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dseehafer

Why did the Germans reject AoN and DP secondary batteries during WWII?

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Greetings all,

 


    Many people have often wondered why it was that the Germans rejected the All-or-Nothing protection scheme even after most other nations adopted it for themselves as they rebuilt and modernized their fleets going into the 1920s and 1930s. Some people have stated that this was because the incremental armor scheme was all the Germans knew and that they rejected it (AoN) because they had no experience or trust with the AoN design. Others still have made the ridiculous claim that the Germans did not have the technology or the know-how to build a ship with an All-or-Nothing scheme. The fact of the matter is that the Germans were paying very close attention to foreign shipbuilding and ship design theory, they were well aware of the AoN scheme and studied and considered it's implementation into their own ships in great detail. In the end, however, they made the conscious decision to stick with the Incremental armor scheme because it offered superior protection characteristics over the AoN scheme at the ranges and conditions at/in which the German fleet was expected to fight.

 

   To better explain the mentality behind this decision we must explore two primary points...

 

   For the first point, we must turn to the French. When, in the final years leading up to the First World War, the French set out to design and build the Normandie class battleships, the Americans were, at the same time, already building the Nevada class battleships. The Nevada class battleships were the first battleships to incorporate the AoN scheme. After a great deal of consideration, the French rejected the AoN scheme for the Normandie. The French rejected the AoN scheme because it revolved around the idea that All-big-gun battleships were the future, and that secondary guns were now limited to the self-defense role against torpedo ships and that all-big-gun battleships would be capable of destroying cruisers and other lighter ships before they got close enough for their lighter guns to become a threat. Essentially, the mentality behind the AoN scheme, as interpreted by the French, was that it only had to protect against heavy caliber shells. This was all well and dandy except for the fact that the French were convinced that the decisive fighting range at which naval battles would be fought would be 6km and that battle ranges wouldn't stray much further than 8km (this is also why French battleships at the time had such short main battery ranges). At such ranges, even the heavy secondary guns of pre-dreadnoughts and armored cruisers were a threat and had to be defended against. In short, the incremental armor scheme was chosen because it was capable of defending against multiple gun calibers from close ranges. 
   The same mentality carried over and applied for the Germans during the years leading up to WWII. The Germans considered it impossible to sustain effective long-range combat in the conditions of the North Atlantic (the primary theater of German naval operations) even despite the advancements in technology concerning radar, rangefinders, and gun stabilization, etc... The Germans found themselves in the same position as the French, they needed extremely strong vertical armor protection capable of defending against multiple shell-calibers from relatively short ranges (within 25km). For these requirements, the incremental scheme was superior to the AoN scheme. Unlike the French, who were quickly proven wrong about their predictions on naval battle ranges (most major naval battles of WWI started around 18km, 10km more than what the French predicted) and had to pull their battleships from the front lines to improve their modest gun ranges... history proved the Germans correct. Battle ranges in the North Atlantic during WWII did not stray beyond 26km and most of the fighting took place within 20km.

 

   The second point is as follows. The AoN scheme lives and dies by the theory of the "immunity zone", that is the combat ranges in which the ship's armor is, in theory, resistant to its own weapons (or weapons of the same caliber). The Germans rejected this theory and understood its limitations. The Germans developed the principle that neither vertical nor horizontal alone would be able to withstand heavy shells. They also understood that heavy weapons won the dispute over armor and that there is no absolute protection. Therefore, German designers decided to distribute the armor in such a way that at critical distances the ship's horizontal and vertical armor would help each other to withstand penetrations to the vital parts of the ship. Any shell passing through the main belt will meet on its way the turtleback, any shells passing through the upper belt will meet on its way the main armored deck, etc... In this way, at the target combat ranges, the ship's vitals are resistant to heavy shells and the rest of the ship is resistant to medium and light shells. The effectiveness of the protection of vital areas at medium-close ranges became apparent with the sinking of the Bismarck who, despite the rest of the ship being thoroughly wrecked, never suffered a magazine explosion and whose machinery remained operational even while the ship was sinking and the order to abandon ship was given.


   As for the extending of the belt even into the bow areas of the ship, the damage sustained by Seylditz at the battle of Jutland proved that not only was this armor useful but also that it should be improved upon in future projects. Indeed it proved useful even in WWII. When the light cruiser Nurnberg was struck in the extreme bow by a submarine-fired torpedo the damage report praised the 18mm bow belt declaring that, had it not mitigated the damage from the torpedo and prevented further cracking in the hull, the ship would have surely been lost. Likewise, when Gneisenau was also struck in the extreme bow by a submarine-fired torpedo the bow belt was credited as the reason why the ship's entire bow was not lost.

