Tirpitz sails on part of Rheinubung

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Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Wed Feb 17, 2016 2:59 pm

Hi All,
Hi Alecsandros, think you have that a little mixed up for the first eight salvos PoW could have fired 3 guns per salvo, and for the remaining she could have fired 5 per salvo, the British fired half the available guns per salvo to increase the rate of fire and help with spotting fall of shot where as the Germans seem to have fired in the salvo system you mentioned earlier.

Hope this helps

Best wishes,
Cag.

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Re: Tirpitz sails on part of Rheinubung

Postby alecsandros » Wed Feb 17, 2016 6:46 pm

Cag wrote:Hi All,
Hi Alecsandros, think you have that a little mixed up for the first eight salvos PoW could have fired 3 guns per salvo, and for the remaining she could have fired 5 per salvo, the British fired half the available guns per salvo to increase the rate of fire and help with spotting fall of shot where as the Germans seem to have fired in the salvo system you mentioned earlier.

Hope this helps

Best wishes,
Cag.

... I did not count guns per salvo,
I counted guns bearing on target (not wooded)...

Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 9:36 am

Hi All,
Could I please ask a favour of Alecsandros, and to everyone who may be able to help too. Maybe I'm being a bit stupid I don't know so could someone check my thought process. In Alberto's table the only trouble I'm having is the Fired salvos column, and the Number of guns in a salvo when not wooded.

If the figure in the Number of guns in a salvo when not wooded is 5, then the figure in the salvos fired column should not be 18 but should be 10, as this is actually the number of salvos that had a potential to have 5 guns per salvo because there was no wooding (And so the first 8 salvos cannot be included and must be treated seperately). The first 8 salvos would have to be calculated with their individual loss rates and we would have two seperate number of effective shells per minute figure given, or if required an averaged figure of the two.

However if the column with the salvos fired contains the figure 18 then the figure in the number of guns in a salvo should not be 5 but be an average of the 18 salvos, (3 x 8 + 10 x 5 divided by 18 i.e. 4,115 giving 4,115 x 18 = 74,07). This would give a figure of 5,8021 in the effective number of shells per minute (4,115 x 1,41) and not 7,0456.

Therefore the statement that PoW had a higher RoF and a higher number of shells per minute, or output, is misleading, obviously meant to imply that 'the guns were ok' and that Captain Leach's decision to disengage was incorrect.

With this in mind would the actuality be that the PoW had a higher Rof but a lower output?

I would be grateful for all your help and maybe point out where I'm going wrong as this makes sense to me!
Best wishes
Cag.

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Re: Tirpitz sails on part of Rheinubung

Postby alecsandros » Thu Feb 18, 2016 9:46 am

Cag wrote:Therefore the statement that PoW had a higher RoF and a higher number of shells per minute, or output, is misleading, obviously meant to imply that 'the guns were ok' and that Captain Leach's decision to disengage was incorrect.

With this in mind would the actuality be that the PoW had a higher Rof but a lower output?

I don't think so.

Dubious and incredible as it seems, Prince of Wales obtained higher rate of fire AND higher output per gun during the 9 minutes of director firing, than Bismarck obtained in her 14 minutes of firing (averages for both, of course).

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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 10:27 am

Hi Alecsandros,
But is my summary of the table correct?
Best wishes
Cag.

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Alberto Virtuani
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Re: Tirpitz sails on part of Rheinubung

Postby Alberto Virtuani » Thu Feb 18, 2016 10:32 am

Cag wrote: "Would it have been better to have averaged out the Guns per Salvo figure to represent the whole of the 26/18 salvos from Bismarck/PoW (E.g. 4,0 for Bismarck 26 x 4 and 4,1 for PoW 8 x 3 + 10 x 5) which would have represented the whole time more precisely?"

Hi Mr.Cag,
I will just try to explain better regarding my table: If we do as you suggest above, I 'm afraid we will mix up tactical (intercept geometry) aspects (turrets bearing or not) with the pure gunnery performance that was, in my intention, the scope of this statistical analysis. Again, my intention was not to measure how many shells the 2 ships actually fired (it is well known and agreed), due to their courses and relative target bearings.

