Scharnhorst and Gneisenau vs Yamato

[Thorsten Wahl]

No. Not at all. A 46cm shell inflicts roughly 20% more striking energy, weighs 20% more, and contains 20% more explosive. There are advantages for the US shell, but Japanese shell will tend to be much more destructive.

But the japanese shell has a projectile cross section wich is 28% larger than the US shell, so the 20% more striking energy argument doesnt count not really in terms of penetration abilities.(Apart from scaling effects)

[alecsandros]

But the japanese shell has a projectile cross section wich is 28% larger than the US shell, so the 20% more striking energy argument doesnt count not really in terms of penetration abilities.(Apart from scaling effects)

Not to mention IJN shells were largely soft-caped, meaning a good chance they would fracture on impact with high-brinell armor. The 0.4sec fuze delay adds to the problems of the 18.1" inch shells, as the time was enough for the shell to pass completely through the ship and exit on the other side, with sufficient remaining velocity for it to travel 40-50 meters underwater after the exit-penetration, and explode without further harming the ship (that, of course, in the event that a shell passing through 33-36 meters of ship, or more, would still be in a fit state to burst)

Example: a 460mm shell attacking a 305mm "class A" plate, at 20* angle of fall, 0* deflection, 500mps striking velocity.
[Presuming the cap would be strong enough to perforate the plate without breaking up]

The shell would, of course, go through the plate, and would have an exit velocity of 380-420mps, depending on the modeling you use.
Now for the shitty part: the fuze delay was 0.4 sec.
That would mean that the shell would travel at least 0.4 x 380 = 152 meters before exploding.

After perforating the belt, the shell would be decaped and yawed. Since it has such a long way to go (152m), it will certainly either:
a) pass through some unarmored parts of the ship, on the other side of the initial impact, and it will go into the water, where it will travel a lot and explode harmlessly away
b) hit the armored belt on the other side of the ship and, due to it being without cap and yawed, it would be almost certainly rendered inert.

So, if the shell doesn't travel underwater before perforating, it doens't have any realistic chances of exploding inside a ship ...

Edit:

Deck hits are even worse, as the reduction in velocity is less than that which occurs on impacts with thick FHA. Consequently, a 460mm shell striking a homogenous armor plate would have a remaining velocity of over 400mps, and it will travel 160m or more, probably perforating the bottom of the ship, or unarmored parts of the sides (depending on the initial angle of fall), before exploding far, far away from the target...

[Karl Heidenreich]

Alex,

Good to see you in the forum again! It seems that my posts have, at least, that good effect to read from your well researched posts.

[Karl Heidenreich]

Consequently, a 460mm shell striking a homogenous armor plate would have a remaining velocity of over 400mps, and it will travel 160m or more, probably perforating the bottom of the ship, or unarmored parts of the sides (depending on the initial angle of fall), before exploding far, far away from the target...

It's like hitting the trawler at Truk!

[lwd]

Lee:

But of course a USN 16" gunned BB were a very real threat to Yamato. Furthermore at ranges equivalant to those of say Washingtion vs Kirishima the twins can punch through all of Yamato's armor except the faceplates of her turrets.

This answer confirms what some of us has commented: we came forward with evidence and direct sources to made a point. This point has been accepted, or was not challenged at all. And then, months after you came again with the old common wisdom stance that shows that you still don't get it.

Not at all. Your statements rather show that you "don't get it".

Ok. Here we go again in the context of the Twins vs. Yamato. Simply put the Twins do not stand a chance because even heavier units cannot. If making plain evident that an Iowa Class battleship is in the low side in a match against the Yamato, then by logic the Twins could not.

But your basic assumption is wrong. You are assuming that "even heavier units cannot" when clearly they can.

First, let's see what an accepted sources, as Richard Worth, have to say on this issue:

Right through the end of WWII, optically trained gunnery was superior to radar-trained gunnery. Mo will shoot best when she can see the target.
Things are best for the Americans if they can strike a decisive blow before the range closes under 30,000 yards, where Yamato is in her immune zone. Mo has no immune zone. If the ships make contact at less than 30,000 yards, Yamato has a huge advantage.
Yamato's 46cm faceplates are effectively impenetrable. Mo also has thick faceplates, but unfortunately for her they are made of homogenous armor. Japanese shells appear to have been very poor against face-hardened armor but very good against homogenous armor.

The sentence from the author here is quite important: "Mo has no immune zone" Which is incredibly relevant to our discussion.

