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A 15" gunned Scharnhorst at North Cape

Posted: Sat Nov 04, 2017 5:09 pm
by paul.mercer
Gentlemen,
At North Cape Scharnhorst was alone and surrounded by hostile forces and had her forward radar knocked out by a shell from Norfolk.
If she had been armed with 3x15" turrets -as I believe was once proposed and had all her radars intact, would she have been able to put up an even better fight against Duke of York, possibly inflicting serious damage or would DoY's superior radar and 10x14" been enough to subdue her - assuming she was not torpedoed by RN cruisers and destroyers?

Re: A 15" gunned Scharnhorst at North Cape

Posted: Sun Nov 05, 2017 1:59 am
by Dave Saxton
It was not the qualities of Scharnhorst’s radar equipment or the caliber of its artillery that caused its loss. It was rather how those equipment was used. If Bey, Peters, and Roth make the same tactical errors as they did historically, then the result will likely be the same.

Nevertheless, if Scharnhorst’s radar equipment remains intact, and it is properly used, then Duke of York is unable to bring Scharnhorst to battle.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Sun Nov 05, 2017 2:43 am
by Paul L
paul.mercer wrote:Gentlemen,
At North Cape Scharnhorst was alone and surrounded by hostile forces and had her forward radar knocked out by a shell from Norfolk.
If she had been armed with 3x15" turrets -as I believe was once proposed and had all her radars intact, would she have been able to put up an even better fight against Duke of York, possibly inflicting serious damage or would DoY's superior radar and 10x14" been enough to subdue her - assuming she was not torpedoed by RN cruisers and destroyers?
pretty sure it was 3 twin 15" gun turrets, not 3 triple 15" gun turrets.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Mon Nov 06, 2017 6:15 pm
by paul.mercer
Paul L wrote:
paul.mercer wrote:Gentlemen,
At North Cape Scharnhorst was alone and surrounded by hostile forces and had her forward radar knocked out by a shell from Norfolk.
If she had been armed with 3x15" turrets -as I believe was once proposed and had all her radars intact, would she have been able to put up an even better fight against Duke of York, possibly inflicting serious damage or would DoY's superior radar and 10x14" been enough to subdue her - assuming she was not torpedoed by RN cruisers and destroyers?
pretty sure it was 3 twin 15" gun turrets, not 3 triple 15" gun turrets.
Quite right! I did mean 3 turrets with 2 x15" in each.
If she had 3 turrets each with 3x15"she would have been a very formidable opponent indeed and probably a serious match for Doy!

Re: A 15" gunned Scharnhorst at North Cape

Posted: Tue Nov 07, 2017 5:15 am
by dunmunro
paul.mercer wrote:
Paul L wrote:
paul.mercer wrote:Gentlemen,
At North Cape Scharnhorst was alone and surrounded by hostile forces and had her forward radar knocked out by a shell from Norfolk.
If she had been armed with 3x15" turrets -as I believe was once proposed and had all her radars intact, would she have been able to put up an even better fight against Duke of York, possibly inflicting serious damage or would DoY's superior radar and 10x14" been enough to subdue her - assuming she was not torpedoed by RN cruisers and destroyers?
pretty sure it was 3 twin 15" gun turrets, not 3 triple 15" gun turrets.
Quite right! I did mean 3 turrets with 2 x15" in each.
If she had 3 turrets each with 3x15"she would have been a very formidable opponent indeed and probably a serious match for Doy!
If we replace all of Scharnhorst's historical 11in hits with 15in hits, then nothing changes. Additionally the proposed mods to fit 38cm guns to S&G would have increased their displacement, making them slower and probably worsening their already poor seakeeping qualities.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Tue Nov 07, 2017 12:01 pm
by Iranon
The main gun-related problem the Germans had at North Cape was that it was 3 against 10; larger calibre would not have helped. That battle was rather one-sided for tactical rather than technical reasons. Starting with the Germans practicing Radar silence under conditions where that was a poor idea, and losing their main set before DoY got the drop on them.

