PoW's gunnery VS BSM's gunnery

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wadinga
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Re: PoW's gunnery VS BSM's gunnery

Post by wadinga »

Fellow Contributors,
Which evidence, please ?
Mr Virtuani previously supplied from Barben's letter:

"This means that B turret missed three salvoes, although ready to carry on, with shell in the guns when the action finished"

Being "ready to carry on" clearly indicates B turret had no opportunity to actually fire after the failure, clearly indicating salvoes 16,17 and 18 were the ones affected.
I have pointed out McMullen was glued to his spotting binoculars and likely had no idea what guns were firing. That was not his responsibility. His assessment "OK" is irrelevant, because he was not in a position to know how bad things were in the turrets. We know because we have the GAR and very small parts of Barben's report. Once McMullen realised what we know he concurred in Leach's decision.
Incorrect, the hit in compass is not determined by the PG film.


Very true. The timing of the Compass Platform hit as described here is completely invented, and then events in the film are arbitrarily allocated to this and other occurrences.
Based on these precise evidences,
There are no precise timing evidences
Even Rowell does not guarantee the salvo chart timings to better than two minutes
Considering it was Wills' hagiography that apparently provoked the current completely unjustified campaign to have Leach pilloried as a coward and a liar I am surprised to see his description quoted. There is no recorded evidence Leach "ordered" a 160 degree turn.

Using the salvo table for PoW which Mr Virtuani has posted:
This discussion is about PoW's gunnery and the clear evidence that B turret failed to fire on the last three salvoes under director control is relevant. That the centre guns of Y turret failed to fire on the last five director controlled salvoes is relevant.
can everybody now please acknowledge the average RoF values, as calculated here
I vote No! The mathematical basis is inaccurate, because the figures for Bismarck are fabricated/assumed.

All the best

wadinga
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,
Wadinga wrote: "Being "ready to carry on" clearly indicates B turret had no opportunity to actually fire after the failure"
No, it merely indicates that the failure was temporary and that at the end of the engagement the turret was perfectly operative.
The only thing we know for sure is that B turret lost 3 salvos in total.
McMullen listed the problem between the ones happening BEFORE the engagement in the official PoW GAR(http://www.hmshood.org.uk/reference/off ... 09guns.htm).

Saturday, 24th May
During the early hours hydraulic pressure failed on the revolving shell ring ship control in "B" turret. This was due to the pressure supply to the turret from the starboard side of the ring main being isolated. The revolving shell ring ship control is fed from the starboard side only, and the non-return valves on the pressure main adjacent to the centre pivot prevent pressure being fed to the starboard side and the revolving shell ring ship control from the port side in the event of the former being isolated from the ring main


thus the firing failures appear to have happened very early in the engagement, not at the end of it, but again this is irrelevant because Leach was obviously unable to evaluate any gunnery event after salvo 15.


Wadinga wrote: "McMullen was glued to his spotting binoculars and likely had no idea what guns were firing. That was not his responsibility. His assessment "OK" is irrelevant"
Sure. The G.O. judgement about his own gunnery is irrelevant (and despite this he "dared" to send a boy to his Captain on his bridge to tell him that guns were ok, implicitly asking him what the hell he was doing with that hard turn under smoke...), while the Captain (who had to steer his ship in the meantime) was precisely counting the shells vs "ordered shots" and building his own "salvo table". There is no need to further comment such a statement.

Leach himself said he was looking at Hood and at the enemy, never he said he concentrated on his guns and never complained about any loss of output (http://www.hmshood.org.uk/reference/off ... .htm#Leach).
Please try to find a single statement where Leach (or anybody else in the Compass Platform) complains (in his report or in the BofI witness) about an actual loss of output, or please stay to facts. Good luck!


Wadinga wrote: "The timing of the Compass Platform hit as described here is completely invented"
No, it's proven by Leach himself in his report + the POW maps. Sorry for that. The PG film confirms it.
See demonstration here (viewtopic.php?f=1&t=8491&start=420#p82741).

There is no way to move this timing but, if Mr.Wadinga has an alternative, please tell us: we are eager to hear some proposals, not only "adamant denials" from him.


