Bismarck in place of PoW

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Re: Bismarck in place of PoW

Post by Dave Saxton » Sun Mar 09, 2014 2:12 pm

Tirpitz conducted its first set of gunnery trials in June 1941. So at the time Tirpitz had not yet conducted any gunnery trials or drills. Also at the time Tirpitz was not yet fitted with all of its firecontrol equipment, optics, or radars. The June shoots revealed defects which sent Tirpitz back to the dockyard for about the next six weeks. It was not until Sept that Tirpitz conducted satisfactory gunnery trials. Tirpitz was in no way prepared for operations in May 1941.
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Re: Bismarck in place of PoW

Post by dunmunro » Sun Mar 09, 2014 7:09 pm

Alberto Virtuani wrote:
Alecsandros wrote: "What would be very interesting to know would be how did the KGV battleships perform in the Pacific, during island bombardments. My intuition is that they did not have turret problems, because they were not manouvreing, but how can we know for sure ?"
According to V.E.Tarrant book (KGV class battleships), in the Pacific, the ships had no major problem with their quad turrets loading mechanisms (the dual turrets never suffered big problems), maybe the issues were solved (only after 1943 as DoY still had problems against Scharnhorst) but I tend to agree with you that it was just because the coastal bombardment were carried out on a stable course, just avoiding to load shells during the turns....

The KGV "Pacific" ships were reported just suffering ventilation problems, the system being inadequate to hot and humid climate, despite improvements implemented after the bad PoW experience.

Re, PoW gunnery readiness on May 24, I don't see any difference with KGV performance. The 7 weeks intensive training imposed by Capt.Leach must be recognised as a very good work and on May 24 PoW fired no worse than KGV did on May 27 (same jamming problems and same output, despite a very worse tactical situation in the DS, with the "need" of violent turns and counter-turns). I don't think KGV would have been much better than PoW on May 24, just my opinion.

Bye, Alberto
According to Roberts in The Final Action, KGV had no recorded loss of output for the first 32 minutes of Bismarck's final battle. DoY and KGV also fought in much worse sea-states than occurred in the DS on May 24. KGV also had fully functioning radar for the first ~20 minutes of the battle. So KGV instead of PoW would have allowed for a dramatic increase in gunnery output and accuracy. If PoW's radars functioned properly she could have used her type 284 for 14in gunnery against Bismarck and her type 281 for 5.25in gunnery against PE. DoY did not suffer a complete turret shell ring jam as per PoW or KGV but she did suffer a partial ammo feed jam in Y turret at salvo 63 that lasted for about 15 minutes. The high speeds and heavy seas encountered by DoY was a major cause of this problem and contributed to the loss of output overall.

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Re: Bismarck in place of PoW

Post by Alberto Virtuani » Sun Mar 09, 2014 8:58 pm

Dunmunro wrote:"According to Roberts in The Final Action, KGV had no recorded loss of output for the first 32 minutes of Bismarck's final battle."
Exactly. 32 minutes, just until she had to turn 180° to north and then.... the shell ring jammed. KGV instead of PoW on May 24 would not have changed her gunnery output as the problem was the design of the quad turret.

The quad loading mechanism was prone to jam under violent turn as was the case for PoW after the disengaement manoeuvre (160° under full rudder) and for KGV when she had to turn 180° (again a sharp turn) to follow BS course.

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Re: Bismarck in place of PoW

Post by dunmunro » Sun Mar 09, 2014 10:20 pm

Alberto Virtuani wrote:
Dunmunro wrote:"According to Roberts in The Final Action, KGV had no recorded loss of output for the first 32 minutes of Bismarck's final battle."
Exactly. 32 minutes, just until she had to turn 180° to north and then.... the shell ring jammed. KGV instead of PoW on May 24 would not have changed her gunnery output as the problem was the design of the quad turret.

The quad loading mechanism was prone to jam under violent turn as was the case for PoW after the disengaement manoeuvre (160° under full rudder) and for KGV when she had to turn 180° (again a sharp turn) to follow BS course.

Bye, Alberto
But the thread is "Bismarck in place of PoW" - KGV made a number of turns before her 180° turn without problems:
Image
and KGV was operating in much rougher seas than KGV. In fact since we don't know what transpired on Bismarck when she was sunk, she may well have suffered similar problems to KGV due to her prolonged gunnery since prolonged gunnery seems to cause problems for most Battleships

In any event, the point is this thrad is to show that Bismarck would have been under a similar disadvantage as PoW (and similaryly long odds for success) if their places were exchanged and Bismarck had been rushed into service.