The high-velocity 28cm guns and the British 14" are credited with comparable penetration of vertical armour, although there would be a large difference in bursting charge vs. rate of fire. Both ships were well-armoured.
The main disadvantage of the small guns is no realistic ability to defeat Duke of York's deck at range. German practice would have been to use HE shells under such conditions, which would still carry a smaller charge than DoY's AP shells.

Scharnhorst had a chaotic design history lacking a unified vision, and the version that got built wasn't what anyone really wanted (a dedicated fast raider and a more typical battleship with larger guns had been considered, and rejected because of expected political fallout).
But while the light guns were a weakness, they were sufficient to make her a credible opponent to DoY,

Re: A 15" gunned Scharnhorst at North Cape

Posted: Tue Nov 07, 2017 7:41 pm
by dunmunro
Iranon wrote:The main gun-related problem the Germans had at North Cape was that it was 3 against 10; larger calibre would not have helped. That battle was rather one-sided for tactical rather than technical reasons. Starting with the Germans practicing Radar silence under conditions where that was a poor idea, and losing their main set before DoY got the drop on them.

The high-velocity 28cm guns and the British 14" are credited with comparable penetration of vertical armour, although there would be a large difference in bursting charge vs. rate of fire. Both ships were well-armoured.
The main disadvantage of the small guns is no realistic ability to defeat Duke of York's deck at range. German practice would have been to use HE shells under such conditions, which would still carry a smaller charge than DoY's AP shells.

Scharnhorst had a chaotic design history lacking a unified vision, and the version that got built wasn't what anyone really wanted (a dedicated fast raider and a more typical battleship with larger guns had been considered, and rejected because of expected political fallout).
But while the light guns were a weakness, they were sufficient to make her a credible opponent to DoY,
From actual AP testing the RN 14in could penetrate 12in (~300mm) armour @ 30degs inclination at ~1500fps (actually about 1470fps) and 14in (350mm) armour at ~1850fps @ 30degs. From the GKDOS AP charts for the 28cm gun at 457m/s and 565m/s intact penetration was ~200mm/240mm with APC rounds. The same charts show 38cm penetration as just under 300mm and 350mm with the same parameters.

Changing to 38cm guns would have increased penetration to about that of the RN 14in (probably a bit better at equivalent ranges) but would probably have reduced the overall hit probability.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Wed Nov 08, 2017 1:47 pm
by Iranon
Standardising for impact velocity is somewhat problematic, and drawing conclusions for "equivalent ranges" without further adjustment is misleading.

An impact velocity of 565m/s would imply a range of ~11km for the British 14" gun, but ~15km for the German 38cm and slightly less for the 28cm gun.
At 11km, the 28cm shells would strike at approximately 630m/s, and at a shallower angle more favourable to vertical armour penetration (which we can ignore here, 30° obliquity would come mostly from target angle). The 38cm shells would strike at approximately 625m/s.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Wed Nov 08, 2017 8:20 pm
by dunmunro
Iranon wrote:Standardising for impact velocity is somewhat problematic, and drawing conclusions for "equivalent ranges" without further adjustment is misleading.

An impact velocity of 565m/s would imply a range of ~11km for the British 14" gun, but ~15km for the German 38cm and slightly less for the 28cm gun.
At 11km, the 28cm shells would strike at approximately 630m/s, and at a shallower angle more favourable to vertical armour penetration (which we can ignore here, 30° obliquity would come mostly from target angle). The 38cm shells would strike at approximately 625m/s.
For the RN 14in with MV = 2475fps, 11km = about 1920fps ( 587m/s) so intact penetration @ 30deg would be greater than 350mm.

28cm AP at 630m/s and 30deg inclination = ~270mm.

38cm AP at 625m/s and 30deg inclination = ~390mm

We can see that DoY is very well protected against the 28cm gun but less so against the 38cm gun.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Thu Nov 09, 2017 7:26 pm
by Dave Saxton
The problem with applying a Scharnhorst with 15" guns and intact radars to the historical North Cape is that Scharnhorst was equipped with the same radar that Prinz Eugen detected and tracked destroyers to ranges exceeding 33 km with in 1944. This would mean that the battleship to battleship range of Scharnhorst's radar was at least 40 km. Therefore, if Bey is using his radar properly then Duke of York doesn't get close enough to force an effective engagement.