 

Spoiler

Damage to Nurnberg after torpedo hit

Nürnberg

 

 

Damage to Gneisenau after torpedo hit

Click screen to close

 


   Another criticism of German capital ships was the failure to adopt a uni-caliber dual-purpose secondary battery. Again, as with the AoN armor scheme, this was very strongly debated and considered. However, in the end, once again a conscious decision was made to split the secondary batteries. The Germans looked at foreign examples and came to the conclusion that a uni-caliber dual purpose weapon could not be both a good anti-ship weapon while simultaneously being just as good of an anti-aircraft weapon. Indeed the threat of torpedo attacks from destroyers and cruisers at the expected short combat ranges in the North Atlantic was such that it was not worth the risk of adopting a uni-caliber secondary battery. Only a dedicated anti-ship secondary weapon would be adequate for this job of self-defense and so the 15cm gun was selected. The long-range AA would be the job of the 10.5cm weapons which also possessed some anti-ship capabilities. Indeed the secondary batteries of German capital ships would boast both the best anti-ship and anti-air capabilities among her European contemporaries. This did not come without its fair share of downsides, however. Splitting the secondary battery wasted much more weight and space than a uni-caliber dual-purpose secondary battery would have. Further, the splitting of calibers made fire-control in the anti-ship role overly complicated. Still, despite all of this, the Germans considered the risk of torpedo attack too high not to have a dedicated anti-ship secondary gun and so the sacrifices were deemed worth taking.


Whether or not these decisions on armor layout and secondary armament were the right ones is certainly debatable. One thing, however, is for certain... that there was a method to their madness and a rhyme to their reason and that these decisions were not the consequence of inability or inexperience as some have claimed.

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Great write up... I would also venture on a limb here and say that the Germans did in some ways have AoN WWI ships, very heavily armored to survive and fight again, but then they couldn't carry as heavy caliber guns.  Newer German ships starting with Scharnhorst (though decision was to go w 11' gun, more ammo, better for raiding than a 15' gun)  then Bismark, moved towards having heavier armament, and armor that was sufficient for Atlantic battles, more inclement weather than other theaters of war= closer ranges, the Germans knew what they were doing and where they were going to fight their battles.

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Interesting read, however I disagree about two things. First, the Seydlitz bow armor proved utterly incapable of stopping AP shells from penetrating, but just thick enough that if a shell penetrated,  it would explode inside and cause more damage than just passing through. This was part of the reason she sank. Next, while the 150/100 mm combination for secondary and AA guns let to them being the best of both in Europe, the US 127 mm DP 5" 38 caliber guns proved the validity of the DP concept, as the rate of fire offset any disadvantages in damage, while also being a great anti aircraft weapon thanks to its high rate of fire and quick traverse speed. 

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Take my up vote!

WdkU3fV.gif

 

Will have to comment more with some thoughts when I have the time!

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5 hours ago, poopoofoofoo said:

Interesting read, however I disagree about two things. First, the Seydlitz bow armor proved utterly incapable of stopping AP shells from penetrating, but just thick enough that if a shell penetrated,  it would explode inside and cause more damage than just passing through. This was part of the reason she sank. Next, while the 150/100 mm combination for secondary and AA guns let to them being the best of both in Europe, the US 127 mm DP 5" 38 caliber guns proved the validity of the DP concept, as the rate of fire offset any disadvantages in damage, while also being a great anti aircraft weapon thanks to its high rate of fire and quick traverse speed. 

 

Seydlitz did not sink.

 

Second, it is not the job of the bow armor to prevent penetrations. You must remember that some armor is not designed to outright reject an incoming shell. Take for example upper deck armor. The job of this armor is not to reject an incoming projectile or bomb, but to get that projectile/bomb to arm and hopefully explode before it reaches the main armor deck, or, in the case of heavier shells, to at least decap the projectile before it reaches the main deck. Far better to have a shell or bomb explode in the area between the decks than to have it explode in the magazines or machinery spaces. The same goes for the bow-belt, its job is to arm/decap a shell before it reaches the ship's forward transverse bulkhead and the magazines behind it. Far better for a shell to explode in the bow, where there is nothing/little of importance, than to have it penetrate the transverse bulkhead and explode in/near the magazines.

 

Rate of fire alone does not a good anti-surface weapon make. The German 105 did not fire much slower than the USN 127/38, further, the German 105 also boasted superior firing range and also fired a shell which did not weigh much less than the 127/38 shell (considering the size difference) at a higher velocity meaning that it also boasted comparable if not slightly superior hitting power to the 127/38. Not to mention that the German 105 also had a dedicated anti-ship AP round as well as HE rounds. Suffice to say that the 127/38 was no shining star when it came to anti-ship capabilities.

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 I confess I am at a bit  of loss, but could the German doctrine by itself dictate the armament of those ships? The situation in WWI and more specifically the success of Commerce Raiding was surely noted. And since most of the German surface actions were revolving around commerce raiding, the Germans might have sacrificed the AA DP mounts would offer at the expense of anti-ship armament. By the time a task force with a carrier would be in range, in an ideal scenario the raider would be already gone thus not necessitating  the use of heavy AA suites. 