Indeed it means at some ranges Yamato has a distinct advantage. It doesn't by any means mean that victory is assured. Furthermore the FC quote is obviously for clear daylight conditions at ranges where the fall of shot could be well observed, furthermore it doesn't speak to the combination of radar and optical that would be superior at longer ranges to pure optical.

Worth's answer to the question of "... The fact is the 16" shells of the Mo where just as capable as the 18" shells of the Yamato." he answered:

No. Not at all. A 46cm shell inflicts roughly 20% more striking energy, weighs 20% more, and contains 20% more explosive. There are advantages for the US shell, but Japanese shell will tend to be much more destructive.

Again we have a categorical answer.

Indeed and I have never contested that. But again that doesn't mean that Yamato's victory is assured in any circumstances. One need only look at San Francisco vs Hiei.

When the counterpart in the discussion insisted, as lwd does, on "... The Iowas were both fast and well armored" the answer is, again, categorical:

Well armored against what? It has already been noted that the Iowas had no IZ against 46cm shells.

That doesn't mean that every shell for Yamato will penetrate even if it does hit or assure it will do critical damage. On the otherhand if you look back at our various discussions I've never questioned that getting hit by Yamato's shells would be bad for any battleship.

Was the trawler at Truk the only enemy ship sunk by the four Iowa class ships?

Certainly they played rolls in sinking other ships. The US however didn't forsake combined arms just to let a single ship wrack up a score.

From this side of the issue I think there is no further need to continue. But in other threads some other important points have been raised, so I proceed to brign them forth to "remind" those USN followers that the most powerfull battleship ever made wasn't American, but Japanese.

For some defintions of "powerful".

The Twins cannot even dream in match a Yamato Class battleship in a fight because even stronger units were not capable to do so. This is the case of an Iowa Class battleship against Yamato. Iowa was heavier, with bigger guns than any of the Twins... and was, also, the lesser ship when facing Yamato.

Your argument as I've pointed out is flawed in a couple of ways. Let's look at them:
1) You seem to be implying that because an Iowa can't defeat a Yamato then the twins can't. The problem here is that if one has a numerical superiority it's not like fighting two one on ones in a row. So even if your assumption that the Iowa couldn't defeat the Yamato were true it wouldn't necessarily mean that the twins couldn't.
2) You postulate that the Iowa has no chance against the Yamato. This is clearly wrong. Indeed in some scenarios the Iowa will have an advantage even if she doesn't victory for the Yamato is not guaranteed.
In summary both your assumptions and logic are faulty which brings your conclusions into considerable question.

Even if we ignore Richard Worth's comments here, or Friedman's or Garzke and Dullin we can come forth to the source of the famous Yamato researcher Skulsky.

We haven't been ignoring them. You have been misinterpreting them.

"Her 46 cm (18 in)guns, with 42-44km range and SUPERIOR optics equipment, were the largest and most MODERN naval guns ever mounted and FAR EXCEEDED the quality and construction of other countries... "
- Yamato: Anatomy of a Ship

Taken out of context this quote is very suspect. While the Yamato's guns were pretty clearly the largest they were just as clearly not the "most modern" ever mounted and I've yet to see evidence of their construction quality exceeding that of other countries. Indeed some aspects of their design seem rather short sighted. In particular the lack of liners.

...Yamato was desgined to resist the thrust and energy from 18" shells that weight 1,460 kg and travelling at 500m/sec. Yamato was not design to withstand 16" guns but 18".

But only in certain range bands. While those would be larger for the 16" shell than for the 18" one it still doesn't mean that Yamato is immune to 16" shells at any range and her armor can be penetrated in a number of circumstances.

The AP shell was designed to go into the water short of the target, maintain it´s trajectory and penetrate the enemy´s TDS. The projectile nose was hidrodynamic so that her trajectory would not be changed by the impact and dive into the water.

Indeed. But this also appearse to have increased the chance of the shell glancing off armor and there is some question of just how well this worked.

But let´s see what the 46 cm shell could do:

Why? No one has questioned that they were impressive and I'm sure most if not all of us have looked up the stats at one point or another.

Iowa´s was quite vulnerable, as you can see, at both ranges, against Yamato´s hits against her main belt and deck armour. At greater distances Yamato´s plunging fire would be to Iowa what Bismarck´s one was to Hood...

The fact that you continue harping on one part of the equation why ignoring the other parts is very telling.

