Here's a proposed German CL, to be laid down in 1928. It differs from the slightly older Ersatz Arcona's in carrying it's main armament in triple turrets, vs twins, and in the choice of a 105mm AA battery versus the 88mm battery on the Ersatz Arcona's. Armor is somewhat heavier as well, probably because of the shorter belt allowed by the use of triple turrets. The reasoning behind these changes is pretty simple: going to triples allows for a shorter, and hence thicker, belt, improving the protection it offers. The 105mm cannon is a more capable gun in the LA role than the 88mm, which lacks hitting power (the 105mm isn't wonderful, but it's better).
Ersatz Medusa, Germany Light Cruiser laid down 1928
Displacement:
8,042 t light; 8,368 t standard; 9,343 t normal; 10,123 t full load
Dimensions: Length overall / water x beam x draught
642.74 ft / 623.36 ft x 62.34 ft x 18.70 ft (normal load)
195.91 m / 190.00 m x 19.00 m x 5.70 m
Armament:
9 - 5.91" / 150 mm guns (3x3 guns), 102.98lbs / 46.71kg shells, 1928 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 4.13" / 105 mm guns (4x2 guns), 35.32lbs / 16.02kg shells, 1928 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
2 - 4.13" / 105 mm guns (1x2 guns), 35.32lbs / 16.02kg shells, 1928 Model
Dual purpose guns in a deck mount with hoist
on centreline aft, all raised guns - superfiring
8 - 1.46" / 37.0 mm guns (4x2 guns), 1.55lbs / 0.70kg shells, 1928 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread
16 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1928 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1,296 lbs / 588 kg
Shells per gun, main battery: 180
16 - 23.6" / 600 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4.72" / 120 mm 364.67 ft / 111.15 m 9.48 ft / 2.89 m
Ends: Unarmoured
Main Belt covers 90 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4.72" / 120 mm 2.76" / 70 mm 4.72" / 120 mm
2nd: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
3rd: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
4th: 0.79" / 20 mm 0.39" / 10 mm -
5th: 0.39" / 10 mm - -
- Armour deck: 1.38" / 35 mm, Conning tower: 4.72" / 120 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 67,681 shp / 50,490 Kw = 32.00 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 1,754 tons
Complement:
474 - 617
Cost:
£2.721 million / $10.883 million
Distribution of weights at normal displacement:
Armament: 162 tons, 1.7 %
Armour: 1,730 tons, 18.5 %
- Belts: 689 tons, 7.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 339 tons, 3.6 %
- Armour Deck: 656 tons, 7.0 %
- Conning Tower: 45 tons, 0.5 %
Machinery: 2,107 tons, 22.6 %
Hull, fittings & equipment: 3,943 tons, 42.2 %
Fuel, ammunition & stores: 1,301 tons, 13.9 %
Miscellaneous weights: 100 tons, 1.1 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
13,778 lbs / 6,250 Kg = 133.8 x 5.9 " / 150 mm shells or 1.8 torpedoes
Stability (Unstable if below 1.00): 1.17
Metacentric height 3.3 ft / 1.0 m
Roll period: 14.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.31
Seaboat quality (Average = 1.00): 1.22
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.450
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 28.67 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 57
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.89 ft / 8.50 m
- Forecastle (24 %): 20.67 ft / 6.30 m
- Mid (50 %): 17.39 ft / 5.30 m
- Quarterdeck (18 %): 17.39 ft / 5.30 m
- Stern: 17.39 ft / 5.30 m
- Average freeboard: 19.27 ft / 5.87 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 88.6 %
- Above water (accommodation/working, high = better): 120.2 %
Waterplane Area: 25,747 Square feet or 2,392 Square metres
Displacement factor (Displacement / loading): 127 %
Structure weight / hull surface area: 101 lbs/sq ft or 495 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.20
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
.