If effective RoF is 1,60 (Bismarck) vs 1,41 (PoW) as per PoW GAR (it's not a definition of mine......), and this figure already accounts for the actual output loss percentage, then it means PoW could fire 1,409 complete (no output loss) salvos per minute and BS 1,597 (not the ones actually fired that are respectively 1,89 for PoW and 1,78 for BS) . As BS salvo is 4 guns and PoW is 5 (assuming not wooded), the final result for effective number of shells that the 2 ships could fire is 7, 04 for PoW and 6,38 for BS.

PoW_vs_Bismarck(104)_firing.jpg
PoW_vs_Bismarck(104)_firing.jpg (37.98 KiB) Viewed 1817 times

Bye, Alberto
Last edited by Alberto Virtuani on Thu Feb 18, 2016 11:37 am, 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)

Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 10:35 am

Hi Alberto,
I understand, you're basing it on what could have been fired and not what was fired?
Best wishes
Cag.

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Re: Tirpitz sails on part of Rheinubung

Postby alecsandros » Thu Feb 18, 2016 10:37 am

Yes, I think it is.

But it's more complicated to analyse the salvos, IMHO.

If we look at the simple number of guns available (not wooded) for each ship, we can obtain the following numbers:

Available guns to fire per minute:
Prince of Wales - 6 guns per 5 minutes, followed by 10 guns per 4 minutes. Average: 7.77 guns per minute.
Bismarck - 8 guns per 14 minutes. Average: 8 guns per minute.

Shots fired:
Prince of Wales: 55 out of 74 in 9 minutes => average 6.11 shots / 8.22 ordered
BIsmarck: 93 out of 112 in 14 minutes => average 6.64 shots / 8.00 ordered

Average shots fired per minute by available guns per minute:

Prince of Wales: 6.11 shots / 7.77 guns per minute = 0.7863 shots per minute per available barell (and 1.0579 ordered per available gun per minute)

Bismarck: 6.64 shots / 8 = 0.830 shots per minute per available barell (and 1.0000 ordered per available gun per minute)

Conclusion: Bismarck fired 0.0437 shots per minute per available gun MORE than PoW, and ordered 0.0579 shots per available gun LESS than PoW.

Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 10:45 am

Hi All,
Thank you Alecsandros and Alberto, that is where I have been going wrong I assumed that this was actual and not theoretical. I realise that the 1,41 figure includes the loss percentage but obviously does not factor in the wooding of the after turret during the salvo 1-8 period.
Thank you for your help
Best wishes and much thanks,
Cag.

Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 10:47 am

Hi Alecsandros,
I thought the figure for Bismarck was 104 ordered not 112?
Cag.

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Alberto Virtuani
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Re: Tirpitz sails on part of Rheinubung

Postby Alberto Virtuani » Thu Feb 18, 2016 10:57 am

Cag wrote: "I understand, you're basing it on what could have been fired and not what was fired?"

Hi Mr.Cag, yes, exactly.

Regarding he number of shells ordered to fire, Antonio's salvo plot shows 104 as the most probable figure matching available infos with photos and PG film) but it could have been (as per his own admission) 108 or 112.....

However final number of effective shells per minute does not change dramatically. Here the same table (power of the spreadsheets :D ) simulating 112 ordered to fire on Bismarck (her actual RoF increases but output loss increases as well, therefore effective RoF is almost the same, always using PoW GAR official definitions and formulas) :

PoW_vs_Bismarck(112)_firing.jpg
PoW_vs_Bismarck(112)_firing.jpg (37.33 KiB) Viewed 1817 times

Bye, Alberto
Last edited by Alberto Virtuani on Thu Feb 18, 2016 11:38 am, edited 11 times in total.
"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: Tirpitz sails on part of Rheinubung

Postby alecsandros » Thu Feb 18, 2016 10:59 am

Cag wrote:Hi Alecsandros,
I thought the figure for Bismarck was 104 ordered not 112?
Cag.

There is no definitive answer...

I used 112 as it seems more plausible to me; but it may as well be 104. If you use 104, the number of shells ordered to be fired by Bismarck becomes even less (per minute per not-wooded gun) than Prince of Wales (it's smaller even using 112)

Cag
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Re: Tirpitz sails on part of Rheinubung

Postby Cag » Thu Feb 18, 2016 12:28 pm

Hi All,
Thanks Alberto I had just done the same calculations myself but not as good looking as yours! So if PoW rear turrets had not been wooded then we'd have these figures, ok I've got it, theoretical not actual, and as a bonus we also have the figures for actual not theoretical too! I thought i had missed something!
Best wishes and much thanks again,
Cag.


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