New Mexico-class Battleship

I'm not so sure about your logic here. While I wouldn't expect many hits near the bottom of the hull at short ranges the trajectories leading to hull impacts could still be pretty common.

No. I'm saying that the engine rooms were usually low enough in the hull that at close range you aren't likely to hit them if the shell hits the hull above the water line.

I believe Rodney's action report claims one hit although there may have been a possibilty of a second. I think one of the observers thought they got two. Even if they got two however the odds would not favor them both being close enough to influence the forward turrets.

Deck penetration at under 20,000 yards are unlikely. This was probably pretty close to the range when Rodney took out Bismarcks forward turrets by the way. She had opened fire at ~23,000 yards.

Without knowing just what the damage that's pretty much pure speculation.

And I think I pointed out that this is an unreasonable expectation.

No. The US BB can easily turn fast enough to keep all her guns bearing at least at any reasonable range.

Except battleships tended to cruise at pretty constant speed and course when firing so this is pretty much a wash.

 

Is it? Certainly not from what I've read.

No that's not what he says. What he said was that a penetration of the belt and turtle deck was either very unlikely or impossible. Note however that Rodney apparently put a 16" round in Bismarck's engineering spaces from under 10,000 yars.

Again not quite right. The angles compound so the angle of the belt defines the minimum impact angle any change in orientation increases the angle and thus the effective thickness.

 

But that's the point isn't it?
The only British capital ships that had any realistic chance of catching Bismarck were the Battlecruisers or the KGV class (28 - 30 knots), the 21 or 22 knot older BB's like New Mexico had virtually zero chance of catching the german battleship.

The German ships were under orders to avoid confrontation with the RN ships, that's why they didn't turn to persue Prince of Wales (which had 2 of 3 turrets out of action at the time IIRC)

Their mission was to sink Allied shipping, not Allied warships.

 

OK, Hood said to blow up from a belt penetration below main deck going through slope of main deck which functioned as BELT at that range and blew the ship up.

Kirishima belt damage

SD damage for belt hits 8” and 14”

Sc, front turret(s) bow blown out at close range via belt

Fuso, all belt

Yamashiro most if not all damage via belt, she steams out takes a said 15 to 30 heavy hits and steams back at the SAME speed taking two more belt hits and sinks. IMO she took no hits or very few via the deck.

JB class BB hit(s) one or more skid along deck and hits secondary magazine one or more through the belt.

French BC hit collapse fore deck via belt.

Bismarck below belt damage from PW. One through the front belt both sides.

PW and BC both sunk via the belt

NC one torpedo on the belt, flash said to reach magazine

Heie, 8” via belt, jam steering gear

USN fast 16” class rammed from the rear, studies show that if damage was enough the ship would have sunk via the stern without damage to armor citadel.

BB in Peal all outside of Arizona / Nevada took most or all damage on the belt.

Toronto, all BB damage via belt

So exactly what BB was destroyed by a deck hit?

Arizona for sure, maybe the Yamato could take this one, maybe.
Italian BB by a Fritz X, no BB could take it
Tirpitz via a HUGE bomb(s), no BB could take it

Bis, after already mission killed did take a several telling 16” hits across her front traverse bulkhead that may have penetrated, maybe not, the front traverse bulkhead is really a belt right? Note that power cables tc were above the armor deck, in armor tubes. So does the Bis take a traverse hit that kill Anton or was it a deck hit behind Anton / Bruno and even if it was a deck hit, did it penetrate the deck or did it damage the armored cables above the armor deck? Dunno. Gut feeling Anton is killed via a traverse bulkhead hit, and only the Yamato could have stopped a BB shell across the front bulkhead. Heck even the Yamato could not take the same hit from the front of the ship against the back of C barbette. As list above, all BB are weak to very weak when shells come from dead ahead.




Sc, dunno it the DY put a engine room hit at range. DY had checked fire, Sc had stood down her gun crew. Sc hit the bow and front turret blown out and was blind in heavy gale. So why did she slow enough to take several belt penetrating torpedoes.

The we go one BB’s deck could have stopped all the damage that sank or damaged the BBs listed above via deck, that being if the Arizona was the Yamato, just maybe it would have enough deck to stop the 16” shell pretending to be a bomb hit.

So in many ways any debate about the Bis having not enough deck maybe meaningless, cause it would appear no BB outside of the Yamato had enough deck. Not sure if the Yamato had enough deck to keep out the 1000 lbs bombs that did her in (along with torpedo). But the non-penetrating main deck bomb hits did the most damage, one on secondary turret, one or more along the primary AA which blew them out. Gotta luv 1000 lbs bombs.

Back to topic any USN BB all the way up to the SD will be taking hits across the front traverse bulkhead / rear of rear barbette and no BB made could keep out such hits. Any hits in front or rear of critical would / could lead to massive flooding.

