Prinz Eugen firing procedures at DS

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Prinz Eugen firing procedures at DS

Post by dunmunro » Mon Sep 24, 2018 11:32 pm

It's time that we have a separate thread for Prinz Eugen because much of what A/A claims for Bismarck is being extrapolated from PE's war diary.


What PE's war diary states:

open fire 0555
ceasefire 0609

salvos fired 28 + unknown number

average rnds per salvo is not stated

distinction between 2, 4 and 8 gun salvos is not stated.

20.3cm rounds fired = 157

20.3cm rounds ordered = 184 (not stated but inferred from the war diary)

The war diary's English translation of " Die S.A. erzielte eine durchschnittliche Salvenfolge von 27-28
sec." states that PE " the heavy artillery attained a salvo rate of 27-28 seconds. " However Google tranlates this as:
The S.A. scored an average salvo score of 27-28 sec.
(pages 40-41)

This is an important difference because "attained" implies maximum whereas "average" implies that RoF was both faster and slower at differing times during the engagement.

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Re: Prinz Eugen firing procedures at DS

Post by northcape » Wed Sep 26, 2018 1:19 am

The original German sentence you quote translates correctly to "average salvo rate".

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 3:06 am

northcape wrote:
Wed Sep 26, 2018 1:19 am
The original German sentence you quote translates correctly to "average salvo rate".
Thanks. That's what I suspected.

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 8:55 am

Image

In the above chart AA claim that PE fired 44 salvos. Yet Jasper states that the average time per salvo was 27.5 seconds. 44 x 27.5 seconds = ~20 minutes... :think: Nowhere in Jasper's statement is there any mention of 3.2 salvos/min or ~19 seconds/salvo or of 44 salvos.

OTOH Jasper states that after Salvo 28 that control was passed to the after director, which then fired " ...rapid partial salvos..." presumably two gun salvos.

A reasonable assumption is that control was passed to the after director 12.8 minutes into the action and that the after control was only able to fire for 1.2 minutes before ceasefire or about 5 x 2 gun salvos. This means that the 28 salvos fired before then fired about 147 rounds.

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Re: Prinz Eugen firing procedures at DS

Post by Alberto Virtuani » Wed Sep 26, 2018 10:39 am

The extremely annoying (also for Mr.Dunmunro) table is built using the same methodology of McMullen in his GAR as anyone can check in Enclosure I (http://www.hmshood.org.uk/reference/off ... 09guns.htm) because this is the only way to compare the same figures between the ships. If anybody can calculate PG "table" using another methodology, he is welcome !

McMullen derived the figures in the table starting from 1) the battle duration,2) the shells fired and the 3) ordered shots. Plus he was aware of the exact number of salvos fired (18) and of the fact that his Y turret was wooded until after salvo 8.

For PG we have the same 1), 2) and 3) exact data (timing is rounded to 14 minutes) and the result is in the table. For Bismarck the only "assumption" is 108 as ordered shots. The problem with PG is that we don't know the exact number of salvos ordered from the aft control. However also in this case, the effective # shells fired per minute is not affected significantly.
The "salvos" in the table are however all 4-guns-salvos for both German ships.

Coming to Mr.Dunmunro assumption, 28 salvos fired from the PG fore control position account for 112 shots, impossible that they fired 147 rounds as Mr.Dunmunro propose (confusing fired shells and ordered shots... :lol: ), at least if Germans were not firing 2 shells per gun or if we don't mix salvos and broadsides.... :lol:


I'm not much interested in the 27-28 seconds (average or peak) declared by Jasper and in the way he counted salvos (no mention of them in his GAR) : he was possibly referring to the RoF for a single gun (full-salvo cycle) possibly when not firing for acquiring the target and in any case we don't know exactly whether PG fired salvos or broadsides (except the Vollsalve).


In alternative, I'm eager to see Mr.Dunmunro reconstruction of the battle letting PG to fire for 20 minutes...... :lol: :lol: :lol:


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Re: Prinz Eugen firing procedures at DS

Post by José M. Rico » Wed Sep 26, 2018 5:39 pm

Obviously, the initial salvos fired by Prinz Eugen starting at 0555 hours took more than 27-28 seconds to reach their target. At 20,000 meters the flight time of the German 20.3cm projectile was 35-36 seconds. Flight times of 28 seconds are only obtained once the distance has gone down to about 16,500 meters.

