More on KGV Class main armament problems

[Byron Angel]

The salvo firing data cited for the British BC's at Jutland were taken from their respective Jutland gunnery logs, details of which were kindly provided to me by a kind and friendly British naval researcher and historian.

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From -
C.B. 272 - Spotting Rules 1916
Admiralty S.W., Gunnery Branch (No. 576)
G. 04439/16
November 1916

4. The following table gives the spread and average firing interval for the various natures of guns, and forms the basis on which the method and rules have been drawn out:-

Gun ----------------------- Average Spread --------------- Average Firing Interval
15-inch ------------------- 200 yards ---------------------- 60 seconds
14-inch ------------------- 200 yards ---------------------- 50 seconds
13.5-inch ---------------- 300 yards ----------------------- 50 seconds
12-inch ------------------ 400 yards ----------------------- 50 seconds
9.2-inch and below ---- 400 yards (at 12,000) -------- 40 seconds


Note - The post-Jutland 1916 Spotting Rules were the first iteration and progenitor of the spotting rules employed by the RN in WW2.


B

[Alberto Virtuani]

Hello everybody,

Bill Jurens wrote: "This, while interesting as representing a personal point of view, would seem to be best seen as somewhat conjectural and speculative. He does describe Leach’s decision as ‘hard and objectively valid’, and I certainly cannot disagree with that interpretation at all."

I see that we read Santarini's judgements exactly in the way that support our view (that's normal).

IMO, he correctly evaluated the PoW gunnery performances and logically understood why British (and fans...) cannot accept to recognize it in order not to discuss Leach's decision.

He IMO incorrectly evaluated Leach decision as the right one, but he was influenced by having assumed as correct the "embellished" official reports. I say it was correct only with hindsight, while very poor militarily at 6:01 on May 24.

Who's right ? We can debate based on facts.


Bye, Alberto

[Alberto Virtuani]

Hello everybody,

Byron Angel wrote: "The following table gives the spread and average firing interval for the various natures of guns
Gun ----------------------- Average Spread --------------- Average Firing Interval
15-inch ------------------- 200 yards ---------------------- 60 seconds
14-inch ------------------- 200 yards ---------------------- 50 seconds
13.5-inch ---------------- 300 yards ----------------------- 50 seconds
12-inch ------------------ 400 yards ----------------------- 50 seconds"

Thanks, this confirms that large guns average firing interval at Jutland was between 50 and 60 seconds, thus from 1 to 1.2 rpgpm., confirming Campbell analysis (based on ship's gunnery logs, official reports and damage reports), who estimated a salvo interval of 25 seconds for both British and German ships as RoF.
The shell expenditure (Lion: 326 13.5" shells in the whole day and evening) confirms that no ship could have fired at the fantastic rate of 2 rpgpm, as this would have emptied her magazines already during the "Run to South" only.

Not better than PoW (or Bismarck) at DS (with a very difficult geometry the the DS encounter), where it was around 1 rpgpm.


Bye, Alberto

[Byron Angel]

Hello everybody,

Byron Angel wrote: "The following table gives the spread and average firing interval for the various natures of guns
Gun ----------------------- Average Spread --------------- Average Firing Interval
15-inch ------------------- 200 yards ---------------------- 60 seconds
14-inch ------------------- 200 yards ---------------------- 50 seconds
13.5-inch ---------------- 300 yards ----------------------- 50 seconds
12-inch ------------------ 400 yards ----------------------- 50 seconds"

Thanks, this confirms that large guns average firing interval at Jutland was between 50 and 60 seconds, thus from 1 to 1.2 rpgpm., confirming Campbell analysis (based on ship's gunnery logs, official reports and damage reports), who estimated a salvo interval of 25 seconds for both British and German ships as RoF.
The shell expenditure (Lion: 326 13.5" shells in the whole day and evening) confirms that no ship could have fired at the fantastic rate of 2 rpgpm, as this would have emptied her magazines already during the "Run to South" only.

