PoW's gunnery VS BSM's gunnery

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

Post by HMSVF » Sun Mar 10, 2019 12:55 pm

paul.mercer wrote:
Sat Mar 09, 2019 10:57 am
Hi Antonio,
@ Paul Mercer,
'we have deeply analyzed that event on a dedicated thread 6 years ago, ... you can read all in here :
viewtopic.php?f=1&t=6276&hilit=hit+comp ... orm#p56258
For any additional help about it, ... just feel free to ask, ... it is only history, ... nothing else.'

Many thanks as ever for your reply,
I have had a look at that topic and while it is very interesting and informative, it does not really address the question that I put in my last post which was, it is really possible to tie down precise timings to the very minute (like when firing stopped, orders given to turn away and exact courses ordered, when the bridge is in chaos with people lying dead or wounded (and no doubt shell shocked) and to add to the confusion more shells either hitting or landing in the sea all around. Without wishing to seem frivolous, I find it difficult to grasp that at that time someone was looking at the clock or their watch and noting down the exact time an order was given. Also, (and I am putting my head on the block with this!) do timings to the very minute actually matter that much when it comes to the overall view of the battle,presumably the timings of when all the ships opened fire and the moment Hood blew up are accurate as are the events until PoW got hit on the Compass platform - but after that?
Hi Paul,

On this I fully agree. The "human" factor to battle (to me) is a key part of having an understanding of what occurred. Whilst you can train, and to some extent simulate lethal situations ,when it comes to the real thing it's completely different.The perceptions of what occurred can be hugely different as well.

I was reading the other day an account from an officer on HMS Indomitable at the Battle of Jutland who witnessed the destruction of HMS Invincible. He said that she blew up without a sound, yet when an officer who stood next to him said that the noise was so great that he though that his ears would explode. Same event witnessed by 2 people with two differing versions of what happened. IHMO this why you have divergence in accounts that what occurred. It's not that people where deceitful - their perception of what was occurring was different to others. Its why you have to be careful with witness testimony. When HMS Queen Mary blew up an officer was adamant that he saw the forward part of HMS Queen Mary stagger onwards, he said that the image of seeing officers and en still at their stations haunted him for the rest of his life. We now know that he couldn't possibly have seen this as it was the forward part of the ship which exploded and the stern that remained afloat. Again, he hadn't lied, but in actuality he couldn't have seen the bridge crew at their stations as he stated.

I would imagine that those who survived the compass platform hit would be at the very least stunned and running on adrenaline (fight or flight response). I believe that you are correct in questioning the veracity of charting and documentation in such an event. Humans are just not built to take such forces and pressure and not have there abilities degraded. At the end of the day these behemoths were products of the analogue age and relied on human input to function. Charts and such were also filled in by humans as opposed to computers and so there is always the degree of ambiguity that wouldn't be present in our modern digital age.

Does it take ha huge difference with the timings? Well I suppose it depends on whether you believe that it holds a significance or was part of a bigger picture. In the space of minutes HMS Hood had sunk,HMS Prince of Wales got a pummelling and turned tail (wisely IMHO). Trying to tie down the exact times to the exact second relying on witness's statements and human inputted charts is problematical IMHO due to reasons I mentioned before. The best that can be achieved IMHO is an approximation whilst recognising that that even then there maybe anomalies.




Best wishes

HMSVF

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Re: PoW's gunnery VS BSM's gunnery

Post by wadinga » Sun Mar 10, 2019 2:27 pm

Hello Paul,

On accuracy of guesstimates based on assumptions made 75 years later:
Hood exploding time : a bit after 06:00 battle time, ... I have evaluated 10 seconds more or less ( we can see the PoW salvoes 13 and 14 on the air being already fired on the photo Nh69724 )
This cataclysmic and for them, victorious and noteworthy event was specifically logged by PG officers as occurring at 06:01:20. Not 10 or 30 seconds past but 20.

The only precise but not necessarily accurate timings we have are from PoW's gunnery system converted into the salvo plot and accompanying map submitted by Rowell. He specifically mentions they might be up to 2 minutes out compared with the real time. The clock which controlled the gunnery plot was not necessarily synchronised with the ship's chronometer standard, but recorded elapsed time.

