Armour Penetration

Warship design and construction, terminology, navigation, hydrodynamics, stability, armor schemes, damage control, etc.
mcubed
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Re: Armour Penetration

Post by mcubed » Sun Oct 18, 2009 1:49 am

Lutscha wrote:
There were no joint problems as in Yamato that I know of, so I don't see a problem there but as of now I have not finished my new book about R.

Never mind, I mis-read your post.

boredatwork
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Re: Armour Penetration

Post by boredatwork » Sun Oct 18, 2009 4:31 am

Please, don't start writing statistics about the ships. Not even about the low rate of fire of Richelieu or the insuficiently armoured decks of Bismarck against plunging fire >25000m. It won't do any good. To many "good designs" have proved to be flaws in battle (South Dakota at Gudalcanal, Hipper as a merchant raider, PoW AA and ATS protection in Java Sea, etc), and viceversa (who could believe the accomplishments of Warspite, a WW1 era BB?). We can only rely on what actually happened. The rest is just speculation.
While I agree with you that in general trying to judge a ship "better or worse" than another is a waste of time - I disagree somewhat that "facts" (what you really mean is "Historical Events" as statistics can be "facts" too) are a superior way to compare the relative merits of a given design.

Consider the following example:

At Jutland Queen Mary was hit by approximately 3-5 heavy shells and exploded killing 1266 men. HMS Lion on the otherhand, suffered 16 hits at Doggerbank and 13 hits at Jutland and survived both battles, her sister Princess Royal suffered 9 heavy hits at Jutland and survived, and finally HMS Tiger suffered 6 hits at Dogger Bank and 15 at Jutland and also survived.

If we look purely at "what actually happened" we could draw the conclusion that Queen Mary was a flawed design compared to both the Tiger and Lion classes as she did not survive as many hits.

Satistically however her armor layout was virtually identical to her half sisters.

So what is the correct interpretation? Obviously that the armor of Queen Mary was insufficient to keep out German fire and once penetrated could result in an explosion that would destroy the ship AND we can INFER by looking at statistics that despite the fact that they did not blow up, Lion and Tiger shared identical protection so they potentially could have.

In otherwords the problem with relying purely on historical events as evidence is the sample of data available is so extremely small that the element of chance has an extraordinarily large impact on any conclusions you could try and draw regarding a design - That a lucky ship achieves more than than expected is not necessarily evidence of good design - likewise that an unlucky ship does not perform up to expectation is not necessarily evidence of faulty design.

More relavent IMO in comparing designs which too many authors ignore is CONTEXT. Too many people for example simply say the American AoN protection was "better" than Bismarck's WW1 style layout (or vice versa), present 1 or 2 arguments in favour of their preference and leave it at that.

The better comparisons on the other hand will list the strengths and weekness of both systems and will present the specific conditions under which each can be expected to excel and then present evidence as to how likely those conditions are to occur in battle. That way rather than being force fed someone's (usually biased) opinion you can evaluate for yourself the likely effectiveness of a given ship in a given situation and therefore the relative merits of 2 or more designs on a situation by situation basis.

alecsandros
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Re: Armour Penetration

Post by alecsandros » Sun Oct 18, 2009 11:19 am

boredatwork wrote:
Consider the following example:

At Jutland Queen Mary was hit by approximately 3-5 heavy shells and exploded killing 1266 men. HMS Lion on the otherhand, suffered 16 hits at Doggerbank and 13 hits at Jutland and survived both battles, her sister Princess Royal suffered 9 heavy hits at Jutland and survived, and finally HMS Tiger suffered 6 hits at Dogger Bank and 15 at Jutland and also survived.

If we look purely at "what actually happened" we could draw the conclusion that Queen Mary was a flawed design compared to both the Tiger and Lion classes as she did not survive as many hits.

Satistically however her armor layout was virtually identical to her half sisters.

So what is the correct interpretation? Obviously that the armor of Queen Mary was insufficient to keep out German fire and once penetrated could result in an explosion that would destroy the ship AND we can INFER by looking at statistics that despite the fact that they did not blow up, Lion and Tiger shared identical protection so they potentially could have.

In otherwords the problem with relying purely on historical events as evidence is the sample of data available is so extremely small that the element of chance has an extraordinarily large impact on any conclusions you could try and draw regarding a design - That a lucky ship achieves more than than expected is not necessarily evidence of good design - likewise that an unlucky ship does not perform up to expectation is not necessarily evidence of faulty design.

More relavent IMO in comparing designs which too many authors ignore is CONTEXT. Too many people for example simply say the American AoN protection was "better" than Bismarck's WW1 style layout (or vice versa), present 1 or 2 arguments in favour of their preference and leave it at that.

The better comparisons on the other hand will list the strengths and weekness of both systems and will present the specific conditions under which each can be expected to excel and then present evidence as to how likely those conditions are to occur in battle. That way rather than being force fed someone's (usually biased) opinion you can evaluate for yourself the likely effectiveness of a given ship in a given situation and therefore the relative merits of 2 or more designs on a situation by situation basis.
Your point of view is very reasonable. In fact, most of the arguments that I've read on this forum are spawned from the intrinsic desire of our, very rational, heads, to mathematically justify this or that position. And, deep down, I think there IS a true, mathematical way, of assesing a ships overall power. But I also think that, for the time being, we do not know that way; and maybe we won't ever know it. And that's because Battleships are tremendously complex units, and complexity, in mathematics, means uncertainty.