This was what I was thinking until I read the USN report on the New Mexico firing 15X ish 6 round salvos, average length between salvos 126 seconds. So actual shell handing on pre 16” / 45 turrets was pitiful to say the least compared to the Bis.

Assuming both were firing broad sides, the big 5 would do a ½ salvo every 65 seconds, the Biz would do it every 12 to 20 seconds. That is better than 3x the rate of fire for ½ and many shells. Full broadsides the Bis would be doing anywhere from 3x to 5x the rate of fire. Meaning in any fight any USN 14” BB would be missioned killed if significantly faster than the Bis. Lets go with a 25 salvo rate on the Bis vs 130 second rate for all 12 guns on the Big 5. That is better than a 5x rate, with ½ as many guns = 2.5x more and bigger shells. Odds are the NM would be overwhelmed very shortly after range was found given a clear weather engagement that just so happens to put both ships in a broadside. In reality a clear weather engagement would put the Bis make firing 4 guns in 20 second bracket broadsides vs 6 guns on the NM in 126 second brackets.

Full report is on navalweapons.com

Could not agree more. Even the Sc may have been destroyed by a non-penetrating hit skidding along the deck till it hit the vertical centerline cap plate to the boiler room.

The IJN fired HE on the Russians at Tsushima.

Agree here, in the end it is a dice game. I mean if I closed on the Bis with Hood and PW and lost the Hood, and then the Bis chased down and sunk the PW, and who knows what happened to my heavy cruiser??? I would say the dungeon master was cheating again.

So saying the Bis would “win”. It really is could have /should have. Just like the Kirishima vs two USN BB, what would it have been like if the SD blew up from a 14” hit that if it was an AP round should have been able to penetrate the barbette. Then the IJN paid full attention to the Washington with their long lance. A timely power failure convinced the IJN that the SD had taken one or more long lance torpedoes and they went after the Washington. If the power had not failed they would have been able to go after the closer SD. Now the SD we know never landed a single hit that night, at point blank range with any type of weapon.

Both ships have enough gun, range and penetration to destroy the other, after that it is a numbers game.

Here I disagree. The SD was missioned killed by secondary guns, the USN DP guns are pitiful in BB vs BB engagements. The Bis’s secondary can rip apart all un-armored or lightly armored works of any ship made. Easily blowing through the protected USN secondary mounts, TT tubes on the Hood etc etc. You don’t want to be close to this type of fast firing weapon. The NW had added on bulges that could not keep out the hard hitting 5.9, in fact the SD and Iowa could not keep bulge flooding hits out from the gun. Only the PW, Vanguard, Bis, Yamato, Montana type of external belt could, and only to the depth of the belt before the bulge. The Iowa could take 4 to 5 penetrating bulge hits via torpedo, which is NOT much. Note I did not say belt penetrating hits, just bulge penetrating hits. The Bis 5.9 can penetrate everything outside of the belt, that would include in front, in back and the entire side of the NM below and above the main belt, which is what only 13 feet of the ship. That is a LOT of flotation and structure damage.

As noted already even the Bis lost its main fire director from an 8” hit, and it may have lost the armored bridge crew due to a 8” via a fluke open armored door, bummer. I’d quit the game if the Dungeon Master told me that one.

 

OK, Hood said to blow up from a belt penetration below main deck going through slope of main deck which functioned as BELT at that range and blew the ship up.

Kirishima belt damage

SD damage for belt hits 8” and 14”

Sc, front turret(s) bow blown out at close range via belt

Fuso, all belt

Yamashiro most if not all damage via belt, she steams out takes a said 15 to 30 heavy hits and steams back at the SAME speed taking two more belt hits and sinks. IMO she took no hits or very few via the deck.

JB class BB hit(s) one or more skid along deck and hits secondary magazine one or more through the belt.

French BC hit collapse fore deck via belt.

Bismarck below belt damage from PW. One through the front belt both sides.

PW and BC both sunk via the belt

NC one torpedo on the belt, flash said to reach magazine

Heie, 8” via belt, jam steering gear

USN fast 16” class rammed from the rear, studies show that if damage was enough the ship would have sunk via the stern without damage to armor citadel.

BB in Peal all outside of Arizona / Nevada took most or all damage on the belt.

Toronto, all BB damage via belt

So exactly what BB was destroyed by a deck hit?

Arizona for sure, maybe the Yamato could take this one, maybe.
Italian BB by a Fritz X, no BB could take it
Tirpitz via a HUGE bomb(s), no BB could take it

Bis, after already mission killed did take a several telling 16” hits across her front traverse bulkhead that may have penetrated, maybe not, the front traverse bulkhead is really a belt right? Note that power cables tc were above the armor deck, in armor tubes. So does the Bis take a traverse hit that kill Anton or was it a deck hit behind Anton / Bruno and even if it was a deck hit, did it penetrate the deck or did it damage the armored cables above the armor deck? Dunno. Gut feeling Anton is killed via a traverse bulkhead hit, and only the Yamato could have stopped a BB shell across the front bulkhead. Heck even the Yamato could not take the same hit from the front of the ship against the back of C barbette. As list above, all BB are weak to very weak when shells come from dead ahead.




