Jasper, Schmalenbach and 6 salvos...

[dunmunro]

Duplicate post.

[paulcadogan]

Hi Duncan,

I see what you're saying. But under my theory, the gabelgruppe accounts for 3 salvos. This involves firing A+B (long), then after a short interval C+D (middle) then, after re-load, A+B again (short). The gap between the first two may be shorter than that between the second two. To go to vollsalve good rapid, there would have to be a delay to allow A+B to reload, with C+D ready to fire. I just can't see that process drawn out over 5 minutes... The battle film showed Bismarck was fully capable of reloading and firing her main armament very quickly.

@Alberto: You said:

Still sticking to 6:00, mostly because of Hunter-Terry dictated timings (that state a 3 minutes delay between the deck hit and the final explosion) and the analysis of NH69724 vs NH69731 (distance covered in around 3 or 3.5 minutes, not in 5 or 5.5 IMO), I must say that I'm still very doubtful about what really happened on board Hood in the interval between the deck hit and the final explosion......

OK, think about this: Hood was steaming at 29 knots and leaving a smoke trail of funnel and gun smoke behind her, covering what..over 900 yards per minute. Even with a full tail wind of 7-10 knots, she would leave the trailing smoke behind her at 19 to 22 knots...say 600+ to 700+ yards per minute... and at the DS, the wind was NOT from astern, but was more, I think, from the starboard quarter..

Now look at NH69724 - which shows the smoke from the boat deck fire trailing just behind the smoke column of the final explosion, and taking into account the gap between Hood and PoW with consideration for their inclination...

If Hood was burning for 3-4 minutes (3 minutes according to Terry, 4 minutes according to one of the cruiser witnesses who said he timed it)...how come the smoke trail from that fire is so short???

[alecsandros]

@Paul

Wind was blowing from N-NE to S-SW at approx 10m/s.

http://www.seekrieg.com/BattleOfDenmarkStraits.pdf

[Alberto Virtuani]

Hi Paul,

you wrote: "If Hood was burning for 3-4 minutes (3 minutes according to Terry, 4 minutes according to one of the cruiser witnesses who said he timed it)...how come the smoke trail from that fire is so short???"

I see your point, but the wind was also dispersing the smoke.... thus the deck fire smoke is just visible for the last seconds (max 1 minute) of its burning before the explosion; the smoke emitted before has already disappeared. Thanks to Alec for the precision about wind force (strong enough IMO).

Demonstration: only the smoke of the last two PoW salvos is visible in the photo, but we know she had fired more than 10 before that time (and at least 6 or 8 should be visible in the large field of the camera).


Bye, Alberto

[alecsandros]

@Alberto
I'm thinking the smoke from the explosion of HOod almost certainly covers the "tail" that the battlecruiser left while approaching her demise position.

Also, after the final turn was completed (both by Hood at 6:00 and PoW at 6:01-6:02), the relative speed of British ships in relationship to their own smoke trail was around 10kts (5/ms, 300meters/minute), because their direction of advance was approx the same as that on which the wind was blowing. Thus 29kts (max...) vs 18kts speed of wind implies only small distancing between ship and (own) puffs of smoke. And the wind will also dissipate that smoke as well, as you said.

[paulcadogan]

@Alecsandros,

That link is a war game from 2005. Brinkmann put the wind at Force 3 at 0600 (8 - 12 mph, 7 - 10 knots). It was at midnight on the 24th that Leach had the wind at Force 4 - 5 from the north.

@Alberto,

Sure the smoke is dispersing, but the boat deck fire flared big and then died down somewhat before the ship blew up. The photo shows a large thick cloud of smoke that ends abruptly rather than dispersing gradually as one would expect...

Paul

[Alberto Virtuani]

Hi Paul,
if we believe that the fire started fiercely and then diminished (somehow augmenting, then pulsating and finally decreasing, as described by someone), then its duration must have been surely more than 1 minute.

The "large thick cloud" we see is not more than 20 seconds before explosion (due to the ship travel speed, as distance between Hood and PoW was 800 meters, sailed in 1 minute).

Can we be 100% sure that this "large thick cloud" is still the boat deck fire result and not already part of the explosion, just after the pillar of flames (still clearly visible) ?


