Talk:Bismarck class battleship

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Contents 1 Beam 2 Main Guns 3 Armor 4 Old discussions 5 Conclusion 6 Based on WWI Design 7 Removal of shell trap feature 8 New Info, Changes 9 New Source 10 The stern 11 Torpedo Bulges

[edit] Beam

So, on the one hand she had a very broad beam, and on the other, her beam was too small. I suggest someone who cares admits that you can't have it both ways and edits the article one way or the other. As it is it looks like a fanboy article. Greg Locock (talk) 02:03, 3 January 2008 (UTC)

[edit] Main Guns

Ok, there's much to work on in this article. The main guns are certainly less powerful than they could have been (the german 16" gun was still in development, yet it was planned to refit the Bismarck class with them eventually), yet judging just by bore is nonsense. In fact, the german 15" gun had higher vertical armor penetration capability than at least the british and possibly the american 16" guns due to higher muzzle velocity. Horizontal it was indeed less because of the lighter shells. However, while british and american main guns were able to deliver about 1.5 shots a minute, the german 15" gun delivered 2.5 (if I remember that right). As you didn't fight a naval battle with just one salvo back then, the weights of the broadsides should be compared related to time as well.

I will gather references as I have time before changing the article, but I thought I'd give others the opportunity to comment. LoneWolfJack 15:49, 31 July 2007 (UTC)

[edit] Armor

The Article totally leaves out decapping. In fact, the armor scheme of the Bismarck class is highly complex and due to lack of documents and as there are only a few naval experts working on them in their free time, progress in reconstructing the ideas behind the armor scheme is slow. What we know is that it was almost impossible to get a shell into her vital areas at short range due to the sloped armor belts behind the main armor. At close range, even 14" guns easily penetrate 80cm of armor, so it doesn't matter if you have a 33cm armor belt like Bismarck or a 35cm like King George V. However, if you have another sloped armor belt behind the main belt, the battered shell that defeated the main armor belt can be stopped with much less effort (thinner armor).

Vertical armor protection is even more complex than the horizontal armor scheme and investigation is still going on. What we know is that Bismarck's horizontal armor had emphasis on protecting the vitals of the ship, which by german way of thinking were the engine rooms the command center and the magazines. While the british an americans built ships to be sent out, fight a battle and eventually return to port for repairs, the germans built ships with the idea of toughness. They wanted ships that could take a lot of damage and still be able to fight as the german navy couldn't just call a ship back home due to lack of strategically placed ports.

In terms of vertical armor this means that the germans again used sloped armor, which makes perfectly sense as no shell comes in at a 90° angle. Also, the vitals of the Bismarck class were positioned in a very clever way. In order to score a vertical magazine hit, the enemy would have to penetrate the top of one of the main turrets and the barbettes, and we're talking about 45cm of stell here if I remember that right. For the engines, a shell coming in at say a 50 or 60 degree angle would not only have to defeat two to three armor belts but also part of the ships structure like hangar or funnel.

It should also be noted that while british and german armor were about equal in quality (the british having a little edge), the american "class a" armor platest used for the Iowa class lagged behind about 30% in strength.

I will gather references as I have time before changing the article, but I thought I'd give others the opportunity to comment. LoneWolfJack 15:49, 31 July 2007 (UTC)

[edit] Old discussions

I made some heavy modifications and tried to get this as wikified as possible. I'm sure it still needs a little work done though. There was a bit of point of view material that I attempted to neutralize, but there may be some of that floating around as well.

The original version of the article also had this note about halfway through the article:

*Note* To simplify the text, the Bismarck Class of battleship (two vessels) will simply be called "Bismarck" henceforth.