Thank you. This is exactly the point I made in the first place. PoW's salvo rate of fire was typical and unremarkable, even compared to known gunnery performance dating back to WW1; it was not "excellent", in the dictionary sense of the word.

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Not better than PoW (or Bismarck) at DS (with a very difficult geometry the the DS encounter), where it was around 1 rpgpm.

I disagree on technical grounds. No sufficiently detailed Bismarck 24 May gunnery data survives to make a technically meaningful comparison re salvo rate of fire.

- - -

A comment re range rates and the black art of naval gunnery. The devil is not range rate per se. If the range rate remains a constant value, the degree of the change in range per unit of time is largely immaterial once found. The true devil is found in the second order function - rate of change of range rate; when this value varies (an all too common circumstance), the gunnery range solution becomes rather more difficult. In the first ten minutes or so of the action, both PoW and Bismarck enjoyed a situation where the rate of change of range rate was probably very small.

Perhaps Mr Jurens could provide some further insights on this point.


B

[wadinga]

Fellow |Contributors,

As has so often been the case when a poster generously supplies genuine original material in their possession for the general improvement of understanding, rather than tactically withholding or redacting it, there has been an attempt to claim it is a "boomerang", injuring their own argument. Of course nothing could be further from the truth.

Firstly the "Spotting Rules" are just that, concerned solely with the initial phase of getting the range and rate of the target before moving on to the "rapid fire" phase. As Bill Jurens (and many, many others) have observed, rates of fire varied considerably, at one extreme being as short as the weapon's loading interval, typically for battleship guns 20-30 seconds, to higher intervals where the spotting requirement meant the fall of shot, and therefore any modification to the continuously-applied corrections from the FC system must be somewhat lengthier than the time of flight.

This, of course, renders the crude statistical method of selecting an arbitrary period of time and dividing number of shells fired during it worthless.

The fact that Bismarck fired 93 shells in 14 minutes means she fired 0.83 rpgpm in average.
If we trust the Baron, it took 5 minutes to fire 40 shells, therefore a slightly higher 1 rpgpm in the first 5 minutes.

By the same naïve logic, since the average speed of traffic in London is 8.34 miles per hour it is a fact that all the speeding tickets issued are invalid.

It is entirely logical that the early part of the 40 shot engagement against Hood should be conducted at the leisurely pace of the German Spotting Rules equivalent, followed by the Baron's incontestable evidence of a speed-up order during the last salvoes.

The attempt to degrade the evidence of the film sequence by claiming it is run 50% faster than reality is pure speculation, and certainly no other part has the "keystone cops" effect about it. German sailors saunter around the decks. Even the shell splashes linger in the air for about as long as one might expect.

For those interested in understanding naval gunnery more deeply, on another site, a complete document has been generously posted, being a digest of the RN's Annual "Progress in Naval Gunnery" covering 1914-36. It has the HMS Hood Association watermark so I imagine we must thank them as well. http://www.admirals.org.uk/records/adm/ ... 86-339.pdf

Even allowing the complication of co-ordinating fire of two ships, and since no-one in PoW saw Hood's splashes near Bismarck, there is no reason to believe salvoes were delayed to observe GIC protocol, the piece from page 49 is of interest:

None of the foregoing sectors allowed a 15 inch gun ship to develop her full output- 3 salvoes per ship per minute

This quote is talking about proper salvoes, ie half the gun armament at once not the feeble output PoW managed and addressed by both Gerald Langley and Oliver Bevir in their responses to the First Sea Lord.

All the best

wadinga

[Alberto Virtuani]

Hello everybody,

@Byron Angel,
thanks for admitting you were unable to find an example of a significantly better RoF in battle fought under the same conditions.

" it was not "excellent", in the dictionary sense of the word"

it was, due to the situation in which it was obtained, with spray obscuring the main rangefinders and a high range closure rate that prevented both Hood and PoW to obtain an initial range and to correctly estimate the range closure rate (see PoW GAR salvo plot, where the enemy track is not a straight line... Hood apparently did even worse, not finding the range at any time...).

