40.6 cm SK C/34's on the Bismarck class

From the Washington Naval Treaty to the end of the Second World War.
Christian VII.
Member
Posts: 80
Joined: Sat Jan 17, 2015 7:49 am

40.6 cm SK C/34's on the Bismarck class

Postby Christian VII. » Tue Feb 03, 2015 2:54 am

Would it have been possible to mount the 40.6cm SK C/34 guns on the Bismarck class BBs?

User avatar
Dave Saxton
Supporter
Posts: 2876
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Dave Saxton » Tue Feb 03, 2015 3:25 pm

The 38cm gun was used largely because it was thought, circa 1935, since only the Nelson class were equipped with 16" guns in Europe, a 16" Bismarck would antagonize the British. The Italians and the French (the preceived most likely opponant at the time) had already decided to go with 15" and the British were pushing for a new treaty limit of 14".

The 16" gun was heavier and so would have required larger and heavier supporting structures, increasing the tonnage of the ship slightly. Bismarck probably could have been equipped with the 16" but the increase in firepower was actually marginal.

The 15" had greater deck penetration out to 32km before the 16" eclipsed it. In terms of belt penetration, velocity is the more important factor. The only advantages for the 16" came at extreme battle ranges.
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.

alecsandros
Senior Member
Posts: 3990
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania
Contact:

Re: 40.6 cm SK C/34's on the Bismarck class

Postby alecsandros » Tue Feb 03, 2015 5:09 pm

Dave Saxton wrote:The 38cm gun was used largely because it was thought, circa 1935, since only the Nelson class were equipped with 16" guns in Europe, a 16" Bismarck would antagonize the British. The Italians and the French (the preceived most likely opponant at the time) had already decided to go with 15" and the British were pushing for a new treaty limit of 14".

The 16" gun was heavier and so would have required larger and heavier supporting structures, increasing the tonnage of the ship slightly. Bismarck probably could have been equipped with the 16" but the increase in firepower was actually marginal.

The 15" had greater deck penetration out to 32km before the 16" eclipsed it. In terms of belt penetration, velocity is the more important factor. The only advantages for the 16" came at extreme battle ranges.

... true,
but the 16" would have an extra advantage - more devastation delivered to the target, because of the much heavier shell.

I would expect the 16"/L52 to require more turret space, barbette space and, if the ammo capacity would stay the same as per Bismarck (120 rounds/gun), given the larger volume occupied by the 16" shells, probably a larger diameter of the main magazines, and thus a slightly increased beam of the ship. This would take away some of it's speed...

User avatar
José M. Rico
Administrator
Posts: 815
Joined: Sat Oct 16, 2004 10:23 am
Location: Madrid, Spain
Contact:

Re: 40.6 cm SK C/34's on the Bismarck class

Postby José M. Rico » Tue Feb 03, 2015 10:05 pm

alecsandros wrote:I would expect the 16"/L52 to require more turret space, barbette space and, if the ammo capacity would stay the same as per Bismarck (120 rounds/gun), given the larger volume occupied by the 16" shells, probably a larger diameter of the main magazines, and thus a slightly increased beam of the ship. This would take away some of it's speed...

Exactly what the H-Class was! :D

http://www.kbismarck.com/h-class-battleships.html

Christian VII.
Member
Posts: 80
Joined: Sat Jan 17, 2015 7:49 am

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Christian VII. » Wed Feb 04, 2015 7:04 am

Dave Saxton wrote:The 38cm gun was used largely because it was thought, circa 1935, since only the Nelson class were equipped with 16" guns in Europe, a 16" Bismarck would antagonize the British. The Italians and the French (the preceived most likely opponant at the time) had already decided to go with 15" and the British were pushing for a new treaty limit of 14".

The 16" gun was heavier and so would have required larger and heavier supporting structures, increasing the tonnage of the ship slightly. Bismarck probably could have been equipped with the 16" but the increase in firepower was actually marginal.

The 15" had greater deck penetration out to 32km before the 16" eclipsed it. In terms of belt penetration, velocity is the more important factor. The only advantages for the 16" came at extreme battle ranges.


But the 40.6cm C/34 fired at a velocity just a mere 10 m/s slower than the 38 cm C/34, thus I'd expect the 40.6 cm to feature a similar trajectory?

