mm and lower 142+19mm) in addition to various other 35-50mm layers on both ships. The lower AD on the Iowa (142+19mm) seems to me to be a significant difference, as it represents an almost 100% increase in protection over the Roma. Next, the belt and barbette armor on the Roma was about 350mm. I ran across a link on 12/29/2005 that indicated that the Fritz-X was rated to penetrate 100-150mm or so of armor. I looked at it, since it was one of the few non-Wikipedia listings, and since it did not specify hit location, I simply passed by. The implication, which everyone seems to agree on, is that the Fritz-X could not penetrate the Roma?s belt or barbette armor, as it was over twice the thickness that the Fritz-X could penetrate. Everyone also agrees that the turrets were not hit. It should be noted that on all battleships of WW2, the belt armor extended both above and below the waterline. Additionally, in the case of the Roma, as well as most other WW2 battleships, the belt armor did not extend all the way topsides (the Scharnhorst and Bismark are two exceptions). Consequently, it is possible to strike the upper side of the Roma and hit the deck armor instead of the belt armor. The quote you supplied from Garzke and Dulin suggests that photography indicates that both hits on the Roma are above the waterline. The process of elimination points to plunging hits that penetrate deck armor. The multitude of Wikipedia entries all seem to eventually point to http://en.wikipedia.org/wiki/Italian_battleship_Roma_%281940%29, which states that "... the other one hit aprow deck between turret #2 and conning tower." This text refers to the second Fritz-X strike. http://www.bobhenneman.info/roma.htm reports the second hit was "abreast "b" turret barbette", which seems to agree with Wiki. The first hit appears to disrupt the Pugilese system from inside the ship. The second hit appears to be the cause of the kill, as it started fires that spread to a magazine. Fitz ? I generally agree with your assessment of the reasons for sinking the Belgrano, and my previous discussion of the possible alternatives should imply this. That a shaped charge could penetrate through an essentially unarmored ship (I?m not familiar with the Vammen) is not particularly surprising. This represents perhaps 12 or so 10mm plates, each one of which is greatly overmatched by a shaped charge the diameter of a Harpoon. Back to the question of the Iowa, penetrating the belt armor requires either an AP projectile of some sort, or multiple shaped charges. Note that the second shaped charge (or even just a conventional explosive charge) must be able to fit through the hole generated by the first shaped charge. This suggests the second charge must be under 200mm diameter, probably under 150mm. One of these is unlikely to destroy a battleship. One RPG-7 should be able to penetrate the Iowa?s belt armor. Sinking the ship is an unlikely result. A sufficiently large shaped charge has a better chance, but it will have to penetrate the internal compartmentalization and then strike a magazine, boiler, etc. Multiple strikes would probably be necessary. Switching to your comment: "The big Russian anti-ship missiles are "carrier-killers" They are designed to penetrate the armoured flight deck, penetrate the hangar deck and spread their havoc deep down into the magazine spaces. That's why they are so big and that's why they have such big, shaped charge warheads. And I doubt very much that they explode on impact. They penetrate the armoured flight deck first by kinetic energy." I also believe that the larger Russian AShMs are indeed designed to kill carriers. However, to get a missile through 150+mm (minimum Iowa thickness from a specific attack angle) of armor requires either an AP nose or projectile in front, or multiple warheads. Missile airframes are simply not up to the task. You seem to be mixing penetration mechanisms. "... designed to penetrate the armoured flight deck ... that's why they have such big, shaped charge warheads." implies detonation on impact. Then later "They penetrate the armoured flight deck first by kinetic energy.". This is clearly a different mechanism, as per your words. Which is it? If it is both, which I suspect, but am not convinced of, for other reasons, please clarify. A kinetic penetration mechanism suggests only a sea-skimming profile (no KE loss from the popup, and harder to intercept), or a very high popup profile, since M3 is about 2800ft/sec, and impact at 30degrees or more from normal represents a noticeable penetration decrease at this velocity. If the KE penetration is perhaps only enough to punch through 15mm of steel, this seems possible, but a large shaped charge seems pointless in this ca
 