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1 hour ago, dseehafer said:

Essentially, the mentality behind the AoN scheme, as interpreted by the French, was that it only had to protect against heavy caliber shells. This was all well and dandy except for the fact that the French were convinced that the decisive fighting range at which naval battles would be fought would be 6km and that battle ranges wouldn't stray much further than 8km (this is also why French battleships at the time had such short main battery ranges). At such ranges, even the heavy secondary guns of pre-dreadnoughts and armored cruisers were a threat and had to be defended against. In short, the incremental armor scheme was chosen because it was capable of defending against multiple gun calibers from close ranges. 

French concerns about Armored Cruiser or Pre-Dreadnought firepower in 1913 seem pretty perplexing.

For context Dreadnought launched in 1906 and after that no more Pre-Dreadnoughts were really lain down, though some were finished. The lain-down dates for the last of them are 1905 for the Lord Nelson's, 1904 for the Mississipi's, 1903 for the first Deutschland, the Russians stopped in 1903 too. For armored cruisers the last one was really Blucher (1907). Both types were almost immediately obsoleted by the Dreadnought and Invincible when they arose, and while Pre-Dreadnoughts might have had some utility for a while (maybe two good Pre-Dreadnoughts could handle Dreadnought for instance, or 5 Pre-Dreads vs. 1 BC at Cape Sarych) by 1913 the first two QE class have not just been built but launched.

Being concerned about ships which were already obsolete and at least 8 years old seems very odd, even if well, it's odder still to think that 8km is going to be the maximum possible engagement range. Did they have particularly poor FCS technology is my thought.

1 hour ago, dseehafer said:

The same mentality carried over and applied for the Germans during the years leading up to WWII. The Germans considered it impossible to sustain effective long-range combat in the conditions of the North Atlantic (the primary theater of German naval operations) even despite the advancements in technology concerning radar, rangefinders, and gun stabilization, etc... The Germans found themselves in the same position as the French, they needed extremely strong vertical armor protection capable of defending against multiple shell-calibers from relatively short ranges (within 25km)

It's a reasonable concept, but being 'cruiser proof' doesn't seem (to me) to have been particularly useful in practice. Not that cruisers shot up battleships all that frequently anyway. For instance:

  • Hiei is probably the battleship most damaged by cruiser gunfire, with San Francisco's hits to her steering gear ultimately dooming her, that's despite a Kongo class being a distributed WWI scheme
  • Superstructure vulnerability remains - I believe Lutjens and Lindeman were killed on the bridge of the distributed Bismarck, Abe was injured on Hiei
  • FCS/radar vulnerability remains - for instance Norfolk hitting Scharnhorst's radar, and Scharnhorst clipping DoY's
  • Until her final engagement (where it was curtains either way) I don't believe Bismarck was struck, let alone damaged by the Suffolk, Norfolk or Sheffield, nor did her scheme protect her any more or less from the Tribal night attack
  • South Dakota was knocked about (18x 8in, 6x 6in), in particular by radar damage but after 26 total hits at Guadalcanal could float, fight and maneuver, that's in a close range engagement on an AoN scheme

Although the idea of defeating battleship-caliber shells with a layered approach and not only defeating, but mitigating any battleship caliber penetrations seems somewhat more worthwhile, worrying about cruisers doesn't seem to have been. Internal armor is one thing, but the upper belt in particular - 160mm of plate x 171m long x ~3m is a big chunk of weight, well it might save you from 8in penetrations but at a point where the ship is lost and SoDak doesn't seem to have done too badly.

1 hour ago, dseehafer said:

As for the extending of the belt even into the bow areas of the ship, the damage sustained by Seylditz at the battle of Jutland proved that not only was this armor useful but also that it should be improved upon in future projects. Indeed it proved useful even in WWII. When the light cruiser Nurnberg was struck in the extreme bow by a submarine-fired torpedo the damage report praised the 18mm bow belt declaring that, had it not mitigated the damage from the torpedo and prevented further cracking in the hull, the ship would have surely been lost. Likewise, when Gneisenau was also struck in the extreme bow by a submarine-fired torpedo the bow belt was credited as the reason why the ship's entire bow was not lost.

In Nurnberg's case I suspect worrying about total ship loss from a torpedo hit to the extreme bow only being prevented by the 18mm strip is more a reflection of the extremely light nature of the design. Off the top of my head destroyers which survived a torpedo hit to the bow include Eskimo, Javelin, Amatsukaze. Cruisers would include the Chicago, Edinburgh, Argonaut, St. Louis - all in no danger of sinking from the hit. I'm sure I'm missing plenty but I think the utilization on Nurnburg was probably rather slight. 

