AHC: Different Deutschland-class Panzerschiffe for Reichsmarine

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Kantai Kessen

Kantai Kessen

en.wikipedia.org

Deutschland-class cruiser - Wikipedia

en.wikipedia.org en.wikipedia.org
AKA when the Germans decided to make the super-duper heavy cruiser

The Deutschland-class was politically very effective, and had a lot of combat potential; it was misused, though, and had a lot of shortcomings.

I am thinking of a timeline in which the German naval design department is not as badly screwed over by the post-Great War turn of events as it was IOTL, and thus manages to produce a better design for the Panzerschiffe that allows it, in turn, to become more effective in Herr Hitler's maritime adventures.

Specifically, what I want is:
  • A displacement of between 10,000 and 15,000 tons standard - the Reichsmarine wants to at least look like it is keeping to the Versailles treaty.
  • A main armament of six 11" guns in two triple turrets, as per OTL. However, the type of gun and the shells they fire can be modified.
  • A top speed of 30 knots - faster than what was possible IOTL, so that the ships can keep pace with later cruiser types.
  • A range of at least 9000 nmi at 20 knots - note that this is 1000 nmi less than what the OTL Deutschlandswere capable of.
    • For this and the above point, the powerplant choice is up to you.
  • Enough 5.9" secondary armament, so that the ships can handle a River Plate-style scenario where they have to fight multiple enemies on two sides at once.
  • A minimum of 6 torpedo tubes, to be a credible threat.
  • Enough armour to be resistant to at least 6" shellfire, and 8" shellfire at long range.
  • At least two scout aircraft and the capacity to store both of them.
  • Good seakeeping.
  • The ability and space to be upgraded with whatever you want.
Is such a ship possible with late 1920s technology?
 
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Peg Leg Pom

Not on less than 20,000 tonnes. You'd need to trade protection, top speed, secondary armament or range to meet the required (but still over the treaty limit) displacement. If they must have 11" guns then substitute for twin gun turrets reduce the top speed by 5 knots and build a small modernised Pre Dreadnought Battleship. The world wouldn't complain as they'd be replacing Pre Dreads and look like coast defence ships with enough range to do flag waving visits.
 
marathag

marathag

Banned
Or make them with superfiring 11" turrets forward for less area to be armored like MN Strasbourg, and develop a real 128mm DP gun in twin mounts, for secondaries. Hangar and catapult at the very rear, again like Strasbourg. Then a more extreme bulbous bow, and transom stern
 
NHBL

NHBL

You can shave some weight by running her light on stores and ammo. Aiso, have her fitted for but not with torpedo tubes. This is still a nearly impossible challenge IMVHO. (Washingtons Standard didn't include fuel.)
 

CV12Hornet

marathag said:
Or make them with superfiring 11" turrets forward for less area to be armored like MN Strasbourg, and develop a real 128mm DP gun in twin mounts, for secondaries. Hangar and catapult at the very rear, again like Strasbourg. Then a more extreme bulbous bow, and transom stern
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A proper 128mm DP? In the 1920s?

I'm not going to say it's impossible, but it's going to be extraordinarily difficult with the technology of the time and is unlikely to be a successful development effort.

Regardless, I tend to agree with Peg Leg Pom. We're talking at least a 50% increase in shp, plus a considerable increase in armor protection (most likely 130mm belt, 150mm over magazines, and a 60mm deck vice 80mm, 100mm, and 45mm on the 12,100-ton Graf Spee). I don't think it's going to be entirely 20,000 tons - it doesn't need nearly the armor protection of design D - but I expect it's going to be tricky to fit everything under 15,000 tons.
 

Garrison

Donor
Peg Leg Pom said:
Not on less than 20,000 tonnes. You'd need to trade protection, top speed, secondary armament or range to meet the required (but still over the treaty limit) displacement. If they must have 11" guns then substitute for twin gun turrets reduce the top speed by 5 knots and build a small modernised Pre Dreadnought Battleship. The world wouldn't complain as they'd be replacing Pre Dreads and look like coast defence ships with enough range to do flag waving visits.
Click to expand...
And would it make any practical difference to the Kriegsmarine if they tried this?
 
marathag

marathag

Banned
CV12Hornet said:
A proper 128mm DP? In the 1920s?

I'm not going to say it's impossible, but it's going to be extraordinarily difficult with the technology of the time and is unlikely to be a successful development effort.