To avoid confusion between the class of ship and the actual battleship, I deleted this and reworded the entire article where it said "Bismarck" to say "Bismarck class".--ScottyBoy900Q∞ 17:12, 26 July 2004 (UTC)

---

There were some obvious mistakes in the text:

– Prince of Wales had no 8 inch guns and did not participate in the final engagement

- Calibers of secondary and AA-Battery were wrong

Nevfennas 19:06, 24 November 2005 (UTC)

• • I'm not doubting this information, but could you please provide some evidence of this. I've got no clue one way or the other, would just like to verify. --ScottyBoy900Q 15:29, 26 November 2005 (UTC)

On the Prince of Wales: Take http://college.hmco.com/history/readerscomp/ships/html/sh_072200_hmsprinceofw.htm as one example. But nearly every page dealing with the King Geoge V class of 1939 will confirm it's armament as ten 14 inch heavy artillery, sixteen 5,25 inch dual purpose secondarys plus additional flak.

Same on Bismarck http://college.hmco.com/history/readerscomp/ships/html/sh_012000_bismarck.htm . On all German capital warships the 6 inch gun was used as secondary and the heaviest AA-Gun was the 4 inch (105mm) twin-mount Nevfennas 16:35, 26 November 2005 (UTC)

• • Looks good. Thanks. Was just curious.--ScottyBoy900Q 03:58, 28 November 2005 (UTC)

---

Was the Tirpitz really involved in 'Operation_Rösselsprung'? That sounds like a infantry/paratroop assault... inland. Deep.... inland. At least from the Baltic. If the Tirpitz had ever made it out of the waters north of Germany, we'd have heard a lot more about it.

Yes, Tirpitz was involved. That 'Operation_Rösselsprung' was the aborted attempt to attack the convoy PQ17, not to be confused with the linked 'Operation_Rösselsprung'. Nevfennas 05:56, 24 April 2006 (UTC)

Two things may probably be added: link to Bismark, the person and link to what HMS is. Stan 22:02, 29 July 2006 (UTC)

---

One thing struck me when reading the article for assessment... What was the "curious oversight in the design of the Bismarck's AA gun directors"? -- Medains 08:04, 5 September 2006 (UTC)

Here is an article comparing the quality of German ship-design during WWI and WWII. The AA gun directors are mentioned as being an overly complex and overloaded design, which probably was the origin of the problem. No idea however about the specific overlooked detail. --Nevfennas 20:24, 5 September 2006 (UTC)

It perhaps refers to the old story (I beleive something close to an urban legend) that the Swordfish were too slow to be targeted, that the Bismark's AA directors didn't have a setting low enough for them. I'm pretty sure the story is false, but it is a common one.

I agree. Since torpedoes are launched more or less at the target the closing speed of the a/c is relatively unimportant in the firing solution. If you want a detailed discussion of the faults with the AA system try www.kbismarck.com/AVKS-700.zip Recent discussion on warships1 suggests it is is as simple that the attack occurred around nightfall. The Swordfishes had radar, so they were OK, whereas the AA gun crews would have been blinded by their own flashes and would not have been able to see the a/c. Sounds pretty likely to me. Greglocock 01:25, 20 February 2007 (UTC)

I serioulsy doubt that Swordfishs were equipped with radar in early 1941. Nevfennas 07:03, 20 February 2007 (UTC)

Well then, you need to read some serious books. Or visit www.warships1.com and read the discussion on Bis and swordfishes. Greglocock 21:27, 20 February 2007 (UTC)

Well, I stumbled over this [page]. Mark III had Radar, but was only used from 1943 on. And as all swordfishs that attacked Bismarck carried torpedos, this would rule out radar. Nevfennas 07:34, 21 February 2007 (UTC)

All but one of 825 Squadron's aircraft nine aircraft (Victorious) were "new" ASV equipped Swordfish. Interestingly, the one aircraft that did not find and attack Bismarck was the one non-ASV equipped plane.

Ark Royal was still using much older Swordfish, and had only received a few ASV equipped aircraft for use by the Squadron COs and some of the section leaders. Of the 30 aircraft embarked only about six of those operational had ASV. Since they needed ASV-equipped planes for shadoweres, their were only about three ASV-equipped planes available for s the strike force. But those planes were critically important elements in locating the target of the attack. It was the direct cause of the attack on HMS Sheffield. quote from warships1 Greglocock 11:07, 21 February 2007 (UTC)

I don't know how much the posters in that forum know, but the sources avaiable to me (including the wiki-article) say that

1. the ASV-variant (the Mark III) of the Swordfish of was not avaiable until 1943
2. both the weight and placement of the radar prohibited the use of torpedoes. The Mark III could still carry lighter bombs or depth-charges, which made it an excellent sub-hunter.