Sc, dunno it the DY put a engine room hit at range. DY had checked fire, Sc had stood down her gun crew. Sc hit the bow and front turret blown out and was blind in heavy gale. So why did she slow enough to take several belt penetrating torpedoes.

The we go one BB’s deck could have stopped all the damage that sank or damaged the BBs listed above via deck, that being if the Arizona was the Yamato, just maybe it would have enough deck to stop the 16” shell pretending to be a bomb hit.

So in many ways any debate about the Bis having not enough deck maybe meaningless, cause it would appear no BB outside of the Yamato had enough deck. Not sure if the Yamato had enough deck to keep out the 1000 lbs bombs that did her in (along with torpedo). But the non-penetrating main deck bomb hits did the most damage, one on secondary turret, one or more along the primary AA which blew them out. Gotta luv 1000 lbs bombs.

Back to topic any USN BB all the way up to the SD will be taking hits across the front traverse bulkhead / rear of rear barbette and no BB made could keep out such hits. Any hits in front or rear of critical would / could lead to massive flooding.

This was what I was thinking until I read the USN report on the New Mexico firing 15X ish 6 round salvos, average length between salvos 126 seconds. So actual shell handing on pre 16” / 45 turrets was pitiful to say the least compared to the Bis.

Assuming both were firing broad sides, the big 5 would do a ½ salvo every 65 seconds, the Biz would do it every 12 to 20 seconds. That is better than 3x the rate of fire for ½ and many shells. Full broadsides the Bis would be doing anywhere from 3x to 5x the rate of fire. Meaning in any fight any USN 14” BB would be missioned killed significantly faster than the Bis on average. Lets go with a 25 salvo rate on the Bis vs 130 second rate for all 12 guns on the Big 5. That is better than a 5x rate, with 2/3 as many guns = 3.33x more and bigger shells. Odds are the NM would be overwhelmed very shortly after range was found given a clear weather engagement that just so happens to put both ships in a broadside. In reality a clear weather engagement would put the Bis make firing 4 guns in 20 second bracket broadsides vs 6 guns on the NM in 126 second brackets.

Full report is on navalweapons.com

Could not agree more. Even the Sc may have been destroyed by a non-penetrating hit skidding along the deck till it hit the vertical centerline cap plate to the boiler room, which then penetrate at that point.

The IJN fired HE on the Russians at Tsushima.

Agree here, in the end it is a dice game. I mean if I closed on the Bis with Hood and PW and lost the Hood, and then the Bis chased down and sunk the PW, and who knows what happened to my heavy cruiser??? I would say the dungeon master was cheating again.

So saying the Bis would “win”. It really is could have /should have. Just like the Kirishima vs two USN BB, what would it have been like if the SD blew up from a 14” hit that if it was an AP round should have been able to penetrate the barbette. Then the IJN paid full attention to the Washington with their long lance. A timely power failure convinced the IJN that the SD had taken one or more long lance torpedoes and they went after the Washington. If the power had not failed they would have been able to go after the closer SD. Now the SD we know never landed a single hit that night, at point blank range with any type of weapon.

Both ships have enough gun, range and penetration to destroy the other, after that it is a numbers game.

Here I disagree. The SD was missioned killed by secondary guns, the USN DP guns are pitiful in BB vs BB engagements. The Bis’s secondary can rip apart all un-armored or lightly armored works of any ship made. Easily blowing through the protected USN secondary mounts, TT tubes on the Hood etc etc. You don’t want to be close to this type of fast firing weapon. The NW had added on bulges that could not keep out the hard hitting 5.9, in fact the SD and Iowa could not keep bulge flooding hits out from the gun. Only the PW, Vanguard, Bis, Yamato, Montana type of external belt could, and only to the depth of the belt before the bulge. The Iowa could take 4 to 5 penetrating bulge hits via torpedo, which is NOT much. Note I did not say belt penetrating hits, just bulge penetrating hits. The Bis 5.9 can penetrate everything outside of the belt, that would include in front, in back and the entire side of the NM below and above the main belt, which is what only 13 feet of the ship. That is a LOT of flotation and structure damage.

As noted already even the Bis lost its main fire director from an 8” hit, and it may have lost the armored bridge crew due to a 8” via a fluke open armored door, bummer. I’d quit the game if the Dungeon Master told me that one.

