Bismarck in place of PoW

Discussions about the history of the ship, technical details, etc.
dunmunro
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Bismarck in place of PoW

Post by dunmunro » Fri Mar 07, 2014 10:49 pm

wadinga wrote:
I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor, dumb bastard die for his country.
No KG V on her own was a match for Bismarck, even when everything was working perfectly. They were hobbled by Washington, by playing by the rules. The Germans lied non-stop during Bismarck's construction, pretending they were complying with various Treaties whilst flouting them. See many other threads on this site. However if the RN could bring a concentration together and snuff the mighty Death Star out, why take a chance on further casualties? How ironic that it was three brave men in a stick and fabric Stringbag that laid the Beast low and served it up for slaughter?
I disagree that a KGV, fully worked up and functioning correctly, was not a match for Bismarck. PoW's lack of work up certainly reduced her gunnery output and her lack of radar ranging resulted in a considerably loss of accuracy. Functioning radar and ~90% output would probably have given PoW 6+ hits by salvo 13

However, lets reverse the situation:

Hood and Bismarck (RN force with Holland on Hood) engage PoW and Prinz Eugen (KM Force with Lutjens on PoW). Bismarck's radar is inoperative and her last turret was accepted from the contractors on April 27 1941.

Hood fires at PE as per the historical situation. Bismarck scores 3 hits on PoW - one forward at the WL, one amidships under the WL, and one through a boat that does no apparent damage. The hit forward would probably cause some flooding (but no loss of fuel), the hit amidships would probably strike the main belt and do very little damage as well.

Hood blows up at ~0600. Bismarck is immediately taken under fire by PoW and PE, while Bismarck's gunners hampered by the violent manoeuvres to avoid Hood lose their FC solution. Lindeman is now faced with taking on two obviously efficient opponents that have suffered no apparent damage, and Bismarck is hit by 7 14in and 20cm rounds in two minutes. What does Lindeman do?

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Re: Bismarck in place of PoW

Post by Steve Crandell » Sat Mar 08, 2014 12:50 am

Bismarck's optical fire control is arguably superior to that of PoW (longer base rangefinder), so Bismarck would not be at the same disadvantage with regard to losing her radar.

At what range would Bismarck's guns be able to penetrate the PoW belt armor over her engineering spaces? I suspect she was within that range, but I really don't know.

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 08, 2014 3:03 am

Steve Crandell wrote:Bismarck's optical fire control is arguably superior to that of PoW (longer base rangefinder), so Bismarck would not be at the same disadvantage with regard to losing her radar.

At what range would Bismarck's guns be able to penetrate the PoW belt armor over her engineering spaces? I suspect she was within that range, but I really don't know.
Given that PoW found the conditions for optical ranging to be very poor, I'm not sure that Bismarck's RFs would do better than PoW's. Also to make it closer to the historical situation, one of Bismarck's guns in A turret will go unserviceable after the 1st salvo.

The GKDOS 100 curves show 360mm penetration at ~12700m @ 35d inclination (600 m/s)

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Re: Bismarck in place of PoW

Post by Steve Crandell » Sat Mar 08, 2014 8:27 am

dunmunro wrote:
Steve Crandell wrote:Bismarck's optical fire control is arguably superior to that of PoW (longer base rangefinder), so Bismarck would not be at the same disadvantage with regard to losing her radar.

At what range would Bismarck's guns be able to penetrate the PoW belt armor over her engineering spaces? I suspect she was within that range, but I really don't know.
Given that PoW found the conditions for optical ranging to be very poor, I'm not sure that Bismarck's RFs would do better than PoW's. Also to make it closer to the historical situation, one of Bismarck's guns in A turret will go unserviceable after the 1st salvo.

The GKDOS 100 curves show 360mm penetration at ~12700m @ 35d inclination (600 m/s)
Have you seen anything from the German side which said they were having trouble seeing the target prior to PoWs smoke screen?

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Re: Bismarck in place of PoW

Post by alecsandros » Sat Mar 08, 2014 8:40 am

dunmunro wrote: Given that PoW found the conditions for optical ranging to be very poor, I'm not sure that Bismarck's RFs would do better than PoW's. Also to make it closer to the historical situation, one of Bismarck's guns in A turret will go unserviceable after the 1st salvo.
Bismarck used 3 radars, only the forward set was damaged.

The GKDOS 100 curves show 360mm penetration at ~12700m @ 35d inclination (600 m/s)
[/quote]
No.
354mm armor at machinery spaces.
Required velocity for "grenz" perforation at 20* compounded impact angle: 454 m/s (27000 meters). Required velocity for "heil" perforation: 472m/s (25000 meters)
Required velocity for "grenz" perforation at 30 compounded impact angle*: 527m/s (18000 meters). Required velocity for "heil" perforation: 573 m/s (15000 meters)
Required velocity for "grenz" perforation at 40* compounded impact angle: 662m/s (8500 meters). Required velocity for "heil" perforation: 767 m/s (2500 meters)

NOte: grenz perforation = projectile perforates plate and has the probability of being in a state fit to burst. Heil perforation = projectile perforates plate and is alwys in a state fit to burst.