Wadinga wrote: "I vote No! The mathematical basis is inaccurate, because the figures for Bismarck are fabricated/assumed"
No, and I'm honestly fed up of hearing words like "fabricated" especially from Mr.Wadinga who has fabricated countless interpretations (Brockmann, Churchill, Bismarck course, etc.etc.) instead of simply reading documents and accepting them.
The 93 shells are not fabricated and Mr.Wadinga has been invited several times to try any combination of "ordered shots" he wants, getting always the same result: PoW RoF, effective RoF and effective # of shells per minute are the ones posted here (viewtopic.php?f=1&t=8491&start=315#p82614).

I think I have explained this point too many times already without getting any answer countering this easy verification....
Mr.Wadinga has now to propose his "assumptions" (good luck!), or finally accept what mathematics tell us regarding average figures.


Bye, 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 dunmunro »

Alberto Virtuani wrote: Wed Apr 03, 2019 8:34 pm Hello everybody,
Wadinga wrote: "Being "ready to carry on" clearly indicates B turret had no opportunity to actually fire after the failure"
No, it merely indicates that the failure was temporary and that at the end of the engagement the turret was perfectly operative.
The only thing we know for sure is that B turret lost 3 salvos in total.
McMullen listed the problem between the ones happening BEFORE the engagement in the official PoW GAR(http://www.hmshood.org.uk/reference/off ... 09guns.htm).

Saturday, 24th May
During the early hours hydraulic pressure failed on the revolving shell ring ship control in "B" turret. This was due to the pressure supply to the turret from the starboard side of the ring main being isolated. The revolving shell ring ship control is fed from the starboard side only, and the non-return valves on the pressure main adjacent to the centre pivot prevent pressure being fed to the starboard side and the revolving shell ring ship control from the port side in the event of the former being isolated from the ring main


thus the firing failures appear to have happened very early in the engagement, not at the end of it, but again this is irrelevant because Leach was obviously unable to evaluate any gunnery event after salvo 15.
I think Barben is incorrect about B turret missing three salvos, since this would mean that one or, possibly, two of the early salvos would have consisted of only a single gun and this would surely have been remarked upon. Additionally Barben states that his counts of rounds/gun is for 18 salvos and only 10 for Y turret, yet Y4 gun shows 6 rounds fired which would indicate a minimum of 11, or more likely, 12 salvos from Y turret. I think Barben has mixed the output from the local control firing into the output for salvo firing. Barben doesn't mention Y turret firing in local control.

Possibly there was an early failure of the shell ring and it failed to load the shell ring, but the error was caught before it resulted in a loss of output, but regardless I am certain now that B turret had a clean shoot and that Barben was mistaken.
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Re: PoW's gunnery VS BSM's gunnery

Post by Bill Jurens »

I am wondering if the analysis might benefit from a reversion to USN gunnery target practices which basically measured efficiency in hits per gun per minute, excluding the first shot from each gun, which was considered a 'warming round'. The full rulebook for gunnery exercises in 1940 is extremely detailed -- about 300 pages long -- and contains a variety of other components which probably can't be accurately measured here. For example, the 'merit' figure for a given exercise was computed by taking the ratio of the actual hits per gun per minute to the 'expected' hits per gun per minute obtained in previous exercises, and taking into account differences in target size, etc. For timing purposes, elapsed time was taken as extending from the order to open fire to the time the last gun in the exercise had fired. Insofar as the number of rounds to be expended was finite in these situations, that system made sense, whereas in actual combat probably one would have fired until either the guns stopped operating or the ship essentially ran out of ammunition. So far as targeting is concerned, I think it's reasonably safe to assume that the targets on each side were about equally large, i.e. in practical terms essentially identical.

I wonder about the 'Guns are OK' commentary. Does it refer to the gunnery system as a whole, i.e. to the guns and the ammunition handling train, etc., or might it merely refer to the fact that the guns themselves -- less of course previously anticipated failures -- were undamaged?

Often these sorts of statements are in fact subject to considerable ambiguity if closely examined.

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Re: PoW's gunnery VS BSM's gunnery

Post by Byron Angel »

Bill Jurens wrote -
I wonder about the 'Guns are OK' commentary. Does it refer to the gunnery system as a whole, i.e. to the guns and the ammunition handling train, etc., or might it merely refer to the fact that the guns themselves -- less of course previously anticipated failures -- were undamaged?

You read my mind.

B
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Re: PoW's gunnery VS BSM's gunnery

Post by dunmunro »

Alberto Virtuani wrote: Wed Apr 03, 2019 8:34 pm

Leach himself said he was looking at Hood and at the enemy, never he said he concentrated on his guns and never complained about any loss of output (http://www.hmshood.org.uk/reference/off ... .htm#Leach).
Please try to find a single statement where Leach (or anybody else in the Compass Platform) complains (in his report or in the BofI witness) about an actual loss of output, or please stay to facts. Good luck!


