Message Traffic heard by RODNEY 24 May 1941

[dunmunro]

Hello everybody,

thanks to Mr.Dunmunro for fairly confirming what I said above.

However, despite all the above "tragedies", PoW was able to straddle as early as at 6th salvo (3 minutes only after open fire), getting Tovey's approval and Santarini's recent correct recognition. No criticism whatsoever against McMullen in the RN ever.

AFAIK, no range data was passed to PoW by Hood (nor vice-versa) http://www.hmshood.com/history/denmarks ... letter.htm .


Bye, Alberto

However, PoW still only managed 3 straddles from 18 salvos and from historical accounts Bismarck did considerably better. KGV, based upon her straddle rate with type 284 ranging, would have had 7-8 straddles during the same time frame, and with higher output, could have expected 8-9 14in hits.

[Alberto Virtuani]

Hello everybody,

we can only speculate whether KGV mountings would have behaved better or worse than PoW's, no one knows whether the same radar would have had time to warm up correctly on board KGV, we don't know whether the KGV GO would have been "superb" as McMullen was, or just "average", no comparison can be done between straddles obtained against Bismarck on May 24 and a sitting duck on May 27.

Historically, we know PoW did this way compared to Bismarck (download/file.php?id=3461).
Not better, not so much worse. Undoubtedly, as Tovey was forced to admit, PoW "started off well".


Bye, Alberto

[dunmunro]

Hello everybody,

we can only speculate whether KGV mountings would have behaved better or worse than PoW's, no one knows whether the same radar would have had time to warm up correctly on board KGV, we don't know whether the KGV GO would have been "superb" as McMullen was, or just "average".

We have a very good idea of how KGV's 14in mountings performed during the first 32 minutes of her action with Bismarck.

There is no indication from any historical source that warm-up was a factor in the type 284 failure. Mcmullen's performance wasn't a factor as he was only one person in the large number involved in the FC system. PoW's performance was actually less than what would have been expected of any modern or modernized RN battleship, but given the lack of work-up by PoW it was an acceptable performance.

[Byron Angel]

KGV's RDF284 should not have experienced any delay issues with respect to warm-up time. Bismarck was alone and crippled. The British were tracking her and knew fairly closely when she would come into sight. There was no need to maintain electronic silence at that point. Warm-up could be commenced at the apropos advance time in order to be fully ready when the engagement was predicted to commence.

B

[dunmunro]

KGV's RDF284 should not have experienced any delay issues with respect to warm-up time. Bismarck was alone and crippled. The British were tracking her and knew fairly closely when she would come into sight. There was no need to maintain electronic silence at that point. Warm-up could be commenced at the apropos advance time in order to be fully ready when the engagement was predicted to commence.

B

There is no historical source that mentions warm-up as a possible cause for type 284 failure on PoW. Type 284 had been in operation for some time in the RN by May 1941 and they must have known it's warm-up characteristics. In any event, warm-up is a fairly recent hypothesis, and even if true, we have no historical data to support that. The official cause was that the Type 284 was "defective" and that type 281 "suffered interference". Paddon, PoW's RCN radar officer claimed to have transmitted ranges to the TS but he also claimed to have three KM targets on his screen...

[Alberto Virtuani]

Hello everybody,

"We have a very good idea of how KGV's 14in mountings performed during the first 32 minutes of her action with Bismarck."

No, we don't, because no data is available for KGV ordered shots (you have assumed them, without any evidence supporting). In addition, KGV fired for 20 minutes from shorter distance at a significantly slower Rate of Fire (1.7 salvo per minute vs 1.9 average for PoW, despite the need to respect time sectors...). If you fire comfortably slowly, the risk of misfires and minor problems is logically much lower...).
For sure the big problem (the jam of the turret) would have occurred on KGV as well as (if ever really solved...) it was addressed only much later on the KGV class ships.

"There is no indication from any historical source that warm-up was a factor in the type 284 failure"

Yes there is, clearly written even in dubitative form (http://www.hmshood.com/history/denmarks ... letter.htm) + we have the explanation given by Dave Saxton viewtopic.php?f=1&t=8491&p=82290&hilit=warm+up#p82290). You may like it or not, but most probably the KGV 284 (same model) would have experienced the same "problem" under the same "radio silence" conditions (viewtopic.php?f=1&t=8552&p=83583#p83578).
Clearly the PoW 284 was not "defective" at all as it worked perfectly few hours later, thus it was functioning.



