More on KGV Class main armament problems

[Bill Jurens]

At least in the USN, the most valid comparison of rate of fire was usually taken to be Shots Per Gun Per Minute (SPGPM). Usually, in target practices, no discrimination was made regarding the reasons behind missed shots although in unusual situations some discrimination might be made between shots missed due to mechanical failure, which was seen, properly, as a gunnery problem, vs shots missed due to tactical issues, e.g. rounds not fired due to inadvertent 'wooding' of lines of fire, etc., for which responsibility would be assessed elsewhere. In any case, the effectiveness of fire was often simply taken as the ratio between Shots Per Gun Per Minute and Hits Per Gun Per Minute, which eliminates -- which (almost) eliminates purely tactical issues.

I, too, have done an analysis of the gunnery at Denmark Strait using the same information available to Adm. Santarini, reaching somewhat different conclusions. A lot depends upon how you look at the numbers...

Bill Jurens

[Byron Angel]

At Matapan 3 RN battleships engaged the RM cruisers at night:

Warspite engaged 3 successive targets and fired 7 broadsides in less than 5 minutes.
Valiant fired 7 broadsides at two successive targets.
Barham fired 6 broadsides at "" "".

Removing time to train her guns, Warspite fired 7 broadsides (equivalent to 14 salvos) in about 3 minutes.

Matapan represented an extremely rare confluence of favorable factors -

> Unaware opponent.
> Total surprise.
> Placid sea.
> Undetected approach.
> Point blank range.
> Accurate open fire range.
> Major force advantage.
> Intelligent battle management (no wasted motion)

- which conspired to create one of those occasions when the main battery guns of these battleships could achieve their nominal maximum mechanical rate of fire -

> Minimal required gun elevation enabled a very fast re-load cycle.
> Point blank range + accurate radar ranging meant no need to await fall of shot or spot corrections.

B

[Byron Angel]

Hello everybody,

"...One rpmpg was the average output expected by the RN for a battleship in WW1...."

When a British WWII ship fired with a better RoF in anger ? Answer please, not generic statements.

If PoW RoF was poor on May 24, then KGV one was simply awful on May 27 and this is not the case....

"I cannot imagine upon what basis Admiral Santarini has concluded that PoW's rate of fire or output at Denmark Strait was "excellent""

As I was apparently unable to explain (KGV did worse on May 27, Bismarck did not better under the same conditions firing 93 shells in 14 minutes), please ask him, I'm sure he will be happy to explain, with his experience as gunnery officer and his studies.

Or, even better, try to find something published that is comparable to his analysis (especially worth of praise is his conclusion that annoys the ones who still (after 78 years...) try to deny PoW and McMullen merits download/file.php?id=3420 just to defend Leach's decision). Of course they would still prefer Kennedy's wonderfully written happy-ending novel to a fact-based analysis...


Bye, Alberto

Methinks you doth protest too much .....

B

[HMSVF]

At least in the USN, the most valid comparison of rate of fire was usually taken to be Shots Per Gun Per Minute (SPGPM). Usually, in target practices, no discrimination was made regarding the reasons behind missed shots although in unusual situations some discrimination might be made between shots missed due to mechanical failure, which was seen, properly, as a gunnery problem, vs shots missed due to tactical issues, e.g. rounds not fired due to inadvertent 'wooding' of lines of fire, etc., for which responsibility would be assessed elsewhere. In any case, the effectiveness of fire was often simply taken as the ratio between Shots Per Gun Per Minute and Hits Per Gun Per Minute, which eliminates -- which (almost) eliminates purely tactical issues.

I, too, have done an analysis of the gunnery at Denmark Strait using the same information available to Adm. Santarini, reaching somewhat different conclusions. A lot depends upon how you look at the numbers...

Bill Jurens

Statistics eh!

[pgollin]

......... P 8 of 14 National Archives document "Copyright and Related Rights 2013 rev http://www.nationalarchives.gov.uk/docu ... rights.pdf

non-commercial research - this might include research for a non-commercial publication (one which will not make any money), such as some academic research. However, it will not include anything for which you or anyone else will receive a financial or equivalent return, and nor will it include research for a body (even a charity) which will use it to receive a return

All the best

wadinga

PLEASE do not selectively quote.

The post I was referring to includes this definitive statement ;

Crown Copyright applies to the unpublished documents in the archives.

To quote ;

You must obtain permission from the Image Library of The National Archives for the reproduction of copies of any records, whether they are protected by Crown copyright, are non-Crown
copyright or are out of copyright, for publication, on the internet, for broadcasting, for exhibition or
for any commercial purpose.

That is very clear.