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fitz    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 3:49:26 PM
"Back to the question of the Iowa, penetrating the belt armor requires either an AP projectile of some sort, or multiple shaped charges..." No it doesn't. I have in front of me at this very moment a penetration diagram based on the actual performance of the LRAC 89 - an obsolete "bazooka" type shoulder fired anti-tank rocket launcher formerly in use in France and elsewhere. This rocket, 88.9mm in diamter and 2.2kg in wieght traveling at a leasurely 300 m/s can penetrate the NATO double heavy target with ease. What is that target? A 40mm RHA plate with a 110mm plate 150mm behind it, both set back at 60 degrees from the vertical. Not only that, but LRAC-89 can penetrate 80 additional 10mm plates, the first 50mm behind the 110mm plate, the rest 10mm behind the first. Here's a very crude representation of how the plates are laid out (it helps to visualize sometimes). / / //////// Now, are you going to try and tell me a 3,000kg Mach 3 missile with a 500kg (not 2.2kg) shaped charge warhead isn't going to defeat Iowa's two armoured decks and still penetrate deep in the ship, when that is exactly the sort of thing it is designed to do? You don't need multiple shaped charges to penetrate more than one plate. The two hull sides and the various compartments and bulkheads on Vammen should theoretically have acted like spaced armour too, but the warhead easily overmatched them. A 1,400kg unpowered bomb traveling at 240m/s handily overmatched what was a pretty decent armoured scheme for the time in 1943. I think we could probably manage the same or better today.
 
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fitz    Oh yeah,    12/30/2005 3:55:42 PM
To address your other point, even small, slow missiles like Harpoon are generally credited with the ability to penetrate 100-150mm of armour plate before exploding. So far as I know, delayed action is used for all anti-ship missile warheads, even the shaped charged ones so that kinetic energy is used to penetrate the vessel, the warhead exploding inside for maximim effect. Large shaped charges are used in some to vent as many compartments as possible as deep into the hull as possible to allow the burning fuel from the missile to spread. Other missiles like Kormoran use a warhead made up of a number of radially aligned small shaped charges to achieve the same effect - but in all directions. My apologies if there was any confusion in my earlier post. But even if some of the big Russian jobs have to use the shaped charge to penetrate the flight deck of a carrier (which is possible but doubtful) these warheads are more than large enough to keep on travelling through multiple decks beyond that. That is after all, the whole idea.
 
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jblange    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 5:52:45 PM
Here is the link to an article, by Robert Novak, that I referred to in my prior post http://www.cnn.com/2005/POLITICS/12/06/novak.marines/index.html
 