I don't see any way McMullen could have corrected the initial range over-estimation better than he did (with only 2 corrections in less than 3 minutes), following the British firing methodology (viewtopic.php?f=1&t=8552&start=75#p83563). KGV's GO was unable (under different conditions) to straddle before the crippled Bismarck did: McMullen was: his performance must be recognized.


Bye, Alberto

[dunmunro]

Hello everybody,

"We have a very good idea of how KGV's 14in mountings performed during the first 32 minutes of her action with Bismarck."

No, we don't, because no data is available for KGV ordered shots (you have assumed them, without any evidence supporting). In addition, KGV fired for 20 minutes from shorter distance at a significantly slower Rate of Fire (1.7 salvo per minute vs 1.9 average for PoW, despite the need to respect time sectors...). If you fire comfortably slowly, the risk of misfires and minor problems is logically much lower...).
For sure the big problem (the jam of the turret) would have occurred on KGV as well as (if ever really solved...) it was addressed only much later on the KGV class ships.

"There is no indication from any historical source that warm-up was a factor in the type 284 failure"

Yes there is, clearly written even in dubitative form (http://www.hmshood.com/history/denmarks ... letter.htm) + we have the explanation given by Dave Saxton viewtopic.php?f=1&t=8491&p=82290&hilit=warm+up#p82290). You may like it or not, but most probably the KGV 284 (same model) would have experienced the same "problem" under the same "radio silence" conditions (viewtopic.php?f=1&t=8552&p=83583#p83578).
Clearly the PoW 284 was not "defective" at all as it worked perfectly few hours later, thus it was functioning.



I don't see any way McMullen could have corrected the initial range over-estimation better than he did (with only 2 corrections in less than 3 minutes), following the British firing methodology (viewtopic.php?f=1&t=8552&start=75#p83563). KGV's GO was unable (under different conditions) to straddle before the crippled Bismarck did: McMullen was: his performance must be recognized.


Bye, Alberto

We have KGV's 14 page GAR - what other "supporting evidence" is needed? It details the losses of output from all causes. Rodney had no difficulty in maintaining two salvos/minute during the engagement for minutes at time even during the opening phases, but visibility and sea state conditions were much more adverse than on ~0553 May 24. There is no reason that KGV could not match Rodney or PoW's output under the same seastate conditions especially as they had more training than PoW.

McMullen states:

No range was obtained before opening fire from the air warning radar set; I think (but am not certain} due to baving been switched-off and slowness in becoming operational after being switched-on again.

The "air warning radar" was the Type 281 which Paddon was operating.

McMullen states that Type 284 could not pass ranges above 24k yds but this is just not true and both Hood (in May 1941 at Scapa Flow) and KGV (against Bismarck) were able to pass ranges above 24k yds from the Type 284 but regardless McMullen says nothing about warm-up issues regarding the Type 284. McMullen is recounting events that happened three decades earlier and he makes many mistakes and confuses the 3 engagements that PoW fought against Bismarck, as PoW's type 284 radar was operational during the last two engagements and prior to the first engagement.

PoW's GAR states:

A range and inclination exercise was carried out with Hood during the forenoon and R.D.F. sets worked well.

2. Friday, 23rd May. - Another range and inclination exercise was carried out during the forenoon with R.D.F. Sets again working well...

4. No results were obtained from either Type 281 or 284 R.D.F.; it is understood that Signal School Officers are now of the opinion that Type 281 suffered interference and Type 284 was defective, although it appeared at the time that 284 was also suffering from interference.

McMullen states:

Once the range was down to about 20,000 yards the T. S. had a good Range Plot including radar ranges from the 14 inch Director Tower set and continual optical range finder ranges, certainly from "B" Turret.

And from the above it seems certain that he confused the first action with the 3rd action as PoW's GAR states:

25th May. - One double salvo was fired at 0131 at a range of 20,000 yards at an enemy ship which might have been Bismarck or Prinz Eugen. A good R.D.F. range was obtained but the target was then lost in funnel smoke and mist and fire could not be continued.