The link to the post is my post dated at Mon May 27, 2019 10:09 pm (uk time) on page 3 of this thread

.

[Alberto Virtuani]

Hello everybody,

Byron Angel wrote: "Matapan represented an extremely rare confluence of favorable factors"

I do agree. I'm not aware of comparable day battles at average range with a much better RoF than the one showed by PoW on May 24.

For sure KGV fired with a lower RoF on May 27 and her effective RoF was not so much better than PoW even during the initial phases (then it dropped), demonstrating that the "theory" of the poor inexperienced ship was just an "excuse" for PoW's Captain.

Bill Jurens wrote: "I, too, have done an analysis of the gunnery at Denmark Strait using the same information available to Adm. Santarini, reaching somewhat different conclusions."

Therefore, let's see what will be written in the new publication and let's compare this work with Adm.Santarini's one. For the time being his work is the only serious study of gunnery at DS officially published.

I have done the same work, having used Antonio's reconstruction of the battle, and have reached the same favorable conclusions regarding PoW performances. It is at least discussed and shown on this forum (download/file.php?id=3463) and I will have it published on a DS dedicated book in the next years.


Bye, Alberto

[paul.mercer]

Gentlemen,
Another question I'm afraid!
If for instance, a ship was firing full broadsides as I believe happened at Matapan and perhaps with Rodney in the final stages of the battle, would their output not be greater than if they just fired salvo's even though perhaps the actual rate of fire overall was slower due to having to reload all the guns at once?
Please don't blow me out of the water on this one!!

[wadinga]

Fellow Contributors,

Paul's question about broadsides requires an answer, but I can't locate and supply a succinct reference. It is clear that even gunnery expert Santarini is muddled by what is meant by salvoes in his concluding table 20, where he states PoW fired twice as many per minute as Bismarck, failing to note that the latter ship was also firing her whole main armament as two closely spaced salvoes.

A salvo is merely the simultaneous firing of several guns together, a broadside is just a salvo with all guns firing.

My explanation would be that use of salvoes, normally firing half the main armament at a time, is as a range testing device enabling more frequent sampling of the range. As the effective range of guns got greater and therefore the time of flight exceeded the mechanical reload time, an individual gun could be ready to fire again before the previous shot had even landed. The "gun ready" lights were located next to the gunlayer in the director and it was he who pressed the trigger to fire a salvo. When the control/spotting officer was confident the range was known and the "rate" of continuous correction applied was also correct, he would authorize broadsides or just rapid salvoes. The guns would then fire pretty much as quickly as they could be loaded, (SPOMO Simultaneous production of maximum output) until spotting indicated the MPI was drifting off the target. The examples from Matapan indicate what could be achieved with well drilled and experienced crews operating reliable loading systems.

The use of crude averaging as applied by Santarini and his followers is irrelevant as we have established the actual rate of output of salvoes varied considerably minute by minute. The Baron reports "Good rapid" marking the start of the process described above, where Bismarck started delivering more shells per minute on Hood.

Even the crude average applied to give PoW 2 salvoes per minute in Santarini's table fails to acknowledge that in one particular minute she fired only one salvo and in another three. A huge Standard deviation. In many individual minutes she did indeed manage as many as 2 salvoes, although even Santarini admits, mainly by being prepared to fire a salvo even though several guns that were supposed to fire in it were not ready in time. If the gunlayer had waited until all the guns which were supposed to be ready for an individual salvo were actually ready, what would the true rate have been?

Since the comparison between PoW's firing rate and Bismarck's has been thoroughly discredited as there are no actual salvo by salvo records for the latter and just the belief that Bismarck fired 40 shells in about the first 5 minutes, an attempt has been made to compare PoW with KGV in completely different conditions. We know that a full gale was blowing and several of Bismarck's secondary mounts were awash and unusable in heavy waves. We know the wind was so strong Swordfish were blown sideways across Ark Royal's decks. Tovey's insistence on "head on" approach made for enormously difficult "rate of change" estimation so there was no requirement for rapid rate of fire. These factors limited KGV's rate of fire, but apparently every gun fired when it was supposed to in the first 25 salvoes, in sharp contrast to PoW.

Which is why Oliver Bevir (Director of Naval Ordnance) and who will not be easily dismissed, stated
"In the Prince of Wales the short time she had been in commission was the dominant factor" something John Leach was also well aware of.

All the best

wadinga

[Alberto Virtuani]

Hello everybody,

"Even the crude average applied to give PoW 2 salvoes per minute in Santarini's table fails to acknowledge that in one particular minute she fired only one salvo and in another three. A huge Standard deviation."

