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Kriegsmarine 8.2 inch guns

Posted: Fri Jul 24, 2015 9:16 am
by RF
I am not a technical expert in gunnery matters so I pose the following questions purely as a layman.

We know that the Hipper class cruisers were armed in accordance with the Wadhington Naval Treaties with 8 inch guns, the designated maximum calibre for cruisers.
The High Seas Fleet before and during WW1 used an 8.2 inch calibre rather than 8 inch, for example on Scharnhorst and Blucher.

Would it have been technically feasible to arm the Hipper class cruisers with 8.2 inch guns without affecting the design of the ships? Would the extra calibre make a significant difference to the weight of fire and to the rate of fire?

Had Prinz Eugen been armed with 8.2 inch guns, would they have been more effective at the DS battle?

Would Hipper have been more effective against Berwick with 8.2 inch calibre?

Re: Kriegsmarine 8.2 inch guns

Posted: Fri Jul 24, 2015 6:04 pm
by tommy303
The 20,3cm L/60 SKC34 was a much harder hitting and longer ranged weapon than the 21cm SK L/40 and 21cm SK L45 (only in Bluecher). The SK L/45 was the more modern of the two 8.2in and it fired a heavier shell to greater range than the older guns, but was inferior to the 20,3cm in both range and weight of shell. There would not have been any advantage to using the 8.2's in the Hipper class.

Re: Kriegsmarine 8.2 inch guns

Posted: Mon Jul 27, 2015 10:07 pm
by Matrose71

some things to correct.

The 21cm SK L/45 didn't shot a heavier shell then the 21cm SK L40, both shot 108kg AP L 3,1, the main differnce was the muzzle velocity 780mps 21cm SK L/40 to 900mps 21cm SK L45.

The range matters most on the shell design, so a 1935 APC shell ( APC L 4,4) for the 21cm SK L45, would also have much more range then the 21cm SK L45 with the AP L 3,1.

Anyway you are absolut correct, that the 20,3cm L60 with 925mps muzzle velocity and 122kg APC L 4,4 shell, was the much stronger weapon.

Re: Kriegsmarine 8.2 inch guns

Posted: Tue Jul 28, 2015 8:08 am
by RF
It seems that we are comparing WW2 guns with WW1 designed guns, which wasn't really what I was getting at. Presumably the same scenario would apply to the 11 inch guns used by the German Navy, but the 11 inch guns on say Scharnhorst were not of the same design as the 11 inch guns used on the Kaisers' ships?

What I was getting at would be a modified version of the 21 cm gun for WW2 as opposed to using 20.3 cm. With previous experience of the 21 cm I am not clear as to why a navy that seemed to specialise in covertly breaking internationally agreed rules on warship size would in this instance conform to the Washington treaties and not simply go for 21 cm and announce it to the world as 20.3 cm? The Germans are hardly likely to let other navies to send representatives on to their warships armed with rulers and protractors to measure the size of gun muzzles!!

What I was enquiring about was whether an updated 21 cm gun would pose design considerations on to the Hipper class cruisers, or whether it would have been possible to simply replace the 20.3 cm with 21 cm, for example on turret size and weight of armour on the turrets. Would the Germans be able to accommodate slightly bigger guns on these ships without altering any of their other characteristics, or would these characteristics be altered to the extent that it would be obvious the guns were bigger than 20.3 cm?

My other thoughts were that with a WW2 21 cm would it offer any significant uplift to hitting and penetration power over the 20.3 cm, particulary in a battle like at DS where Prinz Eugen was firing at POW?

Re: Kriegsmarine 8.2 inch guns

Posted: Tue Jul 28, 2015 9:25 am
by Matrose71

I can't see any advantages for this whole effort.
What can you reach?

A gun with 135-140kg shell weight and a muzzle velocity between 900-925 mps.
That would hardly make any differences, also the german 20,3cm L60 was next to the USS 8"/55 Marks 12 and Mark 15, the hardest hitting 8 inch gun at WWII, also very accurate.