But Yamato was not vulnerable to Iowa´s shells because she was designed to withstand not 40,6 cm but 46 cm AP shells.

This is simply not correct.

We should also note (and this if likely OT because goes only in the direction of Iowa's weakness against contemporary ships that cannot be extrapolated to the Twins) that:
dunmuro:

The magazine placement of the USN fast BB designs was highly vulnerable, and not much better than Hood's. If we replaced Hood with Iowa, there's a chance that she will be destroyed by the same hit that destroyed Hood, while Washington would certainly have suffered the same fate as Hood (assuming the same range and target angle from Bismarck as Hood, when she was blown up).

Clearly this is an opinion and the way it is stated it is not correct.

If to all the above mentioned reasons we add those comments from Friedman, Raven and Roberts, Garzke and Dullin and Skulsky as from Chuck Hawks then we can be settled: Yamato is the very likely winner in a naval combat against the USS Iowa,

Finally you admit that Yamato is not the sure winner that you have maintained for so long.

which is heavier and with bigger guns than the Twins, so by extrapolation the Twins, even both of them, are likely the losers in such a combat.

I'm glad to see that you are finally agreeing with me on this issue as well.

[lwd]

This is document I found two or three years ago while searching the internet. I will post it here for all those interested in this topic of USS Iowa Class vs a Yamato. I place in the same context that both previous posts, in order to dispell the issue of the Twins vs Yamato by proving that a heavier ship (the Iowa) could not deal with Yamato in favorable terms. Here it is:

... I think you should review Strafford Morss’ article in Warship International, No. 2, 1986, pp. 118-136. This will provide details on just how poor our intelligence was about the Yamato class, and where a “desired” range should be maintained in light of the information we had. We assumed the Yamato had 12” side armor and 6.4” deck plating. It was thus calculated that the ship had a 1,000 yard advantage (31 vs 30K) over a So. Dak./Iowa class in terms of deck protection against the 16”/45 caliber guns we thought it was armed with versus the US 16”/45 gun against the Yamato’s deck ....

The problem with this is that there were two considerably different estimates concerning Yamato by ONI during the war. I'm sure it's been posted before but take a look at:
http://www.navweaps.com/index_tech/tech-084.htm

[lwd]

Bgile:

Karl,
From your quote above:
"the Yamato’s actual IZ against the 16”/50 was around 17-33K, depending on what formula one uses ..."
So clearly in the engagement against Kirishima if we substitute Yamato, we are outside her immune zone as well (less than 9,000 yds and her immune zone only goes down to 17,000 yds), and 16" guns will be able to penetrate her citadel. Both ships are able to penetrate each other's armor.

Can you imagine what the 18" of Yamato could have done to South Dakota (after SD miserable performance of firing salvo after salvo and hitting nothing when the combat started?)

Well if you are going to quote SoDak's hits lets quote Yamato's as well.

Instead of 14" of HE we are talking 18"

There is some doubt as to just what type of shells Kirishima hit SoDak. The 18" would have possibly made a difference in the bargett hit but not in the other.

aimed with the finest stereoscopic optics in the world.

While Kirishima had smaller optics at the ranges we are talking about it shouldn't make much of a difference. Kirishima had more guns and a higher rate of fire and managed about 2 hits. On the otherhand SoDak would be firing at a much larger radar target which could make a huge difference especially given all the clutter around Savo. It's also worth thinking about what kind of damage multiple hits for US 16" AP rounds will do to Yamato at that range. Round for Round Yamato packs a bigger punch but if you insist on using real actions to extrapolate from Yamato will be collecting 16" rounds much faster than SoDak will be collecting 18" ones.

The combat will change completely with South Dak sinking in flames and USS Washington trying to make some damage.

That's one possiblity but it's also possible that we'll see little change. Indeed given the fact that Yamato is a bigger target that has both a bigger radar and optical signature both US BBs may well get on target before Yamato does.

Yamato has more chances to absorb punishment,

Indeed she does as I have jus tpointed out.

which can maybe be near to nil as for what we have read from all the authors put together.

What author has stated that a 16" 2700lb AP round that impacts on any ship will produce "nil" damage?

Don't believe neither of the overated USN battleships will survive the night,

It's almost certain that one of the US battleships would survive and there's a decent chance both would.

honestly, ideology is hardly part of naval warfare.

I agree. One of these days you may actually understand.