?
Hard to find a more constant RoF than PoW on May 24 (please see Exhibit A here http://www.hmshood.org.uk/reference/off ... 09guns.htm). The fact that one single minute contains 3 salvos and another just 1 salvo don't affect in any way the fact that PoW fired in average 2 salvos per minute, with a quite constant rate....

"since the comparison between PoW's firing rate and Bismarck's has been thoroughly discredited... "

...only by the ones who prefer their "indeterminateness", of course.
BS fired 93 shells (fact) in 14 minutes and there is no evidence whatsoever that she ceased fire before PG nor that she fired in a significantly less than constant way from RoF viewpoint.
I'm waiting for any different reconstuction of the fire action duration (14 mins) or of my assumed ordered shots (108...) just to check that nothing change significantly here (download/file.php?id=3463)....
More or less than 14 mins ? More or less than 108 ordered shots ? Answer please

"Tovey's insistence on "head on" approach made for enormously difficult "rate of change" estimation"

Exactly the same "rate of change" than on May 24... when PoW fired much more quickly than KGV (salvos per minute), with a higher output loss....getting a comparable number of salvos per minute.


Bye, Alberto

[wadinga]

Fellow contributors,

it has been said

I'm waiting for any different reconstuction of the fire action duration (14 mins) or of my assumed ordered shots (108...) just to check that nothing change significantly...

What exact value is there in creating another equally imaginary and equally (un)likely scenario based on non-existent evidence?

Hard to find a more constant RoF than PoW on May 24

but if we remove all the salvoes where one or more designated guns failed to fire, because they are not "salvoes" per se, what does that do to the statistics? As I pointed out McMullen could fire 6 salvoes a minute provided he was prepared to make each one only a single gun. You can set the rate of fire in elapsed seconds at whatever you like, but if only half your guns are going off, what is the point? And worse, since they missed their chance on one salvo, they have to wait until their group comes around again, meaning individual firing intervals of over two minutes. Still when the crews are having to use sledgehammers and hacksaws just to get the guns to load at all, maybe you need over two minutes.

when PoW fired much more quickly than KGV (salvos per minute), with a higher output loss....getting a comparable number of salvos per minute.

I realise the response was generated in extreme haste to try and bury as many points as quickly as possible, but it has completely ignored the far worse weather conditions prevailing during the final action. Besides how is, even on the presented figures. a .3 spm advantage "much more quickly" in one part of the sentence and only "comparable" in the second ?

In addition, since Bismarck was zigzagging erratically during Tovey's approach the rate of change was much more variable than in Holland's case where his enemy stolidly maintained his course. (Or did he?)

All the best

wadinga

[dunmunro]

Gentlemen,
Another question I'm afraid!
If for instance, a ship was firing full broadsides as I believe happened at Matapan and perhaps with Rodney in the final stages of the battle, would their output not be greater than if they just fired salvo's even though perhaps the actual rate of fire overall was slower due to having to reload all the guns at once?
Please don't blow me out of the water on this one!!

Of course it was greater output. PoW was firing the equivalent of one broadside/minute which is quite leisurely. As I've pointed out in the past, the RoF is set by the visibility and seastate. In her final shoot of the war KGV fired 265 x 14in rounds in 37 minutes and achieved a 98% output.

[Byron Angel]

Gentlemen,
Another question I'm afraid!
If for instance, a ship was firing full broadsides as I believe happened at Matapan and perhaps with Rodney in the final stages of the battle, would their output not be greater than if they just fired salvo's even though perhaps the actual rate of fire overall was slower due to having to reload all the guns at once?
Please don't blow me out of the water on this one!!

Of course it was greater output. PoW was firing the equivalent of one broadside/minute which is quite leisurely. As I've pointed out in the past, the RoF is set by the visibility and seastate. In her final shoot of the war KGV fired 265 x 14in rounds in 37 minutes and achieved a 98% output.

- - -

Hi dunmunro,
Just checking, when you wrote above "one broadside/minute" were you intending to write one salvo/minute?

- - -

I don't have the full details on KGV's last gunnery action (presumably a shore bombardment?), but doing the elementary math from dunmunro's figures, I come up with -

265 rounds / 0.98 = 270 / 10 guns = 27 broadsides in 37 minutes = 1m 22s average interval between broadsides -or- 1m 22s / 2 = 41s interval between 5-gun salvoes ..... which would make sense versus a static non-maneuvering land target ..... approximately equivalent to about 0.73 rpmpg. That having been said, there would likely have been no good reason to hasten the rate of fire under such circumstances - steady as she goes and don't make any stupid mistakes in the gun pit.

FWIW.