Back in college, I've done some reading and wrote some papers about complex system evolution (I was charmed by chaos theory). I wasn't writing about Battleships - no, about abstract complex systems, that were influenced by certain variables and that had a certain, known, evolution law associated with them. The conclusions for me were these: given a C.S., and knowing the evolution law, but slightly altering the input parameters (initial variables), the outcomes - final iteration - of the system was very, very different. There were thousands, tens of thousands, hundreds of thousands of possible outcomes, generated by a slight changes in the input variables.

You're opinion regarding the battle of Jutland is a good example of complex systems in real life - same ships fared completely different, because they were hit by different shells, in different spots.

==============================

Unfortunately, your proposal to judge ships comparatively, system by system in various contexts, seems to be unfeasible: we will be stuck in the same "should/might" statements that plague the forum all over. At best, we will come up with possible outcomes, and not with probable outcomes (because in order to know the probable outcome we would need to know all the input variables and laws of evolution, and that I think would be a lack of modesty)

So, what I'm trying to say is that I don't think we should judge "designs". The "design" is an abstract notion, that "should" behave in a certain way in specific contexts. But the "design" is tricky: PoW was designed to resist far longer under air attack, South Dakota should have made lots of hits with its RDFC in the Second Battle of Guadalcanal, etc.

The ship on the other hand, the real, factual unit, is the one that withstands - or not - 17m waves, attacks from the air, from the sea and underneath it.

And, yes, As you've pointed out, judging a ship only by its battle performance means leting that nasty "luck/unluck" factor get in the way. But that's the way things are. We can't separate "normal" (i.e. expected) outcomes from the "un-normal" (lucky/unlucky) ones, because that would mean to stop leaving in a real world. That is the way reality unfolds itself: by successions of expected and unexpected events (favorable or not) that severely influence the ultimate outcome.

And, to me, that's what history is all about: the events, as they realy, factualy, happened.

So, the next "was Bismarck better than Richelieu" discussion should have a moderate dosage of amusement, because we simply can not realy know "what would have happened if..". Only what we believe/think/hope would have happened.

Cheers

Byron Angel

Re: Armour Penetration

Post by Byron Angel » Sun Oct 18, 2009 12:19 pm

..... I think you make a very good point, alecsandros. Beyond matters of relatively elementary design (X thickness of armor is necessary to protect against Y caliber of gun at Z range, for example) I must agree that comparisons between combat systems as complex as capital ships rapidly become impressively complex and unpredictable.


While on the subject of British battlecruisers at Jutland, here are two more interesting points:

> During the "Run to the South" PRINCESS ROYAL had her Argo range-finder disabled at 3:56 and fired only a single salvo over the following 20 minutes required to get the Argo system back in order.

> During the "Run to the South" TIGER had both Q and X turrets disabled at 3:54, only 3 minutes after having opened fire, and had only two turrets firing for at least twenty minutes of the action.


The devil is always in the details .....


Byron

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Karl Heidenreich
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Re: Armour Penetration

Post by Karl Heidenreich » Sun Oct 18, 2009 6:05 pm

The devil is always in the details .....
Indeed!
An appeaser is one who feeds a crocodile, hoping it will eat him last.
Sir Winston Churchill

yellowtail3
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Re: Armour Penetration

Post by yellowtail3 » Fri Nov 13, 2009 2:22 pm

alecsandros wrote:Bismarck remains, on the top of the pedestal for BBs of the Atlantic.
Both of the North Carolinas were Atlantic battleships. They just happened to find some gainful employment in the Pacific...
alecsandros wrote:Richelieu received a torpedo at Dakar that made huge damage. After quick repairs, he could barely reach 14n. Bismarck received the first torpedo from Victorious and didn't even notice it (yes, I know, I know, to shallow drop, but a torpedo is a torpedo non the less).
I think some torpedoes are vastly more effective than others.
Shift Colors... underway.

alecsandros
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Re: Armour Penetration

Post by alecsandros » Fri Nov 13, 2009 3:24 pm

yellowtail3 wrote:
Both of the North Carolinas were Atlantic battleships. They just happened to find some gainful employment in the Pacific...

I think some torpedoes are vastly more effective than others.
Well, you're right in both aspects.
However, the NC's have their fare share of "bugs", regarding BB to BB fighting. You'll mostly see those in the "Bismarck and her contemporaries" topic. First that come to mind are stability as a gun platform, speed and underwater protection from AP shell traveling udner water. There are points in which they (the NC's) are clearly above the Bismarck (turret armor, artillery calibre, broadside, shell weight) but the discussion is far from being settled.

As for the torpedo hit on Richelieu, there is a school of thought that says the torpedo actualy exploded near the BB, and detonated some depth-charges (1-6) that had been previously launched from other American aircraft. Others say that, due to the shallow depth of the water, the torpedo' shock wave was reverberated by the bottom and thus made much more damage than in was "normaly excepted".
But, taking the comparison beween Bismarck class and Richelieu class one factual step further, we must bear in mind that the Jean Bart received 5-16" shell from Massachussests, at 22000m, that made significant damage. Worse still, Jean Bart's armor did not deflect at least one shell, they all penetrated (though I don't remember how many were duds, adn don't have the book nearby). The Bismarck, as we know, received severe punishment, both from torpedoes and gunfire, and was still afloat (though, admitedly, a smoking wreck).

Of course, the American 16" guns and shells were much, much better than the British ones aboard Rodney, but the Bismarck received not 5 but 20-40 16" - hits.

Anyway, for my part, I see Richelieu's class main problem at it's guns: they were both difficult to reload and had a big scatter area. Those to factors would be crucial in a gunfight, and, as history proved, the Bismarck was exactly in the opposite spectrum both in terms of fire cycle and grouping.

All the best,

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