Regardless, I tend to agree with Peg Leg Pom. We're talking at least a 50% increase in shp, plus a considerable increase in armor protection (most likely 130mm belt, 150mm over magazines, and a 60mm deck vice 80mm, 100mm, and 45mm on the 12,100-ton Graf Spee). I don't think it's going to be entirely 20,000 tons - it doesn't need nearly the armor protection of design D - but I expect it's going to be tricky to fit everything under 15,000 tons.
Click to expand...
The French 130mm/45 was a good DP effort in 1932, thst were a development of the 1924 weapon
 

Cryhavoc101

I would drop the requirement for 11" guns and have 9 x 8" in 3 turrets in order to improve the armour and not increase the weight

The Panzerschiffe caused a bit of an upset and a minor arms race as it was - keeping to a 10,000 ton honest guvnor sized ship that can better survive other cruisers while still capable of acting as a long range raider would serve the Kreigs marine better than the OTL ships.

IMO the 11" guns were not needed

Building a 20,000 ton version of them is going to put the cat among the pigeons and we might see the British not do the AGNA which while it may make certain things better for Germany - IMO it would make a lot things worse for Germany in the long run as the British are less likely to see Germany as a nation who they can make deals with and we see an earlier rearmament and Hitler's brinkmanship tackled a lot harder than it was.
 
marathag

marathag

Banned
CV12Hornet said:
It was also, ultimately, not very successful, and postdates the design effort for the Deutschlands.
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But the 1924 gun showed the way. I don't think the 130mm/45 was a response directly to that,(other than making quad mounts) but the 130 and 138mm guns were developments from Destroyers and Cruisers in the '20s

So yeah, I think a twin DP 128mm was possible in the late '20s.
Would it have teething problems?
sure.
but coming out in 1929 gives plenty of time to debug
 

Korlan

Not possible.

The Deutschlands, as they were IOTL, were pretty much the extreme edge of what was possible with the technology of the time , and they had nowhere near the capabilities listed.

Making a ship with that firepower, speed, range and armament on less than 15000tons empty was not really possible even in the 1940, so in the mid 1920 when the Panzershiffe were designed, no way.

As some other have said, to have what you want, you will need to design a 20000+ tons ship, and Germany trying to build that before 1930 would have caused immediate retaliation by France and Britain, and I don't mean them building heavy ships in answer, I mean invasion and occupation.

OTOH, building a long range heavy cruiser with 6-8 8" guns in 2 turrets, All or Nothing armor protecting only vitals, very long range, top speed 30kts and very high cruise speed (think a Suffren class with a different gun layout and better range) could have been an option, and would have been far less controversial. (I think such a ship would have been a very good long range commerce raider and would not have worried the French or Brits until too late, and so, overall a better option for Germany)
 

CV12Hornet

marathag said:
But the 1924 gun showed the way. I don't think the 130mm/45 was a response directly to that,(other than making quad mounts) but the 130 and 138mm guns were developments from Destroyers and Cruisers in the '20s

So yeah, I think a twin DP 128mm was possible in the late '20s.
Would it have teething problems?
sure.
but coming out in 1929 gives plenty of time to debug
Click to expand...
The 1924 gun was wholly single-purpose, and you citing both it and the 138mm series makes me think you're mixing up DP guns with guns in general in the 4.5"-5.5" caliber range.

Yes, that caliber range is the best for DP guns as a compromise between hitting power in surface combat and the need to elevate and traverse the gun fast enough to be useful in an AA role. But just because you can make guns in that caliber range does not mean you can make a good DP gun. It requires much more in the way of training and elevation speed, as well as rate of fire, especially since the higher elevations needed drive up weight.
 

Gudestein

Kantai Kessen said:
Think a smaller, more lightly armoured version of this would work?

en.wikipedia.org

D-class cruiser (Germany) - Wikipedia

en.wikipedia.org en.wikipedia.org
Click to expand...
Thats what was asked for, but stripping off some armor would only save a few thousand tons. Anyways, not saving the task, but to get closer to those kind of capabilities CODAS propulsion would help. Another experimental gamble though.
PS. Another option is to explore bulbuous bow, transom Stern and a less beamy but more full hull form (High Block coefficient). Might allow a heavier ship with a more central buoyancy (shorter armored belt) to pretend to be lighter than it is.
I did a thread on this earlier. All of these are OTL concepts at the time, but sticking them all together would require quite a pod.
 