Stephen Roskill was one of the officers who looked at PoW's radar before the action and from the GAR is is apparent that the RN Signal School also looked into the lack of radar results and but from what we know neither radar was operating correctly during the first engagement and neither gave any useful ranges during that engagement.


Quite frankly, I am rather puzzled at your rejection of official documents, written at the time, in favour of, obviously inaccurate recollections by elderly men, decades after the fact.

[Alberto Virtuani]

Hello everybody,

"It details the losses of output from all causes."

No, it doesn't, because no GAR details all failures, only major ones are listed (see PoW GAR as an example). Please explain why KGV GAR should list all minor problems in a 2 hours shooting while PoW one (much more detailed) does not (for a 10 minutes battle...)
KGV GAR is so poorly written compared to PoW one that it doesn't even specify the number of ordered shots (and the loss of output...). No way to get to any solid conclusion from it, except that KGV achieved for 20 minutes a slower RoF (1.7) than PoW (1.9), despite not being forced to fire in time sectors as McMullen was.


For sure, 284 was perfectly functioning and only failed to provide initial range (Dave has explained us why viewtopic.php?f=1&t=8491&p=82290&hilit=warm+up#p82290 and why 284 required even more warm-up time than 281).
Another explanation can be that 284 suffered interferences and, again, KGV radar would have suffered the same interference problem, had she been present on May 24.

I simply discard official documents when they state an apparatus was "defective" , while in the same report they say the same apparatus perfectly worked before the battle and few hours later. As a radar has no self-repair capability, the "official" statement is wrong.
The "elderly man" provides a good explanation applicable to both radar sets, as well as to KGV radars that were not different from PoW ones.




I still don't see any different proposal how McMullen could have corrected the initial range over-estimation better than he did (with only 2 corrections in less than 3 minutes), following the British firing methodology (viewtopic.php?f=1&t=8552&start=75#p83563 and following).
Have everybody decided to simply "change topic", instead of acknowledging that Santarini's authoritative and supported judgement about McMullen's "superb performance" when adjusting his fire is simply correct?


Bye, Alberto

[Byron Angel]

KGV's RDF284 should not have experienced any delay issues with respect to warm-up time. Bismarck was alone and crippled. The British were tracking her and knew fairly closely when she would come into sight. There was no need to maintain electronic silence at that point. Warm-up could be commenced at the apropos advance time in order to be fully ready when the engagement was predicted to commence.

B

There is no historical source that mentions warm-up as a possible cause for type 284 failure on PoW. Type 284 had been in operation for some time in the RN by May 1941 and they must have known it's warm-up characteristics. In any event, warm-up is a fairly recent hypothesis, and even if true, we have no historical data to support that. The official cause was that the Type 284 was "defective" and that type 281 "suffered interference". Paddon, PoW's RCN radar officer claimed to have transmitted ranges to the TS but he also claimed to have three KM targets on his screen...

Maybe a misunderstanding here. I actually agree with you. Was just pointing out that there was no longer any reason to be "careful" about turning on the 284.

B

[Alberto Virtuani]

Hello everybody,

From the above, I don't understand anymore if we speak about KGV on May27 or about PoW on May 24....


The order to switch on the PoW's 284 could have been given only after 05:37, when the ship broke the "radio silence" to lauch her "enemy in sight" message.

As per Dave Saxton explanation (viewtopic.php?f=1&t=8491&hilit=warm+up&start=45#p82281, viewtopic.php?f=1&t=8491&hilit=warm+up&start=45#p82290) it could have taken more than 20 minutes (up to 45) to warm-up a 284 set, thus it's almost sure that the Type 284 had no time to warm-up for the initial ranging (05:52) and, probably, not in a reliable way until the end of the fire action (06:02) too.


Of course KGV 284 radar could have been switched on at any time before the battle on May 27 as no "radio silence" was requested by Tovey.