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 5:41 pm

Alberto Virtuani wrote:
Wed Sep 26, 2018 10:39 am
The extremely annoying (also for Mr.Dunmunro) table is built using the same methodology of McMullen in his GAR as anyone can check in Enclosure I (http://www.hmshood.org.uk/reference/off ... 09guns.htm) because this is the only way to compare the same figures between the ships. If anybody can calculate PG "table" using another methodology, he is welcome !

McMullen derived the figures in the table starting from 1) the battle duration,2) the shells fired and the 3) ordered shots. Plus he was aware of the exact number of salvos fired (18) and of the fact that his Y turret was wooded until after salvo 8.

For PG we have the same 1), 2) and 3) exact data (timing is rounded to 14 minutes) and the result is in the table. For Bismarck the only "assumption" is 108 as ordered shots. The problem with PG is that we don't know the exact number of salvos ordered from the aft control. However also in this case, the effective # shells fired per minute is not affected significantly.
The "salvos" in the table are however all 4-guns-salvos for both German ships.

Coming to Mr.Dunmunro assumption, 28 salvos fired from the PG fore control position account for 112 shots, impossible that they fired 147 rounds as Mr.Dunmunro propose (confusing fired shells and ordered shots... :lol: ), at least if Germans were not firing 2 shells per gun or if we don't mix salvos and broadsides.... :lol:


I'm not much interested in the 27-28 seconds (average or peak) declared by Jasper and in the way he counted salvos (no mention of them in his GAR) : he was possibly referring to the RoF for a single gun (full-salvo cycle) possibly when not firing for acquiring the target and in any case we don't know exactly whether PG fired salvos or broadsides (except the Vollsalve).


In alternative, I'm eager to see Mr.Dunmunro reconstruction of the battle letting PG to fire for 20 minutes...... :lol: :lol: :lol:


Bye, Alberto
You've invented 44 salvos - Jasper never states that anywhere in his account. You're the one letting Jasper fire for 20 minutes because you invented 44 salvos despite the 27.5 sec average salvo rate, as stated by Jasper.

We have what Jasper has told us: Open fire at 0555 and cease fire at 0609; 28 salvos via the forward director and an unknown number via the after director. We have an average salvo rate. We have an unknown number of rounds fired per salvo and we don't know if 28 salvos represents a mix of 8 gun and 4 gun salvos, yet logically 28 salvos must be a mix of 8 and 4 gun salvos given the average salvo rate. The stated firing via the after director implies 2 gun salvos.
Last edited by dunmunro on Wed Sep 26, 2018 6:34 pm, edited 1 time in total.

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 5:48 pm

José M. Rico wrote:
Wed Sep 26, 2018 5:39 pm
Obviously, the initial salvos fired by Prinz Eugen starting at 0555 hours took more than 27-28 seconds to reach their target. At 20,000 meters the flight time of the German 20.3cm projectile was 35-36 seconds. Flight times of 28 seconds are only obtained once the distance has gone down to about 16,500 meters.
Yes, and this implies that several salvos were in the air at some points in time but also that the RoF was much higher at some stages of the battle than others.

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Re: Prinz Eugen firing procedures at DS

Post by wadinga » Wed Sep 26, 2018 6:07 pm

Hello Jose,

One of the problems I believe we should address is to decouple reload interval from firing interval. All navies and all ships spent considerable time designing loading systems and drilling to reduce reload time to the lowest value time in seconds compatible with reliable operation. Prinz Eugen's guns may well have been ready to fire again before the shell fired by the same gun had landed. Only when the time of flight is less than the reload time is the rate of fire limited by reload rate.

There is refusal to understand and accept (by some parties) that PoW's slow firing rate which did not shorten even when she was straddling her target (and trying to kill her enemies as a matter of survival) is because her baulky loading system would not allow the rate to speed up, and even then her output was 25% down. Once straddling had been achieved and before future position forecast became accurate, "Good Rapid" would be ordered and the guns would fire as quickly as they could be reloaded whether the previous shot had landed or not.