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weasel_airlift

Kantai Kessen said:
If Hans Zenker thought he could build the BC in this link at 17,500 tons standard, I don't see why my requirements are that crazy:
Click to expand...
That sort of speed and armament would surely come at the expense of armor.

That said: I can think of two ideas of limited plausibility.

First would be a reverse-Dunkerque. Have both of the heavy guns in the back, and the 15 cm (Or better if can be had, 12.8 DP) in the front. A couple of each. Secondaries as well, of course. Plan for, but do not install all of the secondaries, or the torpedoes. If possible, plan for, but do not install all of the armor plate. That is to be added after hostilities, so we can pay lip service to treaties.
Seakeeping is to an extent possible with better hullform than the Germans used, though freeboard also helps.
Space for upgrades is dubious; we are pushing the envelope as it is.
Aircraft and facilities is possible, but they should be folding, so as to take up less space.

The other option is what was suggested: 3 triple 8.2" (May as well use it as a base, it was excellent) two aft, and maybe with the option to swap for larger twin mounts. Either way, I think you'll need to not make it completely up to spec, but rather just plan to bring it up in the event of war.
 

ArtosStark

Of interest to the discussion is an old thread on Shipbucket covering the 1928 proposed BC. Most of the pictures are no longer there but a Springsharp report is. Here is the thread:

And here is the copied post with two Springsharp reports:
Just an interesting comparison, the first SpringSharp report is this ship as designed with 8x12in guns. I could net get him to make 34 knots on 17,500 tons displacement so the report shows a top speed of 30 knots. At 20,000 tons displacement he can make 34 knots, with everything else staying the same. The second report is the design with 12x11 guns. By dropping the cruising speed from 12 knots to 10 everything else can be left the same.

Moltke, Deutschland Battlecruiser laid down 1928

Displacement:
15,686 t light; 16,578 t standard; 17,518 t normal; 18,271 t full load

Dimensions: Length overall / water x beam x draught
690.05 ft / 639.76 ft x 82.02 ft x 27.89 ft (normal load)
210.33 m / 195.00 m x 25.00 m x 8.50 m

Armament:
8 - 12.01" / 305 mm guns (4x2 guns), 865.70lbs / 392.67kg shells, 1928 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
9 - 5.91" / 150 mm guns (3x3 guns), 102.98lbs / 46.71kg shells, 1928 Model
Breech loading guns in turrets (on barbettes)
on side ends, majority forward, 1 raised mount - superfiring
4 - 3.46" / 88.0 mm guns (2x2 guns), 20.79lbs / 9.43kg shells, 1928 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 7,936 lbs / 3,600 kg
Shells per gun, main battery: 120
6 - 19.7" / 500 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 393.70 ft / 120.00 m 13.12 ft / 4.00 m
Ends: 2.36" / 60 mm 131.23 ft / 40.00 m 6.56 ft / 2.00 m
114.83 ft / 35.00 m Unarmoured ends
Upper: 1.57" / 40 mm 524.93 ft / 160.00 m 13.12 ft / 4.00 m
Main Belt covers 95 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Torpedo Bulkhead:
1.77" / 45 mm 524.93 ft / 160.00 m 27.89 ft / 8.50 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.51" / 140 mm 4.13" / 105 mm 4.13" / 105 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm

- Armour deck: 1.57" / 40 mm, Conning tower: 5.91" / 150 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 3 shafts, 88,789 shp / 66,236 Kw = 30.00 kts
Range 8,000nm at 12.00 kts
Bunker at max displacement = 1,693 tons

Complement:
760 - 989

Cost:
£6.755 million / $27.021 million

Distribution of weights at normal displacement:
Armament: 992 tons, 5.7 %
Armour: 4,058 tons, 23.2 %
- Belts: 1,209 tons, 6.9 %
- Torpedo bulkhead: 960 tons, 5.5 %
- Armament: 851 tons, 4.9 %
- Armour Deck: 952 tons, 5.4 %
- Conning Tower: 86 tons, 0.5 %
Machinery: 2,764 tons, 15.8 %
Hull, fittings & equipment: 7,722 tons, 44.1 %
Fuel, ammunition & stores: 1,832 tons, 10.5 %
Miscellaneous weights: 150 tons, 0.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
16,430 lbs / 7,453 Kg = 19.0 x 12.0 " / 305 mm shells or 3.0 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 4.5 ft / 1.4 m
Roll period: 16.3 seconds
Steadiness - As gun platform (Average = 50 %): 56 %
- Recoil effect (Restricted arc if above 1.00): 0.49
Seaboat quality (Average = 1.00): 1.11