[paul.mercer]

I think most here agree that it would be a very uneven match up and the odds would not be with the twins. However if they got lucky, especially if the conditions were very favoreable they might have a chance. The "knife fight" is one area that would tend to give them the best chance another would be a very long range engagement. In the close range engagment the number of guns the twins had combined with thier high rate of fire and flat shooting vs a large target should produce hits much faster than the Yamato would. Since they could penetrate most of Yamato's armor at close range then they have a chance of disableing her before she returns the favor. The long range engagement relies on luck and RFC to degrade Yamato's fire control (or some other lucky curcumsance) before the Yamato does critical damage to the twins.

Gentlemen, it would appear from later posts that Yamato had some very heavy armour, so the statement "Since they could penetrate most of Yamato's armour at close range" is somewhat puzzling. Which armour and where and at what range? Of course a flurry of 11" shells would cause considerable damage, but surely not enough to sink or seriously disable her? Also, if the range is that close then surely the twins risk receiving some heavy blows in return which would almost certainly penetrate their armour and possible disable them. Personally, if given the choice I would rather be behind Yamato's armour in a close range shoot out!

[lwd]

I thought it was posted earlier in the thread but here's the wiki data on Yamato's armor:
http://en.wikipedia.org/wiki/Japanese_battleship_Yamato

Armour: 650 mm (26 in) on face of main turrets[7]
410 mm (16 in) side armour[7]
200 mm (7.9 in) central(75%) armoured deck[7]
226.5 mm (8.92 in) outer(25%) armoured deck

The turret faces are probably proof against any penetrating hit although spalling, edge effects, or missing the armor could still allow of loss of the turret even from the front.
At close range the decks are likewise unlikely to be hit and if hit unlikely to be penetrated.
However if you look at: http://www.navweaps.com/index_nathan/Pe ... ermany.htm
The German 11" gun penetrates Yamato's belt at something over 12,000 yards which is in excess of the ranges at which Kirishima and the US BBs exchanged fire.
Most penetration analysis also assume single hits. Multiple hits in any sort of close proximaty can penetrate armor that a single could not. Then there are the less armored sections ...

[Bgile]

The one question is whether the shell would survive the high velocity impact with armor that thick.

[Thorsten Wahl]

yamatos belt is inclined by 20 degrees so 12.000 yards should be a save distance against these guns

[lwd]

yamatos belt is inclined by 20 degrees so 12.000 yards should be a save distance against these guns

Would it? Didn't someone mention earlier that pentration calculations were based on an assumed 30 degree impact angle? In any case the ranges that Kirishima and the US BBs exchange fire were under 10,000 yards and that was the model suggested for this encounter.

[alecsandros]

.. In any case the ranges that Kirishima and the US BBs exchange fire were under 10,000 yards and that was the model suggested for this encounter.

There is another thing to consider... In practical tests, Krupp found that each shell type had a "usefull" impact velocity, confined within an interval. For 380mm L4.4 for instance, it was about [250mps, 630mps] (I don't remember exactly, but it was near those values). Velocities below 250 and above 630 would cause the shell to explode on impact/be destroyed by the impact force or lack of it.

So, for the 11" guns firing below 10.000y, it is a possibility that the shells would not penetrate at all... [a lengthy discussion should be made following this topic. My opinion is that, in practical terms, the GErman 283mm shells were capable of perforating 410mm of Japanese FH armor, but not capable of perforating German, British, American or Italian face hardened armor of the same thickenss. The main reason is the face-hardness of the armor with respect to the hardness of the perforating cap of the shell --- Japanese FHA was ~ 500-550 Brinell, while 283mm German shell cap hardness was > 600 Brinell]

Also, in perforation/penetration calculus, the ratio between shell diameter (D) and plate thickness (T) is pretty important... As D/T decreases, the probability of successfull penetration also decreases (in a non-linear fashion). Conversely, as D/T increases, the likelihood of penetration increases...
In the given example, 283mm/410mm (ratio 0.69) doesn't look good at all.

[Bgile]

I agree, which is why I made the post four posts ago. But you say it with so much more detail. :)

[lwd]

Certainly the shell could break up or detonate on impact. Whether it did so or not might well be a function of micro faults or irregularities in either the armor or the shell. Then there's the question of whether or not there is significant behind armor effects even if it does so. Certainly I would expect spalling, a high velocity plug would also seem a distinct possibility. Indeed at those velocities the shell might penetrate even if it did break up. That means no high order detonation inside but still significant behind armor effects. Then of course there's the super structure and some of it's critical and more vulnerable contents.