 

Read more, the de-capping, well there was scant evidence one way or the other, and then there were several revisits. I'm not a believer, nor were the BB designers of the day outside of the US and maybe one would argue the Italians against allied shells. IMO, I don't see layers of 1.5" armor doing much to a 15" shell.

Clearly the Yamato, Vanguard, Montana ships all went to external belt and AFAIK single deck.

Don’t know what hit you are talking about, clearly Rodney put hits on Anton, conning tower, and later maybe Bruno, maybe to power cables, maybe through the armor deck. The main deck looks to have been penetrated by multiple rounds at 20k meters with the Bis down by the bow.

Still we are talking a 16” hit across the traverse bulkhead, not a 14” hit on the deck or belt.

All true till the shell overmatches the plate, then plate collapse ensures at perpendicular oblong hole. Overmatch happens at or larger bore vs plate thickness. 15” shells overmatch 13.5” belts. 14” over matches 12.6” belt. Very little to no documentation exist on how shells this large react to over matching plate. The only shells that would be greatly affected by angle were the 11” BC shells, but these have some serious velocity and hence penetration. Off topic on this as both ships have near vertical belts. Already noted that the complex angle really is going to help stop the 11" shell. IMO, not as much against a 15" shell.

I think both ships will blow through both belts, however, belt penetration on the Bis, floods space and will NOT go through the turtle deck, belt penetration on the big 5 lead to machinery spaces. Yes, already stated belt penetration is BAD, but BB shells blowing up in the machine spaces are the worst.

 

Hood almost certainly suffered the catastrophic damage not from a full penetration but rather from a glancing deck hit that shattered the armor and sprayed the magazine below igniting it. From the likely point of the hit until Hood blew up was about two minutes, give or take.
There is no indication of any other belt hits on hood or PoW at Denmark Straight.

Again, very little damage occured to the main belt. Out of 20+ 16" hits I believe only three are identified on the actual 8" belt. The crippling damage was from hits just above that on the secondary battery deck and the third deck below. These opened up Kirishima to massive flooding and progressive flooding over a great lenght of the ship.

Out of 26 identified hits in the after action report only three could be called hits on the belt. All three are 8." Of these, one was a richochet that lodged in the outboard compatment from the actual belt being a spent shell. A second only just hit the top of the belt and damaged several compartments on the second (armor) deck. The third hit the low end of the belt and caused some flooding in the torpedo defense system.

Do you mean the torpedo hit on North Dakota? If so this occured at the forward end of the raft body and the torpedo was well below the belt.

Fuso was sunk by torpedo attack by US destroyers at Surigao Straight. She suffered an amidships magazine explosion and the bow and stern sections took almost an hour to sink afterwards. There was no shell fire on her bigger than 5".

Much like the Kirishima, the Yamashiro suffered a deluge of hits. It is likely that she took 15 to 20 14" and 16" hits the majority being plunging ones as the range was 22,000 to 24,000 yards. Like Kirishima, the damage was mostly above the belt and to the armor deck causing massive progressive flooding and free-surface effect. That Yamashiro had some engine room capacity left isn't that unusual. Kirishima did too. It was the progressive flooding that got Kirishima. It was a final torpedo attack that finished off Yamashiro.

None of hits on Jean Bart were on the belt. One hit penetrated the deck aft into the secondary magazines that were empty.

Neither Dunkerque nor Strasbourg suffered any belt hits at Mers el Kebir.

Bismarck suffered one under water hit from PoW well below the belt and another on the unarmored section of the bow outside the armored raft-body of the ship.

Both were sunk by torpedo attack. Neither took any belt hits.

This is the aforementioned torpedo hit forward abreast turret 1. There was flooding of the torpedo defense system there and the forward magazine of that turret was flooded as a precaution.

Hiei was crippled by short range gunfire and then later finished off by aerial bombardment with 500 lb bombs. Again, the belt did little to protect her against either.

That would be Indiana. The damage was between frames 106 to 130 at or below the waterline and outside the protective box of the raft body (eg., just aft of the armored belt). While flooding did occur over a wide area in the torpedo defense system the holding bulkhead was not damaged and the list Indiana took on was corrected by counter flooding.

The battleships at Pearl with the exception of West Virginia took no belt damage whatsoever. The West Virginia suffered one torpedo hit directly on her belt due entirely to the previous four torpedo hits taken that had caused her to begin to list to port. The seventh torpedo hit stuck the ship above the belt just below the secondary 5" battery.

At Taranto (Toronto is in Canada), the damage was from torpedo attack and all below the belt armor of the ships struck. These include Andrea Doria, Littorio, Caio Duilio and, Cavour.