If all Swordfishs on Victorious had radar that would have negated it's striking capability against surface-ships. Again I consider that highly doubtful. But if you want you can raise that point at Fairey Swordfish, there the topic would fit better (we are getting highly off-topic here) and the guys managing that article will certainly know more about it than I do. Greetings, Nevfennas 18:42, 21 February 2007 (UTC)

Done. One of the references for the Swordfish page is in agreement with my statement above - not too surprising, it was written by the same bloke!Greglocock 00:07, 23 February 2007 (UTC)

[edit] Conclusion

The whole paragraph was misleading and unreferenced. Understanding that anything can happen in war, even at close range I'd have to give the edge to the South Dakota class battleship (1939) because American fire control radar allowed the ship to maneuver AND fire without losing it's target. Optical targeting is hard to maintain when the ship is turning, which means Bismarck would have presented a nice straight moving target as the South Dakota took evasive action AND fired accuratly(whether or not they chose to use a smoke screen).

I'd give them slightly better chances against a North Carolina class battleship simply because Bismarck's guns fire shells heavier than their armor was designed to be effective against. However like the South Dakotas it too could present a an evading target. (The South Dakota like the Iowa class was designed to offer protection from other battleships firing 16" shells so even a lucky hit on the evading South Dakota would probably not have been a show stopper.) Anynobody 09:30, 5 June 2007 (UTC)

[edit] Based on WWI Design

This is an "old chestnut", most notably the assertion that they were based on the Baden and/or Bayern WWI BBs. What is the evidence for this, even accepting that the design was conservative from a fuel source POV? bigpad 14:04, 21 June 2007 (UTC)

What do you mean by "conservative from a fuel source POV"? I believe the statement refers in large part to their armor scheme, which essentially looks like that of ships designed before Jutland. TomTheHand 14:19, 21 June 2007 (UTC)

i believe i can source a source for the link to the Baden, even just in terms of layout. GraemeLeggett 16:18, 21 June 2007 (UTC)

Specifically (1) use of multiple thin armour decks (2) thick upper belt (3) placement of vital combat stations between armour decks (4) shell trap (I think). Bis Armour layout was virtually identical to that of pre Jutland WW1 BBs, if you look in Breyer. The outcome was that Bis had a very narrow, or non existent, IZ against many earlier or contemporary BBs . Now, some of that (1,2 and 3) may have been a result of her intended role as a commerce raider, rather than a line of battle design. If so, that was muddled thinking. It is not an old chestnut at all, it is a sensible observation, somewhat exagerated... but it contains a very strong element of truth. Greglocock 01:22, 22 June 2007 (UTC)

Hi, You often make reference to Breyer. Do you mean his "Battleships and Battlecruisers" tome, which is a first-class *technical reference book but not specifically about Bismarck and needs to be read with other comparative and less technical sources to give a more balanced overall picture. I seem to recall (from many years ago), though, that elements of Bismarck's layout did indeed draw on earlier designs, although I think it would be simplistic for anyone to suggest that she was merely an enlarged Baden (not that this has been said, exactly). bigpad 16:11, 22 June 2007 (UTC)

Yes that's the book. It's not often that less technical references are preferred. If you look at Moltke 1911 Bayern 1912 Ersatz Yorck 1916 Scharnhorst and Bismarck 1935, and the subsequent H class proposals, their armour schemes in cross section are very similar, dominated by the presence of the shell trap , which was introduced in 1880 by White, thick upper belt, and multiple thin armour decks. In comparison the Americans only used a shell trap in 1917 for Pennsylvania, and, interestingly, Mississipi in 1935. The Japanese were very fond of them but dropped them for Yamato, and went for the simple armoured box style. The British dropped them entirely after 1918. Now, I may be reading too much into the shell trap feature, but the Admiralty was exceedingly scathing about them. So EVERYBODY else dropped them and went to armoured box, do you not think that was for a good reason? Greglocock 02:56, 23 June 2007 (UTC)