Bye, Alberto

[Cag]

Hi All

I must apologise for the length of this post, it's my Bismarck salvo chart as requested by Alberto etc for your perusal and no doubt comment which I hope may help.

Bismarck reload time as per conversation with Antonio is 28 seconds. Ranges are as Antonios salvo chart, the flight times are indicated next to the ranges. So as not to offend anyone I've used a chronological time line giving no specific start time.

Lindemanns open fire order 00.00:00
Open fire order acknowledged 00.00:05

Vollsalve
A+B Turrets fired 00.00:08
Range 220hm (36)
Shells land 00.00:44
reload time @ 28 seconds 00.00:36
C+D Turrets fired 00.00:12
Range 210hm (34)
Lands 00.00:46
reload time (28) 00.00:40

Observation of fall of shot and switch to Gabelgruppe 30 seconds
Gabelgruppe
A+B Turrets fired 00.01:16
Range 210hm (34)
Lands 00.01:50
reload time (28) 00.01:44
C+D Turrets fired 00.01:24
Range 200hm (32)
Lands 00.01:56
reload time (28) 00.01:52
A+C or B+D Turrets fired as per AVKS Bracket firing procedures
A+C Turrets fired 00.01:54
Range 190hm (30)
Lands 00.02:24
Reload time (28) 00.02:22

Observation of fall of shot and switch to Wirkungsschießen 'Good Rapid' 18 seconds
Wirkungsschießen
A+B Turrets fired 00.02:42
Range 180hm (28)
Lands 00.03:10
Reload time (28) 00.03:10
C+D Turrets fired 00.02:45
Range 170hm (26)
Lands 00.03:11
Reload time (28) 00.03:13

Observation and correction/continue 'Good Rapid' 15 seconds
Wirkungsschießen
A+B Turrets fired 00.03:26
Range 160hm (24)
Lands 00.03:50
reload time (28) 00.03:54
C+D Turrets fired 00.03:29
Range 160hm (24)
Lands 00.03:53
Reload time (28) 00.03:57

Observation of fall of shot and correction/continue 'Good Rapid' 15 seconds
Wirkungsschießen
A+B Turrets fired 00.04:08
Range 155hm (23)
Lands 00.04:31
Reload time (28) 00.04:36
C+D Turrets fired 00.04:11
Range 150hm (22)
Lands 00.04:33
Reload time (28) 00.04:39

As can be seen I've allowed as much time as possible for fire control switches (possibly too much!) and for open fire protocol. Also I have left a gap between fore and aft turret group firing in Vollsalve and Wirkungsschießen similar to that seen in the Prinz Eugen film which also allows for gaps for observation of fall of shot between each turret group.

I think it quite possible that Schneider fired the after turret group that made up the second half of the fatal hit Wirkungsschießen as he would not have known the effect the first half would have on Hood.

Hope this helps.

Best wishes
Cag.

[dunmunro]

Cag, thanks.

Some more observations:

PE's KTB states a salvo interval of 27-28 seconds, which doesn't compare very favourably with her theoretical reloading cycle of 12 seconds.

PE's film of the battle is notable for apparently excluding all of PE's own salvos; this means that no single piece of film is longer than a PE salvo interval, or 27-28 seconds.

[Alberto Virtuani]

Hi Mr.Cag,
thanks for this great, constructive, piece of work, presented with the usual fairness and respect.

I must say that I have tried to build in "excel" a (much less refined ) salvo plot for Bismarck (as well based on flight times) and I "landed" to an overall elapsed time of 4:28 or 4:29 seconds up to the "fatal" hit, depending on the assumed firing methodology (semi-salvos or full salvos when in "fire for effect" mode) vs your 4:31 or 4:33, thus we are very much in line one with the other (and very close also to what can be considered IMO the minimum "granularity" for this battle definition.....)


3 points (respectively observation, question and suggestion):

1) I see that (despite your attempt to keep "neutral" re. the Bismarck open fire timing discussion) you (IMO correctly) assumed Antonio's reconstruction distances. In doing so, however , you "fire" the first BS salvo from a distance of 220 hm, that is you assume BS open fire at around 5:55 (as at 5:53 the distance from Hood would have been more close to 230/240 hm, with flight times around 40 secs, while at 5:55:30 (my preferred open fire time) it would be around 210 hm).


