Bismarck construction flaws

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VeenenbergR
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List of flaws in the design of the Bismarck

Post by VeenenbergR »

The initial question was to produce a list of flaws and rate its impact on the failed (but much needed) mission of the Bismarck:

1). The team (BM & PEW) was not given full protection of U-boats and Luftwaffe in time or during most of the trip. The reach of the Luftwaffe was limited but nothing was done in time. The team at hand in May 41 was small and therfore vulnerable. After the sinking of the Bismarck ther was no larger force anymore! No flaw of Bismarck itself but of Strategy.

2). The AA-defence was large but to stop a determined medium attack of airplanes definitely more was needed (6 and 15 inch guns which also can shoot AA-shells). Later partly corrected in Tirpitz. The different 4 inch AA groups? A medium flaw, since nothing then was at hand to improve it significantly at that time.

3). The missing pumps and valves between the oil tanks. Therefore Bismarck had to slow down and became finaly a prey of its persuers.
Later corrected in Tirpitz. A minor flaw.

4). British determination and intelligence. No flaw of Bismarck

5). Lütjens long radio calls to the KM betraying his position. No flaw of the Bismarck, but a matter of bad (doomed?) behaviour.

6). Flaws in the armour configuration. In the final fight the Bismarck was silenced within 42 minutes of iheavy and intense shelling with high odds in reducing critical devices (the main range finder and gunnery direction stations). Was that of of flaws in the armour: definitely not!!!
Weak main turret protection? No proof. The hit at 9.02 which dissabled 2 main turrets was extremely lucky and probably hit a roofplate and richorettet aganist the upper barbette of the other turret.
The double layered thin upper and thicker lower armoured deck? With 1 hit in the boilers out of 800 + 100 heavies fired? I would rate it only medium.

7). The weak rudder protection against torpedo's: a slight chance with no emergency devices present: one high risk flaw. Would rate this a big flaw.

8). The 4 inch and 6 inch "double" secondary armament: necessary against aircraft and the known enemy superior destroyer forces. No flaw for raiding lonely capital ships.

Since all battleships at that time had their flaws Bismarck was certainly no exception and not worse compared to the other contemporary desgins.
Compared to Iowa, South Dakota and Yamato, the Bismarck was the weaker party, but a duel of a fresk undamaged Bismarck 1:1 against a South Dakota or Iowa was certainly NO one sided beating. If Bismarck could strike first (depending on weather) and why not, the South Dakata or Iowa (weak protected bridges, like PoW) could be in serious trouble.
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Re: List of flaws in the design of the Bismarck

Post by Bgile »

VeenenbergR wrote:The initial question was to produce a list of flaws and rate its impact on the failed (but much needed) mission of the Bismarck:

1). The team (BM & PEW) was not given full protection of U-boats and Luftwaffe in time or during most of the trip. The reach of the Luftwaffe was limited but nothing was done in time. The team at hand in May 41 was small and therfore vulnerable. After the sinking of the Bismarck ther was no larger force anymore! No flaw of Bismarck itself but of Strategy.
I think more could have been done in stationing U-boats in the Denmarck Strait with the idea of attacking British ships sent to scout there.
VeenenbergR wrote: 2). The AA-defence was large but to stop a determined medium attack of airplanes definitely more was needed (6 and 15 inch guns which also can shoot AA-shells). Later partly corrected in Tirpitz. The different 4 inch AA groups? A medium flaw, since nothing then was at hand to improve it significantly at that time.
Bismarck's AA defense was terrible. The defects have been discussed elsewhere, but the principle problems as I see them were:

Poor AAFC system. This was in common with other navies at this point in the war.

Complete lack of automatic medium AAA (3.7cm in this case). It is my understanding that Bismarck's 3.7cm weapons had to be had loaded one round at a time.

Not nearly enough AA practice, and a number of known flaws which hadn't been corrected.

Large numbers of 2cm weapons would have helped. The few that were present had poor firing arcs.

The 10.5cm AAA was too slow in train and elevation to adequately track aircraft attacking a ship which was maneuvering radically to avoid torpedoes.