I have to confess to a lack of knowledge of shells traps and must bow to your mechanical engineering background here. What I do know is that a relatively large percentage of Bis. displacement went on armour, with maybe only the Yamato class having an even higher %age? Bis. main belt proved more than capable of absorbing heavy enemy fire, although you and others have questioned the ship's ability to absorb plunging fire. That contingency didn't happen until the ship's final battle (if at all?) and it's ironic that a hit to an unarmoured feature of the ship, the rudder, rather than a shell penetrating its hull, sealed its fate. I accept that the forward hit from POW probably made the operation unsustainable but didn't, in itself, cause the ship to be sunk. My point in "less technical refs" is that it's always impt to consider the circumstances in which a ship might be used operationally before coming to conclusions on its overall rating. bigpad 15:02, 28 June 2007 (UTC).

Bis' armor scheme only made sense if ranges were shorter than Jutland, or if all long range encounters were against small calibre weapons. The first makes no sense, post Jutland, and both imply that Bis would always have the speed and manouevring room to force an action at her preferred range agaisnt BBs. Manifestly this did not happen. I think I have demonstrated pretty conclusively that the armour layout is essentially similar to that of a pre WW1 design, upscaled, whereas with the curious exception of a couple of USN boats, everybody else abandoned that layout as WW2 approached, and went to the single box design. In general main belt penetrations are exceedingly rare, there is a very strong argument that main belts were consistently too thick from 1880 right through to 1945. I think I discuss this above.

So having got the armour disposition out of the way I suggest we examine armament, fire control, and propulsion with the same vigour. To get the ball rolling, most WW1 BBs had twin turrets, whereas most Treaty BBs were designed with triple/quad turrets, as a weight saving. Bis stuck with twins. In gunnery control, radar was gaining ground rapidly for rangefinding, and to a lesser extent spotting. I don't know what the british and germans were using as fire control computers, I know what the americans and japanese were up to. Finally the other holdover from WW1 was the use of 3 shafts, which has always been associated in the RN with a weak stern. Greglocock 23:35, 28 June 2007 (UTC)

I would caution against reading too much into general traits. The Kriegsmarine was tailoring its warships to specific operational requirements, and their perceptions of priorities. If the Bismarck had used triple turrets in an A-B-Y configuration, it would have meant risking a greater percentage of the battery in the event of a lucky hit. A & B were disabled simultaneously, after all, so this was clearly a valid concern. Along with this, the Kriegsmarine was determined to preserve maximum fire for chasing fire. Likewise, the secondary battery was designed specifically to counter large (both in size and quantity) British destroyers. The three shaft setup was not ideal, to be sure, but it was a superbly sub-divided system. I would assume that it was dictated by (1) the intended turboelectric drive system, (2) the need to maintain hull-fineness ratios for desired speed coupled to the limiting factor of the Kiel Canal, and (3) a need to maintain minimums for the underwater protection system. As Garzke and Dulin said in Axis and Neutral Battleships in World War II, "The propulsion plant of the Bismarck-class battleships was the most advanced geared-steam turbine drive used in a European capital ship to that date." Whatever its faults, the armour system did protect the ship from sinking; it took multiple torpedoes and scuttling charges to sink her. Its fire-control systems seemed fairly good; it was straddling Hood in just three salvoes, sank her in three minutes, and then inflicted sufficient damage to the Prince of Wales that she was forced to disengage. Granted, the AA fire control was far less effective, and her radars were primarily search sets, not fire-control units.

The last paragraph of the history section particularly bothers me, since it seems to imply that the Bismarck was somehow a backwards and outmoded design. It preserved certain features not used by some other navies, but this does not necessarily make it out-dated. All Axis battleships (and the Sovietskiy Soyuz-class), for example, used split-secondary batteries. It was a questionable design feature, but not evidence that the Germans were somehow uniquely backwards. Breyer and Garzke/Dulin seem to concur that the Bismarcks were a good match for their contemporaries, particularly in the European theatre.