Spoiler

X6XsMHJg.pngPKdcSLA.png

Chicago (left) and Argonaut (right) showing similar torpedo damage to Nurnburg despite the lack of a splinter belt.

Compared to say Exeter eating lots of splinter damage forward at River Plate that might be where an advantage might be. In the case of Lutzow it didn't help, while a 'flotation raft' citadel concept may well have.

2 hours ago, dseehafer said:

The Germans looked at foreign examples and came to the conclusion that a uni-caliber dual purpose weapon could not be both a good anti-ship weapon while simultaneously being just as good of an anti-aircraft weapon.

My general take on the secondary battle is 'the best AA secondary battery is the most useful, and ASuW utility is pretty negligible'. The Bismarck's AA broadside of 4x2 4.1in compares poorly to the USN, but I'd say pretty well compared to the 4x2 5.25in of a KGV, or the 3x2 100mm of the Richelieu, and certainly compared to the 6x1 of the Litorrio's. However, if you'd just outright replaced the 3x 5.9in turrets per broadside with corresponding twin 4.1's I'd guess it'd just be a huge advantage overall. Given that the potency of air power in the mid-1930's looked pretty low, I think this was an understandable and global failing. Given the range of 1936 aircraft included the BG-1, Hawker Osprey, Aichi D1A and other less than fearsome craft.

It's not clear what combination of main-battery, 5.9in and 4.1in fire held off the Tribal's night attack on Bismarck, but it was certainly a combination of the 3, and weakening the 5.9in outfit may not have been a big deal. A survivor account of the sinking of Scharnhorst I read recently (will try and find) suggested that the 4.1in gunners had been told to take cover because there wasn't the anticipation of air attack, and the gunners were livid that they'd been sent away as they thought they could have stopped the destroyer torpedo attacks which clearly the damaged 5.9in battery could not.

Given that Bismarck's 5.9in secondaries in an ASuW were possibly useful once, that Tirpitz' never were, that Scharnhorst's failed to prevent torpedo hits either during the sinking of Glorious or at her loss, that Gneisenau was torpedoed off Brest and that all four were repeatedly attacked from the air, the hindsight seems to be 'AA is more important' - a failing mirrored in the RN's lack of a DP destroyer gun causing heavy losses to air attack, while the majority of RN DD never fired their guns at a surface target.

 

It is interesting to know the original logic, even if the French are clearly mad and it didn't work out when the rubber met the road - then again neither did plenty of pre-war ideas.

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I've always seen it attributed to (and agree with it myself) that the reason that the German's didn't employ DP secondary guns, was the German's never employed destroyer leaders. The German's employed light cruisers for this role (the Japanese also did this) and a 100mm or 120mm gun wasn't seen as heavy enough to stop a light cruiser leading a destroyer flotilla from torpedoing you. 

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4 hours ago, warheart1992 said:

 I confess I am at a bit  of loss, but could the German doctrine by itself dictate the armament of those ships? The situation in WWI and more specifically the success of Commerce Raiding was surely noted. And since most of the German surface actions were revolving around commerce raiding, the Germans might have sacrificed the AA DP mounts would offer at the expense of anti-ship armament. By the time a task force with a carrier would be in range, in an ideal scenario the raider would be already gone thus not necessitating  the use of heavy AA suites. 

 

It should be remembered that Germany's battleships were not designed for commerce raiding. In fact, they found themselves awkwardly forced into this role. A square peg in a round hole if you will. Scharnhorst was Germany's direct response to France's Strasbourg and Bismarck only ended up being the 45,000t 15" monster that she was because she had to counter France's Richelieu (before France announced Richelieu, Bismarck was planned only to displace 35,000t and was to be armed with 13" guns). Germany's battleships were designed to fight French battleships (and any escorts that might accompany them). The Deutschland class were the only German warships built primarily for commerce raiding. However it should be noted that Germany's light cruisers were also designed with the potential for commerce raiding in-mind but first and foremost they were designed to counter French light cruisers (K-class was built to take on France's Duguay-Trouin, for example). 

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5 hours ago, mofton said:

French concerns about Armored Cruiser or Pre-Dreadnought firepower in 1913 seem pretty perplexing.

For context Dreadnought launched in 1906 and after that no more Pre-Dreadnoughts were really lain down, though some were finished. The lain-down dates for the last of them are 1905 for the Lord Nelson's, 1904 for the Mississipi's, 1903 for the first Deutschland, the Russians stopped in 1903 too. For armored cruisers the last one was really Blucher (1907). Both types were almost immediately obsoleted by the Dreadnought and Invincible when they arose, and while Pre-Dreadnoughts might have had some utility for a while (maybe two good Pre-Dreadnoughts could handle Dreadnought for instance, or 5 Pre-Dreads vs. 1 BC at Cape Sarych) by 1913 the first two QE class have not just been built but launched.

