Hits on PoW and Bismarck

[Byron Angel]

Hi Byron,

you wrote (from the Baron): "Consequently, the bulkhead behind Compartment XX was being subjected not only to the pressure of static water, but, on account of the big hole in our hull, to that created by our forward motion. "

Once established that Bismarck was on course around 220° during the time Hood was afloat, the shell must have severed in some way the bulkhead between compartment XX and XXI in such a way that water was pressuring the bulkhead between XX and XIX at high speed (forward motion, not only static).
I agree with you that this can be caused by an unfortunate big piece of steel dislocated by the shell (entering and exiting in comp. XXI) and thrown against the bulkhead between XX and XXI, but the most likely path of the shell is obviously through the bulkhead itself, opening comp. XX to sea water through the bulkhead and the exit hole (this last located as a good candidate above the white false bow wave in comp. XX, as per the photo and as per Thorsten reconstruction).

No simple leakage caused by splinters can account for such a dynamic pressure against the bulkhead between comp. XX and XIX. Only a hole open to sea (through the hull or the fore bulkhead) can.


Bye, Alberto

Please forgive me for wondering why an event of such critical importance as you allege above (i.e., the speculative holing of transverse bulkhead XXI/XX by the projectile) was not remarked upon in the slightest way by anyone aboard Bismarck, including those who took part in the damage control work; this fact is a very large and compelling issue IMO. I would suggest that the rate of flooding would simply reflect the extent of general damage (riddling, perhaps) suffered by the bulkheads and deck as a consequence of the passage of the projectile. Flooding did not simply fill the compartments at the deck level of the hit; it also filled the compartments beneath - to the extent of about 2,000 tons altogether. And we know with reasonable confidence that the projectile did not pass through those lower compartments.

It is worth noting that after sub-optimal stopgap repairs were effected, Bismarck was still considered able to steam at 28 knots.

per Mullenheim-Rechberg -
Lütjens turned down Lindemann's suggestion of heeling the ship first to one side and then the other and reducing speed in order to allow the holes in our hull to be patched. Later, however, we did slow to 22 knots for a while, which at least allowed matting to be placed over the holes, and the flow of water into the ship was reduced. The lasting effect of the hits in Compartments XIV and XXI was that, mainly because of water pressure on the forward bulkheads, our top speed was restricted to 28 knots.

The speed of the ship may certainly have helped to fill the ship faster (Bill Jurens has commented on this phenomenon IIRC), but the real challenge IMO was the hydrostatic pressure bearing upon the container or bulkhead -
312 lbs per square foot at 5 feet depth
614 lbs per square foot at 10 feet depth
1249 lbs per square foot at 20 feet depth
2598 lbs per square foot at 40 feet depth (11+ mt per sq meter)
This is why dams are very much thicker at their bases than at their tops. Bulkhead XIX/XX was as high as a four or five story building; hence the very first immediate step taken was to shore bulkhead XIX/XX before the flooding reached a level would overcome the structural strength of the bulkhead.

B

[Bill Jurens]

Regarding bulkhead construction, one would have to examine the ship's drawings to confirm thicknesses, etc. and admittedly I have not done this, although I have the data here to do so. That being said, in general, bulkheads, as might be expected, are designed to withstand hydrostatic pressure where flooding reaches a depth somewhat over the nominal draft, and often somewhat more so near the ends, where trim issues can locally increase the draft considerably. Deflections, often deflections that would appear to be very disconcerting to those unaware of the structural analysis, would probably occur fairly often, but this would not necessarily mean that the deflected bulkhead was in any way ready to suffer catastrophic failure.

Below the damage control deck, which is usually the lowest continuous deck, strength is more-or-less guaranteed by construction. Above that level, i.e. from about the damage control deck up to the weather deck, structural resistance is typically a bit less stringent. There is of course usually no point in designing the bulkhead so that the lowest portion, which of course would be the portion most highly loaded should typical flooding occur, could resist heads greater than about 1.5 times the regular draft, as after that point, the ship might be expected to be more-or-less in extremis anyway.

Shoring bulkheads, especially if they have been damaged is, of course, pretty much standard practice, if for no other reason than bulkheads adjacent to damaged compartments are quite likely to have been already somewhat compromised by blast, fire, or other unexpected, and often unpredictable, loading situations. So it's assumed that they are damaged, and weaker than nominal, even if they are not. It's not so easy to locate torn welds or failed riveted joints under a half meter of water and often in the dark, so caution usually prevails.