With respect to using AA shells with 15cm guns, the above paragraph is true in spades, and I doubt there was FC provision for their use in any case.

With respect to using AA shells with 38 cm guns, see above. It was attempted by the Japanese with little result. For one thing, the firing of the heavy guns requires that all nearby AA be abandoned, and the resulting smoke cloud makes it impossible to see the attacking aircraft for several seconds.
VeenenbergR wrote: 3). The missing pumps and valves between the oil tanks. Therefore Bismarck had to slow down and became finaly a prey of its persuers.
Later corrected in Tirpitz. A minor flaw.
I consider this a major flaw. US Battleships had remote valve controls for valves located outside the citadel. Bismarck should have had them.

I consider (4) and (5) to be true.
VeenenbergR wrote: 6). Flaws in the armour configuration. In the final fight the Bismarck was silenced within 42 minutes of iheavy and intense shelling with high odds in reducing critical devices (the main range finder and gunnery direction stations). Was that of of flaws in the armour: definitely not!!!
Weak main turret protection? No proof. The hit at 9.02 which dissabled 2 main turrets was extremely lucky and probably hit a roofplate and richorettet aganist the upper barbette of the other turret.
The double layered thin upper and thicker lower armoured deck? With 1 hit in the boilers out of 800 + 100 heavies fired? I would rate it only medium.
I believe Rodney's shells were capable of penetrating Bismarck's forward armored bulkhead at that range, as well as barbettes and turret faces at least partially. I don't believe that hit was lucky, and similar hits were inevitable. It may have been lucky to get the hit that soon, except that if you are shooting at Bismarck's bow aspect, you are fairly likely to hit something important.
VeenenbergR wrote: 7). The weak rudder protection against torpedo's: a slight chance with no emergency devices present: one high risk flaw. Would rate this a big flaw.
All ships are vulnerable to this type of hit, although I think the German 3-screw powerplant made the problem bigger than in some other navies.
VeenenbergR wrote: 8). The 4 inch and 6 inch "double" secondary armament: necessary against aircraft and the known enemy superior destroyer forces. No flaw for raiding lonely capital ships.
I am a proponent of DP secondaries, which I think much superior to the layout on Bismarck. Better vs destroyers, and better vs aircraft. IMO all one really has to do is look at a photo of poor Shonan Maru No 15 trying to sail through the forest of 5" shell splashes from USS New Jersey to be convinced of the efficacy of DP secondaries as defense against destroyers.
VeenenbergR wrote: Since all battleships at that time had their flaws Bismarck was certainly no exception and not worse compared to the other contemporary desgins.
Compared to Iowa, South Dakota and Yamato, the Bismarck was the weaker party, but a duel of a fresk undamaged Bismarck 1:1 against a South Dakota or Iowa was certainly NO one sided beating. If Bismarck could strike first (depending on weather) and why not, the South Dakata or Iowa (weak protected bridges, like PoW) could be in serious trouble.
I agree with the above, except that the US battleships had heavy armored conning towers, similar to Bismarck.
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Re: List of flaws in the design of the Bismarck

Post by dunmunro »

VeenenbergR wrote:

Since all battleships at that time had their flaws Bismarck was certainly no exception and not worse compared to the other contemporary desgins.
Compared to Iowa, South Dakota and Yamato, the Bismarck was the weaker party, but a duel of a fresk undamaged Bismarck 1:1 against a South Dakota or Iowa was certainly NO one sided beating. If Bismarck could strike first (depending on weather) and why not, the South Dakata or Iowa (weak protected bridges, like PoW) could be in serious trouble.
KGV had an 4" thick armoured conning tower, but Captain Leach was not in it, nor was Admiral Holland in Hood's conning tower. At the 2nd Battle of Guadalcanal, Admiral Lee and Captain Davis fought USS Washington, from a open bridge position, just like Admiral Holland and Captain Leach.

Bismarck's conning tower could be penetrated by RN 14, 15, and 16" guns at typical battle ranges, and thus was of little value.
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Recapitulation of flaws of the Bismarck design:

Post by VeenenbergR »

1): Large but ineffective AA-arsenal (despite those futuristic domed Gyro stabilized high angle rangefinder stations). the 3,7 guns had a too low ROF and there were to few 2 cm guns. The Bismarck lacked a well trained AA-crew (with the weaponry at hand this became a fatal omission!!!)