Finally, in regard to the repeat-Bayern charge, I quote Garzke and Dulin: "This...resulted in some speculation that the Bismarck-class battleships were mere copies of these older ships. This is false; the new ships had to be faster and have more protection, range, and gunpower. The percentages allocated to armor protection, propulsion, and armament were not the same. The triple-shaft arrangement and the distribution of the main armament and its caliber were the same, but these were the only similarities." Sacxpert 08:31, 19 August 2007 (UTC)

/All/ designs are compromises. Post Jutland BBs designed by other nations bore little resemblance to their pre-Jutland designs, particularly in fire control, armor layout and armament. Bis shares many characteristics with pre WW1 designs, as identified above, even if the %age weight allocation was different. I don't think anyone used the phrase 'mere copy', obviously Bis was a reasonable design, but was not a very modern design, and did not make the best available use of displacement, even given the beam limitation. The reason I emphasise this is the ridiculous claims that are made about Bis, which are not borne out by detailed study. Your point about the 3 shaft layout is good, but, that was a decision that they made, again, another compromise, and as it turned out, rather an important one. Greglocock 23:37, 19 August 2007 (UTC)

[edit] Removal of shell trap feature

Please reinstate the shell trap, it is mentioned in the admiralty report from 1942, and is clearly visible in Breyer. Greglocock 06:00, 20 August 2007 (UTC)

Don't bother I've done it. Greglocock 06:58, 20 August 2007 (UTC)

Okay, now that the sourcing is clearer, then it perhaps should be included. However, I would point out this from Garzke and Dulin, which seems to imply that this was a good design feature: "The armor slopes considerably reinforced the...belt. Such an arrangement was intended to increase the protection against high-angle hits on the side armor belt, where a shell would be exploded, ricocheted, or rendered inert. It also provided increased protection against bombs for the wing fuel-oil tanks and side-protection system. As a result, the Bismarck-class ships were exceptionally well protected against close-range shell fire."

I also wondered about the immune zone discussion from the Admiralty report; what is the yardstick they were using? If they were saying that the Bismarcks were more vulnerable to shellfire from British guns than British ships at similar ranges, this might be true. However, it is also clear the British 35.6, 38.1, and 40.6 cm guns were all markedly inferior in range and velocity compared to the German 38 cm, and the German gun out-penetrated the 35.6/38.1 guns, while roughly matching the penetration power of the British 40.6 cm. In other words, the British ships would have a reduced zone of immunity against the German 38 cm than they would against their own weapons. This should be examined more thoroughly, if the assertion is to be considered valid. Sacxpert 23:03, 20 August 2007 (UTC)

Then this is one instance where G&D are wrong. They have correctly identified White's reason for introducing it. They ignore practical experience (from Jutland) with its side effects.

The adm report is a war time report, so it compares the IZ of each RN vessel against Tirpitz, using a reasonably accurate (stolen) armour layout. It was not concerned with the classic IZ analysis of a ship fighting its mirror image, it was offering tactical advice to captains. Greglocock 04:25, 21 August 2007 (UTC)

I'd be interested in reading more about shell traps, as I don't recall reading anything about them in the context of Jutland; could you give me some sources/instances?

DK Brown's book 'From Warrior to Dreadnought' includes a lot of the reasoning behind why they went in, and his 'The Grand Fleet' explains why they were never used again. Greglocock 05:34, 21 August 2007 (UTC)

Also, did the Admiralty realize the full striking power of the German 38 cm? Did they have accurate data on that gun's performance in '42? That makes a difference. Doubly interesting b/c of this note from Garzke & Dulin, Allied Battleships in World War II: against the 16"/45 of the USN, the KGV class could protect the machinery spaces from 25,000 to 28,000 yards, and the magazines were protected from 23k to 31k yards. Quite interesting, since the Bismarck was immune to such fire out to a range of 25,000 metres. Since the British guns were less powerful and of lesser range than that, it seems the Bismarck's protection to crucial areas was even better matched. That reinforces the Bismarck's vulnerability to long-range fire, but demonstrates that its critical spaces were better protected at lower ranges, even if the AD was vulnerable beyond 11 km. Sacxpert 04:47, 21 August 2007 (UTC)