It's very difficult -- impossible, really -- to comment very intelligently on the shoring which might have been done aboard Bismarck forward, as no detailed descriptions survive, and it's really unknown from whence the major threats may have been perceived. The main problems, for example, may well have been seen to revolve around deflections and/or failures of decks above due to heavy seas breaking over the bows, etc.

The idea that the shoring was there to prevent overloading due to hydrodynamic (rather than hydrostatic) forces is tempting -- that's what most people, probably including the Baron, might assume -- but without more descriptions of the damage and shoring itself, it's really impossible to attempt to ascribe motivation with any reliability, i.e. to say that it was done for reason 'x' rather than 'y' or 'z'.

The plain fact of it all, is that really we just don't know. We don't know how much shoring was placed, where it was placed, how it was placed, or why it was placed. A jungle where the vines of imagination can grow very quickly indeed.

Bill Jurens

[Herr Nilsson]

@Bill Jurens

That's Bismarck's hydrostatic pressure height plan.

DruckhöhenplanBS.jpg

(21.12 KiB) Not downloaded yet

In regard of damage and hydrodynamic stress:

Evers1.jpg (14 KiB) Viewed 1117 times

Evers2.jpg (50.92 KiB) Viewed 1117 times

It was considered more sensible to make provisional shorings dependend on the location of the damage than to build thicker bulkheads and more stiffenings. (I'm sorry that I can't translate it completely at the moment)

@Antonio

I am OK about opening a dedicated thread about it of course. What is your opinion about it ?

[Alberto Virtuani]

Hello everybody,

Wadinga wrote: "now I'm thinking the unthinkable. The times on the Gefechtsskizze track are wrong by ten whole minutes! "

yes, Mr.Wadinga is thinking the unthinkable, but it's not the first time. He can write a nice fantasy book with all his speculations , like "1990" map being correct, Hood shells being visible in the PG film, Brockmann misleading Pound, Alexander and Churchill, etc.etc.
Of course, heshould be able to do elementary school calculations (that he is not) and draw a decent alternative battlemap with all the above rubbish....

The evident fact is that this guy is trolling the forum since months with nonsense ONLY to try to find excuses for two timid officers !



The torpedo alarm was given at 6:03, explaining Bismarck turn, as simple as that. To understand why PG turned after BS it's enough to see the relative positions of the two ships in Antonio's battlemap (viewtopic.php?f=1&t=8335#p81034), discussing this turn in the right (very interesting) thread.


Bye, Alberto

[Alberto Virtuani]

Byron Angel wrote: "Please forgive me for wondering why an event of such critical importance as you allege above (i.e., the speculative holing of transverse bulkhead XXI/XX by the projectile) was not remarked upon in the slightest way by anyone aboard Bismarck, including those who took part in the damage control work"

The Baron mentions the shell damage to the bulkhead between comp. XX and XXI, Brennecke mentions damages in comp. XX and XXI. Such damages are fully in line with the rapid flooding of comp. XXI (obviously) and XX (due to bulkhead piercing and exit hole above the white bow wave) and the need to reinforce the bulkhead between comp. XX and XIX due to dynamic water pressure (not static as per the Baron).
This is exactly the interpretation of Thorsten from German accounts and resulted in his posted analysis (viewtopic.php?f=1&t=8329&start=75#p80873) and I fully support it, but I guess Mr.Jurens is right when saying that this cannot be established with 100% certainty.

If I understand what you suggest, it is geometrically possible (but in my opinion extremely unlikely), with Bismarck on course around 220°, that the shell entered comp XXI at its almost extreme fore end, passed through it dislodging some very big piece, throwing it backward, open ripped the bulkhead between comp. XXI and XX and exited the hull still from comp. XXI at its extreme aft end. This would account for the dynamic water pressure against the bulkhead between XX and XIX, without a exit hole in comp. XX, but again I find this explanation very unlikely.
No simple leakage through the bulkhead between XX and XXI can account for a dynamic water pressure at high speed.


Bye, Alberto

[wadinga]

Hello All,

Waddya know? Now I can predict the future...…………...

I predict the creation of a drawing showing a shell path entering at the very foremost part of compartment 21 on the port side and leaving at the very aftermost part on the starboard side. This will be the new absolutely accurate and irrefutable shell path, replacing the previous absolutely accurate and irrefutable shell path, proving beyond a shadow of a doubt that the shell arrived from forward of the beam...............ish.

