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Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Fri Oct 02, 2020 8:06 pm
by dunmunro
From KGV's GAR:
At 0929 Type 279 started ranging. By 0940 the range was down to about 8000 yds.
The enemy's list to port was most pronounced, she was heavily on
fire, all guns except "X" and a few secondary armament were out of action, and. .
these were firing spasmodically and gallantly. About 0945 the enemy, who was
yawing considerably exposed her starboard side to view for he first time.
Observers noted at least three large fires amidships and a hole in the bows
near the water line. These fires were presumably caused by APC shell which .
entered the port side and burst before leaving the ship, or possibly from ships
firing from her starboard side.
Bismarck survivors noted that several 14 or 16in APC shells entered the engineering spaces below the waterline, prior to the order to begin scuttling, and these hits were causing progressive and uncontrollable flooding of the ship.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 1:05 am
by wadinga
Hi Dunmunro,

Not all survivors would agree about below waterline shell hits, Here is Junack, http://www.kbismarck.com/bismarck-last-hours.html who was in the engineering spaces:
Gradually the noise of combat became more irregular until it sank, to become nothing more than a series of sporadic crashes; even the control bells from the bridge stopped ringing. All three turbine-rooms were filled with smoke from the boiler-room; fortunately no shells had yet come through the plating protecting the engine-room or the electric generators (though the electric plant on the port side had been hit on the Saturday morning by a shell from the Prince of Wales).
and
The lower decks were brilliantly lit up; a peaceful mood prevailed, such as that on a Sunday afternoon in port - the silence broken only by the explosion of our own demolition-charges below. I myself saw the result of the battle on the battery-deck. There was no electric light, only the red glow from numerous fires; smoke fumes billowed everywhere; crushed doors and hatches littered the decks, and men were running here and there, apparently aimlessly: it seemed highly unlikely that one would survive.
Yet in the 1941 British interrogation report he said:
Kapitänleutnant (Ing.) Junack has stated that one shell penetrated the port turbine room at about 0930. Another entered the boiler room - Section XIII, between 0915 and 0930, starting a fire, possibly of fuel oil. Steam pipes burst, scalding ratings.
There is no insinuation of lying here BTW, simply some self contradiction.

The port No. 2 boiler room and auxiliary boiler room had progressively flooded during the hours after Denmark Straits, joining generation station 4 and some fuel and double bottom compartments. Maybe this leakage had got worse during the violent avoidance of Swordfish and destroyer torpedoes.

All the best

wadinga

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 4:35 am
by dunmunro
Well something was causing Bismarck to have an increasing list to port, that was clearly visible to RN observers.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 9:46 am
by paul.mercer
Gentlemen
Dunmunroe wrote: Bismarck survivors noted that several 14 or 16in APC shells entered the engineering spaces below the waterline, prior to the order to begin scuttling, and these hits were causing progressive and uncontrollable flooding of the ship.
Yet others say there was no penetration, i do find it difficult to believe that even though Bismarck was a heavily armoured ship that 142 &16" shells fired from almost point blank range did not penetrate any part of her armour.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 3:45 pm
by Steve Crandell
The problem with penetrating armor into her engineering spaces was that it's very difficult to get underwater hits at close range. At low trajectories the shells tend to leave the water again after initially hitting it.

Also, the Bismarck armor combination of belt and scarp is theoretically almost impossible to get through at any range.

Now, if the ship was listing to port and someone was on the starboard side, there is a chance to get under the belt, but I don't know what the odds of that would be. Of course a shell from PoW did get under the belt at Denmark Strait, but that was at a range where the trajectory made it more likely.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 5:13 pm
by Mostlyharmless
dunmunro wrote: Sat Oct 03, 2020 4:35 am Well something was causing Bismarck to have an increasing list to port, that was clearly visible to RN observers.
Did Rodney hit Bismarck with a torpedo exploding amidships on the port side?

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 8:53 pm
by dunmunro
Steve Crandell wrote: Sat Oct 03, 2020 3:45 pm The problem with penetrating armor into her engineering spaces was that it's very difficult to get underwater hits at close range. At low trajectories the shells tend to leave the water again after initially hitting it.

Also, the Bismarck armor combination of belt and scarp is theoretically almost impossible to get through at any range.