All ship's chronometers would have been within a very few seconds, if not parts of a second of one another, as they were required to maintain standard time for navigational purposes.

Dreyer and Ince, luckless midshipmen probably responsible for Log entries on PoW's Compass Platform were smashed to pulp by the unexploded shell which also rendered Leach unconscious. Charts of the action from the level below were damaged by blood and the separate Admiral's chartroom was flooded by hot water from a smashed tank. Action plans from PoW are reconstructions made shortly afterwards as is her Log.

All the best

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

Post by Bill Jurens » Sun Mar 10, 2019 5:11 pm

Wadinga wrote:

"I would be interested to hear the observations of an acknowledged expert on World War II naval gunnery about the glib observation, often repeated, that the closeness of Holland's formation made this target switch easy. PoW was not at the same range as Hood, was not on the same azimuth as Hood, and changed course violently moments after Hood's destruction to avoid her wreck, as reported widely by both British and German observers."

Until a true expert arrives I will, with trepidation and humility, put forth my personal conjectures.

The geometric analysis of the situation is quite and also requires some assumptions to be made, e.g. the range difference between Hood and Prince of Wales the latter cut across the line of fire. Taking into account reasonable 4-gun pattern sizes, etc. and assuming the range difference between Hood and Prince of Wales to have been in the vicinity of 500 yards, the hitting spaces would suggest that even a rather crude estimate of range and bearing adjustment would have placed Prince of Wales in fair danger of being hit during the transit.

So little is known regarding the precise maneuvers of POW and/or the firing sequences and corrections that might have been made by Bismarck, and the statistical variation of fall of shot, etc., are such that one can only speak in terms of probabilities. Getting the mean point of impact of the salvo on the target requires a combination of luck, skill, and experience. Similarly, there is a random component -- call it luck if you will -- that relates to the statistical distribution of shot around the mean point of impact and that relation to the target.

Overall, my assessment would be that the shift from one target to the other would have indeed likely been fairly straightforward, and would thus likely result in a rather high probability of hitting Prince of Wales whilst she cut across just in front of Hood.

As they say, that opinion and a Euro or two, might buy you a cup of coffee...

Bill Jurens

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Re: PoW's gunnery VS BSM's gunnery

Post by dunmunro » Sun Mar 10, 2019 6:46 pm

Mr Moderator:

If anyone needs further proof that the table showing PoW only firing for 8:58 (~0553-0602) seconds is a falsification:
Antonio Bonomi wrote:
Sat Mar 09, 2019 1:03 pm


The firing of the last 2 shells from Y turret in local control occurred on the battle minute 06:04 and at 06:05 the PoW was only sailing away to the south east on retreat.

So even using the their own estimates of when PoW fired her last salvo, we can see that it should show 59 rnds/11 minutes or ~5.4 rnds/minute. Of course further firing after ~6:04 was impossible as A+B turrets were wooded and Y turret's ammo feed system was inoperable, even though no ceasefire had been ordered.

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Re: PoW's gunnery VS BSM's gunnery

Post by Bill Jurens » Sun Mar 10, 2019 7:28 pm

dunmuro wrote:

"If anyone needs further proof that the table showing PoW only firing for 8:58 (~0553-0602) seconds is a falsification:"

Insofar as the word 'falsification' implies deliberate attempt to deceive, I would rephrase as "If anyone needs further proof that the table showing PoW only firing for 8:58 (~0553-0602) seconds is in error:

Gets the same idea across, i.e. that the table is incorrect, but lessens the chances of inflaming the creators of same and restarting a bonfire...

Intended constructively...

Bill Jurens.

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Re: PoW's gunnery VS BSM's gunnery

Post by wadinga » Sun Mar 10, 2019 8:47 pm

Hello All,

It's good to see things stated that most if not all can agree on:
So little is known regarding the precise maneuvers of POW and/or the firing sequences and corrections that might have been made by Bismarck,
This would seem to be considerably at odds with some of the pronouncements made round here.

Since I don't think you can get a coffee, in say Paris, (or Milan),for less than 3 euro 25 , that makes the observation much more valuable than 2 cents' worth!

