15in Up Gunned Gneisenau v 1939 Modernized Renown

[Matrose71]

Defeating the belt doesn't matter because its the slope plus the belt is what that matters. I believe that not even Okun say that defeating the belt and slopes of German battleships together was possible at even point blank range, even for 16-inch guns?

Two cents in this...

I know this. It was only an arithmetic to proove that SH/GS had the best vertical protection of all BB's till 18000-19000m. It was better than Bismarcks.
The slopes and the low main deck were constructed as "explosion decks", because the german engineers wanted a straight main belt and not an inclined belt.
So they knew that the main belt could be defeated, so they put the slopes behind this belt.

and the Germans didn't have the resources to up-gun them, which - to do it properly? - would have been a lot of work, not just a minor yard period. And while 15" guns may have improved them, they still would have been somewhat undergunned against the RN's KGV's, and decisively outgunned by any USN battleship built after the 1920s.

I don't know all that much about this - were the Germans serious in efforts to re-gun Gneisenau?

Gneisenau was at the docks and the work has begun and the new 15inch turrents were at the docks. It wasn't a mystery to upgunn the twins because the bore of the barbettes from the tripple 11inch turrent was equal to the double 15inch turrent. And to cut the forward ship at turrent A with the bow to lengthen the forward ship about 10m isn't a mystery too.
What do you mean with "do it properly"? Do you think the german can built SH/GS, BS/TP and don't have the know how to do this properly?
Sometimes i think there are some mystery myths about german ship building at WWII.
And they have had the recources!
To not upgun and repair the ship was a political decision from Hitler, because he thinks that submarines can do the job better and won't put the recources to this refit. He was no big fan of the german BB's because he don't understand very much of navy doctrin, tactics and strategies.

Edit:

If they're going to add a heavier main battery, they're going to make already wet ships even wetter... they'll have to add some buoyancy, which isn't going to be quick & easy. that's what i meant.

That isn't correct because of the 10m longer forward ship. This will boost the draft about 500-700ts so the ships aren't wetter.

[Gary]

Off the top of my head, Scharnhorsts main belt was thicker than Bismarcks but the upper belt was quite a bit thinner (On Scharnhorst)

[yellowtail3]

Gneisenau was at the docks and the work has begun and the new 15inch turrents were at the docks.

Were they? I didn't know that. It would be really neat to see a picture of that...

To not upgun and repair the ship was a political decision from Hitler, because he thinks that submarines can do the job better and won't put the recources to this refit. He was no big fan of the german BB's because he don't understand very much of navy doctrin, tactics and strategies.

I"d say that Hitler showed good judgement, there - lone-wolf battleships weren't all that useful, esp. after 1942. Better to put the crew to some good use.

If they're going to add a heavier main battery, they're going to make already wet ships even wetter... they'll have to add some buoyancy, which isn't going to be quick & easy. that's what i meant.

That isn't correct because of the 10m longer forward ship. This will boost the draft about 500-700ts so the ships aren't wetter.

well, there's your extra buoyancy. Were they gonna add a nice flare to the bow?

[Karl Heidenreich]

yellowtail3:

If they're going to add a heavier main battery, they're going to make already wet ships even wetter... they'll have to add some buoyancy, which isn't going to be quick & easy. that's what i meant.

You are correct and I mentioned that already. Not being an easy issue was the cause that it was never performed. But, my friend, you are correct again.

My comment stands and is accurate, Karl - a battleship shooting 9-16" guns w/2700 pound shells is a LOT more dangerous to Gneisenau, than one shooting 10-14" guns w/1600 pound shells. Upon meeting such a ship, Gneisenau's best move would be to go to full throttle in the opposite direction (as she did upon encountering Renown).

I think there is material for a discussion on this but it`s out of topic: this is a Renown vs Gns thread, not Treaties BBs vs. Gns.

Warmest regards,

[Thorsten Wahl]

This is not a thread Scharnhorst against any other battleship. Using killerarguments when a discussion is not going on a favorable direction of the own opinion is some kind of annoying.

The Scharnhorst Class was not designed to compete with every battleship around the world. The RN and USN Ships were not the expected enemies.
they were built to counter the french dunkerque class, also a classic arms race. At this time the german approach was less "Größenwahn" as later with the Z-Plan.

[Karl Heidenreich]

Matrose71:

Sometimes i think there are some mystery myths about german ship building at WWII.

You are SO right! There are plenty myths and biases in these issues. And not only in naval topics but all around WWII, which is something we have been discussing for some time in other WWII related threads.

[Karl Heidenreich]

Thorsten:

The Scharnhorst Class was not designed to compete with every battleship around the world. The RN and USN Ships were not the expected enemies.
they were built to counter the french dunkerque class, also a classic arms race. At this time the german approach was less "Größenwahn" as later with the Z-Plan.