Hood by a shell from Bismark. Warspite took a Fritz X guided bomb that nearly sank her. Roma was sunk by a Fritz X that penetrated her deck. Arizona was sunk by a bomb that penetrated the deck between turrets 1 and 2. Both Tennessee and Maryland at Pearl suffered several bomb hits on turret tops and decks that resulted in partial penetrations.
Kirishima suffered most of the serious flooding due to deck penetrations. Dunkerqure at Mers el Kabir was crippled by two deck penetrations that wiped out most of the engine room crew from vapor and smoke. At the same battle the old French battleship Bretagne suffered a deck penetration that detonated the amidship magazine sinking her. Most of the damage to Yamashiro was from deck penetrations or splinter damage that penetrated the deck.

Both Bismarck and Scharnhorst took severe damage above their belt. Both suffered several hits on it as well. In both cases hits on the armored barbettes or turrets themselves knocked out the main battery. Turrets being knocked out by glancing hits is not uncommmon. Jean Bart's only turret suffered such a hit. So did Dunkerque. Several British battlecruisers at Jutland had hits of this sort that damaged turrets and in some cases resulted in sinking of the ship.

Military History Online - Capital Ship Surface Actions World War II

While that only covers battleship on battleship I can post up resources to show the other cases. Belt hits are rare and the armor belt on a battleship from demonstrable results is largely a waste of weight. This is why post WW 2 ships stopped being built with them.

 

I've read quite a bit about it and there is very good evidence for it.

That's your problem.

There is little evidence that it was part of the US design. On the other hand there is very strong evidence that the Italians incorporated it as a part of their protective schemes on the VV class.

Whether they do or not is dependent on a number of factors in particular the angle of impact. However the design rational for the upper armored deck on US battleships was to initiate the fuse on AP bombs.

See Bismarck's Final Battle - Part 2

It's not at all clear exactly what route the shells followed.

I think that's over stating the case. Probably won't go through is a more accurate statement. Consider that most of these armor penetration analsys don't get into things like the effects of multiple hits, edge effects, etc. Furthermore it's clear that one didn't need to pentrate Bsimrack's turtle deck to render her defenceless.

 

Good evidence? OK, I’ve read all of Nathan’s post and the revisions. I’ll stick to “my problem” of noting the lack of evidence on decapping plate working. Since this is Nathan’s whole premise, the burden of proof rest on him and his revisions, I say the evidence was lacking from the get go, only to be partially if not completed refuted later by Nathan himself leaving us now with a complex "may" with many variables.

And the point is? Like I’ve said not used by the BB designers of the day with all possible evidence. Decapping is a Nathan theory based on scant evidence and many revisions. I’ll stick to my simple logic of decapping = minor foot note.

Agree, you left out design of shell, which evidently would seem per Nathan that the USN 16” shell is the MOST prone to decapping but I digress.

Agree, stated many times already belt penetration alone is bad enough, merely pointing out that a belt penetration on the Bis is not as bad as a belt penetration on the New Mexico, one leads to flooding one leads to big machine spaces and flooding. Yes yes yes belt penetration is bad… just not as bad on the Bis.

To quote Nathan "Belt armor accomplishes two things. It preserves flotation, and it protects the vitals. With regard to flotation, Bismarck's belt was unremarkable. With regard to the vitals, the belt was truly formidable in combination with the slope armor behind it"

 

Funny how you consider deck penetration to be any horizontal surface and belt penetration only limited to actual armor belt. So please change my belt to any hull penetration (by whatever means) killing most ships thanks. Note the deck penetrations listed would have killed any BB so saying the Bis lacks deck, all BB lack deck in relation to what actually sank them. The only deck penetration that may have prevented the sinking of the ship would be the Yamato vs the 16" "bomb" dropped on the Arizona.. maybe.

Now to your point, yes the Bis had lots of damage from the Rodney on her T, yes it would appear that damage was deck based. This is ONLY after the ship was missioned killed. What type of hit did damage to the Bis before? Two hits on the hull via PW, several torpedos on the hull. So your statement about deck being important vs belt does not stand historical damage when it actually counted. If the Bis had a Yamato deck, it would not have mattered one bit in actual combat.


Let me tackle the first one as an example? Hood, which I said the shell went through the belt and then through the deck slope which at that point is functioning as a belt (vertical surface). I'll leave your other "deck" hits to other threads.

1920, trials with built up targets representing Hood were conducted and showed that her magazines could be reached by a 15-in shell penetrating the 7-in (178mm) belt.

Two of these sketches are reproduced below

http://www.navweaps.com/index_inro/INRO_Hood_p1.htm



So lots of pet theories right? But the most direct is a 15" going though the belt leading to a big boom, apply Occum's razor.

 

If you've read much on it then you surely must be aware that there was a fair amount of testing that confirmed that the decapping phenomena exists. So no it wasn't lacking "from the get go". There were and are issues of just when it occurs and what is required to decap an projectile but that's another matter.

But there is clear evidence that it was.

On the contrary it was and is based on real evidence. The details of what was happening and how were indeed revised but that's a rather positive note. As for your "simple logic" it may be simple but it's not logic.