If I understand what you suggest, it is geometrically possible (but in my opinion extremely unlikely), with Bismarck on course around 220°, that the shell entered comp XXI at its almost extreme fore end, passed through it dislodging some very big piece, throwing it backward, open ripped the bulkhead between comp. XXI and XX and exited the hull still from comp. XXI at its extreme aft end

The same modus operandi as usual. First define the result required: it must be 220T, then manipulate the evidence to suit. If your bluff is called ie no evidence of shell penetration of bulkhead or ship's side in XX, rework the evidence again. Never lose sight of the objective:220T, never let evidence determine the result.


Is there a high quality version of the Gefechtsskizze accessible where you can read the annotations properly?


Here is interesting comment by Antonio from 2014:

the Prinz Eugen "Gefechtsskizze" submitted by Prinz Eugen ( Kpt Brinkmann ) to Vize-Adm Hubert Schmundt has been cause of a lot of troubles for Kpt H. Brinkmann.

Hans Henning von Schulz on 2009 confirmed it to me during the interview I had with him in Salzburg for several hours, same did Otto Schlenzka ( PG A/A gunnery port side ) a year before in Kiel.

Von Schulz was the responsible designed by Brinkmann to respond to all Schmundt request as well as re-constructing the Bismarck war diary.

Schmundt declared the Prinz Eugen " Gefechtsskizze " useless and wortheless to measure Prinz Eugen versus enemy distance on his own letter of June 16th, 1941
Here the statement he wrote :
The position of "Prinz Eugen" in relation to "Prince of Wales" cannot be derived from the battle sketch. It is useless and worthless. The ship is herewith directed to resubmit a new battle sketch that is based on the actual data provided by the computing station, and in the future, [PG is admonished] to pay greater attention to the preparation of battle sketches. Furthermore, the question is to be resolved, why the torpedo installations, which really had to be up and running since the time of the sighting of the opponent, took such a long time to report "all clear and ready", as is evident from the War Diary on page 23.
This also caused Ltnt Reimann to submit his own map and tracks from were Schmundt could realize that he overestimated his distances to the enemy PoW and consequently did not fire his torpedoes.

Schmundt told Brinkmann to use Jasper ( computing station ) available data, that is why I use them as well as reference and I do not give much importance to the " Gefechtsskizze " distances, while I know also that Reimann map distances were intentionally drew over stated for Schmundt.

Might the distances be wrong because the times are wrong?


All the best

wadinga

[Alberto Virtuani]

Hello everybody,

Wadinga wrote: "First define the result required: it must be 220T, then manipulate the evidence to suit"

despite having been already rubbished by me (viewtopic.php?f=1&t=5752&start=930#p80769),
by Mr.Jurens (viewtopic.php?f=1&t=8329&start=135#p80975) and
even by Mr.Nilsson (viewtopic.php?f=1&t=8329&start=150#p80997), this guy is back, without shame, trolling the forum with his usual petulance...

Bismarck course was around 220°until Hood explosion and this cannot be denied anymore, proven by PoW salvo plot distances.No evidence need to be manipulated to suit, it is a well known and accepted fact by everybody here, except him.

The exact shell position and path inside Bismarck is another story (in which I'm not interested very much). I don't support at all the scenario of a hit entering and exiting comp. XXI, but this is what I understand someone else (Byron) is saying.


Why is Mr.Wadinga unable to understand and accept this simple fact of course 220°? Is it his very serious personal limitation at geometry, his arrogance preventing to accept his defeat, or just his declared agenda (viewtopic.php?f=1&t=8249&p=77574&hilit=devoted#p77574) ?


Bye, Alberto

[Byron Angel]

Byron Angel wrote: "Please forgive me for wondering why an event of such critical importance as you allege above (i.e., the speculative holing of transverse bulkhead XXI/XX by the projectile) was not remarked upon in the slightest way by anyone aboard Bismarck, including those who took part in the damage control work"

The Baron mentions the shell damage to the bulkhead between comp. XX and XXI, Brennecke mentions damages in comp. XX and XXI. Such damages are fully in line with the rapid flooding of comp. XXI (obviously) and XX (due to bulkhead piercing and exit hole above the white bow wave) and the need to reinforce the bulkhead between comp. XX and XIX due to dynamic water pressure (not static as per the Baron).
This is exactly the interpretation of Thorsten from German accounts and resulted in his posted analysis (viewtopic.php?f=1&t=8329&start=75#p80873) and I fully support it, but I guess Mr.Jurens is right when saying that this cannot be established with 100% certainty.