B

[Alberto Virtuani]

Hello everybody,

Wadinga wrote: "What exact value is there in creating another equally imaginary and equally (un)likely scenario based on non-existent evidence"

Mr.Wadinga should at least try to tell us a number (because a number of shots were actually ordered on board Bismarck)...
It will make him clear that there is no value that can change the fact that Bismarck was unable to deliver more shells/minute against PoW compared to the British ship he would still like to believe as a poor inexperienced one.

I see (and fully understand) his reluctance to tell us whether he believes (like Mr.Dunmunro) that Bismarck ordered shots were just 96...or even 124 (making her output loss equivalent to the "green" PoW).... But, please, tell us ! May we finally have an answer here ?

"what does that do to the statistics?"

Nothing at all, of course: the actual RoF is still 2 salvos per minute (1,2, 3, 4 or 5 guns actually firing are anyway a salvo) and also the effective RoF remain the same (1.5 salvos per minute) because it already takes into account the output loss...It's a simple mathematical calculation...once McMullen methodology (http://www.hmshood.org.uk/reference/off ... 09guns.htm) is understood and digested (download/file.php?id=3463)

"it has completely ignored the far worse weather conditions prevailing during the final action...Bismarck was zigzagging erratically... "

+ the fact that KGV's radar was working to provide initial range, that distance was much shorter on May 27 and that the enemy was a sitting duck. Oh, pardon, a duck erratically zig-zagging at 6 knots (thus changing her position by 50 meters during the flight time of the British shells (vs the 300 meters closure range of the May 24 conditions).... Bravo!

I see somone still insist to post just in the "extreme haste to try and bury as many points as quickly as possible" (Mr.Wadinga kind words, not mine)...

"a .3 spm advantage "much more quickly" in one part of the sentence and only "comparable" in the second ?"

Oh, poor me !
I see that the fundamental difference between actual salvos per minute (2 vs 1.7, thus .3 difference) and effective salvos per minute (keeping into account the loss of output) is still not absorbed... Poor me, I don't know how to interpret such a refusal of accepting the basics of what McMullen listed in the PoW GAR table (http://www.hmshood.org.uk/reference/off ... 09guns.htm)....




I will not comment on pure speculations about KGV output loss, because the KGV GAR does not allow to say much (missing the fundamental ordered shots figure): for sure no broadside was fired by KGV until 9:20 (see her GAR in ADM 234/509) during phase III, when range was below 10000 yards and no comparison can be done with May 24 conditions....
The KGV peak RoF of 1.7 salvos (not broadsides) per minute, that we are comparing to PoW 2 spm RoF, was achieved in the first part of the action (phase II) but after the initial ranging salvos...


Bye, Alberto

[wadinga]

Fellow Contributors,

Spot-on observation Byron, no mad rush as the enemy is not manoeuvring or indeed firing back!

Of course it was greater output. PoW was firing the equivalent of one broadside/minute which is quite leisurely. As I've pointed out in the past, the RoF is set by the visibility and seastate.

This is kind of correct except I wonder in which minute PoW actually got 10 shells away. A bit difficult when one gun packs up after the first shot. Theoretically, ie not being leisurely, she should have been able to fire two broadsides in a minute- 20 shells in all. That is if her personnel and equipment had been as good as Cunningham's revitalised antiques at Matapan. In PoW at DS generally speaking, each gun was getting between a minute up to a minute and 15 secs to reload and still they missed salvoes. Only in the "magic minute" at 06:00 did a group manage a 35 second reload and fire.

Time of flight is a factor as well.

McMullen decided he wanted to fire about two salvoes per minute and any gun which could not keep up with the schedule, ie most of them at one time or another, had to hold fire for ages until their group fired again. Or more likely were trying hard with sledgehammers and hacksaws not to miss two salvoes in a row.

All the best

wadinga

[Alberto Virtuani]

Hello everybody,

"I wonder in which minute PoW actually got 10 shells away....Theoretically...she should have been able to fire two broadsides in a minute- 20 shells in all.."

I wonder in which minute KGV actually got 10 shells away (having being her peak RoF 1.7 salvos/minute... was she possibly armed with twelve 14" guns?).

Theoretically Bismarck should have been able to fire 3 broadsides per minute - 24 shells and surely she did not.... at least if someone doesn't want to say that Bismarck fired only during 4 minutes out of 14 (336 theoretically possible shells....implying the usage of blow torches and dynamite, in addition to sledgehammers and hacksaws, from German side not to miss 4 salvos in a row due to their own guns problems).

"Time of flight is a factor as well."

Finally, a correct statement. At shorter range you can fire at a faster RoF, because you don't have to wait much time for spotting the fall of shots and to make any necessary correction. PoW fired from longer distance than KGV, thus her "excellent " RoF (download/file.php?id=3045) is even more remarkable.


Bye, Alberto