Now, if the ship was listing to port and someone was on the starboard side, there is a chance to get under the belt, but I don't know what the odds of that would be. Of course a shell from PoW did get under the belt at Denmark Strait, but that was at a range where the trajectory made it more likely.
The RN opened fire at ~24K yds and KGV was beyond 12-14k yds until ~0930 (open fire was 0848) so there was lots of time for diving shells to pass under Bismarck's belt. Additionally, depending on the extent of the port list, it might be possible for an 14-16in APC shell to penetrate the 5.7in upper belt or mainbelt and enter the machinery spaces, because the list reduces the obliquity of the armoured scarf.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 8:54 pm
by dunmunro
Mostlyharmless wrote: Sat Oct 03, 2020 5:13 pm
dunmunro wrote: Sat Oct 03, 2020 4:35 am Well something was causing Bismarck to have an increasing list to port, that was clearly visible to RN observers.
Did Rodney hit Bismarck with a torpedo exploding amidships on the port side?
it seems unlikely based upon survivor accounts and wreck surveys.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 9:51 pm
by Steve Crandell
dunmunro wrote: Sat Oct 03, 2020 8:53 pm
Steve Crandell wrote: Sat Oct 03, 2020 3:45 pm The problem with penetrating armor into her engineering spaces was that it's very difficult to get underwater hits at close range. At low trajectories the shells tend to leave the water again after initially hitting it.

Also, the Bismarck armor combination of belt and scarp is theoretically almost impossible to get through at any range.

Now, if the ship was listing to port and someone was on the starboard side, there is a chance to get under the belt, but I don't know what the odds of that would be. Of course a shell from PoW did get under the belt at Denmark Strait, but that was at a range where the trajectory made it more likely.
The RN opened fire at ~24K yds and KGV was beyond 12-14k yds until ~0930 (open fire was 0848) so there was lots of time for diving shells to pass under Bismarck's belt. Additionally, depending on the extent of the port list, it might be possible for an 14-16in APC shell to penetrate the 5.7in upper belt or mainbelt and enter the machinery spaces, because the list reduces the obliquity of the armoured scarf.
But substantially increasing the obliquity of the main belt. I doubt there is much difference in penetration. Going through the deck is problematic because British shells had a shorter fuse activation than most other navies and probably wouldn't travel far enough to reach the engineering spaces. Of course, that would also imply that PoW's shell wouldn't have done the damage it did. You just never know, and these things don't always act as designed.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Sat Oct 03, 2020 10:08 pm
by dunmunro
Steve Crandell wrote: Sat Oct 03, 2020 9:51 pm
dunmunro wrote: Sat Oct 03, 2020 8:53 pm
Steve Crandell wrote: Sat Oct 03, 2020 3:45 pm The problem with penetrating armor into her engineering spaces was that it's very difficult to get underwater hits at close range. At low trajectories the shells tend to leave the water again after initially hitting it.

Also, the Bismarck armor combination of belt and scarp is theoretically almost impossible to get through at any range.

Now, if the ship was listing to port and someone was on the starboard side, there is a chance to get under the belt, but I don't know what the odds of that would be. Of course a shell from PoW did get under the belt at Denmark Strait, but that was at a range where the trajectory made it more likely.
The RN opened fire at ~24K yds and KGV was beyond 12-14k yds until ~0930 (open fire was 0848) so there was lots of time for diving shells to pass under Bismarck's belt. Additionally, depending on the extent of the port list, it might be possible for an 14-16in APC shell to penetrate the 5.7in upper belt or mainbelt and enter the machinery spaces, because the list reduces the obliquity of the armoured scarf.
But substantially increasing the obliquity of the main belt. I doubt there is much difference in penetration. Going through the deck is problematic because British shells had a shorter fuse activation than most other navies and probably wouldn't travel far enough to reach the engineering spaces. Of course, that would also imply that PoW's shell wouldn't have done the damage it did. You just never know, and these things don't always act as designed.
As long main belt obliquity doesn't exceed ~35 degs it won't make much difference.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Mon Oct 05, 2020 9:13 am
by paul.mercer
Gentlemen,
Regarding the 'list' which i presume was there before the start of the final battle, what puzzles me is what made her list like that?
Bismarck had taken a torpedo hit in her steering compartment which jammed her rudders, according to the Baron, when attempts were made to enter the compartment they were prevented by water surging through the hole, but surely there would have been more watertight bulkheads to stop the water from entering the rest of the ship and she could have been counter flooded to right herself? I believe that one of the pictures of the wreck shows where the stern broke off at what would appear to be one of the bulkheads which appears to be intact.
I presume that it would take quite a lot of water to make a pronounced and visible list in a ship the size of Bismarck, so I wonder if it was caused by the shoring up of the hit in the bow giving way as she maneuvered at speed to avoid the torpedoes

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Mon Oct 05, 2020 10:04 am
by wadinga
Hello Paul,

You seem to be discounting Prince of Wales' other hit at Denmark Straits.