[edit] New Info, Changes

I've made a few changes, from Anthony Preston's book; I hope they are constructive. I'll add the references when I've checked the ISBN and page numbers. Xyl 54 18:09, 3 December 2007 (UTC)

Your additions are mostly good and helpful. However, I think your addition about the QE and R battleships is a bit off-topic. There's not much point comparing the Bismarcks to pre-Washington battleship designs. The older ships had inferior armoring for modern combat, deficient AA batteries, far slower operational speeds, and their main battery, while similar in size and layout, was capable of far less performance, as range and penetration tables show. They're radically different ships, and comparing them isn't particularly germane, even though they could faced each other in battle. Sacxpert (talk) 06:25, 5 December 2007 (UTC)

Thanks

Yes, I can see what you mean; I was trying to make sense of this section, and it referred to the Nelsons. it struck me that Warspite and the others, with the same armament, were a better example; the caveat about ‘earlier design’ and ‘other compromises’ was there already.

The thesis here seems to be that the Bismarks were under-gunned for their size, so examples of similar sized ships with larger armaments, or smaller ships with similar armaments, would be relevant, I thought;

on the other hand/ the antithesis,that those ships were slower, or, like Hood, were less well protected, isn’t so well developed.

It occurs to me that a good comparison is the Littorios, which, with a similar armament, speed and protection, were also of a similar displacement. Xyl 54 (talk) 16:22, 6 December 2007 (UTC)

[edit] New Source

OK, I've added the details of Preston's book; despite the lurid title, it's has good technical detail for the beginner, and backs up some of the design flaws mentioned in the other sources.
(—Preceding unsigned comment added by Xyl 54 (talk • contribs) 16:37, 6 December 2007 (UTC) : that was quick! I was only gone 5 minutes!)
He also gives a useful caveat:-
"In the light of the extraordinary admiration for the Bismarck and her sister Tirpitz, their inclusion in the ranks of the worlds worst warships might seem eccentric, or downright perverse. The real facts, however, point in the opposite direction to the widespread reverential attitude to any example of German technology, particularly that of the Hitler era." Xyl 54 (talk) 16:57, 6 December 2007 (UTC)

[edit] The stern

I've brought this here:
"the freak torpedo hit (described as a "one in a million" shot) scored on Bismarck's rudder"
(I thought it had a "citation needed" tag last time I was here, but there isn't one now.)
“one in a million shot” ?
Well if the stern was 40 ft long and the ship 800 ft in total, then it was a one in twenty shot, at least.
What is this trying to say? That it was a pure fluke that Bismarck was damaged?
She wasn’t the only ship damaged in this way during the war, and she wasn’t the only ship that was disabled by air strike.
I thought that was the point at issue in this section, that the damage might have been less serious, if the stern had been designed better. And the section title, "Achilles heel"; it implies something invulnerable save for a tiny weak spot. My impression is that it was more of a glass jaw. —Preceding unsigned comment added by Xyl 54 (talk • contribs) 17:54, 21 January 2008 (UTC)
(Sorry, I forgot to sign this on monday. Xyl 54 (talk) 13:17, 23 January 2008 (UTC))

Well, one-in-twenty shot is a bit high. Consider first that a torpedo had to strike the ship and detonate in the first place, which was by no means guaranteed. Then it would have to hit extremely proximal to the rudder in order to disable the steering gear. The odds are certainly better than one in a million, but far worse than one in twenty that a "shot" (or drop in this case) would inflict such crippling damage. Someone might have called it that, and it should have a cite tag.