But that's not right either. A belt penetration on New Mexico doesn't necessarily imply a hit in ht emachine spaces. Nor does one on Bismarck imply that flooding is the only damage.

For a fraction of her vitals.

 

Doesn't that render the whole thing rather pointless?

That's a tautology.

That's an incredibly strange way of defining things.

I'm pretty sure this one was discarded by the RN experts who analized the results after the battle. So it violates one of the primary requirements for using Occam's razor.

 

It is convention that the vertical armor on a warship's hull is considered its "belt." Where several different thicknesses are involved or the armor extends forward and aft of the main raft body these are considered secondary belts or sometimes termed forward belt, battery belt (if it covers secondary guns), etc.
Horizontal armor is considered deck armor. But, only heavily armored decks are generally considered here. Splinter armor on a deck is usually refered to as such or not mentioned in the armoring scheme.
The way I described the hits is the way they are described in every naval history and technical text on ships.
Penetrations of the hull in unarmored areas are listed as such. Penetrations or hits on areas below the waterline that have some protective system inboard are refered to as such or as hits on the torpedo defense system.

Selecting a single case and trying to make that into a general argument is fallacious. In the Bismarck's case no amount of armor would save her from being pounded in her final action. However, there are literally hundreds of examples from 20th century naval combat to show that deck armor does significantly limit damage and is far more frequently exposed to damage than belt armor is.
The deck armor may not stop an outright penetration but it frequently does stop or minimize splinter damage to the spaces it protects. In the same vein, much thinner side vertical armor does the same thing.
This is why today the US Navy has their carriers built with a near complete lightly armored hull and multiple armored decks. This is done not so much to prevent penetration by a heavy weapon, missile or, bomb but to minimize the area that such weapons effect after detonating.

The most common way to sink any ship, and the most common in WW 2, was to damage it below the waterline and flood it. This was most commonly caused by torpedo hits. Near miss bomb damage comes in second. Shell and bomb damage directly on the ship could turn it into a floating wreck but, it was usually still afloat.

I'll let you argue that Mr. Jurgens is wrong in his analysis for one:

Loss of HMS Hood

To summarize his analysis: The belt makes up a miniscule fraction of the danger space of shells being fired from Bismarck. An underwater hit below the belt would have resulted in flooding of the magazine and likely have put the fires out before the magazine could detonate.
A hit on the deck with either a penetration or just a glancing hit that shatters the armor would allow hot fragments into the powder magazines of the aft turrets (the British put the powder magazines on top with shell rooms below, the reverse of German and US practice) and would have resulted in a fire without flooding. This would lead to a magazine explosion.
Given the large target area of the deck and small target area of the belt the deck hit hypothesis is most likely the outcome.

But, the actual analysis of gunfire as occured at Denmark Straight shows the probability of hitting the belt abreast of the aft turrets is extremely small due to the small area the belt covers relative to the total target area / danger space the shells create.

The best theory is the one that gets the results. Hood's belt aft is nearly submerged. An underwater hit or a hit that results in massive flooding will likely cause the magazine to be self extinguishing. A hit in the shell room vice a powder magazine will likewise not probably cause a magazine explosion.
To apply Occam's Razor here is to conclude given the large deck area, relatively thin deck armor and the danger space of the falling rounds it is most likely a deck hit that caused the fatal damage.

 

How about a simple test, live AP round of 15” hitting a scaled de-capped plate and a scaled main deck plate all made of the same stuff that the actual round and plate would be made of, fire say 50 rounds, get data and get a “confirmed”? Oh well what is the best data? AFAIK it was semi scaled mockups that led the Italians to design one class of ships that AFAIK was show by Nathan that BB’s de-capping plate would not have been effective in actual combat. The designers of the time with all data available did not designed decamping plate; other than the one Italian BB line.


Please start a new thread showing the BEST data out there? As none of the Big 5, nor the Bis have such plate or issues.

One line of ships right, on some partial semi-scale testing and base on some spaced plate design. Yawn… I’m done.

Yawn, real evidence is a whole mess of BB shells fired at angle against actual de-cap plate. So start a thread with the "real evidence".

Really? Wow go figure… once you have to extrapolate to the extreme you know your position is lost right? LOL

And so? Never said otherwise. A hit on the Bis’s belt will not go through the deck. Period. So for this topic the Big 5 will have a much harder time putting in a mission killing critical hit on Bis’s machine space via the main armor belt. At no time did I say the Bis could not be damage, destroyed, or was completely protected from the USN’s 14” round. I’ve clearly indicated that at 20K each ship has more than enough punch to damage or destroy the other. You want to argue the counter and extrapolate it to the extremes, fine.

Then post your counter argument, what is it? Do you have one? Don’t think so. As it would be near comical to say a belt penetration on the Bis has a significantly greater chance of being a critical hit vs the same penetration on the NM.