True. It is very clear in the G&D book on these ships.

[yellowtail3]

This is not a thread Scharnhorst against any other battleship. Using killerarguments when a discussion is not going on a favorable direction of the own opinion is some kind of annoying.

If you mean me, thought the discussion was going in quite a favorable direction.I don't want you annoyed, but I still don't think re-arming the two little German battleships would have made them all that much more effective against Renown, let alone other recent battleships

The Scharnhorst Class was not designed to compete with every battleship around the world. The RN and USN Ships were not the expected enemies.

well, they certainly met that design goal!

they were built to counter the french dunkerque class, also a classic arms race. At this time the german approach was less "Größenwahn" as later with the Z-Plan.

I like the Dunkerques.

And I'm hopin' Matrose71 can find a picture of SK38 guns and turrets sitting on the dock alongside Gneisenau...

[Thorsten Wahl]

What thicknesses of armor does HMS Renown had after modernisation
maximum thickness at deck 2x2" = 4" ~ 102 mm?
Belt 9" 229 mm
Barbettes 9" 229mm
if is this is correct the german SK 38 gun may penetrate belt and barbettes at every distance less then 35 km
deck is save until 22 km if you take 51 mm + 51 mm as equivalent to 1X100 mm

on the other side
Gneisenau
deck 80 mm + 50 mm over machinery save until ~23 km
deck 95 mm + 50 mm over magazines save until ~25 km
but hump over maschinery is a potential weakpoint
Belt 350 mm + 105 mm slope + 45mm unknown but probably impenetrable at any distance over 5 km

then the SK 38/52 has a higher ROF as the Mk I/42
and its also high-likely that the SK 38/52 has a lower dispersion
additional Gneisenau is the faster ship it has ability to dictate range of a gunfight

comparision of fire control is not possible for me at this time, but early hits in the measuring equipment will degrade probably further shooting to only a fraction from the theoretical value

in theory the outcome should show Gneisenau as winner

[Bgile]

What thicknesses of armor does HMS Renown had after modernisation
maximum thickness at deck 2x2" = 4" ~ 102 mm?
Belt 9" 229 mm
Barbettes 9" 229mm
if is this is correct the german SK 38 gun may penetrate belt and barbettes at every distance less then 35 km
deck is save until 22 km if you take 51 mm + 51 mm as equivalent to 1X100 mm

on the other side
Gneisenau
deck 80 mm + 50 mm over machinery save until ~23 km
deck 95 mm + 50 mm over magazines save until ~25 km
but hump over maschinery is a potential weakpoint
Belt 350 mm + 105 mm slope + 45mm unknown but probably impenetrable at any distance over 5 km

then the SK 38/52 has a higher ROF as the Mk I/42
and its also high-likely that the SK 38/52 has a lower dispersion
additional Gneisenau is the faster ship it has ability to dictate range of a gunfight

comparision of fire control is not possible for me at this time, but early hits in the measuring equipment will degrade probably further shooting to only a fraction from the theoretical value

in theory the outcome should show Gneisenau as winner

The 11" doesn't penetrate 4" of deck armor until over 30,000 yds.

[Karl Heidenreich]

Bgile:

The 11" doesn't penetrate 4" of deck armor until over 30,000 yds.

Steve, we are discussing arming the Gneisenau with 15" and theorize a fight against Renown, we are not discussing it using the 11" she had.

Best regards,

[dunmunro]

Renown has 4" + 1" of D steel deck armour over the magazines and about 3.5" over the machinery, but the armour is layered and there are thinner decks above the MAD. There is a 2.5" turtle deck behind the 9" main belt which is also inclined about 12 degrees.

[Bgile]

Bgile:

The 11" doesn't penetrate 4" of deck armor until over 30,000 yds.

Steve, we are discussing arming the Gneisenau with 15" and theorize a fight against Renown, we are not discussing it using the 11" she had.

Best regards,

OK, my mistake. 29,000 yds then. Not much difference. Neither one is very good at deck penetration because of the flat trajectory.

[Dave Saxton]

I doubt that the effective thickness will equal the sum of the total thickness in the case of Renown. If we assume it does, then the 38cm can defeat it from about about 22-23km.

What is interesting is that according to Gkdos curves the 28cm L/4.4 can defeat 100mm as the initial angle of fall reaches about 32* This can occur at only about 23,770 meters range. Because of the relatively low weight it looses speed quicker resulting in steeper angles of fall at relatively shorter ranges.

[Karl Heidenreich]

Bgile:

OK, my mistake. 29,000 yds then. Not much difference. Neither one is very good at deck penetration because of the flat trajectory.

I do believe that a 15" shell from Bismarck, plunging, was the one that blew Hood. Hardly flat trajectory.