Bye, Alberto

[Byron Angel]

According to the best analysis and conclusions of qualified investigating British naval officers and technical experts after having spent months of study and interviewing scores of witnesses, Bismarck opened fire at 0555, bracketed Hood with her initial 400m forking group, then straddled and hit Hood on her third or fourth salvo by 0557. She again straddled and hit Hood on her fifth or sixth salvo. Bismarck switched target to Prince of Wales around 0601 and hit her three (possibly four) times within 1 or 2 minutes. To sum up Bismarck scored al least five hits on two targets in approximately seven minutes.

On the other hand, Prince of Wales opened fire at 0553 at least 1,500 yards over, took three minutes to find the range, got lucky with a straddle and hit (as opposed to simply crossing the target) at 0556. She got a second straddle and hit around 0558, and a third and final straddle and hit around 0600. All this was achieved while under no effective opposing fire; when finally taken under effective fire by Bismarck Prince of Wales completely lost the plot.

Readers are invited to draw their own conclusions about relative gunnery efficiency.

B

[Alberto Virtuani]

Hello everybody,

"when finally taken under effective fire by Bismarck Prince of Wales completely lost the plot."

PoW "lost the plot" after 6:00, when the ship initially heeled violently due to avoiding maneuvers and then turned hard away at full speed under smoke, not because she was "under fire".
In no place (official reports, interview, letters) McMullen complained about having been "disturbed" in his gunnery performance by incoming shells/fall of shots (he was by the spray over the fore turrets rangefinders), as logical (even the Baron was not much "disturbed" when Bismarck was under an awful concentration of fire from 4 ships on May 27, until his own rangefinder was directly hit...).


Indeed, "readers are invited to draw their own conclusions about relative gunnery efficiency." (download/file.php?id=3461): IMO, PoW performance was not very brilliant (but not tragic) from loss of output viewpoint, fairly good from precision and efficiency viewpoint, "excellent" from Rate of Fire (that do not depend on luck in any way) viewpoint and "superb" from initial range adjustment viewpoint (as per Adm.Santarini judgements in his book "Hood and Bismarck").


Bye, Alberto

[dunmunro]

Hello everybody,

From the above, I don't understand anymore if we speak about KGV on May27 or about PoW on May 24....


The order to switch on the PoW's 284 could have been given only after 05:37, when the ship broke the "radio silence" to lauch her "enemy in sight" message.

As per Dave Saxton explanation (viewtopic.php?f=1&t=8491&hilit=warm+up&start=45#p82281, viewtopic.php?f=1&t=8491&hilit=warm+up&start=45#p82290) it could have taken more than 20 minutes (up to 45) to warm-up a 284 set, thus it's almost sure that the Type 284 had no time to warm-up for the initial ranging (05:52) and, probably, not in a reliable way until the end of the fire action (06:02) too.


Of course KGV 284 radar could have been switched on at any time before the battle on May 27 as no "radio silence" was requested by Tovey.


Bye, Alberto

There is no historical evidence for concluding that warm-up was an issue.

[Bill Jurens]

The records recording radar performance are quite anecdotal. So far as 'warm-up' is concerned, I don't see that as much of an issue in any case insofar as the entire unit could probably be energized and warmed up without being connected to the antenna, i.e. keeping 'radio silence' would not require units to be turned off entirely.

I'd be surprised, however, to find that the shock of gunfire, etc. would not be causing problems with vacuum tubes, etc. as in the early days of radar this seems to have often been quite an issue. It took a while before proper methods of shock mounting, and shock resistant electronic components were developed.

Some reports on the British side seem to allude to 'interference', with the suggestion that it may have been due -- at least in part -- to deliberate German attempts to 'jam' the British radars. Also quite plausible, but not something I can comment upon with any degree of true expertise.

Bill Jurens

[dunmunro]

Hello everybody,

"It details the losses of output from all causes."

No, it doesn't, because no GAR details all failures, only major ones are listed (see PoW GAR as an example). Please explain why KGV GAR should list all minor problems in a 2 hours shooting while PoW one (much more detailed) does not (for a 10 minutes battle...)
KGV GAR is so poorly written compared to PoW one that it doesn't even specify the number of ordered shots (and the loss of output...). No way to get to any solid conclusion from it, except that KGV achieved for 20 minutes a slower RoF (1.7) than PoW (1.9), despite not being forced to fire in time sectors as McMullen was.