The demonstration of the "excellence" of PoW RoF comes from Bismarck, that did not achieve a better one, despite the "indeterminateness" excuses (download/file.php?id=3463).


Bye; Alberto

[Alberto Virtuani]

Hello everybody,

Wadinga wrote: ".....here has been an attempt to claim it is a "boomerang.....""

...like the May 31 Tovey's letter to Pound ?
...or like the attempt to hide the importance of the ADM 205/10 papers ?

Yes, big booooooomerangs ! We are still in debt with this forum member for these decisive self-goals, let's hope he keeps going this way.

" the evidence of the film sequence by claiming it is run 50% faster than reality is pure speculation"

tell to whom said " at least 33%" , not to me....


The only incontrovertible fact is that Bismarck was able to deliver only 93 shells in 14 minutes... no way to deny this fact, especially not having any idea of the battle development (courses, timing, etc.) due to the "indeterminateness" excuse.


Bye, Alberto

[dunmunro]

PE's War Diary suggests that Hood had accurate range data from her first salvos, as they fell close to PE right from the start.

We don't know with certainty Bismarck's open fire (3 independent RN observations suggest ~0553) and ceasefire times; we only know PE's because her war diary survived but unfortunately it doesn't give accurate open fire and cease fire times for Bismarck.

Additionally, the allocation of time sectors suggests Hood was also firing at 2 salvos/minute.

[Alberto Virtuani]

Hello everybody,

"PE's War Diary suggests that Hood had accurate range data from her first salvos...We don't know with certainty Bismarck's open fire (3 independent RN observations suggest ~0553) and ceasefire times"

I really don't know how to answer to someone who is able to mention PG KTB generic observations about British splashes (without any reference to place them at any precise timing...) but still denies, in the same post, what is clearly written in the same KTB: BOTH German ships returned fire during minute 05:55....
Of course, the theory that Bismarck might have ceased fire long time before (or after) PG is just a speculation based on...nothing at all, in the hope to support the "indeterminateness" party.

This forum member should decide (making peace with himself) whether he wants to trust the PG War Diary or not...



Anyway, I agree Hood was initially firing 1 rpgpm (as PoW and BS, btw) but still, after 8 minutes battle, all she did was to wash the decks of PG and to send a single splinter on board the cruiser, while PoW had already hit three times.
Not an impressive gunnery performance even if with an "excellent" initial RoF, under those conditions.

I say initial, because we don't know how long Hood was actually able to keep up with PoW. Schmalenbach counted only 10 salvos from Hood and in the PoW Salvo plot there is "Hood out of action" after 6 salvos, pointing to Hood having "abandoned" her time sectors for reasons not linked to the German fire (as the first German shells were still in the air at that time...).



Schmalenbach himself gives the only "timing" for the first observed salvo from Hood and he is quite clear that until 5:55:xx (after 4 or 5 salvos from Hood) he did not observe any British shell splash, only one that cannot be called in any way a "near miss", being around 110 meters far from the extreme bow...

PG_British_Splashes.jpg (41.42 KiB) Viewed 695 times

Bye, Alberto

[Bill Jurens]

Mr. Virtuani wrote:

"This forum member should decide (making peace with himself) whether he wants to trust the PG War Diary or not..."

I may be wrong -- I've certainly been wrong before -- but didn't the Germans themselves characterize much of the Prinz Eugen documentary material as being 'useless'?

Bill Jurens

[Alberto Virtuani]

Hello everybody,

Bill Jurens wrote: "... didn't the Germans themselves characterize much of the Prinz Eugen documentary material as being 'useless'?"

Schmundt defined "useless and worthless" the PG battlemap (http://www.hmshood.com/history/denmarks ... tlemap.gif), because of the totally wrong tracks for Hood and PoW and their distances that he recommended to check with Jasper.