Leach was being asked to describe his observations of Hood and the causes for her loss. He didn't go into details that were not relevant to the questions being put to him.

Leach mentions in his narrative that only 5 guns were in action prior to salvo 9.
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,
Dunmunro wrote: " I am certain now that B turret had a clean shoot and that Barben was mistaken"
Respectfully, there is no certainty at all.
As Mr.Cag had posted (viewtopic.php?f=1&t=6834&p=76847&hilit= ... ers#p76843), Mr.Barben was personally present precisely in B turret during the action (while no Vickers' technician was present in Y turret viewtopic.php?f=1&t=6834&p=76847&hilit= ... ers#p76847). It's very unlikely that he could be wrong stating that B turret failed to fire 3 shots, while I agree he is probably wrong in the count of Y4 shells (possibly having included a local salvo shot).

I suspect the failure in B turret happened around salvo 11 or neven before, when the shell ring was empty and had to be reloaded from the shell rooms (viewtopic.php?f=1&t=6834&p=76847&hilit= ... ers#p76849).

Dunmunro wrote: "Leach mentions in his narrative that only 5 guns were in action prior to salvo 9."
Leach does NOT comment that "only" 5 guns out of 6 were in action before the turn to open Arcs, as this is a very normal problem that can occur to any ship: Prinz Eugen had one gun out of action for most of the battle as well, we don't know about Bismarck and Hood.

Anyway (and this fact is certain) in no place (final report and BofI witness) Leach complained about actual guns operation nor performance. He just said he had "in his mind" the fear that problems could have potentially happened...



Whatever McMullen meant with "everything is ok", it's clear he was so furious (his words) to dare to send such an unconventional message down to the bridge.



Now, if we can all agree about the average RoF values as defined by McMullen in his GAR (point 1), 2) , 3) + the consequent point 4) and about the fact that whatever assumption for Bismarck "ordered shots" gives similar values for the German ship (I have not seen yet any alternative proposed by any forum member...), we can move on analyzing the other (in Italic font) aspects of both ships gunnery.

1) PoW actual RoF was very slightly better (1.89 vs 1,85) than Bismarck (assuming 108 ordered shots for Bismarck, much better if less than 108).
2) PoW output loss was larger than Bismarck's (26% lost shots vs 14%) due to mechanical problems / human errors
3) PoW effective RoF (1.4-1.5) was slightly less than Bismarck's one (1.6-1.65) but still in line with it (due to larger output loss).
4) PoW effective # shells delivered / minute was clearly higher than Bismarck's (7-7.4 vs 6.4-6.6).
5) PoW found her target before Bismarck, and 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 heavily 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 probable 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).


Bye, 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 wadinga »

Fellow Contributors,

Bill Jurens has commented:
I wonder about the 'Guns are OK' commentary. Does it refer to the gunnery system as a whole, i.e. to the guns and the ammunition handling train, etc., or might it merely refer to the fact that the guns themselves -- less of course previously anticipated failures -- were undamaged
There is an unwarranted assumption that McMullen sending a boy with a message to the bridge was as a reaction to PoW commencing a turn which was disrupting his gunnery and about which he was "furious". One might consider how long it took this messenger to get from where ever he was, after receiving the order from McMullen, to the Compass platform. That is too late to affect circumstances, since the turn is already underway and it would take some while to countermand. A far more likely motive is simply that McMullen's communications with the Captain were broken, due to virtually everybody on the Compass Platform being dead or wounded and the voice pipes and open line telephones smashed.

This obsession with the turn being the motive for sending the "unusual" message ignores the fact that as Brooke notes, the gunnery team was warned the ship would be making a major turn to port as the closing course of 280T was unnecessary once decisive range was reached. Only when the turn exceeded the bearing at which the DCT could track the target was it inconvenient enough for McMullen to get at all "furious".

The Gunnery Officer's responsibility in action was not monitor the minutiae of loading and firing of his guns, about which he could know nothing in the DCT, but in addition to personally supervising his spotting and rate crew, liaising continuously with the Captain about targets and manoeuvres. Losing contact with the Compass platform was a serious matter and his patently incorrect and imprecise "the guns are OK" was a mere assurance to the Captain that despite losing communications the Gunnery system was still operating.