2): No secondary DP arrangement. Question: were 12 relatively well protected 6 inch guns AND 16 unprotected heavy AA guns (together 28 guns) with a high ROF worse than the so highly prized US 20x5 inch guns? Against aircraft the US 20 guns were defeinitely better but against a couple of attacking destroyers??? This combined with 1) was an extra fatality!!!

3): The lack of pumps and valves for fuel protection. Later corrected in Tirpitz. This meant that damage contaminated fuel tanks too much and Bismarck was forced to slow down on speed during the vital escape attempt.

So ONLY ONE REAL MAYOR FLAW of the Bismarck design doomed the Bismarck:

- the large but rather ineffective AA-defenses!!!!!!!!!

Since in those days the AA-defenses of other capital ships were no better the operation with the Bismarck and Prinz Eugen became a costly affair since the Germans made a couple of serious mistakes:

A). They didn't train the AA-defences to a level that they were able to ward off attacks of couples of (slow flying) aircraft (f.e. against likely opponents: the Swordfish!!!).

B). Lütjens did not refuel at Norway and made a very serious error in radioing his long messages to the KM which betrayed his position.

If A) was sound probably Bismarck could have made his escape to Brest despite B).

Do you ALL agree on this recapitulation????
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Re: Recapitulation of flaws of the Bismarck design:

Post by Bgile »

VeenenbergR wrote:1): Large but ineffective AA-arsenal (despite those futuristic domed Gyro stabilized high angle rangefinder stations). the 3,7 guns had a too low ROF and there were to few 2 cm guns. The Bismarck lacked a well trained AA-crew (with the weaponry at hand this became a fatal omission!!!)

2): No secondary DP arrangement. Question: were 12 relatively well protected 6 inch guns AND 16 unprotected heavy AA guns (together 28 guns) with a high ROF worse than the so highly prized US 20x5 inch guns? Against aircraft the US 20 guns were defeinitely better but against a couple of attacking destroyers??? This combined with 1) was an extra fatality!!!

3): The lack of pumps and valves for fuel protection. Later corrected in Tirpitz. This meant that damage contaminated fuel tanks too much and Bismarck was forced to slow down on speed during the vital escape attempt.

So ONLY ONE REAL MAYOR FLAW of the Bismarck design doomed the Bismarck:

- the large but rather ineffective AA-defenses!!!!!!!!!

Since in those days the AA-defenses of other capital ships were no better the operation with the Bismarck and Prinz Eugen became a costly affair since the Germans made a couple of serious mistakes:

A). They didn't train the AA-defences to a level that they were able to ward off attacks of couples of (slow flying) aircraft (f.e. against likely opponents: the Swordfish!!!).

B). Lütjens did not refuel at Norway and made a very serious error in radioing his long messages to the KM which betrayed his position.

If A) was sound probably Bismarck could have made his escape to Brest despite B).

Do you ALL agree on this recapitulation????
I think consensus is very hard to get here. I agree with B for sure. I'm not sure of A because I'm not sure Bismarck's AAA was physically capable enough even if well trained. British losses would probably have been higher, but brave and determined pilots might still have succeeded.
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Re: List of flaws in the design of the Bismarck

Post by Bgile »

dunmunro wrote:
KGV had an 4" thick armoured conning tower, but Captain Leach was not in it, nor was Admiral Holland in Hood's conning tower. At the 2nd Battle of Guadalcanal, Admiral Lee and Captain Davis fought USS Washington, from a open bridge position, just like Admiral Holland and Captain Leach.

Bismarck's conning tower could be penetrated by RN 14, 15, and 16" guns at typical battle ranges, and thus was of little value.
USS Washington wasn't the target of effective gunfire. South Dakota was, and their after action report stated that they appreciated having the armored control positions.