Being concerned about ships which were already obsolete and at least 8 years old seems very odd, even if well, it's odder still to think that 8km is going to be the maximum possible engagement range. Did they have particularly poor FCS technology is my thought.

It's a reasonable concept, but being 'cruiser proof' doesn't seem (to me) to have been particularly useful in practice. Not that cruisers shot up battleships all that frequently anyway. For instance:

  • Hiei is probably the battleship most damaged by cruiser gunfire, with San Francisco's hits to her steering gear ultimately dooming her, that's despite a Kongo class being a distributed WWI scheme
  • Superstructure vulnerability remains - I believe Lutjens and Lindeman were killed on the bridge of the distributed Bismarck, Abe was injured on Hiei
  • FCS/radar vulnerability remains - for instance Norfolk hitting Scharnhorst's radar, and Scharnhorst clipping DoY's
  • Until her final engagement (where it was curtains either way) I don't believe Bismarck was struck, let alone damaged by the Suffolk, Norfolk or Sheffield, nor did her scheme protect her any more or less from the Tribal night attack
  • South Dakota was knocked about (18x 8in, 6x 6in), in particular by radar damage but after 26 total hits at Guadalcanal could float, fight and maneuver, that's in a close range engagement on an AoN scheme

Although the idea of defeating battleship-caliber shells with a layered approach and not only defeating, but mitigating any battleship caliber penetrations seems somewhat more worthwhile, worrying about cruisers doesn't seem to have been. Internal armor is one thing, but the upper belt in particular - 160mm of plate x 171m long x ~3m is a big chunk of weight, well it might save you from 8in penetrations but at a point where the ship is lost and SoDak doesn't seem to have done too badly.

In Nurnberg's case I suspect worrying about total ship loss from a torpedo hit to the extreme bow only being prevented by the 18mm strip is more a reflection of the extremely light nature of the design. Off the top of my head destroyers which survived a torpedo hit to the bow include Eskimo, Javelin, Amatsukaze. Cruisers would include the Chicago, Edinburgh, Argonaut, St. Louis - all in no danger of sinking from the hit. I'm sure I'm missing plenty but I think the utilization on Nurnburg was probably rather slight. 

  Reveal hidden contents

X6XsMHJg.pngPKdcSLA.png

Chicago (left) and Argonaut (right) showing similar torpedo damage to Nurnburg despite the lack of a splinter belt.

Compared to say Exeter eating lots of splinter damage forward at River Plate that might be where an advantage might be. In the case of Lutzow it didn't help, while a 'flotation raft' citadel concept may well have.

My general take on the secondary battle is 'the best AA secondary battery is the most useful, and ASuW utility is pretty negligible'. The Bismarck's AA broadside of 4x2 4.1in compares poorly to the USN, but I'd say pretty well compared to the 4x2 5.25in of a KGV, or the 3x2 100mm of the Richelieu, and certainly compared to the 6x1 of the Litorrio's. However, if you'd just outright replaced the 3x 5.9in turrets per broadside with corresponding twin 4.1's I'd guess it'd just be a huge advantage overall. Given that the potency of air power in the mid-1930's looked pretty low, I think this was an understandable and global failing. Given the range of 1936 aircraft included the BG-1, Hawker Osprey, Aichi D1A and other less than fearsome craft.

It's not clear what combination of main-battery, 5.9in and 4.1in fire held off the Tribal's night attack on Bismarck, but it was certainly a combination of the 3, and weakening the 5.9in outfit may not have been a big deal. A survivor account of the sinking of Scharnhorst I read recently (will try and find) suggested that the 4.1in gunners had been told to take cover because there wasn't the anticipation of air attack, and the gunners were livid that they'd been sent away as they thought they could have stopped the destroyer torpedo attacks which clearly the damaged 5.9in battery could not.

Given that Bismarck's 5.9in secondaries in an ASuW were possibly useful once, that Tirpitz' never were, that Scharnhorst's failed to prevent torpedo hits either during the sinking of Glorious or at her loss, that Gneisenau was torpedoed off Brest and that all four were repeatedly attacked from the air, the hindsight seems to be 'AA is more important' - a failing mirrored in the RN's lack of a DP destroyer gun causing heavy losses to air attack, while the majority of RN DD never fired their guns at a surface target.

 

It is interesting to know the original logic, even if the French are clearly mad and it didn't work out when the rubber met the road - then again neither did plenty of pre-war ideas.

 

As I understand it, it wasn't that the French did not consider pre-dreds and armored cruisers to be obsolete.. rather, that they understood that a 9-12" gun is still a 9-12" gun and is still going to hurt, no matter the kind of ship its on.... especially from within 8km.