Who should have "characterized as being useless much" of the PG KTB, please ?


Bye, Alberto


P.S. on a comic tone, can anyone imagine what Schmundt would have said, had he seen Tovey's point 19 of the despatches, with the retreat time of PoW declared to be 06:13, with PoW almost ramming his ships by that time ?

[Bill Jurens]

@ Mr. Virtuani:

O.K. So I take it that you are assuming -- for whatever reasons -- that the battle track charts are in error, but the KTB is not. You are certainly entitled to that assessment.

I am confused about one other thing. You write:

“Schmalenbach himself [...]did not observe any British shell splash, only one that cannot be called in any way a "near miss", being around 110 meters far from the extreme bow...”

and then include a .jpeg image, with a quote apparently from Schmalenbach himself, stating in part “...except for 2 impacts [that landed] forward...(approximately 100 meters in front of the stem.”

How did ‘approximately 100 meters in front of the stem’ become ‘around 110 meters from the extreme bow’? Where did the extra 10 meters come from?

Bill Jurens

[Alberto Virtuani]

Hello everybody,

Bill Jurens wrote: "So I take it that you are assuming -- for whatever reasons -- that the battle track charts are in error, but the KTB is not"

No, I don't assume anything. I say what Adm.Schmundt criticized: the PG battlemap only and NOT the KTB... I can criticize the PoW log (with its totally wrong timings and accept the PoW Salvo Plot data (except the BS track) without having to throw away both of them + all the other PoW documents.

It's really funny to see how British docs are lightly considered truthful (even Tovey's despatches point 19 and 17 or the Pinchin's "Plot"...) while German documents are somehow always looked at with suspicion...
Please, tell me who criticized "much" of the PG documents, except this single aspect....

Bill Jurens wrote: " Where did the extra 10 meters come from?"

...simply from the Pythagorean theorem... 100 meters in front and 50 on the left makes 111,xxxx meters distance... I beg pardon for rounding to 110....


Bye, Alberto

[dunmunro]

PE's War Diary states that Bismarck fired before PE and that PE opened fire at 0555. Busch states (see below) that Bismarck fired just after PoW's first salvo.

Busch, in his Prinz Eugen book states that Hood's first two salvos fell 100 yards forward of PE's bow and then straddled. The War Diary via Schmalenbach, also makes a similar statement (a shell splash 100 metres forward and another at 50 metres amidships) and notes further salvos landing astern but doesn't give precise timing. Jasper and Schmalenbach were observing their targets through very high power, narrow field, optics and it is not surprising that they couldn't see much around them as Busch notes. Schmalenbach's ability to see Hood's shell splashes indicates that they were very close indeed. The accuracy of Hood's initial salvos indicates the use of radar ranging, which we know was employed by PE as well.

The visibility was good but the steadiness of the air was apparently poor and Jasper was unable to identify either target as a battleship (Schmalenbach not identify Hood until she was sinking)

[Alberto Virtuani]

Not at all,

PG KTB says explicitly and TWICE that both BS and PG answered fire together at minute 05:55 or after 4 - 5 salvos from Hood....

Busch account is not the PG KTB, so please admit you were simply wrong again and then come back with the accounts "dramatically" written (like the British novels depicting PoW surrounded by water walls, due to German shells, while McMullen reported nothing at all).

Schmalenbach saw a splash 100 meters from the bow: which "narrow field", possibly 120° narrow ? Jasper was looking through a narrow field instrument and saw nothing but reported 4 salvos falling close (no straddles, no near misses, see below his report).

Holland was unable to distinguish between BS and PG, so what ?



In any case after 8 minutes fire, Hood could not send but some water and a single splinter on board PG, while PoW was repeatedly straddling and hitting BS: just luck ? Possibly, but I don't think so at all....


Bye, Alberto

PG_British_splashes_Jasper.jpg (69.84 KiB) Viewed 669 times