Where Bismarck is concerned, I agree that her conning tower should not have been proof against even 14" shells at close battle range. However, close examination of the wreck shows hits from major calibre shells but NO penetrations. A witness states that the interior was wrecked and that he could see light coming through holes. That part is inconsistent, but I don't think there is much doubt the interior was wrecked by the end of the "battle". The witness stated that while he was there a cruiser shell came through the open door. The door was probably propped open so it wouldn't get jammed from the outside, trapping the occupants.

There is no doubt that heavy conning tower armor can protect against cruiser size AP shells at any range, which the KGV 4" armor cannot. It can protect against heavy shells at long range. I think it is worthwhile to have ship control functions (helm, EOT, etc) under heavy armor, but that is just my opinion.

Late war, it was impossible to put all the added radar dislays and AA plots under heavy armor. There just wasn't room, and they gradually came to occupy spaces outside the citadel.

A good example of this is North Carolina. She started with her radar displays only in her CIC next to main battery plot deep inside her citadel. By the end of the war, she had a large space behind the pilot house in the superstructure which had multiple plots and radar displays to facilitate AA defense, which was by then of primary importance. The only armor was an inch or two designed to protect against fragmentation and strafing.
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Re: List of flaws in the design of the Bismarck

Post by dunmunro »

Bgile wrote:

Where Bismarck is concerned, I agree that her conning tower should not have been proof against even 14" shells at close battle range. However, close examination of the wreck shows hits from major calibre shells but NO penetrations. A witness states that the interior was wrecked and that he could see light coming through holes. That part is inconsistent, but I don't think there is much doubt the interior was wrecked by the end of the "battle". The witness stated that while he was there a cruiser shell came through the open door. The door was probably propped open so it wouldn't get jammed from the outside, trapping the occupants.
This article suggests that it was penetrated:

http://www.navweaps.com/index_inro/INRO_Bismarck_p3.htm

but the circular nature of the CT would have made high obliquity impacts more likely.

In any event, the value of an armoured CT is debatable.
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Post by Bgile »

Mr. Statz's interview is the one I was referring to. IMO it would make the basis for a good movie.

How do you explain Bill Juren's statement that there were no holes in the conning tower?
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Post by dunmunro »

Bgile wrote:Mr. Statz's interview is the one I was referring to. IMO it would make the basis for a good movie.

How do you explain Bill Juren's statement that there were no holes in the conning tower?
Well, we know her 14" armour was penetrated elsewhere, so if the CT was not penetrated, then that was just a matter of sheer luck, but the article by G&D states:

"Most of the British shells struck the forward superstructure of Bismarck with the hits late in the action simply rearranging the debris created by earlier shell hits. A few shells struck and penetrated the 350mm conning tower, the upper splinter belt and the lower side belt."


Testing of the RN 14/45 showed that it was able to penetrate RN 14" armour at 30deg obliquity at about 1850 fps, and could regularly penetrate 12" at 30deg at ~1500fps, so if the CT survived unholed, it was just lucky.
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Post by Bgile »

I agree with your logic ... I just can't explain physical observation of the site. You'd have thought there would be nice round holes instead of divits.

You'd have thought a 14" AP from Kirishima would penetrate S.Dakota's 12" barbette, too. And yes, it almost had to be AP because of the damage to the barbette, the lack of bombardment frag damage, and the documentation that they switched ammunition.

I wonder how high the velocity has to be for those shells to shatter. Is there such a thing as too high an impact velocity?
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Most shells struck the forward superstructure?????

Post by VeenenbergR »

"Most of the British shells struck the forward superstructure of Bismarck with the hits late in the action simply rearranging the debris created by earlier shell hits. A few shells struck and penetrated the 350mm conning tower, the upper splinter belt and the lower side belt."
We discussed already the 2 shells of the Rodney and 2 of the KGV which hit the side belts and of which only 2 fully penetarted (those of the Rodney). These were hits at short range late in the battle and caused many casualties under the crew which took shelter under the main (weather) deck. This implies that the Bismarck was not hit at the belt in the first 44 minutes at all (or it had to be under the mud-line).