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.419
Length to Beam Ratio: 7.80 : 1
'Natural speed' for length: 25.29 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 2.50 degrees
Stern overhang: 49.21 ft / 15.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (60 %): 23.62 ft / 7.20 m
- Mid (60 %): 22.97 ft / 7.00 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (40 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 19.66 ft / 5.99 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 125.9 %
- Above water (accommodation/working, high = better): 100.1 %
Waterplane Area: 32,692 Square feet or 3,037 Square metres
Displacement factor (Displacement / loading): 99 %
Structure weight / hull surface area: 157 lbs/sq ft or 767 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.53
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

Moltke, Deutschland Battlecruiser laid down 1928

Displacement:
15,941 t light; 16,845 t standard; 17,518 t normal; 18,057 t full load

Dimensions: Length overall / water x beam x draught
690.05 ft / 639.76 ft x 82.02 ft x 27.89 ft (normal load)
210.33 m / 195.00 m x 25.00 m x 8.50 m

Armament:
12 - 11.02" / 280 mm guns (4x3 guns), 669.80lbs / 303.81kg shells, 1928 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
10 - 3.46" / 88.0 mm guns (5x2 guns), 20.79lbs / 9.43kg shells, 1928 Model
Anti-aircraft guns in turrets (on barbettes)
on side ends, majority forward, 3 raised mounts - superfiring
Weight of broadside 8,245 lbs / 3,740 kg
Shells per gun, main battery: 120
6 - 19.7" / 500 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 393.70 ft / 120.00 m 13.12 ft / 4.00 m
Ends: 2.36" / 60 mm 131.23 ft / 40.00 m 6.56 ft / 2.00 m
114.83 ft / 35.00 m Unarmoured ends
Upper: 1.57" / 40 mm 524.93 ft / 160.00 m 13.12 ft / 4.00 m
Main Belt covers 95 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Torpedo Bulkhead:
1.77" / 45 mm 524.93 ft / 160.00 m 27.89 ft / 8.50 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.51" / 140 mm 4.13" / 105 mm 4.13" / 105 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm

- Armour deck: 1.57" / 40 mm, Conning tower: 5.91" / 150 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 3 shafts, 88,789 shp / 66,236 Kw = 30.00 kts
Range 8,000nm at 10.00 kts
Bunker at max displacement = 1,212 tons

Complement:
760 - 989

Cost:
£6.914 million / $27.655 million

Distribution of weights at normal displacement:
Armament: 1,031 tons, 5.9 %
Armour: 4,139 tons, 23.6 %
- Belts: 1,209 tons, 6.9 %
- Torpedo bulkhead: 960 tons, 5.5 %
- Armament: 932 tons, 5.3 %
- Armour Deck: 952 tons, 5.4 %
- Conning Tower: 86 tons, 0.5 %
Machinery: 2,764 tons, 15.8 %
Hull, fittings & equipment: 7,857 tons, 44.9 %
Fuel, ammunition & stores: 1,577 tons, 9.0 %
Miscellaneous weights: 150 tons, 0.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
16,260 lbs / 7,375 Kg = 24.3 x 11.0 " / 280 mm shells or 2.9 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 4.6 ft / 1.4 m
Roll period: 16.1 seconds
Steadiness - As gun platform (Average = 50 %): 49 %
- Recoil effect (Restricted arc if above 1.00): 0.49
Seaboat quality (Average = 1.00): 1.07

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.419
Length to Beam Ratio: 7.80 : 1
'Natural speed' for length: 25.29 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 2.50 degrees
Stern overhang: 49.21 ft / 15.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (60 %): 23.62 ft / 7.20 m
- Mid (60 %): 22.97 ft / 7.00 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (40 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 19.66 ft / 5.99 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 128.0 %
- Above water (accommodation/working, high = better): 100.1 %
Waterplane Area: 32,692 Square feet or 3,037 Square metres
Displacement factor (Displacement / loading): 97 %
Structure weight / hull surface area: 160 lbs/sq ft or 780 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.52
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Click to expand...
 
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