Bismarck firing procedures at DS

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Byron Angel
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Re: Bismarck firing procedures at DS

Post by Byron Angel »

Antonio Bonomi wrote: Mon Feb 22, 2016 7:44 am Hello everybody,

@ Alberto Virtuani,

many thanks Alberto for your nice compliments :oops:

You correctly wrote :
However, IMHO, due to the fact that PoW salvo 20 was fired by one of the same guns that fired salvo 19 (Y1 or Y4), and that this salvo landed at 6:03:25, as per photo NH69731, I would not assume PoW salvo 20 could land before 6:03:55 (giving at least 30 seconds to reload the same gun as per theoretical RoF of British 14"). What do you think ? Does this match with the other evidences ?


Based on the above assumption of 30 seconds being the minimum reload time ( rate 2 shells each minute ) for the PoW guns ( Y1 or Y4 in this case ) we can move the PoW salvo 19th showed on photo Nh 69731 being fired at 06.03 and 00 seconds from the previous 06.03 and 10 seconds I was calculating before.

I obtained the previous time by subtracting 20 seconds from the salvo 20th that is the milestone reference being fired at 06.03 and 25 seconds, because 20 seconds is the time between salvo 20th and 21st, .... as we can see on the PG film, ... but now it is clear that it was not the real PoW guns reloading time since the gun that fired salvo 21st was another one not firing on salvo 20th, ... the Y3.

The salvo 20th from PoW landing at 06.03 and 45 seconds is the base reference in synch with PG battle map showing the Prinz Eugen first turn.

This movement of salvo 19th of 2 guns departing from PoW at 06:03:00 is perfectly in line with PoW gunnery plot map, which shows the Y turret local control salvos being fired starting at 06:03:00 exactly, ... and everybody can check the X they traced there.

I like to underline that the photo Nh 69731 not only shows the PoW salvo 19th Landing at 06:03:15 after 15 seconds flight time, ... but it shows also the Bismarck salvo 16th landing on PoW on the same moment, ... so we can assume Bismarck salvo 16th being fired at 06:03:00 and landing on PoW at 06:03 and 15 seconds as well.

PoW salvo 19th and Bismarck salvo 16th are in synch and have been fired almost simoultaneously.

But if Bismarck salvo 16th was fired at 06:03:00 ... and the salvo 17th we can see at the beginning of the PG film was fired at 06:03:29 seconds ... we have an interval of 29 seconds between the 2 salvos ... enough to make the turn of 50 degrees to starboard from course 220 to course 270 ... all seems to match well ... :think:

Hope all is clear ... and thanks for the value add input. This is exactly what I am looking for to improve my work ... :wink:

Bye Antonio :D


I have a question regarding the underlying logic of the gunnery re-construction of PoW's 19th salvo outlined above. As I understand it,
Salvo fired at 6:03
Time of Flight - 15 seconds
Salvo landed 6:03:15

What was the range at which this salvo is thought to have been fired?

B
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Alberto Virtuani
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Re: Bismarck firing procedures at DS

Post by Alberto Virtuani »

Hi Byron,
a very interesting discussion indeed (good you found the time to dig into such an old debate :clap: ). Please be aware that in our published reconstruction of the battle (Storia Militare on 2017), we have not detailed so much the event, just indicated the timing as being around 6:03, but we had prepared for that publication also a tentative salvo plot for all ships involved, accounting for the local fired salvos,(very slightly) different from Antonio's 2005 reconstruction (that was still the reference and the basis for the discussion at the time the 2016 psst was written).


To answer your question, we should know at which distance Alwin fired his guns at salvo 19 (the problem is that we don't have a precise salvo plot for the local salvos and this is a pity). Based on the most recent Antonio's reconstruction, PG is at slightly less than 14 km from PoW at 6:03 (the turn had no effect yet to significantly open the range from its minimum distance reached at around 6:02:40, Bismarck is 1500 meters behind (from film analysis), but salvo 19 falls quite short vs PG (let's say at least 1500 to 2000 meters short).

If Alwin fired his salvo at around 6:03, with an estimated (future point) range of 11500 or 12500 meters, the flight time of the British 14" shell would have been around (or slightly less than) 20 seconds (http://www.hmshood.com/history/denmarks ... times2.htm).
Thus it seems reasonable to say that salvo 19 was fired at around 6:03 (with due tolerance of 5-10 seconds of course, because here we speak about seconds, not several minutes, as someone was trying to imagine...).


Bye, Alberto
"It takes three years to build a ship; it takes three centuries to build a tradition" (Adm.A.B.Cunningham)

"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)
Byron Angel
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Re: Bismarck firing procedures at DS

Post by Byron Angel »

Alberto Virtuani wrote: Tue Oct 16, 2018 7:39 am Hi Byron,
a very interesting discussion indeed (good you found the time to dig into such an old debate :clap: ). Please be aware that in our published reconstruction of the battle (Storia Militare on 2017), we have not detailed so much the event, just indicated the timing as being around 6:03, but we had prepared for that publication also a tentative salvo plot for all ships involved, accounting for the local fired salvos,(very slightly) different from Antonio's 2005 reconstruction (that was still the reference and the basis for the discussion at the time the 2016 psst was written).