Can we all agree that based on the entry and exit wounds on the Compass platform, PoW was steering about 280 degrees when hit?

All the best

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

Post by Bill Jurens » Sun Mar 10, 2019 10:08 pm

I am not sure. Close measurements of the drawings in Prince of Wales War Damage Report, which include quite detailed diagrams of the projectile trajectories, show that the compass-platform hit seems to have approached at very nearly 45 degrees off the starboard bow. Whether that's an actual angle as measured on the ship -- which would be difficult to make in the first place insofar as one would be measuring at best to the approximate centers of holes, etc. and might be neglecting refractive effects -- or just a more or less 'close enough' approximation made by the draftsman who would have had a 45-degree set-square near at hand on the drafting table, and who might only have something sketched on the back of an envelope as a reference document -- is open to debate, especially when the practical consequences of a small error in measurement or depiction are essentially nil.

Our detailed data is -- or would seem to be -- only this. What compass course Prince of Wales might have been steaming when the projectile arrived would seem to be somewhat conjectural, insofar as it is dependent upon the precise geometric relationship between POW and Bismarck one time-of-flight prior, and -- insofar as we don't really have an exact time for the hit, nor a precise track chart vs time for POW or Bismarck, nor a precise range which would allow time of flight to be extracted, it's all fairly 'iffy'.

It's a bit like a police investigation into a shooting, where the trajectory through the victim, provided an accurate reconstruction can be made in the first place, can still only lead to an approximate derivation of the relative positions of the gun, shooter, and target at the time the projectile was fired. One can come reasonably close, but there are limits...

Bill Jurens.

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Re: PoW's gunnery VS BSM's gunnery

Post by dunmunro » Mon Mar 11, 2019 12:01 am

Bill Jurens wrote:
Sun Mar 10, 2019 7:28 pm
dunmuro wrote:

"If anyone needs further proof that the table showing PoW only firing for 8:58 (~0553-0602) seconds is a falsification:"

Insofar as the word 'falsification' implies deliberate attempt to deceive, I would rephrase as "If anyone needs further proof that the table showing PoW only firing for 8:58 (~0553-0602) seconds is in error:

Gets the same idea across, i.e. that the table is incorrect, but lessens the chances of inflaming the creators of same and restarting a bonfire...

Intended constructively...

Bill Jurens.
Mr Moderator; when the same table is presented year after year (despite lengthy objections from forum members that the table is in error) with the stated intent to prove that PoW's volume of fire was equivalent or better than Bismarck's, it's hard not to reach the conclusion that the intent is to deceive.

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Re: PoW's gunnery VS BSM's gunnery

Post by dunmunro » Mon Mar 11, 2019 12:24 am

Bill Jurens wrote:
Sun Mar 10, 2019 10:08 pm
I am not sure. Close measurements of the drawings in Prince of Wales War Damage Report, which include quite detailed diagrams of the projectile trajectories, show that the compass-platform hit seems to have approached at very nearly 45 degrees off the starboard bow. Whether that's an actual angle as measured on the ship -- which would be difficult to make in the first place insofar as one would be measuring at best to the approximate centers of holes, etc. and might be neglecting refractive effects -- or just a more or less 'close enough' approximation made by the draftsman who would have had a 45-degree set-square near at hand on the drafting table, and who might only have something sketched on the back of an envelope as a reference document -- is open to debate, especially when the practical consequences of a small error in measurement or depiction are essentially nil.

Our detailed data is -- or would seem to be -- only this. What compass course Prince of Wales might have been steaming when the projectile arrived would seem to be somewhat conjectural, insofar as it is dependent upon the precise geometric relationship between POW and Bismarck one time-of-flight prior, and -- insofar as we don't really have an exact time for the hit, nor a precise track chart vs time for POW or Bismarck, nor a precise range which would allow time of flight to be extracted, it's all fairly 'iffy'.

It's a bit like a police investigation into a shooting, where the trajectory through the victim, provided an accurate reconstruction can be made in the first place, can still only lead to an approximate derivation of the relative positions of the gun, shooter, and target at the time the projectile was fired. One can come reasonably close, but there are limits...