Only the gun layer, ie the man with the trigger, at his telescope had the gun ready lights to tell him when sufficient guns to constitute a worthwhile salvo were ready, and he would fire when his sights were on.

I am quite happy to have the above described as a fabrication/assumption although only after people have read The Pocket Gunnery Book available on the web.

This however is pure interpretation:
implicitly asking him what the hell he was doing with that hard turn under smoke.

I suspect the failure in B turret happened around salvo 11, when the shell ring was empty and had to be reloaded from the shell rooms
This observation/assumption/suspicion directly contradicts Barben who we are told was actually in B turret and reported:.
This means that B turret missed three salvoes, although ready to carry on, with shell in the guns when the action finished
Is it seriously proposed that it should read "This means that B turret missed three salvoes, but then fired some more, although ready to carry on, with shell in the guns when the action finished"

The qualifier "although" clearly means that despite the failure, this was overcome and the guns were loaded and ready to take part again by the end, not that they had managed to fire some guns before the end of the action. If they had fired again it would be superfluous to add "although ready to carry on, with shell in the guns when the action finished".

The estimate/assumption/suspicion of salvo 11 is typical of how apparently "logical" assumptions made may mislead. It is presumably estimated/assumed/suspicioned because the proposer has done some sums. Why allow the shell ring to become completely depleted when with gaps between double salvoes approaching a minute mean that while shells and cartridges are being hoisted and rammed, the shell ring is clear to rotate and be topped-up? A failure of logic rescued only by being described as a suspicion instead of being asserted.

Speaking of assertions of the timing of the Compass Platform hit:

Leach's narrative:
And at 0602 compass platform was hit and majority of personnel killed. Navigating Officer was wounded; Commanding Officer unhurt.
This directly contradicts the assertions made by Mr Virtuani,
Therefore the hit in compass platform happened around 06:00:50,
he should not cite it in his support and should as a courtesy admit this.

BTW Unhurt compares with "blown to fragments or severed femoral artery or splinter through face or blinded or permanently deafened etc.

All the best

wadinga
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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,

I intentionally avoid to answer again and again (helping to divert the discussion from the main topic) to irrelevant (albeit interesting) points (e.g. 1) when and why McMullen sent the boy with his message "everything is ok" or 2) if and when B turret failed to fire 3 out of her 18 shots, or 3) which are the responsibilities of the G.O. when commanding a firing action vs the Captain's observations of the same firing action, or 4) at what time the compass platform was hit and when exactly Leach ordered the turn away).


I repeat my questions and I would like to get an answer at last:

1) Has everybody understood McMullen's precise normalization (http://www.hmshood.org.uk/reference/off ... 09guns.htm) and my approximate (but still precise enough) calculation (viewtopic.php?f=1&t=8491&start=420#p82731) for PoW average (actual and effective) RoF figures ?

2) Are we all in agreement by now about the fact that Bismarck's 93 fired shells, once assumed any "ordered shot" figure, give a result for average (actual and effective) RoF very close to PoW ones (viewtopic.php?f=1&t=8491&start=435#p82755 , points 1),2),3) and 4) at the end of the long (sorry for that) post) ?
In case there is anybody who would still like to deny the figures, he is kindly asked to present his own alternative, tough, because just saying "no" will not make things progressing here...

3) Can we move to discuss the other gunnery parameters ( , points 5) to 11)) by now ?


Bye, 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 Bill Jurens »

Mr. Virtuani presented a listing a few memos ago in which he wrote:

"7) PoW was initially heavily handicapped by having only the fore turrets bearing for the first 8 salvos, and despite that, she hit first."

I'd be interested in knowing how the sequence and timing of hits, particularly on Bismarck, has been established. So far as I know, there is no really detailed narrative from Bismarck that addresses this, nor for that matter any specific information which might exclude the possibility of one or more hits from Hood.

So to assert that PoW "hit first" would seem to be problematical.

I'd again repeat my previous question regarding the examination of the Denmark Strait German film, i.e. I would be interested in knowing precisely how the timing was established. Particularly when there is no sound attached, and there are no things such as people moving in the picture to give some visual indication of appropriate speeds, it's quite conceivable that the film could have been significantly increased in the editing room, and in fact one might even expect this sort of chicanery in what amounted to a propaganda film. If sound is being recorded, the speeding up the film also alters the pitch of spoken speech etc., and although we can tolerate a certain amount of this without being able to detect it, we can pick it up quite easily, so jiggering sound film is (or was) a bit more difficult. With modern technology this problem is much more easily cured. We have, for some reason, a fairly high tolerance for speed errors in film presentation, even when familiar objects are being depicted, with errors of 20% or so quite difficult to detect unless the items in the frame are quite familiar. Motion pictures shown on television are quite routinely -- and undetectably -- sped up or slowed down by surprising amounts to make them fit into the rather regular clock schedule needed there, vs a motion picture presentation where overall presentation time is only loosely fixed.