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Arbalest    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 8:09:21 PM
A quick check of your LRAC 89 performance figures (40mm + 110mm) plus "Not only that, but LRAC-89 can penetrate 80 additional 10mm plates ..." yields 950mm penetration. Quite good for an 89mm weapon. I suspect you have a typo, and actually meant "8 additional 10mm plates" for 320mm penetration. This puts LRAC 89 in the same class as the Strim F1 89mm, RL-83 (Blindicide), ACL/APX 80 and the early RPGs. While one shaped charge will indeed penetrate more than one plate, to get an internal explosion it is necessary to either have the projectile from the original shaped charge hit something (a boiler, a magazine, etc.) or to have a second explosive charge follow and pass through the hole. An APHE projectile is designed to do this; the Seydlitz (WW1) took several hits if this type from 12-inch projectiles and survived. WW2 battleships are much more survivable. One reasonably modern shaped charge, detonating on the Iowa?s belt armor, will likely put a hole through it. The hole is dependent on the diameter of the shaped charge. An RPG-7 should do it, but the hole will be small. See http://www.strategypage.com/gallery/articles/solved.asp for details and pictures of real-world damage results. Simply being hit by a shaped charge is not enough; something vulnerable inside must be hit, or a secondary explosive must follow and detonate inside. A 20-in diameter shaped charge might make a hole potentially 6 inches in diameter, but maybe only 3 or 4. Any following rounds need to get through this hole to detonate on the inside. A 155mm shell going off is unlikely to sink an Iowa or any other WW2 battleship. Can you provide a link verifying "...small, slow missiles like Harpoon are generally credited with the ability to penetrate 100-150mm of armour plate" (before warhead detonation)? Punching through 15-20mm seems quite possible, and 50mm plates may buckle, but 76mm and up seems unlikely. Your statement concerning the Kormoran implies that there may be some sort of AP nose in front of the warhead. I?m inclined to believe that this is true, but I don?t know. If you are suggesting that other missiles (Harpoon, Sunburn, etc.) have this feature, please say so. As for a "... 3,000kg Mach 3 missile with a 500kg (not 2.2kg) shaped charge warhead ..." penetrating the Iowa?s deck, the missile must either detonate the shaped charge warhead on impact, or have about a 250kg AP nose (and enough space behind it so the rest of the missile will survive the impact). Otherwise, as far as penetrating 310mm of armor is concerned, the missile is essentially a large dirt clod. For some reason, you keep associating the velocity of a shaped charge with its armor-penetrating performance. Shaped charge cone angle, cone diameter, standoff distance, liner material, explosive type and amount, and presence of wave-shaping devices in the charge, are several of the important factors; velocity (before detonation) is not. Placing the shaped charge on a mount next to the target, with the optimum standoff will generate the maximum penetration. Adding velocity to the shaped charge will, theoretically, I suppose, add to the velocity of the "carrot", but it jeopardizes the optimum standoff distance. At M3 (roughly 2800ft/sec) a half-millisecond detonation error equals about a 1.4 foot standoff error, which will more than offset any added velocity.
 
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fitz    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 9:20:25 PM
Sorry, typo. It was supposed to read 8 (eight) additional 10mm plates, not 80. That's what I get for not proofing my stuff. As for secondary effects, that is handled by the fire - the actual destructive part of the anti-ship missile (I thought we had discussed this already). Gun launched projectiles achieve destructive effect through blast damage. Missiles do it with fire from the fuel not used in the flight to the target. This can be extremely nasty (think HMS Sheffield or USS Stark). The Russians for example mount the shaped charge warhead BEHIND the fuel tank on their missiles - so as to better spread the incendiary around. Tests of western missiles like Harpoon have shown that detonation of the warhead has little overall effect on the target - fire does the majority of the damage. Tests done with intert (concrete filled) and live warhead rounds show little difference in total damage done. On the missile that hit HMS Sheffield for example, the warhead did not explode. One of the two that hit USS Stark also did not explode. The fires caused by both were enormous however. The armour penetration figures for Harpoon were quoted from Friedman, in a book (you know, those paper things), not from the web. So I can't give you a link. I prefer books anyway. You don't get squat for useful, reliable information on the web. The velocity of the Russian rounds is important from an impact standpoint if they use that energy for kinetic penetration of the target - which is likely since the warhead is mounted toward the rear of the missile and would not achieve the desired effect if contact fused. I'm quite aware that velocity does not improve the performance of the shaped charge. That wasn't the point. Sorry if I didn't make it clear. I guess I knew what I was getting at, it just didn't come out well.
 
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Yimmy    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 9:25:26 PM
I don't believe anti-ship missiles use shaped charge warheads at all. I was under the impression that they used semi-armour piercing warheads, in the form of high explosives behind a hardened nose cone.
 
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fitz    RE:USS Iowa and the USS Wisconsin bite the dust   12/30/2005 9:35:40 PM
"I don't believe anti-ship missiles use shaped charge warheads at all. I was under the impression that they used semi-armour piercing warheads, in the form of high explosives behind a hardened nose cone." Western ones generally don't notable exceptions being Kormoran and the abortive Condor. The Russian's have on most of theirs since the P-15 (Styx) came out 45 years ago. I have a picture of the warhead on a HY-2 Silkworm (reverse-engineered Chinese copy) that shows the cone of the shaped charge rather convincingly.
 
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