 

The upper belt was not only for protection against cruisers, it also played an important role in the protection of the ship against heavy caliber shells as well. Remember that the Germans armored the ship so that the vertical and horizontal armor components would help each other. Take away the upper belt and now there is nothing standing in the way of the main armor deck. Now you have to increase the thickness of the main armor deck to compensate (and deck armor is much heavier than upper belt armor where the total area of protection is concerned). The fact that the upper belt also provides a degree of protection against light and medium shells is just a bonus, especially when most AoN ships had no significant protection in these areas and were left entirely vulnerable. Now, I know what the rebuttal is going to be so let me spare some folks some breath... "But the upper belt cannot guarantee protection against medium shells, all its going to do is arm the shell and cause it to detonate inside the ship instead of passing through!" Don't worry, the Germans realized this possibility as well. That is why there is a splinter bulkhead just a few meters behind the upper belt, to prevent any unnecessary damage to the ship's non-vital internal areas from an exploding shell that just penetrated the upper armored belt. Of course, this splinter bulkhead would be useless against heavy shells but again, if you get rid of the upper armored belt and splinter bulkhead you'd need to compensate by increasing the deck thickness, and that would add more weight in armor.

 

Concerning torpedo attacks from enemy ships... I'd like to add that early in the North cape battle Scharnhorst's secondaries repelled the destroyer Savage from making an attack. Shortly after this Savage joined up with Saumarez and the two were once again ordered to attempt a torpedo attack and were once again repelled by accurate fire from Scharnhorst's secondaries. It wasn't until Scharnhorst's drop in speed that successful torpedo attacks were carried out and by this time it is likely that few secondary guns remained in operation on Scharnhorst. Also, Tirpitz's secondaries were indeed useful when they sank the British submarine X-5. Your other points on the subject stand.

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We need to look at design constraints to understand AoN armor scheme, Congress limited the weight of battleships so engineers had to come up with something that maximized armor protection, fire power, and speed. If Congress didn't limit weight I believe the USN would have still utilized the incremental armor layout. Carrying over after the Washington Naval Treaty battleships were limited in weight all over the world, AoN was mainly adopted at this point so other nations could maximize armor protection in return for staying under treaty limits, the Germans didn't care about treaty limits so they went with incremental armor instead and designed it in a way to maximize the likely close range fighting they were predicting

 

For DP mounts, uniformity is a key point not brought up yet. On German ships you have several different shell calibers and guns are taking up allot more space (also adding to tonnage),  but the USN was aware of the limits of the 5"/38 which is why the 5"/54 came into development also

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The USN wanted a 5"/51 dual purpose gun.  They couldn't get that on a reasonable weight per gun mount, so they settled for the 5"/38 which was designed to improve the surface firepower of the gun over the 5"/25 AA gun.  The post WW 2 5"/54 gun was the gun the USN really wanted finally realized.  So, the USN really was willing to take a small hit in surface firepower to continue to have good AA firepower.

The Germans weren't willing to make that compromise, hence a dual secondary battery.  I think they made a serious mistake here, particularly with those triaxially stabilized 10.5cm mounts that really worked pretty crappily on the whole.  They had terrible reliability, and the fact that the loaders weren't on the mount meant it was moving while they were trying to load the guns.  I'd say the Germans, as usual, over-engineered the design and ended up with a poor one as a result.

 

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48 minutes ago, Murotsu said:

The USN wanted a 5"/51 dual purpose gun.  They couldn't get that on a reasonable weight per gun mount, so they settled for the 5"/38 which was designed to improve the surface firepower of the gun over the 5"/25 AA gun.  The post WW 2 5"/54 gun was the gun the USN really wanted finally realized.  So, the USN really was willing to take a small hit in surface firepower to continue to have good AA firepower.

The Germans weren't willing to make that compromise, hence a dual secondary battery.  I think they made a serious mistake here, particularly with those triaxially stabilized 10.5cm mounts that really worked pretty crappily on the whole.  They had terrible reliability, and the fact that the loaders weren't on the mount meant it was moving while they were trying to load the guns.  I'd say the Germans, as usual, over-engineered the design and ended up with a poor one as a result.

 

 

Good points all around, however, It is worth noting that the reliability/mechanical/electrical problems were fixed with the 1937 version of the German 10.5cm mount. Further, the traverse speed of the mount and guns were also improved. However, only Tirpitz enjoyed these mounts fully (half of Bismarck's mounts were of the 1933 model). All other Kriegsmarine warships in-service had to make do with the buggy 1933 model. Still not solved with the 1937 mount was, as you mentioned, the fact that the crew had to stand outside the turret. Even this was solved with the fully enclosed 10.5cm mounts (which also improved, once again, the traverse speeds of the mount) that would have been featured on ships such as the H-class battleships, the O-class battlecruisers, and the M-class light cruisers (you can see these turrets on FDG in-game).