We know Bismarck was listing to port hours before the final battle. This earlier 14" underwater hit was near amidships on the extreme port side where further flooding would cause maximum listing effect unlike holes in the bow or stern which are close to the centreline and would have minimal listing effect. As I pointed out:
The port No. 2 boiler room and auxiliary boiler room had progressively flooded during the hours after Denmark Straits, joining generation station 4 and some fuel and double bottom compartments. Maybe this leakage had got worse during the violent avoidance of Swordfish and destroyer torpedoes.
Bismarck had blazed away at the destroyers and had wallowed in heavy seas after the stern hit, shocking and straining the shored-up bulkheads. There is no mention of any collision mat to seal the outer hull. The TDS had limited damage but was leaking, allowing the flooding of these engineering spaces days before. It seems likely to me renewed flooding started and out-weighed the counter flooding on the starboard side already done.

In the final action Bismarck's fire-control would have to initially compensate for the list and then for the erratic motion of a slow moving vessel more at the mercy of wave action than a fast moving one, and finally for the continual turning imposed by the jammed rudder. The extremely limited number of straddles achieved was outstanding work but multiple tight straddles are normally required to secure hits and this proved unachievable.

All the best

wadinga

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Tue Oct 06, 2020 9:08 am
by paul.mercer
Thanks Wadinga,
I suppose that it proves that just two or three hits in the 'wrong place' can almost cripple a powerful ship like Bismarck, it seems that even without the
jammed rudder she would have been at an extreme disadvantage against one, let alone two RN battleships like KGV or Rodney, had it come to a battle in which she could not use her full speed.

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Tue Oct 06, 2020 11:42 am
by wadinga
Hello Paul,

I have been overlooking another potential source of the list which pre-existed the final battle. :oops: Ark Royal's crews claimed three torpedo hits in their attack and while Lutjens' signals describe two, "a hit amidships" and the rudder hit, no lesser source than the Baron contests this, saying he experienced two hits forward of his position and one aft. One at least of the FAA crews said they scored a hit amidships on the port side and whilst Lutjens may have described Victorious' earlier hit as "inconsequential" this later strike might have slammed in "below the belt" and reopened the flooding from PoW's hit as well creating its own. Masked by the overwhelming concern over the jammed rudders, this hit might have received lower damage control priority and interest, but with a gradually increasing list as a result, Bismarck's gunnery the following day would surely be compromised even compared with her performance against the destroyers overnight.

I consider these "wrong place" hits outside the armoured citadel may often have significant outcomes in actions, which for me render the detailed, complex and long-running arguments about shell vs armour impact performance as if they were precise engineering, somewhat academic, based as they mainly are, on artificial proving ground experiments.

I believe Bismarck was developing a debilitating list to port, due to progressive flooding, for some hours before the final battle, which was then exacerbated by the shell hits she received, and finally resulted in a capsize to port as described by eye witnesses.

All the best

wadinga

Re: Bismarck final battle and German main battery accuracy Qs.

Posted: Tue Oct 06, 2020 4:02 pm
by Thorsten Wahl
In the final action Bismarck's fire-control would have to initially compensate for the list and then for the erratic motion of a slow moving vessel more at the mercy of wave action than a fast moving one, and finally for the continual turning imposed by the jammed rudder.
without firecontrol ist almost impossible to hit anything above… say ten Kilometers.

if your ship is functioning in a normal way the firecontrol Computer will give you precise values for your firing solution and if ther is anything unusal/noticeable you should be able to see a problem as is happend -the friring solution should be steadily and you can solve the problem usually by manual input.

but in a case of completely insteadines in course, speed, list and so on you are not able to oversee and manually compensate a problem(especially lots of smaller ones) if such occurs.

during the first stages of the battle the british ships were closing from the front. the germans could only use the Forward turrets to Zero in. This alone doubles the normals timeintervals for standard shooting procedures the Germans used.

the the opposite courses led to a very high approach speed shrinking distance by about one Kilometer in one Minute.

the british ships are allowed to individually maneuver to get out of a firing solution.