As to the idea that other ships were disabled from the air, this is undoubtedly true. However, I'm having trouble remembering any capital warship disabled by a single torpedo hit in this fashion, making it more of a fluke. Moreover, the rest of the underwater protection scheme appears to have been quite adequate; the torpedo attack from the Victorious produced little in the way of damage, and the ship also appears, based on the testimony of the Bismarck survivors, to have endured the torpedo attack from the Dorsetshire without taking much damage, either. Thus, Achille's Heel seems apropos. Sacxpert (talk) 07:16, 22 January 2008 (UTC)

Out of 11 (or so) torpedo hits on Yamato 2 were aft of the rear turret. So, if you are just counting proportion of hits then 5% seems a little parsimonious. Given the known weaknesses of the Bis' stern any hit there is a cause for concern. As to the proportion of torpedoes dropped by Swordfishes (I think you do have to be specific about the a/c and the nationality) that hit, sorry, I don't have any good numbers. 1 in 5 or 1 in 10 maybe? Greg Locock (talk) 07:36, 22 January 2008 (UTC)

I wasn't that serious about the 1 in 20, I just cavilled at the 1 in a million.

The section reads as if it was the merest fluke that brought down the "invincible" battleship. The alternate explanation was that the stern was poorly designed, and the ship was crippled by a hit any other battleship would have sailed away from. I’m trying to determine which, because if it's the latter, then the section needs re-writing. —Preceding unsigned comment added by Xyl 54 (talk • contribs) 13:22, 23 January 2008 (UTC)

(Sorry, again!Xyl 54 (talk) 13:42, 23 January 2008 (UTC))

Replies:

Sacxpert: "I'm having trouble remembering any capital warship disabled by a single torpedo hit in this fashion"; well, so am I. Is it because they weren't hit, or because they weren't disabled?

Greg:"Given the known weaknesses of the Bis' stern"; Are we? Is it agreed that the stern was poorly designed?

Xyl 54 (talk) 13:45, 23 January 2008 (UTC)

Note that other BBs were NOT immune to trouble with hits on the stern, think Jutland, and there are several other examples of steering problems. The Germans obviously thought so by inference since their subsequent designs paid a great deal more care to sorting the stern out (see Breyer). I don't have a good dead tree reference for the general criticism, from memory, although no doubt Preston says as much. I'm not really convinced that Preston is a great independent source since he talks to the same people I do! The point about the 3 shaft layout wrecking the integrity of the keel was why RN and USN avoided it where possible. Quite possibly the Germans would have liked to use it but the beam problem prevented a 4 screw layout - the beam problem also causing me to have the relentless emphasis on her great beam etc - they couldn't fit 4 screws in when everyone else could. Maybe the TDS was a lot wider than most peoples. Oops, wrong emphasis!Greg Locock (talk) 21:27, 23 January 2008 (UTC)

Concerning other ships: USS Pennsylvania (BB-38) was effectively wrecked by a single torpedo hit in her stern. Nevfennas (talk) 22:57, 23 January 2008 (UTC)

I am by far and away not an expert in this field, but having just read Bob Ballard's book he identifies a systematic design weakness in the stern section of all German capital ships, not "defective welding", as the cause of the Bismarck's loss of its stern section during foundering. Can someone more competent than me comment on this discrepancy, please? Pyrope 16:38, 18 May 2008 (UTC)

Can you dig out the actual quote from ballard? Are you saying that Ballard has been (ahem) misquoted? That's not exactly unusual with articles edited by fanboys. I'd certainly agree that the stern design was old-fashioned compared with what other navies did, and the third shaft fundamnetally introduces a weakness that cannot be designed around (well, it can, by adding a lot of weight). Ship design is a compromise and the compromise they went for led to a weak stern. Greg Locock (talk) 02:58, 19 May 2008 (UTC)

