PoW's gunnery VS BSM's gunnery

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Alberto Virtuani
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,
Herr Nilsson wrote: "the table has about the same information value like a top trumps card game."
while leaving to "Herr Nilsson" his opinion, the table has the value of a (methodologically correct) comparison between the average effective RoF and # shells/minute of the three ships.
"Top trumps card" or "bridge" game ? This is what we currently have.... surely better than novel accounts of participants who wanted just to underline PoW deficiencies, in order not to raise any doubt about Leach's decision. I see that it's still difficult to quietly accept what crude figures (as well as the other statistics) tell us :

PoW_BS_gunnery_comp.jpg
PoW_BS_gunnery_comp.jpg (87.61 KiB) Viewed 1088 times

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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Herr Nilsson
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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

Using the same method for PoW and Bismarck in case of the only known values are the number of shells fired and the approximate duration of firing. Would the table be the same?
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Alberto Virtuani
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

approximately the same, with the very limited influence that the ordered shots value has on the "effective" values....

Bye, Alberto
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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

And how many salvos were fired?
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

try yourself any value and you will see this is not affecting significantly the "effective" results...

Alberto
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"There's always a danger running in the enemy at close range" (Adm.W.F.Wake-Walker)
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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

Ok, 55 shots, let‘s assume 70 ordered shots. PoW is firing 6 and 4 gun salvos. That means 14 salvos in about 9 minutes. That means 1.55 salvos per minute. ....
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,

PoW line is a fact written by McMullen: I will not follow any attempt to change this line or to say PoW fired in a different way, in case evidence is not presented.
Bismarck has been "normalized" to PoW firing method: for Bismarck we can try any combination of ordered shots but the result will not change, as "only" 93 shells were actually fired.

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: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

But then you're using additional information. What if PoW was sunk and you don't know nothing more than shells fired and the approximate duration of the firing?
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

...but she was not sunk...Hood was and that’s why there is no table for her.
Info for PoW is 100% sure.

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

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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

Yes, and that‘s the crucial point. Your table does not pass the acid test of just using the same information for PoW we have for Bismarck. That means the table may be right for PoW, but the methodology is inappropriate for ships without a similar detailed GAR.
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Marc

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Alberto Virtuani
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

No, because Bismarck shooting is “normalized” to PoW methodology and everybody can try any combination of ordered shots for her, getting almost the same final results....

The crucial point is that we know for sure the “only” 93 shells...

Try and check. Good luck for your attempts.

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: PoW's gunnery VS BSM's gunnery

Post by Bill Jurens »

Mr. Virtuani wrote:

"Hi Mr.Jurens,
you're welcome (my name is Alberto Virtuani)."

My sincere apologies. I was writing in haste and suffered a 'stupid attack'.

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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson »

27*4=108
46*4=184
18*5=74?
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

more or less than 108 for Bismarck ? Take a decision and stick to it. In any way results will not change. Try and check.

Bye, Alberto
Last edited by Alberto Virtuani on Sun Mar 24, 2019 9:19 pm, edited 3 times in total.
"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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Alberto Virtuani
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,

as the table method seems to be too difficult (and debatable if applied to Bismarck), let's get back to basics: does anybody feel that a ship firing 55 shells in 9 minutes (having had 40% of her armament wooded for almost half battle) was much inferior (in terms of effective RoF) to a ship firing 93 shells in 14 minutes with all turrets bearing ? I don't.
Had PoW approached Bismarck with Y turret always bearing, she could have ordered 16 shots more (8 salvos * 2guns). With an output loss of 26% she could have fired 16*0,74= almost 12 shells more. Approximating (incorrectly, just not to use McMullen's "table"), PoW would have fired 67 shells in 9 minutes = 7,4 shells per minute, while Bismarck would have fired 93/14 = 6,6 shells per minute.
As you see, almost nothing changes if we don't use a precise methodology, approximating instead.


All the other statistics are still valid and show how (differently than Hood) PoW fired quite well compared to Bismarck, despite the attempt to say the opposite to justify his Captain's decision to disengage:

1) PoW actual RoF was very slightly better than Bismarck (assuming 108 ordered shots for Bismarck, any other value is welcome....).
2) PoW output loss was larger than Bismarck's (26% lost shots vs 14%)
3) PoW effective RoF was slightly less than Bismarck's one but still in line with it (due to larger output loss).
4) PoW effective # shells delivered / minute was clearly higher than Bismarck's (once accounted for Y turret not bearing for 8 salvos)
5) PoW hit the enemy less minutes (3) after having opened fire than Bismarck (3.5 -4)
6) PoW hit the enemy form a much longer distance (from around 4000 yards more)
7) PoW was initially handicapped by having only the fore turrets bearing for the first 8 salvos, and despite that, she hit first.
8) PoW hit only 3 times vs the 5 hits achieved by Bismarck, therefore her hit rate was worse than Bismarck's
9) In addition Bismarck had to switch target (this had probably not much impact, but it has to be kept into account). PoW had no such a problem.
10) No ship was able to hit enemy when maneuvering in emergency (PoW turned however 20° to port without affecting much the gunnery).
11) The 3 hits of PoW inflicted more serious damages to BS than vice-versa (while BS was devastating against Hood)

All the above, except 1), 2), 3) and 4) depend also on luck. 1), 2), 3) and 4) depend only on ship's gunnery efficiency.


Bye, Alberto
Last edited by Alberto Virtuani on Sun Mar 24, 2019 9:57 pm, edited 10 times in total.
"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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