Since Northcape has provided:

The original German sentence you quote translates correctly to "average salvo rate".

We may assume this is actual firing rate and compensates for those times when the time of flight was longer because it includes for those times when it was shorter. There would be no point in recording it unless it related to the same gun firing.

BTW Since Alberto is in possession of a document suitable for inclusion in your archives, I would have thought that a quid pro quo for allowing the endless (and shameless) promotion of their forthcoming publication in these threads, would be submission of a copy for your (and our) interest. :cool:

Alberto wrote:
Well, I have read the secret document that Jasper wrote to Raeder after the mission, have you ?
All the best

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Re: Prinz Eugen firing procedures at DS

Post by alecsandros » Wed Sep 26, 2018 6:46 pm

wadinga wrote:
Wed Sep 26, 2018 6:07 pm
is because her baulky loading system would not allow the rate to speed up, and even then her output was 25% down. Once straddling had been achieved and before future position forecast became accurate, "Good Rapid" would be ordered and the guns would fire as quickly as they could be reloaded whether the previous shot had landed or not.
Prince of Wales NEVER had the CONTINOUS firing solution towards the enemy. She fired 18 salvos on director control, in about 9 minutes, of which 3 salvos (no 6, 9, 13) straddled.
Her official G.A.R. clearly describes how the officers ATTEMPTED to KEEP the FIRING SOLUTION on the enemy, but that was not attained:

"6. Salvoes 1 and 2 were spread for line, salvo 1 falling right and salvo 2 in line over. Salvoes 3 and 4 were fired as a down ladder and fell over. Salvoes 5 and 6 were fired as a further down ladder; 5 fell over and 6 straddled. It had been decided after Prince of Wales' last firing to use a 200-yard as opposed to a 100-yard zigzag, as the spreads were in the nature of 350 yards. Accordingly salvoes 7 and 8 were fired as a 200-yard zigzag about salvo 6's range. Both 7 and 8 were observed as over and salvoes 9 and 10 were fired as a regaining down ladder. Salvo 9 was seen to straddle, 10 short, and salvoes 11 and 12 were fired as a 200-yard zigzag about salvo 9's range. Both of these were spotted as short, and salvoes 13 and 14 were fired as a regaining ladder up: 13 appeared to straddle, 14 went over, and a further zigzag was fired with salvoes 15 and 16 about salvo 13's range; [.....]"

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Re: Prinz Eugen firing procedures at DS

Post by José M. Rico » Wed Sep 26, 2018 6:51 pm

wadinga wrote:
Wed Sep 26, 2018 6:07 pm
One of the problems I believe we should address is to decouple reload interval from firing interval. All navies and all ships spent considerable time designing loading systems and drilling to reduce reload time to the lowest value time in seconds compatible with reliable operation. Prinz Eugen's guns may well have been ready to fire again before the shell fired by the same gun had landed. Only when the time of flight is less than the reload time is the rate of fire limited by reload rate.
I understand, but in this case, the rate of fire during the initial salvos is limited by the gunnery officer since he has to wait to observe the fall of shot in order to introduce the necessary firing corrections. "Rapid fire" won't be ordered until a straddle is observed.
wadinga wrote:
Wed Sep 26, 2018 6:07 pm
Since Northcape has provided:

The original German sentence you quote translates correctly to "average salvo rate".

We may assume this is actual firing rate and compensates for those times when the time of flight was longer because it includes for those times when it was shorter. There would be no point in recording it unless it related to the same gun firing.
That's a reasonable assumption.
wadinga wrote:
Wed Sep 26, 2018 6:07 pm
BTW Since Alberto is in possession of a document suitable for inclusion in your archives, I would have thought that a quid pro quo for allowing the endless (and shameless) promotion of their forthcoming publication in these threads, would be submission of a copy for your (and our) interest. :cool:

Well, if Alberto wants to submit a document for publication in the website's archives, he can always contact me via e-mail and let me know about it. I will be glad to publish anything of interest.