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1 hour ago, Psycodiver said:

We need to look at design constraints to understand AoN armor scheme, Congress limited the weight of battleships so engineers had to come up with something that maximized armor protection, fire power, and speed. If Congress didn't limit weight I believe the USN would have still utilized the incremental armor layout. Carrying over after the Washington Naval Treaty battleships were limited in weight all over the world, AoN was mainly adopted at this point so other nations could maximize armor protection in return for staying under treaty limits, the Germans didn't care about treaty limits so they went with incremental armor instead and designed it in a way to maximize the likely close range fighting they were predicting

 

For DP mounts, uniformity is a key point not brought up yet. On German ships you have several different shell calibers and guns are taking up allot more space (also adding to tonnage),  but the USN was aware of the limits of the 5"/38 which is why the 5"/54 came into development also

 

I don't know if the idea that the Germans did not care about treaty limits was the reason why they went with the incremental armor scheme (although the AoN scheme certainly saves weight in comparison). The Scharnhorst class used the incremental scheme but it didn't break any treaty limits. Even the Bismarck class didn't technically break any treaty rules as the latest treaty in-place when Bismarck was laid down was the Anglo-German naval agreement of 1935 which simply stated that Germany's total fleet could amount to no more than 35% of the total tonnage of the existing British fleet. The Germans only declared the Bismarcks to be 35,000t for political reasons, but there was nothing "illegal" per-say about the Bismarcks actually being 40,000t battleships.

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@dseehafer

Another nice write up mate +1 again :-)

 

Just want to add one important point - as in every other organization there are human beings making decisions. And it is important to understand that the German Navy - be it Kaiserliche Marine, Reichsmarine or Kriegsmarine were highly conservative forces - which was a large factor in all kinds of important design decisions. You can see it everywhere from designing armor, turret layouts, compartmentalisation, etc. All the fancy innovative stuff such as Panzerschiffe, night vision and so on was only brought forward whenever external pressure was large enough. Same applies to the army as well btw - the organization was far from being innovation friendly either.

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One of the advantages of the All Or Nothing scheme was that for SAME weight allotment, you could have a much better-protected citadel zone. That is, you could increase the armor thickness over the critical areas without increasing the same weight allotment that incremental armor scheme would have called for.

However, there is one drawback to note. If you do not do the AoN scheme properly, you can fail to include sufficient reserve buoyancy within the protected area.to compensate for the unprotected ends being flooded which the USN, and I think RN too, considered in their executions. I am not sure if I recall it correctly, but the Italians were guilty of doing exactly this flawed execution.

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I can attest to some of the actual ship design aspects from the real world being in game because I have taken some bow Torpedo hits on my German ships and while taking some damage it's often minimal, but on some other ships that may seem similar I can take massive damage from bow on torp hit, and now that you mentioned in this thread about German bow armor it did make me realize this.

Edited by Admiral_Thrawn_1

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2 hours ago, Hurlbut said:

One of the advantages of the All Or Nothing scheme was that for SAME weight allotment, you could have a much better-protected citadel zone. That is, you could increase the armor thickness over the critical areas without increasing the same weight allotment that incremental armor scheme would have called for.

However, there is one drawback to note. If you do not do the AoN scheme properly, you can fail to include sufficient reserve buoyancy within the protected area.to compensate for the unprotected ends being flooded which the USN, and I think RN too, considered in their executions. I am not sure if I recall it correctly, but the Italians were guilty of doing exactly this flawed execution.

Hmm, I don't think this was the case for the RM BBs. The only time any of them took more than 1 torpedo was Littorio at Taranto, and that was more to due with pump issues.

The first two hits happened almost simultaneously, the first hitting the TDS abreast the main battery turrets, and most of the force was absorbed by the TDS, although area was weakened. The second torpedo hit the extreme stern, obviously very far from the TDS. However the damage was not considered threatening, and no counter flooding was even bothered with (ship only took a 2º list, later reduced to 1.5º). These hits combined caused only minor flooding.

The real damage-dealer was the third hit which came 45 minutes later, and hit just forward of the first hit, outside the TDS zone. That blew a huge hole in the bow (11x9m), and fairly rapid flooding. Due to the hurried execution of the ship's fitting out, however, a lot of the anti-flooding systems were disabled or rapidly overwhelmed. Electrical and ventilation passageways allowed the flooding to spread far from the damaged areas, not helped by the damage from the nearly first hit. However, the ship was flooding for over four hours before the flooding became a serious threat to the ship's buoyancy.

For context, in June of 1942 Littorio was torpedoed again in the exact same spot. The breach was much smaller (hull was not weakened by a prior hit in the same area like at Taranto), and although there was some flooding the ship shrugged the hit off and continued with the mission, eventually returning to port under her own power.