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

Post by Alberto Virtuani »

Hello everybody,
Bill Jurens wrote: "I'd again repeat my previous question regarding the examination of the Denmark Strait German film, i.e. I would be interested in knowing precisely how the timing was established."
I'm reluctant to speak, as I'm afraid I'm not the one who, having studied the film for several years, could have better provided an explanation.
I can imagine however that this person could (understandably) not be willing to answer anymore, due to the treatment reserved to him very recently in this forum...


The very evident thing that allows to time the PG film (battle sequence only, of course ) is the Prinz Eugen turn in the very first seconds (minute 5:40 -5:55 here https://www.youtube.com/watch?v=pPmkOtSveXY).
At this time, the stanchions of the cruiser deck railings are "moving" backwards (to allow to keep Bismarck in the camera field). This means PG is turning (quite hard) to starboard. This turn is clearly marked on PG battlemap (http://www.hmshood.com/history/denmarks ... tlemap.gif) at 06:04 (end of turn at, let's say, 06:04:15).
Thus the film start is quite easily timed to this moment in time.
The splashes of PoW local controlled salvos 20 and 21 are almost perfectly matching this timing (vs what is marked in the PoW salvo plot), and they exclude (obviously) that the turn to starboard of the cruiser is the second one (that she did at 06:07).
Of course no chance such a turn could have happened when Hood was still afloat and firing, as a forum member tried to sustain here.

As per the film speed, I was the first one to point out that it looked to have been increased in the version we have available.
I agree with Mr.Jurens that in a propaganda clip you must show Bismarck firing "as a machine gun", thus probably the increase.
How much was the speed increased ? I would say (my opinion of course, as I'm not a film expert) at least 50%, possibly more, looking at the water waves/spray around Prinz Eugen.
This would imply that 1 minute in the film is 1 minute and 30 seconds minimum in reality, and the whole film sequence (when the "insertion" of Hood explosion is removed) lasts 2 minutes and 15 seconds at least. This is only my personal opinion, though, but it would be key to establish when Bismarck turned back to port on 220° as discussed here (viewtopic.php?f=1&t=8335&start=375#p82424), before everybody suddenly "left "this topic.



Bill Jurens wrote: "to assert that PoW "hit first" would seem to be problematical"
We have evidences pointing to the fact that Hood never fired to BS and that PoW hit at salvo 6. However, before we possibly discuss these evidences, I have clearly said (viewtopic.php?f=1&t=8491&p=82759#p82757) that I would prefer to have an answer to my questions and an explicit acknowledgement that points 1), 2) 3) and 4) in my "listing" (viewtopic.php?f=1&t=8491&start=435#p82755) are accepted before ("before" is not underlined this time, as this seems to be considered too offensive...) doing it, to avoid to have to come back to the same discussion from zero each time.


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 Byron Angel »

While on the subject of McMullen's graphical gunnery plot -


1 - A chart notation timed at approx 0556:00 describes Hood as being "out of action". Can anyone shed light on its possible meaning?


2 - A chart notation timed at approx. 0557:50 describes A arcs as now being open. After PoW's initial course alteration to port between 0554 and 0555, the chart suggests that PoW maintained a steady course (@ 280 deg?) until forced to evade Hood at approx. 0601 or thereabouts. Yet, durng that period of time the notations of (presumably) true target bearing continue to slowly drift more and more forward of the beam of PoW.

For example -
Salvo 5 - target bearing 332 deg @ approx. 0555:30
Salvo 6 - target bearing 331 deg @ approx. 0555:55
Salvos 7 through 13 - target bearing recorded as holding steady at 330 deg between approx. 0556:45 and 0559:40

Yet right around Salvo 9 at approx. 0558, A Arcs are described as now being opened. This does not work from a strictly geometrical point of view. What am I missing?