Maybe your counter is BB don't need a belt, cause what? The belt only covers a "fraction of her vitals". Heck look at all the weight saved....

So can we safely sum up that a belt penetration is bad on the Bis and can be Ghost Busters "bad" on the NM. Yes, yes I got you already the main belt only covers a portion of the ship, yes yes I got you already it could be "bad" for the Bis too, yes yes I got you that just maybe it would not be as "bad" just bad on the NM.. Yawn..

 

To sum it up the belt = hull. OK thanks. So how does this backup the claim that "Judging from historical results I'd say that the belt on both ships will play a nearly insignificant role in the outcome and in the amount of damage taken. The deck is far more important in terms of damage control.

Dunno, as it would seem ships sink because of hull damage.

Well there were actually two cases that I've listed, but fallacios, or lack of time? Hood was the first example for deck vs hull. Clearly a 15" going through the HULL could and IMO did blow the Hood up. Most of the ships you listed were HULL damage. So it would be you that has to look for single case of deck penetration killing a ship. Yes there are a few, I listed them, and I've pointed out that all or almost all of them were destroyed by hits that would have done the SAME to any other BB.

Ya lost me, I mean we are talking BB here right and we have come to the conclusion that Hull = belt and TDS right. Do BB sink or are mission killed by Hull or Deck? Lets get the totals:

Sc, clearly the first(s) close range hull hit put Anton out and ripped a massive hole in the front of the ship and put Bruno's fan on the blink. She was at that second mission killed.

Sc's twin damaged by wait for it...... a mine, and put out of the war. I call that hull.

Bis, took 4 or more hull hits before the torpedo hit the rudder ( I would call that hull but hey)

Sister Bis, takes one or more massive bombs, heck AFAIK the bomb went through the ship and exploded underneath the HULL, so is that a hull hit?

So for the Germans it is 3 Hull and 1 deck, the deck hit no BB could stop.

Japan,

Yamato, Musashi, yep lots of hits, Hull, deck, I would say more hull damage, but hey lets call it does not matter.

Fuso / Yama.. yep massive hull damage via torpedo. Yama herself lost 1/3 of her turrets and was down to 5kts before getting a burst of speed to 15 knots. You say 20 to 30 major rounds went through her deck, yet she turned completely around and made the same speed or even greater in retreat only to be hit with two more torpedoes... I gonna say that -20 knots and 1/3 of the main battery and then to sink after the two torpedoes… is um HULL. I will also note that it is near laughable to pretend an ancient battleship, already heavily damage go hit by 20 to 30 BB rounds and was still able to steer and maintain speed…

Hyu / Ise hybrid Carriers… OK don’t know much about them are the BB? CV-BB, BBCV dunno.

Kongo: Torpedo = Hull, Yamashiro, close range, progressive flooding doubtful there was significant deck penetration, so Hull. Heie, gunfire via the Hull. Haruna, no fuel, guns gutted, rust killed her.

So IJN, 5 hull, 3 does not matter, 2 I don’t know.

USN,
Arizona deck, could any deck keep out the 16” bomb / shell? Dunno.
Ok, Cal, WeeVee, mainly hull
Nevada, progressive flooding from torpedo so hull
NC, well was not mission killed
SD missioned killed some through the hull none thought the deck, so I’ll go with the hull

So total please 5 hull, 1 deck, once again don’t know if any deck or deck design would have stopped the lost of the ship.

I could go on, but it ain’t looking good for the deck guys. 8:2 hull vs deck and the RN lost most /all her BBs including the Hood to hull.

 

oldman,

With regards to your comparison of ship damage. First off, comparing shell damage to torpedo damage is like comparing apples to oranges. Torpedo protection of a warship does not rely on belt armor alone, there are various protection schemes that have been designed to defeat or limit the damage caused by a torpedo. Second the facts differ greatly from your post.

The Scharnhorst, while heavily damaged by the Duke of York, was not in sinking condition. At the conclusion of the gun duel, the Scharnhorst was actually outdistancing the British battleship and cruisers. At this point Admiral Frasier ordered his destroyers to torpedo the Scharnhorst, which they did. The Scharnhorst, hit by several torpedoes, slowed rapidly, allowing all British units to gain on her. As the Duke of York closing to "point blank" range she resumed firing on the now doomed German ship. The Scharnhorst did not survive this last deluge of shells and torpedoes.

As for the Gneisenau, she was not put out of the war by a mine as you have stated. She was docked in Kiel for repairs to the mine damage, which was expected to take only two weeks, she was docked with her ammunition still aboard. During a British air raid on the night of 26-27 February, 1942, she was hit by one 454 kilogram bomb. This hit lead to a deflageration of the powder in turret Anton's magazine. The resulting explosion and fire necessitated the reconstruction of turret Anton, the magazine, and much of the bow structure.