If I understand what you suggest, it is geometrically possible (but in my opinion extremely unlikely), with Bismarck on course around 220°, that the shell entered comp XXI at its almost extreme fore end, passed through it dislodging some very big piece, throwing it backward, open ripped the bulkhead between comp. XXI and XX and exited the hull still from comp. XXI at its extreme aft end. This would account for the dynamic water pressure against the bulkhead between XX and XIX, without a exit hole in comp. XX, but again I find this explanation very unlikely.
No simple leakage through the bulkhead between XX and XXI can account for a dynamic water pressure at high speed.

Bye, Alberto

Mullenheim-Rechberg stated the BOTH bulkheads formed section XXI were damaged -
That first hit, forward of the armored transverse bulkhead in the forecastle, passed completely through the ship from port to starboard above the waterline but below the bow wave. It damaged the bulkheads between Compartments XX and XXI and Compartments XXI and XXII and left a one-and-a-half-meter hole in the exit side. Before long we had nearly 2,000 tons of seawater in our forecastle.

- - -

Mullenheim-Rechberg (by my interpretation of his language) consigned to principal risk factor to hydrostatic pressure. The forward motion component mentioned may simply refer to inertia effect. Dynamic pressure presumes that the fluid in question is moving an striking the bulkhead with some velocity - a factor not demonstrated. Readers are, of course, free to interpret as they see fit.
Consequently, the bulkhead behind Compartment XX was being subjected not only to the pressure of static water, but, on account of the big hole in our hull, to that created by our forward motion.

- - -

Once again, there is no mention or corroboration of any sort whatsoever from the German side that the projectile passed through bulkhead XXI/XX and exited the ship through section XX. While it is perfectly reasonable to offer the idea as a theory or a possibility, to categorize it as "irrefutable fact" is IMO intellectually both unreasonable and untenable.

B

[Byron Angel]

"The exact shell position and path inside Bismarck is another story (in which I'm not interested very much). I don't support at all the scenario of a hit entering and exiting comp. XXI, but this is what I understand someone else (Byron) is saying."

With all due respect, can you point to a single solitary German reference source stating that the projectile exited through section XX?

B

[Byron Angel]

"Bismarck course was around 220°until Hood explosion and this cannot be denied anymore, proven by PoW salvo plot distances."

Disagree. An examination of the salvo plot and McMullen's notations

1 - If the dashed line on the plot is supposed to represent McMullen's estimation of the course of Bismarck, it contains two distinct course alterations before 6:00:00. Was McMullen wrong?

2 - "Fall of shot plotted as they appeared from Prince of Wales. At such ranges, all that could be surmised with any confidence would have been their status of straddle or short or over; it was not realistically possible to determine the error distance; the case of an over it was quite likely that the fall of shot would not even be seen.

The salvo plot is certainly helpful, but the uncertainty factors involved must be recognized.

B

[Alberto Virtuani]

Hi Byron,
I said AROUND 220° as per McMullen estimation in the salvo plot (the dotted line vary from 205° to 225° if I remember correctly).

The fact that Bismarck was closing very fast (and not going away on around 270° as in the PG film) is irrefutable,as demonstrated mathematically by me (viewtopic.php?f=1&t=5752&start=930#p80769), confirmed by Mr.Jurens (viewtopic.php?f=1&t=8329&start=135#p80975) and by Mr.Nilsson when using a 230° course (that is still around 220° viewtopic.php?f=1&t=8329&start=150#p80997).
We can debate the precision of the distances in the salvo plot, applying a tolerance (spread, observations, etc.), but McMullen was hitting an enemy that was closing extremely fast at a relative closing speed of 30 knots and this is irrefutable.



All the discussion about the shell path is another story and I agree it is debatable: you have your view, I have mine and both are possible, but the direction from where the shell came on board is not, because Bismarck could not have been on course 270, especially at an early stage of the battle, and this hit is considered by German witnesses as the first received one (see Lorenzen).
I hope this helps to clarify my view and not to follow a blatant troll in his fantasies.


Bye, Alberto

[wadinga]

Hello Byron,

Good points. As can be seen in the photographs the effect of the vessel pitching at high speed in big seas pressurises the flooded compartments on a cyclical basis increasing pressure over and above effects of mere speed and increased "water head" above normal waterline. As a Gunnery Officer these considerations are unlikely to be understood by the Baron as being beyond practical experience. To those charged with shoring bulkheads against the shocks provided by 2,000 tons of water surging around in the fo'c'sle, whilst being accelerated up and down as Bismarck powered through Atlantic swells, it was a different matter.