Given the evidence, I don't believe the reserve bouncy was insufficient in Italian ships.

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6 minutes ago, Admiral_Thrawn_1 said:

I can attest to some of the actual ship design aspects from the real world being in game because I have taken some bow Torpedo hits on my German ships and while taking some damage it's often minimal, but on some other ships that mU seem similar I can take massive damage from bow on torp hit, and now that you mentioned in this thread about German bow armor it did make me realize this.

It would probably depend on the ships you're in when you take hits. All torpedoes deal 10% less damage against your bow and stern, so this can better more or less than normal depending on the TDS of your ship. For example, in a battleship like Tirpitz or Roma, if you have to take a torpedo hit, you almost always want to eat it along your citadel, as that's where your TDS is. In a light cruiser or destroyer, since you have next to no TDS (if you have it all all), you might want to eat it in your bow or stern over the middle of your ship, as it will do less damage.

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1 minute ago, Phoenix_jz said:

It would probably depend on the ships you're in when you take hits. All torpedoes deal 10% less damage against your bow and stern, so this can better more or less than normal depending on the TDS of your ship. For example, in a battleship like Tirpitz or Roma, if you have to take a torpedo hit, you almost always want to eat it along your citadel, as that's where your TDS is. In a light cruiser or destroyer, since you have next to no TDS (if you have it all all), you might want to eat it in your bow or stern over the middle of your ship, as it will do less damage.

For battleships it can vary from ship to ship, Conqueror for instance only has a 30% TDS but can heal 60% of regular penetration damage, and has plenty of heal 'headroom' thanks to it's power. A torpedo hit to the TDS of say a 20,000 damage torpedo will do 14,000 damage which can be healed down to 12,600. The same torpedo to an extremity would do 18,000 damage but after a repair turn into 7,200 'permanent' damage. Far better not to take it on the TDS as long as you can a) survive the alpha and b) have repair party availability before getting sunk.

The German BB's are pretty similar - sub 30% TDS and can repair 50% of the damage from torpedo hits outside the TDS. Again so long as alpha and repair party aren't problems you're a bit better off. Tirpitz with only 22% TDS in particular is poor.

Yamato's well worth taking on the belt, 55% means a 9,000 damage hit with 8,100 damage after repair - plus it's not taking up repair use, and has much lower alpha threat. If you ate one in the bow it'd do 18,000 healable to 9,000 - more damage and repair use.

Montana's in the middle about 40% damage reduction then 10% heal just about equals 50% repair for non-citadel hits, probably worth taking on the belt and saving the heal for other damage.

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1 hour ago, mofton said:

For battleships it can vary from ship to ship, Conqueror for instance only has a 30% TDS but can heal 60% of regular penetration damage, and has plenty of heal 'headroom' thanks to it's power. A torpedo hit to the TDS of say a 20,000 damage torpedo will do 14,000 damage which can be healed down to 12,600. The same torpedo to an extremity would do 18,000 damage but after a repair turn into 7,200 'permanent' damage. Far better not to take it on the TDS as long as you can a) survive the alpha and b) have repair party availability before getting sunk.

The German BB's are pretty similar - sub 30% TDS and can repair 50% of the damage from torpedo hits outside the TDS. Again so long as alpha and repair party aren't problems you're a bit better off. Tirpitz with only 22% TDS in particular is poor.

Yamato's well worth taking on the belt, 55% means a 9,000 damage hit with 8,100 damage after repair - plus it's not taking up repair use, and has much lower alpha threat. If you ate one in the bow it'd do 18,000 healable to 9,000 - more damage and repair use.

Montana's in the middle about 40% damage reduction then 10% heal just about equals 50% repair for non-citadel hits, probably worth taking on the belt and saving the heal for other damage.

Interesting. I had never considered it from that angle before.

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On 2/16/2018 at 6:25 PM, dseehafer said:

 

It should be remembered that Germany's battleships were not designed for commerce raiding. In fact, they found themselves awkwardly forced into this role. A square peg in a round hole if you will.

 

I remember reading around that this was the case.  The Kriegsmarine wanted to build up to contest the Royal Navy, not settle for commerce raiding.  The war came too early for the KM.  With the rapid successes across Europe early on, I think that Raeder was pressured to get the Kriegsmarine to contribute something before the war was over and won (let's admit it, it looked absolutely great for Germany by the time France fell).  I'm thinking Raedar had to throw his ships to do something because when the war was won, people are going to look at the services and what they contributed.

"What did the navy do for the victory?"

That kind of pressure.  Inter-service rivalry is always a real thing in any country.  The KM didn't get a big piece of the pie before the war and if they showed doing nothing in a German victory, well, even less of a reason to do so afterwards.

 

I could even imagine Goering in such a situation:  "Why put resources in the navy when you could put your faith in the Luftwaffe?"

Edited by HazeGrayUnderway

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