Your claim of the Tirpitz being sunk by a bomb that passed through the hull is false. That was from the attack on September 15, 1944, the Tirpitz would not be sunk until a month later. The Tirpitz was sunk by two, possibly three "Tallboy" bombs on November 12, 1944. The first, striking between turrets Anton and Bruno was a dud, the second hit portside by the catapult and funnel, and a possible third hit in the vicinity of turret Ceaser. The second bomb detonated within the hull, not outside it.

All of this information can be found in "Battleships: Axis and Neutral Battleships in World War II" by William H., Jr. Garzke and Robert O., Jr. Dulin

I'll post more after doing some more research.

 

No. You are wrong. The belt armor does not equal the hull. Not in any way, shape or, form. It is that simple. If you think the armored belt on a WW 2 era ship is the equivalent or represenatlve of the whole hull you have zero understanding of naval architechture of the period.

The reason I said the belt is relatively unimportant is that it generally covers a small fraction of the ship vertically. It usually, by WW 2 at least, only covers about two thirds of the lenght of the hull on each side, sometimes less, as well.
The deck armor is far more important. It provides a horizontal surface that will resist most splinter penetratons from all but the heaviest hits. This limits the amount of flooding that can progressively spread upwards as the ship sinks. It also acts as a fire boundry. Both are critical to damage control. The belt isn't.
Additionally, it can be demonstrated that armor however thick cannot be relied on to keep heavy naval shells from a battleship from penetrating the hull and doing significant damage. Therefore the best use of armor is to prevent splinter damage that will significantly increase progressive flooding and the chances of multi-compartment fires.

 

Since a picture is worth a thousand words here is a drawing of the USS San Francisco showing the damage she received November 12-13, 1942. The location of her armor belt is clearly marked and, as you can see, covers very little of the hull.
http://www.researcheratlarge.com/Ships/CA38/Plate2.jpg

 

oldman,

Regarding Japanese battleships. The Yamato and Musashi were sunk by aircraft alone. Both were sunk after many bomb and torpedo hits. While the Musashi was hit by some 19 torpedoes, those hits were scattered all around the ship. As for the Yamato, the Americans learned their lesson and she sank after only 11 torpedo hits, but they were concentrated mostly on her port side.

Regarding the fates of the Yamashiro and Fuso, you can go here for more information FUSO or read his book entitled "Battle of Surigao Strait"

Pertaining to the Ise and Hyuga, both battleships were lost to many bomb hits and near misses,
Imperial Battleships
Imperial Battleships

Kongo was torpedoed by Sealion II
Hiei suffered sever damage during the the First Naval Battle of Guadalcanal. As she is withdrawing from the scene she is attacked by many times between 0615-1745 by American aircraft. Hiei suffers a few bomb hits and 4 torpedo hits.
Imperial Battleships
IMPERIAL JAPANESE NAVY MYSTERIES
Kirishima is battered beneath the waves by the USS Washington, USS South Dakota, and their escorts
http://www.navweaps.com/index_lundgren/Kirishima_Damage_Analysis.pdf
http://www.navweaps.com/index_lundgren/Battleship_Action_Guadalcanal.pdf
Haruna is bombed on July 22, 24 and 28, 1945, before finally settling on the bottom of Kure harbor
Imperial Battleships

Pertaining to the US battleships.

The only one I disagree with is the USS South Dakota. No shells, penetrated her main belt, and much of her damage was confined to the superstructure.
http://www.navsource.org/archives/01/015753.jpg

 

There are a wealth of tests listed at: Decapping Revisited
and the conclusion is not what you state it to be. More testing would have been nice but it would also have been very expensive. The point has been made however. Decapping was and is a real phenomena. At least one class of battleships was designed to take advantage of it (I've seen some argue that Bismarck's deck system also was so designed). There is real data to support it and it was widely known if not well understood.

That's conjecture and while it's clear that the VV class did use it it's not so clear that others did not.

Why?

Indeed you made several over genearlized coments and were proven wrong.

That may be "real evidence" but it's not the only real evidence. As stated there was a wealth of test by a number of different countries. Indeed subscale tests were often used because they were cheaper and easier to collect the data from. The fact that you seem to have a more restrictive set of data that you are willing to accept than the armor and armorment developers of the time is your problem not ours.

What are you talking about? I wasn't extrapolating at all much less to extremes.

A hit on New Mexico's belt isn't going through her armored deck either. So what's your point.

But now you are talking about a very small subset of possible hits and indeed possible critical hits. POW's hit on Bismarck was a mission killing one that didn't need to hit her belt. Rodneys hit that took out her forward battery would also have been if the mission was already killed. Same with the hits in her engineering spaces.

I don't have any disagreement with this.

This however is a strawman.