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Re: Bismarck in place of PoW

Post by alecsandros » Sat Mar 08, 2014 8:47 am

The change up Duncan proposed is interesting, and it shows the value of a good tactical positioning. As far as I know, KGVs guns would damage the Hood, but not so much as Bismarck's 38cm guns did. Certainly a hit through the main belt at 16km with the 14" shell in a state fit to burst was unlikely (though not impossible). And without that devastating hit , or some other coming fast that would take Hood out, KGV+Prinz Eugen would get sunk quickly, as Bismarck would turn, open her aft turrets and comence rapid fire at 23-25 shells/minute starting at ~ 5:59.

Also the ranging process and brief period of rapid fire made by the Bismarck ws unlikly to be repeated on the KGV, which was lacking RPC, nd lacking the stability as a gun platform of the Bismarck, and of course, her rate of fire.

KGV was a good battleship class, but it was no Bismarck. The British themselves observed that.

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 08, 2014 7:31 pm

alecsandros wrote:
dunmunro wrote: Given that PoW found the conditions for optical ranging to be very poor, I'm not sure that Bismarck's RFs would do better than PoW's. Also to make it closer to the historical situation, one of Bismarck's guns in A turret will go unserviceable after the 1st salvo.
Bismarck used 3 radars, only the forward set was damaged.

The GKDOS 100 curves show 360mm penetration at ~12700m @ 35d inclination (600 m/s)

No.
354mm armor at machinery spaces.
Required velocity for "grenz" perforation at 20* compounded impact angle: 454 m/s (27000 meters). Required velocity for "heil" perforation: 472m/s (25000 meters)
Required velocity for "grenz" perforation at 30 compounded impact angle*: 527m/s (18000 meters). Required velocity for "heil" perforation: 573 m/s (15000 meters)
Required velocity for "grenz" perforation at 40* compounded impact angle: 662m/s (8500 meters). Required velocity for "heil" perforation: 767 m/s (2500 meters)

NOte: grenz perforation = projectile perforates plate and has the probability of being in a state fit to burst. Heil perforation = projectile perforates plate and is alwys in a state fit to burst.
In this scenario all of Bismarck's radars are non functional - just as per PoW historically , one of Bismarck's gun's is defective from the 1st salvo and her gunnery output is lowered because of lack of training and minor defects in the turrets.

The armoured thickness for PoW's machinery spaces, with the backing plates, is 350mm armour + 20mm backing plate = ~360mm, and of course there is the probability that RN armour is superior to KM armour which could increase the effective thickness even higher, but for the sake of argument we can consider KM and RN armour as equal. I took the inclination as being 35d since this approximates the actual inclination during the battle, and I used the Grenz curve.
Last edited by dunmunro on Sat Mar 08, 2014 7:40 pm, edited 1 time in total.

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 08, 2014 7:35 pm

alecsandros wrote:The change up Duncan proposed is interesting, and it shows the value of a good tactical positioning. As far as I know, KGVs guns would damage the Hood, but not so much as Bismarck's 38cm guns did. Certainly a hit through the main belt at 16km with the 14" shell in a state fit to burst was unlikely (though not impossible). And without that devastating hit , or some other coming fast that would take Hood out, KGV+Prinz Eugen would get sunk quickly, as Bismarck would turn, open her aft turrets and comence rapid fire at 23-25 shells/minute starting at ~ 5:59.

Also the ranging process and brief period of rapid fire made by the Bismarck ws unlikly to be repeated on the KGV, which was lacking RPC, nd lacking the stability as a gun platform of the Bismarck, and of course, her rate of fire.

KGV was a good battleship class, but it was no Bismarck. The British themselves observed that.
Historically Bismarck with fully functioning radar and all guns operational only managed ~7 hits (or less) during the historical battle. With no radar, poorer training, one gun non-functional and lower output, I would expect Bismarck to do worse than historically.

A 14in hit could certainly dive under Hoods belt although penetration is also quite possible.

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 08, 2014 7:49 pm

Steve Crandell wrote:
dunmunro wrote:
Steve Crandell wrote:Bismarck's optical fire control is arguably superior to that of PoW (longer base rangefinder), so Bismarck would not be at the same disadvantage with regard to losing her radar.

At what range would Bismarck's guns be able to penetrate the PoW belt armor over her engineering spaces? I suspect she was within that range, but I really don't know.
Given that PoW found the conditions for optical ranging to be very poor, I'm not sure that Bismarck's RFs would do better than PoW's. Also to make it closer to the historical situation, one of Bismarck's guns in A turret will go unserviceable after the 1st salvo.

The GKDOS 100 curves show 360mm penetration at ~12700m @ 35d inclination (600 m/s)
Have you seen anything from the German side which said they were having trouble seeing the target prior to PoWs smoke screen?
The range estimates from the KM side were grossly in error until they got to within ~radar range. It is not a question of seeing the target, but of being able to optically range on it - which is two very separate issues and in mirage conditions optical ranging was probably ineffective until the range closed and then PoW would have her long base turret RFs in operation as well, as steering the course taken by Lutjens historically would have caused less spray interferance to PoW's forward turrets (especially B turret and it's 35ft duplex RFs).

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Re: Bismarck in place of PoW

Post by alecsandros » Sat Mar 08, 2014 9:16 pm

dunmunro wrote:
In this scenario all of Bismarck's radars are non functional - just as per PoW historically , one of Bismarck's gun's is defective from the 1st salvo and her gunnery output is lowered because of lack of training and minor defects in the turrets.
the main turrets of Tirpitz and Bismarck were considered "excellent" after final firing trials. there is no incident that I know of which took out a turret or a gun within the turret.
The armoured thickness for PoW's machinery spaces, with the backing plates, is 350mm armour + 20mm backing plate = ~360mm, and of course there is the probability that RN armour is superior to KM armour which could increase the effective thickness even higher, but for the sake of argument we can consider KM and RN armour as equal. I took the inclination as being 35d since this approximates the actual inclination during the battle, and I used the Grenz curve.
... There was also 50mm oak wood backing between the cemented armor and the Ducol steel, which may have added as an elastic support mass. From the drawings I've seen in G&D, the belt was declined ~ 12* next to machinery, so it was not flat...

In my angles above I considered a compunded angle, including shell falling angle, lateral obliquity, and plate declination.

Nobody says KGV's belt was a pushover. Their problem was not armor, but armament (the quad turrets...)
As shown by her older brother, KGV herself had plenty of problems with her quads on May 27th. Duke of York may have had some against Scharnhorst.

So in this scenario, Prince of Wales can have a nasty turret jam in the middle of the battle... Etc...

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Re: Bismarck in place of PoW

Post by dunmunro » Sat Mar 08, 2014 9:58 pm

alecsandros wrote:
dunmunro wrote:
In this scenario all of Bismarck's radars are non functional - just as per PoW historically , one of Bismarck's gun's is defective from the 1st salvo and her gunnery output is lowered because of lack of training and minor defects in the turrets.
the main turrets of Tirpitz and Bismarck were considered "excellent" after final firing trials. there is no incident that I know of which took out a turret or a gun within the turret.
The armoured thickness for PoW's machinery spaces, with the backing plates, is 350mm armour + 20mm backing plate = ~360mm, and of course there is the probability that RN armour is superior to KM armour which could increase the effective thickness even higher, but for the sake of argument we can consider KM and RN armour as equal. I took the inclination as being 35d since this approximates the actual inclination during the battle, and I used the Grenz curve.
... There was also 50mm oak wood backing between the cemented armor and the Ducol steel, which may have added as an elastic support mass. From the drawings I've seen in G&D, the belt was declined ~ 12* next to machinery, so it was not flat...

In my angles above I considered a compunded angle, including shell falling angle, lateral obliquity, and plate declination.

Nobody says KGV's belt was a pushover. Their problem was not armor, but armament (the quad turrets...)
As shown by her older brother, KGV herself had plenty of problems with her quads on May 27th. Duke of York may have had some against Scharnhorst.

So in this scenario, Prince of Wales can have a nasty turret jam in the middle of the battle... Etc...
However, why didn't the KM consider Tirpitz to be fit for operations until the fall of 1941? Surely if Bismarck is rushed into service her efficiency will fall?

The simple inclination, from PoW to Bismarck, historically, without taking into account angle of fall was 32d.

KGV had no problems for the first 32 minutes of the battle.

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N squared

Post by dunmunro » Sat Mar 08, 2014 10:03 pm

Another way to examine the battle is to use the N squared law.

If we assign a value to KGV (fully efficient, with radar) of 1 and the same value to Bismarck and say a value of .33 to PE then we get a ratio of 1 to (1 + .33) squared or 1 to 1.77. However given PoW's problems her actually efficiency was probably more like .6 to .8 so the KM force had at least a 2-1 advantage in effective fighting power and possibly as high as 3-1.

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Re: Bismarck in place of PoW

Post by Dave Saxton » Sun Mar 09, 2014 12:17 am

dunmunro wrote:The range estimates from the KM side were grossly in error until they got to within ~radar range.
Brinckmann's faulty estimate had nothing to do with either the optical range finders aloft capabilities or the range of Prinz Eugen's radar.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck in place of PoW

Post by alecsandros » Sun Mar 09, 2014 6:46 am

dunmunro wrote: =
However, why didn't the KM consider Tirpitz to be fit for operations until the fall of 1941? Surely if Bismarck is rushed into service her efficiency will fall?
I don't know... Some hints are that the Tirpitz had RPC problems, among others, and she required some adjustments. The Bismarck also had a problem related to her RPC in March 1941...

other problems were related to the main elevators (that were transporting 38cm shells from the magazine to the shell handling room) - one broke down during trials. But the turrets themselves , or the guns , were not reported to have problems. They might, who knows ? IF the ships were in combat for longer times.

===
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 ?

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Re: Bismarck in place of PoW

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

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
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