Indeed, if Bey is using his radars properly the entire battle takes a completely different course. He likely finds the convoy before Burnette finds him. Johannesson's destroyers, protected by Scharnhorst over powering the close escort from relatively long range, do an acceptable job on the convoy and they, and Scharnhorst, return to base just before Fraser can get in position to cut off their return. 15" radar directed fire effectively drives away Burnette's cruisers should they get there.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Mon Nov 13, 2017 7:10 pm
by RF
dunmunro wrote:
If we replace all of Scharnhorst's historical 11in hits with 15in hits, then nothing changes. Additionally the proposed mods to fit 38cm guns to S&G would have increased their displacement, making them slower and probably worsening their already poor seakeeping qualities.
There were heavy hits on Norfolk I believe - if they had been 15 inch rather than 11 inch that ship could have been sunk?

Re: A 15" gunned Scharnhorst at North Cape

Posted: Mon Nov 13, 2017 7:13 pm
by RF
Paul L wrote: pretty sure it was 3 twin 15" gun turrets, not 3 triple 15" gun turrets.
Gneisenau was scheduled for twin 15 inch turrets installation after the Channel Dash - until the ship was burn't out in an RAF raid.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Mon Nov 13, 2017 9:00 pm
by Paul L
RF wrote:
dunmunro wrote:
If we replace all of Scharnhorst's historical 11in hits with 15in hits, then nothing changes. Additionally the proposed mods to fit 38cm guns to S&G would have increased their displacement, making them slower and probably worsening their already poor seakeeping qualities.
There were heavy hits on Norfolk I believe - if they had been 15 inch rather than 11 inch that ship could have been sunk?

Yes that's always an issue.
I recall the reason the 15" guns were pushed was because earlier tests showed that 11" shell exploding inside an engine room damage the engine, while a 15" shell exploding in the same engine space resulted in destruction.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Tue Nov 14, 2017 5:14 am
by Dave Saxton
RF wrote:
dunmunro wrote:
If we replace all of Scharnhorst's historical 11in hits with 15in hits, then nothing changes. Additionally the proposed mods to fit 38cm guns to S&G would have increased their displacement, making them slower and probably worsening their already poor seakeeping qualities.
There were heavy hits on Norfolk I believe - if they had been 15 inch rather than 11 inch that ship could have been sunk?
15" HE and SAP would be much more devastating.

I don't think the historical battle is indicative of the Scharnhorst's potential given 11" or 15" guns. In the case of the historical Duke of York battle segment, Scharnhorst was unaware of Fraser's approach and presence until it was surprised at only 11,000 meters range. Before the Scharnhorst could really reply, it lost its forward battery. It's like a sporting match where the opponent is spotted four scores, and 2/3 of your players, as well as your best scorer (foretop radar), are eliminated from the field right at the start of play. Scharnhorst was forced into giving a stern chase and firing only three guns for an extended period of time. After B turret came back on line, Scharnhorst would fire using two turrets at long intervals by changing course to bring B turret to bear and then returning to course. Not much should be expected of any warship given those circumstances.

If we construct a scenario in that Bey switched on his intact foreward radar* while the Duke of York was still far enough away to give Scharnhorst a better tactical position, but not so far away that Scharnhorst can simply refuse battle, then I think a 15" gun Scharnhorst could have presented itself as a worthy opponent to Duke of York.

In my opinion, Bey committed a tactical error historically when he turned east instead of west. If Scharnhorst turns west (Duke of York was approaching from the west off the Scharhorst's starboard bow), and goes into the wind and seas, he basically takes the British cruisers and destroyers out of the fight. He also forces Duke of York to counter march.

* This of course would require a scenario of Bey employing radar silence and switching on before the range became too close. This would also be ridiculous of Bey if his forward radars are intact and Burnette is already shadowing him and reporting his position.

Re: A 15" gunned Scharnhorst at North Cape

Posted: Tue Nov 14, 2017 6:27 pm
by RF
There is a further issue here - what if as well Bey had kept his five destroyers in close company and available to give torpedo attack support in any duel with DOY?