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Re: Bismarck in place of PoW

Post by dunmunro » Mon Mar 10, 2014 12:35 am

and KGV was operating in much rougher seas than KGV.
should read "...and KGV was operating in much rougher seas than PoW."

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Re: Bismarck in place of PoW

Post by alecsandros » Mon Mar 10, 2014 6:31 am

dunmunro wrote: But the thread is "Bismarck in place of PoW" - KGV made a number of turns before her 180° turn without problems:
It's true Duncan, yet that 9:20 turn was the sharpest (180*)...

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Re: Bismarck in place of PoW

Post by delcyros » Sat Mar 15, 2014 12:45 am

I tend to agree and would even go further to say that I haven´t seen any other BB (or cruiser..) gunnery performance at medium or long range, conducted by the RN, which obtained the same skill of gunnery as PoW did in Denmark Strait.
It´s 5.1% hit rate was an exceptionally good performance in comparison to other combat cases. It may have been aided by the fact that PoW was lucky to achieve a 100% straddle to hit ration, for which probability is actually not very high. Still, compared to KGV, she straddled and hit much earlier, with less guns to bear and at somehow longer mean ranges under more acute angles of approach and against a faster target. Admittently, environmental conditions were more benign, too.

In order to meet PoW´s gunnery performance under normal hit-probability niveaus at DS, a KGV would need to straddle roughly three to four times as often as PoW did. Not very likely...

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 15, 2014 1:32 am

delcyros wrote:I tend to agree and would even go further to say that I haven´t seen any other BB (or cruiser..) gunnery performance at medium or long range, conducted by the RN, which obtained the same skill of gunnery as PoW did in Denmark Strait.
It´s 5.1% hit rate was an exceptionally good performance in comparison to other combat cases. It may have been aided by the fact that PoW was lucky to achieve a 100% straddle to hit ration, for which probability is actually not very high. Still, compared to KGV, she straddled and hit much earlier, with less guns to bear and at somehow longer mean ranges under more acute angles of approach and against a faster target. Admittently, environmental conditions were more benign, too.

In order to meet PoW´s gunnery performance under normal hit-probability niveaus at DS, a KGV would need to straddle roughly three to four times as often as PoW did. Not very likely...
Yet PoW did this with less than optimal output and no radar ranging.

How do you know what hit rate KGV achieved against Bismarck? KGV claimed straddles very early on and then after about 5 minutes claimed 14 straddles from 34 salvos.

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Re: Bismarck in place of PoW

Post by paulcadogan » Sat Mar 15, 2014 3:44 am

delcyros wrote:I tend to agree and would even go further to say that I haven´t seen any other BB (or cruiser..) gunnery performance at medium or long range, conducted by the RN, which obtained the same skill of gunnery as PoW did in Denmark Strait.
Imagine what might have happened if Hood had done what she was supposed to and passed her opening range estimate to PoW - PoW might have been able to straddle (and hit?) with her second salvo (the first would have been short, but close enough that a single up-ladder might have crossed the target).
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Re: Bismarck in place of PoW

Post by alecsandros » Sat Mar 15, 2014 7:42 am

...@Paul
Indeed, she could have done better. But the interesting fact remains that all 3 hits were obtained BEFORE Bismarck shifted her 38cm battery to her. Hits and straddles stoped immediately as the ship was taken under heavy gunfire. )Admitedly, this coincided with her slight turn to avoid Hood/s wreckage, followed by another turn, to disengage.)

What if Prince of Wales were taken under fire at 5:55 ?

====

@Delcyros

Prince of Wales % hits is 5.1% mainly because she suffered a heavy loss of output. From 78 shells ordered, she fired 59. Ratios are: 3 hits/78 ordered = 3.85% and 3 hits / 59 actualy fired = 5.1% [the implication being that a lower number of shells actualy fired artificaly raises the hit ratio]

By comparison, Bismarck, in a better position than Prince of Wales (using all her artillery all the time and without abrupt course changes in the main part of the battle), fired 93 shells out of 104 possible. The numbers of hits is not known, but somewhere between 5 and 7. Ratios were between: Lower estimate: 5 / 104 = 4.81% and 5 / 93 = 5.37 %; higher estimate: 7 / 104 = 6.7% and 7/ 93 = 7.52%
===

Personaly, I consider the 3 hits from 13 salvos of Prince of Wales in 6 minutes pretty good, because the rate of range change was incredible, and at that angle of approach, I guess it takes some skill to find the range. [Open fire at 23.5km at 5:53, turn to disengage at 13.5km at 6:01. That's 8km in 8 minutes. Rate of approach 1 km/minute !]