For sure, 284 was perfectly functioning and only failed to provide initial range (Dave has explained us why viewtopic.php?f=1&t=8491&p=82290&hilit=warm+up#p82290 and why 284 required even more warm-up time than 281).
Another explanation can be that 284 suffered interferences and, again, KGV radar would have suffered the same interference problem, had she been present on May 24.

I simply discard official documents when they state an apparatus was "defective" , while in the same report they say the same apparatus perfectly worked before the battle and few hours later. As a radar has no self-repair capability, the "official" statement is wrong.
The "elderly man" provides a good explanation applicable to both radar sets, as well as to KGV radars that were not different from PoW ones.




I still don't see any different proposal how McMullen could have corrected the initial range over-estimation better than he did (with only 2 corrections in less than 3 minutes), following the British firing methodology (viewtopic.php?f=1&t=8552&start=75#p83563 and following).
Have everybody decided to simply "change topic", instead of acknowledging that Santarini's authoritative and supported judgement about McMullen's "superb performance" when adjusting his fire is simply correct?


Bye, Alberto

It is not a minor event when a battleship fails to fire a main armament round.
GARs are written specifically to detail all loses of output. PoW's report does detail all loses of output as does KGV's and I was able to build chart reconstructing the ouput from both ships, based upon their GARs. The Barben report conflicts with the PoW GAR and if Barben is correct the variation in rounds fired changes from 55 to 56. However, for Barben to be correct, B turret would have had to miss 3 consecutive salvos and yet we have no source for such a thing happening. As I've stated in the past, I have relied on the HMS Hood's website transcription of PoW's GAR and it is possible that there have been omissions from that transcription, but if that is not the case then I'd have to conclude that Barben was incorrect. We also know that Barben's report was sent to the Admiralty so they were aware of the variation between the reports.

For sure, 284 was perfectly functioning and only failed to provide initial range (Dave has explained us why viewtopic.php?f=1&t=8491&p=82290&hilit=warm+up#p82290 and why 284 required even more warm-up time than 281).
Another explanation can be that 284 suffered interferences and, again, KGV radar would have suffered the same interference problem, had she been present on May 24.

I simply discard official documents when they state an apparatus was "defective" , while in the same report they say the same apparatus perfectly worked before the battle and few hours later. As a radar has no self-repair capability, the "official" statement is wrong.
The "elderly man" provides a good explanation applicable to both radar sets, as well as to KGV radars that were not different from PoW ones.

You have no historical basis for the first statement, above. After the fact speculation is interesting, but it must have a historical basis to be considered conclusive. It is fine to include speculative conclusions in written history as long as the conclusion is clearly stated to be speculative.

PoW had a different radar outfit than KGV, and PoW's outfit was much more complex and much newer than KGV's. KGV had a type 279 WA radar versus type 281 WA radar in PoW. These two radars operate on different frequencies and it is possible that type 281 was the source of the interference, or it may have been caused by the incomplete state of the other 8 radars that were being fitted on PoW (4 x type 285 and 4 x Type 282). It may have been an intermittent short caused by seawater ingress into cabling for the Type 284. Paddon states that the Type 281 antennae was damaged during the first action and was not subsequently available. Another possibility is that the FC radio link was the cause, but while I can speculate on causes, all I can know for sure is that the type 284 and type 281 failed to provide any ranges and that the stated cause was that Type 284 was defective and Type 281 suffered interference and Paddon's account of 3 KM targets on his Type 281 radar screen supports interference.

HMS Suffolk also had a type 284 and type 279 and both operated, mostly, efficiently. However the Type 284 did breakdown on at least one occasion:

[May24]1622 (B) - 1700 (B). Type 284 temporarily out of action. Visibility clearing from north-westward. Opened out distance from enemy.

Yet it had functioned correctly for several days prior and was back in action shortly thereafter. Electronics were just inherently unreliable in those days and even Bismarck complained about the unreliable nature of her radars. But this doesn't mean that the ship could not repair them or correct minor faults, or even just find that the gear worked again, when previously it hadn't - intermittent operation of tube based electronics was pretty common, as I recall from my youth. The lack of work-up and training of the crew on PoW was probably a factor as well, as much of the training would have been supplemented with "on the job experience" given sufficient time.