At least according to navweaps the 40.6cm gun featured superior belt penetration at all distances, and better deck penetration up until around 20 km.

http://www.navweaps.com/Weapons/WNGER_15-52_skc34.htm
http://www.navweaps.com/Weapons/WNGER_16-52_skc34.htm

alecsandros
Senior Member
Posts: 3990
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania
Contact:

Re: 40.6 cm SK C/34's on the Bismarck class

Postby alecsandros » Wed Feb 04, 2015 7:38 am

José M. Rico wrote:
alecsandros wrote:I would expect the 16"/L52 to require more turret space, barbette space and, if the ammo capacity would stay the same as per Bismarck (120 rounds/gun), given the larger volume occupied by the 16" shells, probably a larger diameter of the main magazines, and thus a slightly increased beam of the ship. This would take away some of it's speed...

Exactly what the H-Class was! :D

http://www.kbismarck.com/h-class-battleships.html


:D

alecsandros
Senior Member
Posts: 3990
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania
Contact:

Re: 40.6 cm SK C/34's on the Bismarck class

Postby alecsandros » Wed Feb 04, 2015 7:39 am

Christian VII. wrote:
Dave Saxton wrote:The 38cm gun was used largely because it was thought, circa 1935, since only the Nelson class were equipped with 16" guns in Europe, a 16" Bismarck would antagonize the British. The Italians and the French (the preceived most likely opponant at the time) had already decided to go with 15" and the British were pushing for a new treaty limit of 14".

The 16" gun was heavier and so would have required larger and heavier supporting structures, increasing the tonnage of the ship slightly. Bismarck probably could have been equipped with the 16" but the increase in firepower was actually marginal.

The 15" had greater deck penetration out to 32km before the 16" eclipsed it. In terms of belt penetration, velocity is the more important factor. The only advantages for the 16" came at extreme battle ranges.


But the 40.6cm C/34 fired at a velocity just a mere 10 m/s slower than the 38 cm C/34, thus I'd expect the 40.6 cm to feature a similar trajectory?

At least according to navweaps the 40.6cm gun featured superior belt penetration at all distances, and better deck penetration up until around 20 km.

http://www.navweaps.com/Weapons/WNGER_15-52_skc34.htm
http://www.navweaps.com/Weapons/WNGER_16-52_skc34.htm


... navweapons is a perfectible source.

German offical documents show differences of ~ 5% in terms of penetration between the 2 guns, and the weight difference would not justify the 16" gun.

User avatar
Dave Saxton
Supporter
Posts: 2876
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Dave Saxton » Wed Feb 04, 2015 3:05 pm

Christian VII. wrote:But the 40.6cm C/34 fired at a velocity just a mere 10 m/s slower than the 38 cm C/34, thus I'd expect the 40.6 cm to feature a similar trajectory?

The 1030kg weight vs 800kg weight means that the heavier shell will lose less velocity per range. This means that the lighter shell will start getting steeper angles of fall sooner. This is why the 15" will have greater deck penetration until the battle range is very great.
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.

Christian VII.
Member
Posts: 80
Joined: Sat Jan 17, 2015 7:49 am

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Christian VII. » Wed Feb 04, 2015 5:29 pm

Dave Saxton wrote:
Christian VII. wrote:But the 40.6cm C/34 fired at a velocity just a mere 10 m/s slower than the 38 cm C/34, thus I'd expect the 40.6 cm to feature a similar trajectory?

The 1030kg weight vs 800kg weight means that the heavier shell will lose less velocity per range. This means that the lighter shell will start getting steeper angles of fall sooner. This is why the 15" will have greater deck penetration until the battle range is very great.


But at such high weights wouldn't the difference in fall off be rather small? And considering that the lighter shell starts out faster I'd suspect that the extra 10 m/s wouldn't be all lost until quite some range?

But then again I'm just guessing, I don't have the ballistic charts for the two guns so I can only speculate :)

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Paul L » Thu Feb 05, 2015 5:12 am

Twin 16" turret weight in at 1452 tons and had a barbette diameter of 11m. Bismarck turrets weight in at 1047 tons and the Barbette diameter was about 10 meters. So to make this work you'd have to have the Bismarck built even bigger than it was to compensate the extra mass and width needed for larger turrets.