===

A small note: I don't think the numbers coming from Denmark Strait, in terms of hit ratios, are meaningfull, because the battle was very short (10 minutes), and only a small numer of heavy shells were fired (93 Bismarck, 59 Prince of Wales, about 40 Hood. Total: 192 shells from 3 ships, average = 64 shells/ship). Added to that, the first 3 or 4 salvos for either side were with cold guns, thus straddles or hits were difficult to achieve. So perhaps 30-40% of total shells fired were fired from cold guns. Thus the total of shells fired from warm guns was no more than ~ 120 or so, from all 3 heavy ships.

Another way to look at it: the ships expended about 8-9% of their magazines. Compare this to the battering at Bismarck's last battle (Rodney and KGV using around 50% of their magazines), Casablanca (Massachussets firing ~ 95% of her magazines), North Cape (Duke of York expending ~ 60% of magazines).

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Re: Bismarck in place of PoW

Post by dunmunro » Mon Mar 17, 2014 7:13 am

alecsandros wrote:...@Paul
Indeed, she could have done better. But the interesting fact remains that all 3 hits were obtained BEFORE Bismarck shifted her 38cm battery to her. Hits and straddles stoped immediately as the ship was taken under heavy gunfire. )Admitedly, this coincided with her slight turn to avoid Hood/s wreckage, followed by another turn, to disengage.)

What if Prince of Wales were taken under fire at 5:55 ?

====

Another way to look at it: the ships expended about 8-9% of their magazines. Compare this to the battering at Bismarck's last battle (Rodney and KGV using around 50% of their magazines), Casablanca (Massachussets firing ~ 95% of her magazines), North Cape (Duke of York expending ~ 60% of magazines).
PoW was under fire from Prinz Eugen. If Bismarck had fired on PoW instead of Hood, then the battle would have had a very different outcome. PoW's loss of accuracy was undoubtedly due to her maneuvers not from being under fire.

Massachussets fired 786 of ~1300 available rounds or about 60% of her magazine, but these were fired over 6 or more hours, IIRC.

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Re: Bismarck in place of PoW

Post by alecsandros » Mon Mar 17, 2014 7:52 am

dunmunro wrote:
Massachussets fired 786 of ~1300 available rounds or about 60% of her magazine, but these were fired over 6 or more hours, IIRC.
Point taken;
the idea was that it was a brief engagement with to few shots and hits to draw statistical conclusions.

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Re: Bismarck in place of PoW

Post by paulcadogan » Mon Mar 17, 2014 2:29 pm

dunmunro wrote:PoW was under fire from Prinz Eugen. If Bismarck had fired on PoW instead of Hood, then the battle would have had a very different outcome. PoW's loss of accuracy was undoubtedly due to her maneuvers not from being under fire.
I tend to agree. McMullen makes no mention in his report of any difficulties due to incoming fire except the effect on the transmitting station when a "heavy hit" was felt after firing salvo 12. The effect was corrected quickly.
A.F.C.T., Mk IX. - The 14-in. table was run continuously for 32 hours and proved most reliable. The only incidents which occurred were as follows:-
During the first action after firing salvo 12, a heavy hit was felt on the starboard side and the director setting mechanical pointer was seen to be oscillating violently. At the same time a fuze was noticed to blow at the panel in the 14-in. T.S. The director setting control trigger was used to move off the mechanical pointer. On release, the pointer settled in line with the indicator pointer and no further trouble was experienced.
And he did specifically comment on the German gunnery and again, makes no mention of interference with his activity.
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Re: Bismarck in place of PoW

Post by alecsandros » Mon Mar 17, 2014 3:29 pm

I disagree.
Hood exploded and Bismarck shifted fire immediately to Prince. The Prince turned to disengage at the same time Bismarck turned to avoid torpedoes.
Bismarck hit at least 3 times, while Prince 0 times. And they were both turning hard.

btw Prinz Eugens first salvo was fired at 5:59 on the Prince, precisely the last minute Prince got a hit. Than the Prince continued firing about 8 salvos ( 3 on local control ) with zero straddles and hits.

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Re: Bismarck in place of PoW

Post by Steve Crandell » Mon Mar 17, 2014 3:57 pm

I don't know about this instance, but navies ALWAYS try to target each opposing ship because incoming fire does tend to make it more difficult to shoot back.

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