To answer your question, we should know at which distance Alwin fired his guns at salvo 19 (the problem is that we don't have a precise salvo plot for the local salvos and this is a pity). Based on the most recent Antonio's reconstruction, PG is at slightly less than 14 km from PoW at 6:03 (the turn had no effect yet to significantly open the range from its minimum distance reached at around 6:02:40, Bismarck is 1500 meters behind (from film analysis), but salvo 19 falls quite short vs PG (let's say at least 1500 to 2000 meters short).

If Alwin fired his salvo at around 6:03, with an estimated (future point) range of 11500 or 12500 meters, the flight time of the British 14" shell would have been around (or slightly less than) 20 seconds (http://www.hmshood.com/history/denmarks ... times2.htm).
Thus it seems reasonable to say that salvo 19 was fired at around 6:03 (with due tolerance of 5-10 seconds of course, because here we speak about seconds, not several minutes, as someone was trying to imagine...).


Bye, Alberto

I'm puzzled. Why did Aylwin set a range of </= 14,000 yds for his fire from Y turret when he was presumably aware that: (a) the gun range of the last controlled double-salvo from PoW (salvoes 17 & 18) was at 14,000 yards; (b) the fall of shot of salvoes 17 & 18 was seen (as implied by McMullen's track chart) to have fallen well short; (c) PoW, after having been hit, had made a radical 160deg turn away and placed Bismarck more or less directly astern?

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Alberto Virtuani
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Re: Bismarck firing procedures at DS

Post by Alberto Virtuani »

Hi Byron,
good doubt, for which we don't have enough info, however. We don't know which bearing, inclination and range data was coming to the TS "computer" else than turret "Y" own observations at that stage of the battle (the fore turrets, the radar, McMullen's and the aft director were not of any help).

Of course Alwin was aware that PoW had turned, but, when salvo 18 was fired, she was still (very slightly) closing the range to Bismarck (PoW went on course 220° only after 6:02 and significantly started to open range only after 6:02:30). Apparently at that point he had no feeling that Bismarck had turned away at around 6:03 yet.

It's only my speculation, based on my poor gunnery knowledge, that he possibly started his fire action using the same elevation than salvo 18 (14.000 yards = 12,8 km), aiming to adjust first the cursor and only later taking care of the range. Another possible explanation is that he based his shooting only on what his rangefinder was telling him at that time, simply underestimating initially the range to 11,5-13 km.


The only sure info we have is that the photo shows two (apparently well grouped) shots falling quite short and the position of PoW compared to Hood indicates that the timing is far after central control salvos landing, around 6:03:xx.


Bye, Alberto
"It takes three years to build a ship; it takes three centuries to build a tradition" (Adm.A.B.Cunningham)

"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)
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Re: Bismarck firing procedures at DS

Post by northcape »

Alberto Virtuani wrote: Tue Oct 16, 2018 8:36 pm

It's only my speculation, based on my poor gunnery knowledge,
Finally some words of truth and correct self-assessment! Congratulations and respect!
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Re: Bismarck firing procedures at DS

Post by alecsandros »

Byron Angel wrote: Tue Oct 16, 2018 6:33 pm I'm puzzled. Why did Aylwin set a range of </= 14,000 yds for his fire from Y turret when he was presumably aware that: (a) the gun range of the last controlled double-salvo from PoW (salvoes 17 & 18) was at 14,000 yards; (b) the fall of shot of salvoes 17 & 18 was seen (as implied by McMullen's track chart) to have fallen well short; (c) PoW, after having been hit, had made a radical 160deg turn away and placed Bismarck more or less directly astern?

B
IMHO it is of little relevance how Claude Aylwin fired turret Y on local control. Prince of Wales was becoming shrouded in chemical smoke and observations from the aft turret to the target (Bismarck) , and of the previous fall of shot, was probably most difficult .
Geoffrey Brooke writes in "Alarm to starboard": "Aylwin, not receiving the expected control orders, assumed we were hors de combat and switched to local control. Each turret was equipped with rudimentary fire control gear for just this emergency and he now used it to get off - rather wildly as was to be expected - three or four salvos over the starboard quarter. Clouds of black smoke now began to billow out of our funnels - the Captain had ordered a smoke screen - and as the turned continued , the Prince of Wales began to come round behind it."
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Alberto Virtuani
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Re: Bismarck firing procedures at DS

Post by Alberto Virtuani »

Hello everybody,
"a provoking ignorant hooligan wrote: "Finally some words of truth and correct self-assessment! Congratulations and respect!"
...waiting since months for his own self-assessment... The arrogance (and self-pomposity) of these guys is unbearable. :lol: :lol: :lol:


Bye, Alberto
"It takes three years to build a ship; it takes three centuries to build a tradition" (Adm.A.B.Cunningham)

"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)
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wadinga
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Re: Bismarck firing procedures at DS

Post by wadinga »

Hello Alecsandros,

Having posted what you have just posted and given that McMullen did not know where 17 & 18 landed
and salvoes 17 and 18 were fired as an up regaining ladder. The fall of shot of these salvoes is not certain, but it is probably that they went short;
or the local control salvoes
went into local control and fired three salvoes as he was able to see under the smoke.
The fall of shot of these three salvoes is uncertain.
And Brooke whom you quote doesn't see these shots land anywhere either.

Are you as certain as Antonio and Alberto that the single splashes seen the film and associated stills are Aylwin's local control shots?

All the best

wadinga
"There seems to be something wrong with our bloody ships today!"
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