I always see the German 16" guns and 15" guns and 11" guns -all designed and built at the same time as a real waste. Had they realised war was eminent by the end of that decade I'd bet they would only have built a 14" gun and had enough by 1940 for all 4 Battleships to be armed with 6-8 of these. If anything else an improved gun for the PBS and follow on would be more worth while...but that's me.
"Eine mal is kein mal"

Christian VII.
Member
Posts: 80
Joined: Sat Jan 17, 2015 7:49 am

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Christian VII. » Thu Feb 05, 2015 12:13 pm

I've always been of the opinion that the German 11" gun was a great design, was very deadly for its size and IIRC featured the smallest salvo spread of any naval gun in the world.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Paul L » Thu Feb 05, 2015 7:49 pm

Christian VII. wrote:I've always been of the opinion that the German 11" gun was a great design, was very deadly for its size and IIRC featured the smallest salvo spread of any naval gun in the world.



If it had been able to retro fit it to the PBS I would have supported it, but making it exclusively for the Twins was a luxury Germany could not afford. The 11C28 was excellent Panzerschiffe weapon.
"Eine mal is kein mal"

User avatar
tommy303
Senior Member
Posts: 1526
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Re: 40.6 cm SK C/34's on the Bismarck class

Postby tommy303 » Fri Feb 06, 2015 12:39 am

If it had been able to retro fit it to the PBS I would have supported it, but making it exclusively for the Twins was a luxury Germany could not afford. The 11C28 was excellent Panzerschiffe weapon.


The older 28cm of the Panzerschiffe used a shorter L/3.7 APC shell. The 28cm L/54 of the Scharnhorst class was designed around the new, vastly improved L/4,4 family of APC. This new shell gave the twins much better armour penetration, but had a too great an overall length to fit in the shell hoists of the Panzerschiffe. I would not say Germany could ill afford having the new 28cm gun, as it represented an incremental design improvement and its design specification dated to before Hitler renounced the Versailles treaty which limited ships to 28cm calibre maximum.

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.

Paul L
Senior Member
Posts: 300
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Paul L » Fri Feb 06, 2015 1:54 am

tommy303 wrote:
If it had been able to retro fit it to the PBS I would have supported it, but making it exclusively for the Twins was a luxury Germany could not afford. The 11C28 was excellent Panzerschiffe weapon.


The older 28cm of the Panzerschiffe used a shorter L/3.7 APC shell. The 28cm L/54 of the Scharnhorst class was designed around the new, vastly improved L/4,4 family of APC. This new shell gave the twins much better armour penetration, but had a too great an overall length to fit in the shell hoists of the Panzerschiffe. I would not say Germany could ill afford having the new 28cm gun, as it represented an incremental design improvement and its design specification dated to before Hitler renounced the Versailles treaty which limited ships to 28cm calibre maximum.



Given how little time they had 11" 15" and 16" were a terrible duplication of effort. As many historians have noted , Grand Admiral Raeder never reconciled his basic miss understanding of the Time line Hitler was marching to. He still believed he had at least a decade to build his fleet.

The PBS hoists could be rebuilt to the same specs and standard as the Twins. The Barbette is the same diameter in both cases to a new turret basket[?] could be rebuilt to fit. Alternatively if and when the Twins are up gunned to 15" guns , their turrets + basket & hoists could be back fitted to the PBS...with 500 tons of weight compensation.

Triple 11" c-28 were 590 tons of which the three guns amounted to 144 tons leaving 446 tons turret . By comparison the Twins turrets weight in at 750 tons each with 157 t guns leaving ; 593 ton turret.

I'm told the ROF for both turrets was the same at > 3 rounds per minute - suggesting the loading mechanisms were similar. most of the difference In turret mass must be the heavier armor of the Twins turrets, [360mm vs 160mm]. However the armor on these turrets is about 1/3 of its mass or 165 tons vs 220 tons or only < 60 tons difference.

The Twins turrets must also be larger ; but the guns are not that much bigger [9%]. Perhaps that is the effect of having a turret that was supposed to be able to mount 3 x 33cm guns instead of 3 x 28cm guns. So the only real option would be to swap out the C-28 turrets for the C-34 turrets and rebuild the turret race accordingly. or build new turrets for the C-34 guns to operate in the PBS hull.
"Eine mal is kein mal"

User avatar
Dave Saxton
Supporter
Posts: 2876
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: 40.6 cm SK C/34's on the Bismarck class

Postby Dave Saxton » Fri Feb 06, 2015 2:43 am

The twin's turrets also had much heavier armour.
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.


Return to “Naval History (1922-1945)”

Who is online

Users browsing this forum: No registered users and 3 guests