B
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Re: PoW's gunnery VS BSM's gunnery

Post by Bill Jurens »

You may not be missing anything. It could be that the terms 'open' and 'closed' with respect to 'A-arcs' involved components of both a physical and operational nature. So although the A-might have been physically open, i.e. there was no danger of shooting off intervening superstructure, they might have been considered operationally closed due to the knowledge that firing to close to the intervening superstructure would, either immediately or eventually, result in a degradation of men, equipment, or both.

I alluded to this in my paper on the loss of Hood, where I stated that although Hood's A-arcs might have been geometrically open -- which according to plausible reconstructions of the action, they probably were, the feeling might have been that they were not comfortably open in a situation where men were fighting fires amidships, etc. Which is probably why Hood's after turrets didn't fire very often, or at all.

It could be that A-arcs on PoW were considered closed for the after turret until range had been found, i.e. they were considered closed for cold-gun and ranging salvos early on in the action to minimize the extent of cumulative damage from muzzle blast. When it was felt that the after guns could actually make a reasonable contribution, then it might have been considered time to operationally 'open' them again, even though they were, geometrically, even more closed than before...

This is somewhat speculative to be sure, but would not seem to be entirely implausible.

The "Hood out of action" notation is a strange one, unless the observer felt that the fires seen amidships were perceived to be very serious -- i.e. considerably more serious than they appear to have actually been via observations on Hood herself. It could be that the observer noticed a fairly long lag in salvo interval from Hood, and this -- coupled with an observation that the after turrets were not firing -- led the witness to assume that she was really not operating very well at all.

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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani »

Hello everybody,

I agree with Mr.Jurens explanations regarding the "A-arcs" annotation, both for PoW and Hood, as already proposed by several members here (including me, here viewtopic.php?f=1&t=7714&p=72037&hilit= ... ing#p72037 or,very recently, here e.g. viewtopic.php?f=1&t=8335&p=81473&hilit= ... age#p81473).


Regarding the "Hood out of action" annotation, it's more mysterious for me.
I would not say the fire on the boat deck can be the "responsible" as at 05:56:00 (PoW Salvo Plot annotation timing) the first German shells were possibly still in the air, or the very first salvo just landed, not hitting anyway. Also, Hood was seen firing up to the end (possibly not continuously) or even after the fatal hit.
The boat deck hit can be quite precisely timed at around 05:57:30 by reading jasper GAR (2 Vollsalve + flight times + observation and 2 Gabellgruppe salvos + flight time....) and confirmed by Hunter Terry as happening at minute 05:57.
I tend to think that the annotation is related to the agreed firing procedure and that the explanation is either:
1) that due to the own ship fire in some way the GIC firing procedure failed on board PoW and the ship started firing independently ("considering" therefore Hood out of action) or
2) that for any unknown reason, Hood gunnery had any problem that prevented her to respect her GIC intervals, making "de facto" PoW free to fire at her discretion.




Any answer to my questions here (posting.php?mode=reply&f=1&t=8491#pr82757)?

In the absence of any further (reasoned and supported) denial / (credible) alternative, can we consider that the points 1), 2) 3) and 4) are by now fully accepted as average figures for PoW and BS Rate of Fire ?

BS vs PoW gunnery performances.jpg
BS vs PoW gunnery performances.jpg (63.32 KiB) Viewed 1247 times

Also can we agree that the PG film battle sequence starts at around 06:04, for the reasons explained here (viewtopic.php?f=1&t=8491&start=435#p82759) ?

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)
pgollin
Senior Member
Posts: 382
Joined: Sat Jan 11, 2014 12:01 pm

Re: PoW's gunnery VS BSM's gunnery

Post by pgollin »

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Re gun arcs.

For RN large ships there were three limits.

The most restricted were the "ordinary" A-arcs, these were set during gun testing and depended upon physical AND subjective testing of the blast on adjacent structures and on positions where crew members would, or might, be positioned during action. The subjective testing was by an employee of the DNC's department who stood in the exposed position and gave his report on the physical effects. The DNC's constructors had rule of thumb charts but pressure sensors were unreliable and the subjective tests were important. The stops were usually set for these limits.

There were also slightly larger arcs where further damage or physical effects were seen as acceptable. It was left to the admiral/captain as to whether the stops were adjusted to these limits (or somewhere between).

In addition, there were further limits which were ONLY available when the guns were not firing. These were the physical limits where the barrels would physically come up against structures. To get to these the one or two physical stops above were removed after various safety measures were put in place. Any movement to the final stops had to be overseen by senior gunnery department personnel.

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