Sure. The quote runs "...there was no structural support to hold the end of the stern in place once the ship turned over. These facts strongly suggest that a structural failure occurred before the ship sank and that the stern broke off at the surface. This hypothesis is supported by what had happened to the pocket battleship Lũtzow during the invasion of Norway and the subsequent career of the Prinz Eugen, which were both similarly weak in the stern. In 1940 the Lũtzow took a torpedo hit aft and suffered a stern collapse, although separation did not occur. In February 1942 off Norway Prinz Eugen was similarly hit and damaged, and her stern collapsed at approximately the same spot as the Bismarck's broke off ... Naval architects now know that the Bismarck's stern was the only structural weakness on the ship, and its fatigue failure represents the largest such event we know that has affected a warship ... Only after the damage suffered by the Prinz Eugen were German warships of heavy cruiser size and larger modified to strengthen their sterns." (Ballard & Archbold, 2007; p. 215-216) Not a mention of welding anywhere, defective or otherwise. In addition, looking at the photos he provides of the detachment area before and after failure it is quite clear that this section of the hull was riveted in the traditional manner, not welded. Unfortunately there is no discussion of this in the text so that's just my OR. However, one of the captions runs "Students of battleship design were excited by our discovery of the severed stern. Such a spectacular structural failure is suggestive of a serious weakness in the Bismarck's design." (Ballard & Archbold, 2007; p. 209) Another indication that a design fault was their preferred cause. I'd also like to throw the Lũtzow and Prinz Eugen examples in to the earlier debate over the "one in a million" torpedo hit. Three German capital ships disabled by a single torpedo to the stern during just three years is hardly long odds. In fact, Prinz Eugen's rudders ended up locked to port before the collapse, in a manner identical to the Bismarck's experience. Anyway, the citation is: Ballard, R. & Archbold, R. 2007. Robert Ballard's Bismarck. Chartwell Books, Inc., New Jersey. pp. 232. ISBN 978-0-7858-2205-9 Hope that helps? Pyrope 14:26, 19 May 2008 (UTC)

Thank you very much for that. I don't know if Ballard has any engneering/naval architecture experience (I don't think so) so he is not necessarilly in a fit position to judge some of that, but at least it kills the welding red herring. Greg Locock (talk) 01:53, 20 May 2008 (UTC)

[edit] Torpedo Bulges

So we have one part that says:

"The underwater protection system was built around a single torpedo bulkhead of 45 millimetres thickness,[11] coupled to an outboard void space; no bulges were fitted."

and another that says:

"Interior ROV footage showed that the "terrible destruction" the Anglo-American expedition reported was in fact the torpedo bulges, which were specially designed to absorb the energy of torpedoes and plunging shells. Underneath the torn bulge sheeting, the ship's 320 mm (12.6 inch) thick main belt armour appeared to be intact."

These are contradictory, not only on whether the ships had bulges, but also on the depth of the armour belt. —Preceding unsigned comment added by 217.155.40.13 (talk) 18:49, 30 April 2008 (UTC)

The main belt is not the same thing as a torpedo bulkhead. The main belt is on the exterior of the ship, and was at its thickest, 320 mm, near the waterline. This trailed off to 170 mm, and then the rest of the hull, down to the ship's bottom, was unarmoured. A torpedo bulkhead is mounted inboard, and is intended to absorb the explosive energy of a torpedo detonating against the external hull, or inside the outermost compartments of the hull. The Bismarck had a TD 45 mm thick, completely separate from the outer armour. It was inside the ship, mounted perpendicularly to the ship's bottom.

As to the question of bulges, Breyer's diagram of the Bismarck's armouring scheme (pg. 301) clearly illustrates the vertical side of the hull. A torpedo bulge, as the name implies, curves outward from the line of the hull. Also, Garzke and Dulin describe the outer spaces as a void space, not a torpedo bulge. So, I don't know where the "torpedo bulge" comments originate, but they don't accurately describe the ship's construction. Sacxpert (talk) 03:18, 1 May 2008 (UTC)

Yup, Bis did not have torpedo bulges, and her torpedo defence system was pretty much below the line of the belt (there was a the sloping deck that formed the upper limit of the TDS, which was the main armor deck). So, I think we can assume very safely that the ROV quote above is either incorrect or false. So it does not belong in the article. Greg Locock (talk) 09:22, 1 May 2008 (UTC)