Bill Jurens.
We also know that PoW was making a series of high speed turns, possibly under full helm, to avoid the wreck of Hood just as the compass platform was hit.

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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani » Mon Mar 11, 2019 9:07 am

Hello everybody,
back from the wonderful city of Paris, where I have lived in late 1990's and where I still have good friends.


Regarding "the table showing PoW only firing for 8:58 (~0553-0602) seconds is a falsification:"
Bill Jurens wrote: "Insofar as the word 'falsification' implies deliberate attempt to deceive, I would rephrase.... "
Thanks to the moderator for stopping this further provocation: it attempted to the honor of a long time dead RN officer, however...
The table for PoW defining her firing action duration as 8,58 minutes is not Alberto Virtuani's table. It is Colin McMullen's table (http://www.hmshood.org.uk/reference/off ... 09guns.htm) and cannot be countered only because it annoys (even if I appreciate the difficulties of the forum members not wanting to accept the truth about PoW gunnery performance).
McMullen could have included the last local salvos, fired after her Captain had scrambled her gunnery with the turn away, but this way the table would have been a nonsense, not providing the view of her gunnery performance and this way really "deceiving" his superiors.


The same forum member wrote: "even using the their own estimates of when PoW fired her last salvo, we can see that it should show 59 rnds/11 minutes or ~5.4 rnds/minute"
Why not adding also the second engagement salvos then ? Or possibly even the interval between the first and the second engagement ? The ones who refuse to accept PoW performance could get to a much better result mixing data with the second engagement 12 salvos fired in 12 minutes (of course fired under very different conditions) or with a total of 33 salvos (and 100 shells) fired in 13 hours ... This would really be a "falsification"...
Luckily, the PoW GAR gives us a correct table.



Regarding Bismarck and Prinz Eugen (my part of the table...), I agree we could get a better comparison if we had the salvo plot of the German ships, but as there is no evidence whatsoever that the German ships slowed their fire during turns (PG fired continuously during turns, as per Jasper report) and as we have photos and film showing Bismarck firing during turns, the "assumption of 14 minutes (it may be 13,5 or 14,5 of course, nothing changes) firing (5:55 to 6:09, 100% sure for PG, most probable for Bismarck as only fantasy can imagine Bismarck ceased fire much before PG for any secret reason, is fully confirmed.
The other "assumptions" (ordered shots) does not affect at all the effective RoF of Bismarck. Thus the "annoying" table (built following McMullen's methodology (http://www.hmshood.org.uk/reference/off ... 09guns.htm) is showing a good comparison between the three ships, waiting for any different "assumption":

PoW_BS_PG_Output_Comparison_McMullen_rounded.jpg
PoW_BS_PG_Output_Comparison_McMullen_rounded.jpg (56.43 KiB) Viewed 594 times

Alternatives are welcome: I remember that the same forum member "imagined" Bismarck opening fire at 5:53 (much worse for him in this case...) but then he presented a "redacted" table with not much credible cease fire timing (based on no solid evidence), while we have the photo of the "last" (probably) salvo of Bismack fired when PG was already on her starboard beam, thus around 6:09, when Jasper was ordered not to fire over his flagship, if nobody is able to present a completely different battle reconstruction.


Bye, Alberto
Last edited by Alberto Virtuani on Mon Mar 11, 2019 10:44 am, edited 1 time in total.
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Re: PoW's gunnery VS BSM's gunnery

Post by wadinga » Mon Mar 11, 2019 10:42 am

Fellow Contributors,

It has been said
I agree we could get a better comparison if we had the salvo plot of the German ships,
and this true, because we have no recorded times from Bismarck for the first salvo, no recorded time for the last and no evidence the German ships fired continuously because this table is based entirely on unwarranted assumptions (fabricated evidence) about Bismarck's firing. Like:
but as there is no evidence whatsoever that the German ships slowed their fire during turns
Since Jasper says:
The battery was twice temporarily and laterally displaced from the target during this maneuver
If a gun is displaced from the target there is no point in firing it. Therefore his observation:
Firing continued during these turning manoeuvres
should be taken to mean no order to "cease fire" was given because of the violent turns, but the impossibility of keeping the guns on target means no firing actually took place. Exactly the same situation as PoW. Therefore periods of non firing for one German ship is proven and refusal to acknowledge that the table is based on a false premise may cause readers to evaluate the reason for continuing to assert these unwarranted assertions through posting the same inaccurate table over and over again.