The need to lighten the bows and ease the load on threatened bulkheads after high speed had torn away the external collision mats was indicated by the proposal (apparently discounted) to jettison the anchors and anchor chains. In a normal peacetime situation collision mats would have been protected by only proceeding at minimal speed. Bismarck could not proceed at minimum speed.

Bill has observed

Below the damage control deck, which is usually the lowest continuous deck, strength is more-or-less guaranteed by construction. Above that level, i.e. from about the damage control deck up to the weather deck, structural resistance is typically a bit less stringent.

It is worth remembering that the hull sides which resist the sea, have frame spacing at about 1m intervals. It is impractical to have longitudinal supports to athwart ship bulkheads at this kind of spacing, so when they have to resist the sea they need shoring up.

In connection with the idea that the eighteen recorded ranges at which salvoes were fired, with the dispersion characteristics of those salvoes and no certainty which of them actually included the shells which hit Bismarck, constitute a precise method of rigidly defining her course as 220T as claimed by:

it is a well known and accepted fact by everybody here,

Needs a response and I'd like to borrow your elegant and eloquent phrase:

to categorize it as "irrefutable fact" is IMO intellectually both unreasonable and untenable.

There are at least two rates applicable solely from PoW's vector contribution respecting 300T and later 280T.


All the best

wadinga

[Alberto Virtuani]

Hello everybody,

Wadinga wrote: "precise method of rigidly defining her course as 220T "

Q.E.D.
The troll is back, not able to read what I have already said to Byron and jumping on any slightest opportunity to re-open a closed discussion:
AROUND 220° should be more readable for his limited view.

But "around" means that in no way he will be able to move Bismarck on around 270°, before Hood explosion, as he was incorrectly stating before being rubbished by everybody here (carefully avoiding to answer them viewtopic.php?f=1&t=8329&start=135#p80975 & viewtopic.php?f=1&t=8329&start=150#p80997), only trolling and trolling again to counter a very inconvenient reconstruction based on PG film that has demolished his loved fairy tale...).


Deal with this IRREFUTABLE evidence, if able, http://www.hmshood.org.uk/reference/off ... encIVa.gif , apply all tolerances, do some homework and finally propose an alternative Bismarck track, instead of posting only nonsense !


Bye, Alberto

[Bill Jurens]

My thanks to Herr Nilsson for posting the diagram, which helps to confirm my earlier presentation regarding shoring and flooding boundaries, etc.

I was very impressed upon my visit to Bismarck, and my examination of subsequently obtained videotape of the Bismarck wreck with the elegant and well-thought out design details, which demonstrate a considerable depth and understanding of engineering principles, particularly with regard to weight saving. Structurally, the design was very efficiently executed indeed. There were, of course, problem areas with the design, but these revolved around much larger issues, such as difficulty in establishing -- or more properly maintaining -- an optimal position for the longitudinal center of buoyancy, particularly as machinery weights were adjusted during building, but that is another story entirely. Readers will note, via the posted diagram, that the bulkheads higher in the ship were not maintained watertight near the centerline, as flooding in such areas would be impossible without the ship being already in a sinking condition, and that -- as I noted in my earlier memo -- that the watertight subdivision was indeed carried somewhat higher near the ends. This represents excellent attention to detail.

With apologies, I would address Mr. Virtuani, and once again point out -- perhaps more directly than I have previously -- that the presentation of arguments in extreme form with the extensive addition of personal slurs, various cartoon faces and animations, and wildly varying font sizes and styles adds nothing to his arguments, and in fact actually detracts from the points he is trying to make. When one has to read through perhaps twenty lines of this sort of material, in the process sifting out the visual and verbal 'noise' in order to extract what amounts to perhaps a half-sentence of coherent commentary, one is inclined not to read the full posting at all. I would try to shout less and say more.

Bill Jurens.

[wadinga]

Hello Bill,

what amounts to perhaps a half-sentence of coherent commentary

Which of the last twenty Alberto posts was that in?

The self-proclaimed precise calculator has failed to admit there must be at least two different rates of closure because PoW changed course, reducing the rate of closure considerably, during the approach.


As Byron has observed

Fall of shot plotted as they appeared from Prince of Wales. At such ranges, all that could be surmised with any confidence would have been their status of straddle or short or over; it was not realistically possible to determine the error distance; the case of an over it was quite likely that the fall of shot would not even be seen.

Even McMullen didn't know which ranges were hits:

No hits were observed, but it is likely from results observed that fire was effective between salvoes 5 and 16.

Hardly a surveying technique. Besides is 230T for instance "around 220T" what about 240T? Bismarck isn't diverging from PG by 50 degrees in the film, much less.


All the best

wadinga