2) I'm a bit surprised of the "gabelgruppe" firing methodology you have assumed: (in my full ignorance of German firing procedures, I have asked several times for help from an expert, without any success up to now....), I have always thought that BS would have fired A+B, followed by C+D and finally again A+B (the turrets already re-loaded and available for firing first) .
You say that, according to "AVKS" she fired A+C (or B+D) that for me is quite a non-sense: Schneider had to wait the reload time of one of the aft turrets before he could fire the 3rd semi-salvo....Also this way he was unable to have all the 3 semi-salvos in the air at the same time as explained by the Baron in his book session dedicated to Bismarck firing control.
Could you please post your "AVKS" source (what is AVKS ? Sorry for asking a perhaps stupid question) about this (key) aspect ? Is there any clear reason for such a (IMHO) "convoluted" firing procedure ?


3) The Baron accounts (in my Italian translation version) for "fire for effect" (or "rapid fire") ordered twice by Schneider, once after the gabelgruppe, the second time after the Hood deck fire has already been spotted and "broadcasted". If we trust his account (and I do), this IMO means that, after the first "fire for effect" "broadside" (or "double"", I'm unsure how to call it....), Schneider needed to correct the parameters (thus interrupting the "fire for effect"), possibly firing another single semi-salvo, spotting its fall of shells and then ordering "fire for effect" again, finally firing the fatal "broadside".
In my own salvos reconstruction attempt, I assumed this way and thus I ended up to a fatal hit delivered by C+D, as per the famous picture (Schmitz) depicting the "final volley" fired by the aft group and according to the Baron count of 40 shots in total (vs your 44) ordered to sink the Hood.

Still I have a doubt that Bismarck was ever firing "broadsides", even when in "fire for effect" mode, because Leach testimony re. the fatal hit is quite precise: he said he saw 3 splashes (2 long and 1 short or viceversa), therefore he suspected one shell had hit his flagship......he seems not to mention 8 shells salvos (even if 4 landing 2 seconds before the other 4).....


Bye, Alberto

[dunmunro]

1) I see that (despite your attempt to keep "neutral" re. the Bismarck open fire timing discussion) you (IMO correctly) assumed Antonio's reconstruction distances. In doing so, however , you "fire" the first BS salvo from a distance of 220 hm, that is you assume BS open fire at around 5:55 (as at 5:53 the distance from Hood would have been more close to 230/240 hm, with flight times around 40 secs, while at 5:55:30 (my preferred open fire time) it would be around 210 hm).

That is a good point, and increasing the time of flight for all salvos would add another 30-40 seconds to the time estimate. Thus, as Bismarck opened fire at ~0553 we are right at ~0558 for the magazine explosion.

[Alberto Virtuani]

@Dunmunro:
Hi Duncan,
yes, we are right, but ONLY IF we accept your "theory", and nobody apparently does ......

Bye, Alberto

[dunmunro]

@Dunmunro:
yes, we are, but ONLY IF we accept your "theory" ......


Bye, Alberto

This isn't really "my" theory as the Blake and Walker boards, after carefully examining volumes of data, came to the conclusion that all 3 battleships opened fire within one minute. However, let's leave this aside and simply consider that if Bismarck opened fire at 0553 that Hood exploding at 0558 is quite consistent with Bismarck's practical rate of fire at the ranges involved.

[Alberto Virtuani]

Hi Duncan,
it is your "theory" because all German official reports state BS opened fire at 5:55, and the British Admiralty, in the Battle Summary No.5, corrected the previous errors stating Germans opened fire 2 minutes after British.

I agree about the consistency of 5:53 vs 5:58, however both timings are not the ones officially recorded and historically accepted (5:55 and 6:00).

Bye, Alberto

[dunmunro]

Conan Doyle:

Gregory (Scotland Yard detective): “Is there any other point to which you would wish to draw my attention?”

Holmes: “To the curious incident of the dog in the night-time.”

Gregory: “The dog did nothing in the night-time.”

Holmes: “That was the curious incident.”

The curious incident in this case is that there were multiple RN observers looking at Bismarck with professional curiousity and none remarked on the length of time that it took for her to open fire...None! None of the RN "dogs" barked!