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Re: Prinz Eugen firing procedures at DS

Post by alecsandros » Wed Sep 26, 2018 6:58 pm

José M. Rico wrote:
Wed Sep 26, 2018 6:51 pm
"Rapid fire" won't be ordered until a straddle is observed.
With all due respect,
rapid fire will be ordered by the Artillery Officer on duty according to tactical conditions. If the first salvo of the Vollsalve straddles, and the other 2 (of the same Vollsalve) do not*, it means the range was not properly acquired**. Also, if the enemy is altering course or expected to alter course at any moment, rapid fire wouldn't be opened.

* It means the enemy is closer then thought, and corrections of elevation need to be executed. After they are done, another ranging salvo will be produced. But in that time, depending on exact geometry, bearing will oprobably change as well, thus turret will need to be re-trained on the future bearing (expected) of the enemy ship.

**Historically Bismarck DID have a proper Vollsalve right from the start, with semisalvo1 being short, semisalvo2 long, semisalvo3 straddle (with hit - all 3 being from the first Vollsalve). Thus Bismarck's firing solution was actualy correct from the first "salvo".

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 7:10 pm

Alberto Virtuani wrote:
Wed Sep 26, 2018 10:39 am
The extremely annoying (also for Mr.Dunmunro) table is built using the same methodology of McMullen in his GAR as anyone can check in Enclosure I (http://www.hmshood.org.uk/reference/off ... 09guns.htm) because this is the only way to compare the same figures between the ships. If anybody can calculate PG "table" using another methodology, he is welcome !

McMullen derived the figures in the table starting from 1) the battle duration,2) the shells fired and the 3) ordered shots. Plus he was aware of the exact number of salvos fired (18) and of the fact that his Y turret was wooded until after salvo 8.

Now for an "...extremely annoying..." rebuttal of the above statements.

McMullen's table: "[Enclosure (I)] SUMMARY OF FORMS S.1146 - (f) - First Action" is based upon salvos fired under AFCT control via the forward DCT. It doesn't include salvos fired by other methods and the ceasefire time for the table is when the forward DCT was wooded. Yet A/A's table includes all salvos fired by PE and even invents the numbers of salvos fired.


McMullen derived the figures in the table starting from 1) the battle duration,2) the shells fired and the 3) ordered shots. Plus he was aware of the exact number of salvos fired (18) and of the fact that his Y turret was wooded until after salvo 8.
1) The battle duration was 0553 - 0611 as stated in PoW's log. The duration of 14in firing was 0553 - 0603 + an unknown interval which could be as long as 8 minutes.
2) the shells fired = shells fired under AFCT control and specifically excluded shells fired via other control methods.
3) the number of ordered shots = shots ordered while under AFCT control and excludes shots fired via other control methods.

McMullen was aware of the number of salvos fired under his (AFCT via forward DCT) control (18) and Jasper was aware of the number of Salvos fired (28) under his (forward director) control. Mcmullen's table includes a mix of 3 and 5 gun salvos and logically Jasper's 28 salvos must include a mix of 8 and 4 gun salvos. Unlike McMullen Jasper doesn't tell us the number of rounds fired or ordered during the 28 salvos fired under his control.

McMullen's table, above, includes an average salvo interval which Jasper also states, but unlike Jasper McMullen gives us the exact range and timing of each salvo fired under AFCT control. This allows us to note that maximum salvo rate occurs from ~0559:40 - ~0600:50 when 4 salvos are fired and that there are intervals of ~one minute (~0557-8 and ~0601-2) where no firing occurs. Yet A/A would have us believe that both Bismarck and PE fired at completely regular intervals with no increases or decreases in the RoF... :oops:

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Re: Prinz Eugen firing procedures at DS

Post by alecsandros » Wed Sep 26, 2018 7:23 pm

dunmunro wrote:
Wed Sep 26, 2018 7:10 pm
logically Jasper's 28 salvos must include a mix of 8 and 4 gun salvos.
and the initial Vollsalve how many guns had in it ?

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Re: Prinz Eugen firing procedures at DS

Post by dunmunro » Wed Sep 26, 2018 7:26 pm

alecsandros wrote:
Wed Sep 26, 2018 7:23 pm
dunmunro wrote:
Wed Sep 26, 2018 7:10 pm
logically Jasper's 28 salvos must include a mix of 8 and 4 gun salvos.
and the initial Vollsalve how many guns had in it ?
Page 39 of PE's War Diary states 8 guns.

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