Instead of reposting this thoroughly unprincipled table, this contributor could repost the very useful plan he provided before, showing the Compass Platform and
the shell path identified from photographs
, which is surely not 45 degrees off PoW's centreline, of a shell which was unlikely to have suffered any "refractive effects" since it entered through a window space.

If we are considering provocation however, aside from doing pointless statistics on unwarranted assumptions, silly suggestions such as:
Why not adding also the second engagement salvos then ?
are only made in order to further annoy those who have serious contributions to make. However this particular contributor does have something else useful to bring to the discussion at this time...…….How much is a cup of coffee in Paris these days?

All the best

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

Post by Alberto Virtuani » Mon Mar 11, 2019 10:58 am

Hello everybody,
Wadinga wrote: "If a gun is displaced from the target there is no point in firing it."
Jasper_Turns(KTB).jpg
Jasper_Turns(KTB).jpg (29.26 KiB) Viewed 561 times
Deeply sorry, Jasper statement is unambiguous, PG firing continued during the turns.
The convoluted "interpretation" given above ("...should be taken to mean no order to "cease fire" was given because of the violent turns, but the impossibility of keeping the guns on target means no firing actually took place...") is clearly shown incorrect also by the PG film showing Bismarck firing during a turn (minute 7:05 here https://www.youtube.com/watch?v=pPmkOtSveXY where Bismarck fires the main armament after having started since some seconds her second turn, well visible from the fact that her silhouette is changing rapidly as seen from PG).

Any attempt to state that Germans ceased fire during their maneuvers is based on no evidence whatsoever and even contradicts what is said by Jasper and what is visible in the PG images...but the attempt is very well understandable, because it is the only way to counter what gunnery data confirm us in the "annoying" table (download/file.php?id=3413): PoW performance was excellent and in line with Germans.


Wadinga wrote (quoting me): "silly suggestions such as:"Why not adding also the second engagement salvos then ?" are only made in order to further annoy those who have serious contributions to make"
No, sorry again, the truly silly suggestion was made by a forum member who tried to say that the correct firing duration for PoW is not 8,58 minutes (55 shells) but it should have been assumed to have been 11 minutes (59 shells): this is totally incorrect and it contradicts the official PoW GAR (http://www.hmshood.org.uk/reference/off ... 09guns.htm).
The only possible comparison (not 100% perfect possibly, but very close to it) is the one presented in the "annoying table", where the centrally controlled, high RoF action duration only are confronted.


Bye, Alberto
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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson » Mon Mar 11, 2019 1:34 pm

@all

Reading the German original of Jasper's statement I tend to agree with Alberto. I disagree that the film shows Bismarck during a turn. Bismarck is on a straight course the whole time.
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Marc

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Re: PoW's gunnery VS BSM's gunnery

Post by Alberto Virtuani » Mon Mar 11, 2019 2:04 pm

Hello everybody,
Herr Nilsson wrote: "Bismarck is on a straight course the whole time."
I just disagree with the above. In the PG film, Bismarck silhouette is unchanged from minute 5:40 till minute 6:51 (after the first insertion o Hood explosion and PoW), while it changes considerably after and until 7:12, showing a clear turn to port of Bismarck from course around 270°to a more southerly course.

Demonstration was already available here (the dedicated thread for discussing this topic) from Antonio...viewtopic.php?f=1&t=8335#p81065


Bye, Alberto
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Re: PoW's gunnery VS BSM's gunnery

Post by Herr Nilsson » Mon Mar 11, 2019 2:32 pm

@all

No, Bismarck is firing almost abeam (~ 265°-268°) the whole time. The first picture with a considerable change is NH 69730 (~259°) and finally the "final salvo" (~251°). So actually Prinz Eugen is turning in front of Bismarck.
Regards

Marc

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