From the drawings of Ballard I can detect NO damage at the large forecastle, except for a small hole in the vertical structure and a very small hole on the (large) horizontal roof!!! This is very strange since this built up area is the first place to hit the ship from longer and closer ranges.

Some (2-3) heavy shells landed oblique near the CT (must be at longer range, early in the battle) and some did hit the CT ate in the battle, at short range, without penetrations. The door however has been smashed away (and perhaps her was a heavy hit, killing the personal inside).
The rangefinder on top of the CT was hit we know, perhaps by an 8 inch shell.

There are signs of heavy hits and lighter calibres behind the forward 6 inch turret in the superstructure (port side) and the after turret roof here was also blown away (8 inch or heavier).

The main fighting mast was undoubtly hit too, but the admirals bridge was, according witnesses, not at all hit.

The main rangefinder and gunnery direction station in the top were hit.

The raised deck behind Bruno was hit too by one heavy shell.

These are ALL the hits on the forward superstructure.

The pictures of Ballard shows us clearly the damage around the CT.
But other damage is difficult to detect.

If this was a major part of the damage on the Bismarck, apart from the 3 known hits on the barbette, 2-3 known hits on the turrets and unknown hits on the after structure (funnel, aircraft hanger, after rangefinder, the AA-guns aso) these are ALL the hits on the Bismarck.

If this is true what is then true of the 70 heavy hits and 250 or more smaller hits???
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Post by dunmunro »

Bgile wrote:I agree with your logic ... I just can't explain physical observation of the site. You'd have thought there would be nice round holes instead of divits.

You'd have thought a 14" AP from Kirishima would penetrate S.Dakota's 12" barbette, too. And yes, it almost had to be AP because of the damage to the barbette, the lack of bombardment frag damage, and the documentation that they switched ammunition.

I wonder how high the velocity has to be for those shells to shatter. Is there such a thing as too high an impact velocity?
Even a non penetrating hit might cause spalling inside the CT.

IIRC, the IJN 14" hit struck the deck just before striking the barbette, and this probably caused the shell to be decapped.

The RN testing showed no indication of a tendency to shatter, even at very high striking velocities. The RN had two suppliers of 14" APC shell, Hadfield and Firth, with the Hadfield being distinctly superior. Of 11 Hadfield rounds fired at 12"/30deg plate at SVs above 2100fps, only one failed. Of 6 14" Firth APC shells, at SVs over 2100fps, one failed but two other were broken after penetration. The Firth shells generally had a ~50% failure rate at any SV, but for that reason, I suspect that they would not have been accepted into service use.

KGV was much farther away from Bismarck for most of the battle, and Bismarck's slow speed meant that the inclination between her and both RN BBs was constantly changing, probably leading to to high number of high obliquity hits.
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Re: Most shells struck the forward superstructure?????

Post by Tiornu »

We discussed already the 2 shells of the Rodney and 2 of the KGV which hit the side belts and of which only 2 fully penetarted (those of the Rodney).
No failed 14in hits were identified on the main belt by Bill Jurens, only three or four penetrations.
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RADAR

Post by Ramius »

Another flaw that I may add, is the lack of adequate RADAR. This was not necesarily a design flaw more than a cosmetic and strategic one. This was not necesarily their fault, but im sure that better sets would have been created later in the war
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Re: List of flaws in the design of the Bismarck

Post by RF »

Bgile wrote:
I think more could have been done in stationing U-boats in the Denmarck Strait with the idea of attacking British ships sent to scout there.
I believe that Hitler once raised this point in his conferences with Raeder.

From the German standpoint the U-boats were needed for the tonnage war and Donitz was not keen to divert subs from this, particulary as Hitler had already directed U-boats into the Med to support the Italians and Afrika Korps.

The cruisers on the Northern Patrol were expendable so far as the British were concerned, largely light cruisers. They were fast, manouverable and equipped with depth charges, not really the best targets for U-boats diverted from the shipping lanes.

Possibly this is one of the reasons for Hitler's proposed airborne seizure of Iceland, to use airpower against these ships. Apart from the problems with poor weather and logistics it was never a realistic proposition - in any case the Luftwaffe airstrength was already needed for Russia and the Med.
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