Another 1915 German battleship study

In our progress through the "Red Book" (that is what we are traversing in our presentation of designs), we have reached a design study for a German battleship, supposedly circa 1915, that had 12-16.5in BLR and 12-6in QF guns. The size was nominally 60,000 tons, but Springsharp required a greater displacement to achieve adequate hull strength. The dimensions were 920ft x 120ft x 34ft. The intended weights were:

• Hull: 21,020 tons
• Machinery: 6,700 tons
• Armament: 3,810 tons
• Protection: 23,670 tons
• Miscellaneous: 4,800 tons

The Springsharp weights were:

• Hull: 27,013 tons
• Machinery: 6,092 tons
• Armament: 3,585 tons
• Protection: 22,118 tons
• Fuel, ammunition and stores: 8,191 tons

Ger/BB/1915 60K 16.5in guns, Germany Battleship laid down 1915

Displacement:
 58,809 t light; 62,785 t standard; 67,000 t normal; 70,372 t full load

Dimensions: Length overall / water x beam x draught
 923.22 ft / 920.00 ft x 120.00 ft x 34.00 ft (normal load)
 281.40 m / 280.42 m x 36.58 m  x 10.36 m

Armament:
     12 - 16.50" / 419 mm guns (4x3 guns), 2,480.00lbs / 1,124.91kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
     16 - 6.00" / 152 mm guns (6 mounts), 100.00lbs / 45.36kg shells, 1915 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 31,360 lbs / 14,225 kg
 Shells per gun, main battery: 150

Armour:
  - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 620.00 ft / 188.98 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 104 % of normal length

  - Torpedo Bulkhead:
  3.00" / 76 mm 620.00 ft / 188.98 m 32.00 ft / 9.75 m

  - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 15.0" / 381 mm 9.00" / 229 mm  14.0" / 356 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

  - Armour deck: 5.00" / 127 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines,
 Geared drive, 4 shafts, 160,838 shp / 119,985 Kw = 28.50 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 7,588 tons

Complement:
 2,081 - 2,706

Cost:
 £8.615 million / $34.459 million

Distribution of weights at normal displacement:
 Armament: 3,585 tons, 5.4 %
 Armour: 22,118 tons, 33.0 %
    - Belts: 5,846 tons, 8.7 %
    - Torpedo bulkhead: 2,202 tons, 3.3 %
    - Armament: 5,965 tons, 8.9 %
    - Armour Deck: 7,643 tons, 11.4 %
    - Conning Tower: 462 tons, 0.7 %
 Machinery: 6,092 tons, 9.1 %
 Hull, fittings & equipment: 27,013 tons, 40.3 %
 Fuel, ammunition & stores: 8,191 tons, 12.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   92,334 lbs / 41,882 Kg = 41.1 x 16.5 " / 419 mm shells or 14.6 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 8.0 ft / 2.4 m
 Roll period: 17.8 seconds
 Steadiness - As gun platform (Average = 50 %): 66 %
   - Recoil effect (Restricted arc if above 1.00): 0.82
 Seaboat quality  (Average = 1.00): 1.33

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.625
 Length to Beam Ratio: 7.67 : 1
 'Natural speed' for length: 30.33 kts
 Power going to wave formation at top speed: 46 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.80 ft / 7.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 86.1 %
  - Above water (accommodation/working, high = better): 189.1 %
 Waterplane Area: 82,625 Square feet or 7,676 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 240 lbs/sq ft or 1,171 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.10
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily