My attempt at the Seydlitz upgunned with 6-17in guns

I tried designing the battlecruiser Seydlitz, modified to have 6-17in guns, with one twin turret on the forecastle and two turrets aft, one in the superfiring position. The old turrets and barbettes in echelon are removed. The speed is 27 knots. The Seydlitz would outgun the Renown and Repulse, although the Seydlitz would be slower. The Seydlitz is much better protected, however. This is the Springsharp report:

Seydlitz, upgunned, Germany Battlecruiser laid down 1914 (Engine 1911)

Displacement:
 27,774 t light; 29,235 t standard; 31,300 t normal; 32,952 t full load

Dimensions: Length overall / water x beam x draught
 664.70 ft / 658.14 ft x 93.50 ft (Bulges 98.43 ft) x 30.51 ft (normal load)
 202.60 m / 200.60 m x 28.50 m (Bulges 30.00 m)  x 9.30 m

Armament:
      2 - 16.93" / 430 mm guns (1x2 guns), 2,425.91lbs / 1,100.37kg shells, 1914 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      4 - 16.93" / 430 mm guns (2x2 guns), 2,425.91lbs / 1,100.37kg shells, 1914 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1914 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   12 guns in hull casemates - Limited use in heavy seas
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1914 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 15,874 lbs / 7,200 kg
 Shells per gun, main battery: 90
 4 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.8" / 300 mm 393.70 ft / 120.00 m 9.84 ft / 3.00 m
 Ends: 3.94" / 100 mm 246.06 ft / 75.00 m 9.84 ft / 3.00 m
   18.37 ft / 5.60 m Unarmoured ends
 Upper: 5.91" / 150 mm 393.70 ft / 120.00 m 9.84 ft / 3.00 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead and Bulges:
  1.77" / 45 mm 393.70 ft / 120.00 m 30.51 ft / 9.30 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.84" / 250 mm 3.15" / 80 mm  9.84" / 250 mm
 2nd: 9.84" / 250 mm 3.15" / 80 mm  9.84" / 250 mm
 3rd: 3.94" / 100 mm 1.18" / 30 mm  1.18" / 30 mm

   - Armour deck: 3.15" / 80 mm, Conning tower: 11.81" / 300 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 89,580 shp / 66,827 Kw = 27.00 kts
 Range 4,200nm at 14.00 kts
 Bunker at max displacement = 3,718 tons (100% coal)

Complement:
 1,176 - 1,529

Cost:
 £4.071 million / $16.285 million

Distribution of weights at normal displacement:
 Armament: 1,984 tons, 6.3 %
 Armour: 8,624 tons, 27.6 %
    - Belts: 3,371 tons, 10.8 %
    - Torpedo bulkhead: 787 tons, 2.5 %
    - Armament: 1,700 tons, 5.4 %
    - Armour Deck: 2,512 tons, 8.0 %
    - Conning Tower: 253 tons, 0.8 %
 Machinery: 3,999 tons, 12.8 %
 Hull, fittings & equipment: 13,168 tons, 42.1 %
 Fuel, ammunition & stores: 3,526 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   33,397 lbs / 15,148 Kg = 13.8 x 16.9 " / 430 mm shells or 4.7 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 5.7 ft / 1.7 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 68 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.35

Hull form characteristics:
 Hull has raised forecastle, rise forward of midbreak
 Block coefficient: 0.554
 Length to Beam Ratio: 6.69 : 1
 'Natural speed' for length: 25.65 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  34.45 ft / 10.50 m
    - Forecastle (34 %): 34.45 ft / 10.50 m (24.61 ft / 7.50 m aft of break)
    - Mid (67 %):  24.61 ft / 7.50 m (14.76 ft / 4.50 m aft of break)
    - Quarterdeck (15 %): 14.76 ft / 4.50 m
    - Stern:  14.76 ft / 4.50 m
    - Average freeboard: 24.70 ft / 7.53 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 115.9 %
  - Above water (accommodation/working, high = better): 147.6 %
 Waterplane Area: 43,119 Square feet or 4,006 Square metres
 Displacement factor (Displacement / loading): 96 %
 Structure weight / hull surface area: 202 lbs/sq ft or 989 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 2.00
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

What do you think of the Derfflinger with 8-17in guns?

I tried the upgunned Derfflinger with 6-17in guns, and the design seemed undergunned. I added bulges and used 8-17in guns, 12-5.9in QF guns, and 4-88mm AA guns (with 4-50cm torpedo tubes). The dimensions are: 690ft x 95ft (100ft bulges) x 31ft. The Standard displacement is 31,014 tons. The speed is 26 knots, with a range of 5300nm at 14 knots. The lower belt is 11.8in with an upper belt of 9in. The deck is just 1.57in. This is the Springsharp report:

Derfflinger class upgunned, Germany Battlecruiser laid down 1914 (Engine 1911)

Displacement:
 29,292 t light; 31,014 t standard; 33,700 t normal; 35,849 t full load

Dimensions: Length overall / water x beam x draught
 696.85 ft / 690.29 ft x 95.14 ft (Bulges 100.07 ft) x 31.50 ft (normal load)
 212.40 m / 210.40 m x 29.00 m (Bulges 30.50 m)  x 9.60 m

Armament:
      8 - 16.93" / 430 mm guns (4x2 guns), 2,425.91lbs / 1,100.37kg shells, 1914 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1914 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 20,726 lbs / 9,401 kg
 Shells per gun, main battery: 90
 4 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.8" / 300 mm 410.11 ft / 125.00 m 9.84 ft / 3.00 m
 Ends: 3.94" / 100 mm 131.23 ft / 40.00 m 9.84 ft / 3.00 m
   148.95 ft / 45.40 m Unarmoured ends
 Upper: 9.06" / 230 mm 410.11 ft / 125.00 m 13.12 ft / 4.00 m
   Main Belt covers 91 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead and Bulges:
  1.77" / 45 mm 410.11 ft / 125.00 m 29.53 ft / 9.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 10.6" / 270 mm 3.15" / 80 mm  10.6" / 270 mm
 2nd: 5.91" / 150 mm 1.97" / 50 mm  1.18" / 30 mm

   - Armour deck: 1.57" / 40 mm, Conning tower: 11.81" / 300 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 78,829 shp / 58,806 Kw = 26.00 kts
 Range 5,300nm at 14.00 kts
 Bunker at max displacement = 4,836 tons (100% coal)

Complement:
 1,243 - 1,616

Cost:
 £4.702 million / $18.806 million

Distribution of weights at normal displacement:
 Armament: 2,591 tons, 7.7 %
 Armour: 9,366 tons, 27.8 %
    - Belts: 4,414 tons, 13.1 %
    - Torpedo bulkhead: 794 tons, 2.4 %
    - Armament: 2,567 tons, 7.6 %
    - Armour Deck: 1,326 tons, 3.9 %
    - Conning Tower: 265 tons, 0.8 %
 Machinery: 3,519 tons, 10.4 %
 Hull, fittings & equipment: 13,816 tons, 41.0 %
 Fuel, ammunition & stores: 4,408 tons, 13.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   33,288 lbs / 15,099 Kg = 13.7 x 16.9 " / 430 mm shells or 4.7 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 5.5 ft / 1.7 m
 Roll period: 17.9 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.80
 Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.542
 Length to Beam Ratio: 6.90 : 1
 'Natural speed' for length: 26.27 kts
 Power going to wave formation at top speed: 48 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.53 ft / 9.00 m
    - Forecastle (20 %): 19.69 ft / 6.00 m
    - Mid (50 %):  19.69 ft / 6.00 m
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 20.47 ft / 6.24 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 118.0 %
  - Above water (accommodation/working, high = better): 137.3 %
 Waterplane Area: 45,500 Square feet or 4,227 Square metres
 Displacement factor (Displacement / loading): 91 %
 Structure weight / hull surface area: 209 lbs/sq ft or 1,020 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.41
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

I wonder how to rearm the German battlecruisers with 17in guns?

I realized that I would want to rearm the German battlecruisers with 17in guns, not just the battleships. That raises the question if ships like the Derfflinger could be armed with 8-17in guns, or would the armament have to be 6-17in guns? Could the ships have 8-17in guns and give up some speed? We could add bulges to increase the beam. That would almost certainly be necessary, due to the great force from firing a broadside. Perhaps they become 26 knot ships, rather htan

The Kaiser class with 6-17in guns

I did what I suggested and ran a Springsharp design for an up-gunned Kaiser class with 6-17in guns. I did away with bulges and kept the speed at 21 knots. There are 2-17in guns forward and 4-17in guns aft. The displacement was greatly reduced, down to 27,700 tons normal. This is the Springsharp report:

Kaiser class-upgunned (6-17in guns), Germany Battleship laid down 1915 (Engine 1911)

Displacement:
 23,543 t light; 24,937 t standard; 27,400 t normal; 29,370 t full load

Dimensions: Length overall / water x beam x draught
 572.18 ft / 565.62 ft x 95.14 ft x 29.86 ft (normal load)
 174.40 m / 172.40 m x 29.00 m  x 9.10 m

Armament:
      2 - 16.93" / 430 mm guns (1x2 guns), 2,425.91lbs / 1,100.37kg shells, 1915 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      4 - 16.93" / 430 mm guns (2x2 guns), 2,425.91lbs / 1,100.37kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1915 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1915 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 16,080 lbs / 7,294 kg
 Shells per gun, main battery: 90
 5 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 311.68 ft / 95.00 m 9.84 ft / 3.00 m
 Ends: 7.09" / 180 mm 219.82 ft / 67.00 m 9.84 ft / 3.00 m
   34.12 ft / 10.40 m Unarmoured ends
 Upper: 7.09" / 180 mm 311.68 ft / 95.00 m 9.84 ft / 3.00 m
   Main Belt covers 85 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.57" / 40 mm 311.68 ft / 95.00 m 29.86 ft / 9.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 2nd: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 3rd: 6.69" / 170 mm 3.15" / 80 mm  3.15" / 80 mm

   - Armour deck: 2.36" / 60 mm, Conning tower: 15.75" / 400 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 3 shafts, 33,548 shp / 25,027 Kw = 21.00 kts
 Range 7,900nm at 12.00 kts
 Bunker at max displacement = 4,433 tons (100% coal)

Complement:
 1,064 - 1,384

Cost:
 £3.959 million / $15.838 million

Distribution of weights at normal displacement:
 Armament: 2,010 tons, 7.3 %
 Armour: 8,428 tons, 30.8 %
    - Belts: 3,514 tons, 12.8 %
    - Torpedo bulkhead: 542 tons, 2.0 %
    - Armament: 2,348 tons, 8.6 %
    - Armour Deck: 1,715 tons, 6.3 %
    - Conning Tower: 308 tons, 1.1 %
 Machinery: 1,498 tons, 5.5 %
 Hull, fittings & equipment: 11,608 tons, 42.4 %
 Fuel, ammunition & stores: 3,857 tons, 14.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   37,315 lbs / 16,926 Kg = 15.4 x 16.9 " / 430 mm shells or 5.6 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 6.1 ft / 1.9 m
 Roll period: 16.1 seconds
 Steadiness - As gun platform (Average = 50 %): 61 %
   - Recoil effect (Restricted arc if above 1.00): 0.82
 Seaboat quality  (Average = 1.00): 1.66

Hull form characteristics:
 Hull has rise forward of midbreak, low quarterdeck 
 Block coefficient: 0.597
 Length to Beam Ratio: 5.94 : 1
 'Natural speed' for length: 23.78 kts
 Power going to wave formation at top speed: 46 %
 Trim (Max stability = 0, Max steadiness = 100): 37
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.25 ft / 8.00 m
    - Forecastle (20 %): 24.61 ft / 7.50 m
    - Mid (69 %):  24.61 ft / 7.50 m (14.76 ft / 4.50 m aft of break)
    - Quarterdeck (15 %): 14.76 ft / 4.50 m (16.40 ft / 5.00 m before break)
    - Stern:  14.76 ft / 4.50 m
    - Average freeboard: 21.82 ft / 6.65 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 95.7 %
  - Above water (accommodation/working, high = better): 157.3 %
 Waterplane Area: 39,245 Square feet or 3,646 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 208 lbs/sq ft or 1,018 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.91
  - Longitudinal: 2.30
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

The up-gunned Kaiser class

I am not sure that my design for up-gunning the Kaiser class is correct. A better solution might have been to just go with 6-17in (43cm) guns. That way, the two turrets in echelon would be removed and new barbettes and turrets would be built for the bow and stern guns. There would still be one turret forward, now with 2-17in guns and two turrets aft, with one in the superfiring position. Each of those would have 2-17in guns, giving a total of 6-17in guns. My initial solution requires a massive reconstruction amidships to add a barbette and turret on the centerline, between the funnels.

The upgunned Kaiser class

I made an attempt to rearm the Kaiser class battleships with 8-17in guns (43cm). I am not sure how successful the design is, but the design satisfies Springsharp:

Kaiser class-upgunned, Germany Battleship laid down 1915 (Engine 1911)

Displacement:
 26,874 t light; 28,603 t standard; 31,300 t normal; 33,458 t full load

Dimensions: Length overall / water x beam x draught
 572.18 ft / 565.62 ft x 95.14 ft (Bulges 98.43 ft) x 29.86 ft (normal load)
 174.40 m / 172.40 m x 29.00 m (Bulges 30.00 m)  x 9.10 m

Armament:
      2 - 16.93" / 430 mm guns (1x2 guns), 2,425.91lbs / 1,100.37kg shells, 1915 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      2 - 16.93" / 430 mm guns (1x2 guns), 2,425.91lbs / 1,100.37kg shells, 1915 Model
   Breech loading guns in a turret (on a barbette)
   on centreline amidships
      4 - 16.93" / 430 mm guns (2x2 guns), 2,425.91lbs / 1,100.37kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1915 Model
   Breech loading guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1915 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 20,932 lbs / 9,495 kg
 Shells per gun, main battery: 90
 5 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 311.68 ft / 95.00 m 9.84 ft / 3.00 m
 Ends: 7.09" / 180 mm 219.82 ft / 67.00 m 9.84 ft / 3.00 m
   34.12 ft / 10.40 m Unarmoured ends
 Upper: 7.09" / 180 mm 311.68 ft / 95.00 m 9.84 ft / 3.00 m
   Main Belt covers 85 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead and Bulges:
  1.57" / 40 mm 311.68 ft / 95.00 m 29.86 ft / 9.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 2nd: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 3rd: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 4th: 6.69" / 170 mm 3.15" / 80 mm  3.15" / 80 mm

   - Armour deck: 2.36" / 60 mm, Conning tower: 15.75" / 400 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 3 shafts, 31,011 shp / 23,134 Kw = 20.00 kts
 Range 7,900nm at 12.00 kts
 Bunker at max displacement = 4,855 tons (100% coal)

Complement:
 1,176 - 1,529

Cost:
 £4.847 million / $19.388 million

Distribution of weights at normal displacement:
 Armament: 2,617 tons, 8.4 %
 Armour: 9,269 tons, 29.6 %
    - Belts: 3,523 tons, 11.3 %
    - Torpedo bulkhead: 542 tons, 1.7 %
    - Armament: 3,051 tons, 9.7 %
    - Armour Deck: 1,817 tons, 5.8 %
    - Conning Tower: 337 tons, 1.1 %
 Machinery: 1,384 tons, 4.4 %
 Hull, fittings & equipment: 13,604 tons, 43.5 %
 Fuel, ammunition & stores: 4,426 tons, 14.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   38,961 lbs / 17,672 Kg = 16.1 x 16.9 " / 430 mm shells or 5.6 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 6.0 ft / 1.8 m
 Roll period: 16.8 seconds
 Steadiness - As gun platform (Average = 50 %): 62 %
   - Recoil effect (Restricted arc if above 1.00): 0.93
 Seaboat quality  (Average = 1.00): 1.66

Hull form characteristics:
 Hull has rise forward of midbreak, low quarterdeck 
 Block coefficient: 0.659
 Length to Beam Ratio: 5.75 : 1
 'Natural speed' for length: 23.78 kts
 Power going to wave formation at top speed: 45 %
 Trim (Max stability = 0, Max steadiness = 100): 37
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.25 ft / 8.00 m
    - Forecastle (20 %): 24.61 ft / 7.50 m
    - Mid (69 %):  24.61 ft / 7.50 m (14.76 ft / 4.50 m aft of break)
    - Quarterdeck (15 %): 14.76 ft / 4.50 m (16.40 ft / 5.00 m before break)
    - Stern:  14.76 ft / 4.50 m
    - Average freeboard: 21.82 ft / 6.65 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 100.9 %
  - Above water (accommodation/working, high = better): 150.7 %
 Waterplane Area: 41,571 Square feet or 3,862 Square metres
 Displacement factor (Displacement / loading): 95 %
 Structure weight / hull surface area: 231 lbs/sq ft or 1,130 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.92
  - Longitudinal: 2.29
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

I wonder if some of the earlier German dreadnoughts might be uparmed with 17in guns

I was pleasantly surprised that the German Koenig class battleships could be re-armed with 8-17in guns, at least by using Springsharp. I am reasonably sure that the Bayern class could be armed with 6 or 8 17in guns, at least if the ships were bulged. The question is if the Kaiser class, if not the Helgoland class might be armed with 17in guns. I am sure that 16.5in guns would be easier, but I am interested in the 17in gun. I may experiment tonight, with Springsharp, to see what I can do. This page has German battleship specifications.

An upgunned Koenig class battleship

I thought that a Springsharp design for a 17in-gunned Koenig class battleship would be interesting. I was pleased that 8-17in guns was possible. I had expected to have to accept 6-17in guns. You can judge if what I have done was reasonable. The hull is bulged and new barbettes and gun turrets are required. This is the Springsharp report:

Koenig class-upgunned, Germany Battleship laid down 1911 (Engine 1912)

Displacement:
 25,534 t light; 27,184 t standard; 29,500 t normal; 31,353 t full load

Dimensions: Length overall / water x beam x draught
 579.72 ft / 573.16 ft x 96.78 ft (Bulges 100.07 ft) x 31.17 ft (normal load)
 176.70 m / 174.70 m x 29.50 m (Bulges 30.50 m)  x 9.50 m

Armament:
      8 - 16.93" / 430 mm guns (4x2 guns), 2,425.91lbs / 1,100.37kg shells, 1911 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1911 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1911 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 20,932 lbs / 9,495 kg
 Shells per gun, main battery: 90
 5 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 344.49 ft / 105.00 m 9.84 ft / 3.00 m
 Ends: Unarmoured
 Upper: 7.09" / 180 mm 344.49 ft / 105.00 m 9.84 ft / 3.00 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead and Bulges:
  1.57" / 40 mm 344.49 ft / 105.00 m 31.17 ft / 9.50 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 2nd: 6.69" / 170 mm 1.18" / 30 mm  1.57" / 40 mm

   - Armour deck: 2.36" / 60 mm, Conning tower: 11.81" / 300 mm

Machinery:
 Coal and oil fired boilers, steam turbines, 
 Direct drive, 3 shafts, 34,844 shp / 25,994 Kw = 21.00 kts
 Range 8,000nm at 12.00 kts
 Bunker at max displacement = 4,168 tons (80% coal)

Complement:
 1,125 - 1,463

Cost:
 £3.301 million / $13.205 million

Distribution of weights at normal displacement:
 Armament: 2,617 tons, 8.9 %
 Armour: 8,945 tons, 30.3 %
    - Belts: 3,175 tons, 10.8 %
    - Torpedo bulkhead: 626 tons, 2.1 %
    - Armament: 3,165 tons, 10.7 %
    - Armour Deck: 1,736 tons, 5.9 %
    - Conning Tower: 243 tons, 0.8 %
 Machinery: 1,498 tons, 5.1 %
 Hull, fittings & equipment: 12,475 tons, 42.3 %
 Fuel, ammunition & stores: 3,966 tons, 13.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   34,533 lbs / 15,664 Kg = 14.2 x 16.9 " / 430 mm shells or 5.0 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 6.1 ft / 1.9 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.89
 Seaboat quality  (Average = 1.00): 1.63

Hull form characteristics:
 Hull has rise forward of midbreak, low quarterdeck 
 Block coefficient: 0.578
 Length to Beam Ratio: 5.73 : 1
 'Natural speed' for length: 23.94 kts
 Power going to wave formation at top speed: 45 %
 Trim (Max stability = 0, Max steadiness = 100): 33
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.25 ft / 8.00 m
    - Forecastle (20 %): 24.61 ft / 7.50 m
    - Mid (72 %):  24.61 ft / 7.50 m (14.76 ft / 4.50 m aft of break)
    - Quarterdeck (15 %): 14.76 ft / 4.50 m (16.40 ft / 5.00 m before break)
    - Stern:  14.76 ft / 4.50 m
    - Average freeboard: 22.09 ft / 6.73 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 107.7 %
  - Above water (accommodation/working, high = better): 153.4 %
 Waterplane Area: 39,730 Square feet or 3,691 Square metres
 Displacement factor (Displacement / loading): 90 %
 Structure weight / hull surface area: 217 lbs/sq ft or 1,061 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.91
  - Longitudinal: 2.15
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

What Jellicoe feared was upgunned German ships

What Admiral Jellicoe feared was that the Germans would modify their existing battleships, such as the Koenig class, with 17in (43cm) guns. I have seen the possibility belittled in some published sources, but I think that if Germany had not been so focused on the losing proposition of using submarines against merchant shipping, they might have found the resources to build the 43cm guns and to modify their existing ships.

Using submarines against merchant shipping was really mistaken in WWI. Perhaps the main reason was political, rather than strategic, in that unrestricted submarine warfare brought the United States into the war. That was the real reason that the Allies won. Without that intervention, the war might have ended as a stalemate, with Imperial Germany surviving. What Germany needed to accomplish at sea was to break the British blockade. That was not going to happen by attacking British merchant shipping.

The sort of ship that the British worried about: the Ger/CB/1918

Admiral Jellicoe worried about German ships armed with 17in guns. Even the Hood class ships seemed inadequate compared to such battlecruisers (particularly). I thought that I would try a battlecruiser design with 8-17in (43cm) and with a 32 knot speed. My dimensions are 820ft x 111.5ft x 32.8ft. The lower belt is 12.6in and the deck is 4.1in. The Germans had to use coal-fired boilers, due to their strategic situation. This is the Springsharp report:

Ger/CB/1918, Germany Battlecruiser laid down 1918 (Engine 1927)

Displacement:
 48,686 t light; 50,841 t standard; 54,700 t normal; 57,788 t full load

Dimensions: Length overall / water x beam x draught
 821.58 ft / 820.21 ft x 111.55 ft x 32.81 ft (normal load)
 250.42 m / 250.00 m x 34.00 m  x 10.00 m

Armament:
      8 - 16.93" / 430 mm guns (4x2 guns), 2,425.91lbs / 1,100.37kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 20,926 lbs / 9,492 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.6" / 320 mm 590.55 ft / 180.00 m 9.84 ft / 3.00 m
 Ends: 3.94" / 100 mm 131.23 ft / 40.00 m 9.84 ft / 3.00 m
   98.43 ft / 30.00 m Unarmoured ends
 Upper: 9.45" / 240 mm 590.55 ft / 180.00 m 9.84 ft / 3.00 m
   Main Belt covers 111 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 590.55 ft / 180.00 m 32.81 ft / 10.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.6" / 320 mm 7.87" / 200 mm  11.8" / 300 mm
 2nd: 5.91" / 150 mm 5.91" / 150 mm  1.97" / 50 mm

   - Armour deck: 4.13" / 105 mm, Conning tower: 13.78" / 350 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 235,264 shp / 175,507 Kw = 32.00 kts
 Range 10,000nm at 13.00 kts
 Bunker at max displacement = 6,947 tons (100% coal)

Complement:
 1,787 - 2,324

Cost:
 £10.090 million / $40.359 million

Distribution of weights at normal displacement:
 Armament: 2,616 tons, 4.8 %
 Armour: 17,047 tons, 31.2 %
    - Belts: 5,612 tons, 10.3 %
    - Torpedo bulkhead: 1,693 tons, 3.1 %
    - Armament: 4,014 tons, 7.3 %
    - Armour Deck: 5,300 tons, 9.7 %
    - Conning Tower: 428 tons, 0.8 %
 Machinery: 8,169 tons, 14.9 %
 Hull, fittings & equipment: 20,855 tons, 38.1 %
 Fuel, ammunition & stores: 6,014 tons, 11.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   67,262 lbs / 30,509 Kg = 27.7 x 16.9 " / 430 mm shells or 8.9 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 7.3 ft / 2.2 m
 Roll period: 17.3 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.70
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.638
 Length to Beam Ratio: 7.35 : 1
 'Natural speed' for length: 28.64 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -9.84 ft / -3.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  39.37 ft / 12.00 m
    - Forecastle (20 %): 31.17 ft / 9.50 m
    - Mid (64 %):  31.17 ft / 9.50 m (21.33 ft / 6.50 m aft of break)
    - Quarterdeck (15 %): 21.33 ft / 6.50 m
    - Stern:  21.33 ft / 6.50 m
    - Average freeboard: 28.28 ft / 8.62 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 105.6 %
  - Above water (accommodation/working, high = better): 206.8 %
 Waterplane Area: 69,307 Square feet or 6,439 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 213 lbs/sq ft or 1,038 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.37
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The German battlecruiser design GK-4542

The GK-4542 battlecruiser design dated from 1918. The main improvement was the 30-knot speed with thicker deck armour, along with more beam. The armament is still 8-16.5in BLR, 12-5.9in QF, and 8-88mm AA guns. The lower belt is 11.8in with a 3.94in deck. The dimensions are now 787ft x 110ft x 32.8ft. The displacement is much greater than that which was planned. I had to use very lightweight machinery to keep the displacement from growing even more. The specification is not very complete, so there is some uncertainty in my mind as to what was intended. This is still a very potent ship. The GK-4542 has much more punch than the Hood and is better protected, besides. This is the Springsharp report:

GK-4542, Germany Battlecruiser laid down 1918

Displacement:
 40,405 t light; 42,078 t standard; 46,000 t normal; 49,138 t full load

Dimensions: Length overall / water x beam x draught
 787.40 ft / 787.40 ft x 109.91 ft x 32.81 ft (normal load)
 240.00 m / 240.00 m x 33.50 m  x 10.00 m

Armament:
      8 - 14.96" / 380 mm guns (4x2 guns), 1,674.25lbs / 759.43kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 14,796 lbs / 6,711 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.8" / 300 mm 590.55 ft / 180.00 m 9.84 ft / 3.00 m
 Ends: 3.94" / 100 mm 111.55 ft / 34.00 m 9.84 ft / 3.00 m
   85.30 ft / 26.00 m Unarmoured ends
 Upper: 9.45" / 240 mm 590.55 ft / 180.00 m 9.84 ft / 3.00 m
   Main Belt covers 115 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 590.55 ft / 180.00 m 32.81 ft / 10.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.8" / 300 mm 7.87" / 200 mm  11.4" / 290 mm
 2nd: 5.91" / 150 mm 5.91" / 150 mm  1.97" / 50 mm

   - Armour deck: 3.94" / 100 mm, Conning tower: 13.78" / 350 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 161,170 shp / 120,233 Kw = 30.00 kts
 Range 10,000nm at 13.00 kts
 Bunker at max displacement = 7,060 tons (100% coal)

Complement:
 1,569 - 2,041

Cost:
 £7.726 million / $30.905 million

Distribution of weights at normal displacement:
 Armament: 1,850 tons, 4.0 %
 Armour: 15,135 tons, 32.9 %
    - Belts: 5,335 tons, 11.6 %
    - Torpedo bulkhead: 1,693 tons, 3.7 %
    - Armament: 3,256 tons, 7.1 %
    - Armour Deck: 4,470 tons, 9.7 %
    - Conning Tower: 381 tons, 0.8 %
 Machinery: 6,396 tons, 13.9 %
 Hull, fittings & equipment: 17,025 tons, 37.0 %
 Fuel, ammunition & stores: 5,595 tons, 12.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   63,360 lbs / 28,740 Kg = 37.8 x 15.0 " / 380 mm shells or 9.5 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 7.5 ft / 2.3 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.54
 Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.567
 Length to Beam Ratio: 7.16 : 1
 'Natural speed' for length: 28.06 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -9.84 ft / -3.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.09 ft / 11.00 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (64 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 26.51 ft / 8.08 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 95.0 %
  - Above water (accommodation/working, high = better): 196.3 %
 Waterplane Area: 61,370 Square feet or 5,701 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 194 lbs/sq ft or 949 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.42
  - 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

The German L24 battleship design

The German L24 battleship design is a bit longer and somewhat faster, at 26.5 knots. The armament and protection are unchanged. The dimensions are now about 787ft x 105ft x 29.5ft. The normal displacement came out a bit light, at 42,700 tons. As usual, the boilers are coal-fired. This is the Springsharp report:

L24, Germany Battleship laid down 1916

Displacement:
 36,518 t light; 38,359 t standard; 42,700 t normal; 46,172 t full load

Dimensions: Length overall / water x beam x draught
 787.95 ft / 787.40 ft x 104.99 ft x 29.53 ft (normal load)
 240.17 m / 240.00 m x 32.00 m  x 9.00 m

Armament:
      8 - 16.54" / 420 mm guns (4x2 guns), 2,260.56lbs / 1,025.37kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 19,487 lbs / 8,839 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 574.15 ft / 175.00 m 9.84 ft / 3.00 m
 Ends: 5.12" / 130 mm 196.85 ft / 60.00 m 9.84 ft / 3.00 m
   16.40 ft / 5.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 574.15 ft / 175.00 m 0.00 ft / 0.00 m
   Main Belt covers 112 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 574.15 ft / 175.00 m 29.53 ft / 9.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.8" / 350 mm 9.84" / 250 mm  13.8" / 350 mm
 2nd: 6.69" / 170 mm 1.18" / 30 mm  1.18" / 30 mm

   - Armour deck: 1.97" / 50 mm, Conning tower: 13.78" / 350 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 96,539 shp / 72,018 Kw = 26.50 kts
 Range 10,700nm at 13.00 kts
 Bunker at max displacement = 7,813 tons (100% coal)

Complement:
 1,484 - 1,930

Cost:
 £6.346 million / $25.384 million

Distribution of weights at normal displacement:
 Armament: 2,436 tons, 5.7 %
 Armour: 12,098 tons, 28.3 %
    - Belts: 3,644 tons, 8.5 %
    - Torpedo bulkhead: 1,482 tons, 3.5 %
    - Armament: 4,382 tons, 10.3 %
    - Armour Deck: 2,227 tons, 5.2 %
    - Conning Tower: 363 tons, 0.8 %
 Machinery: 3,956 tons, 9.3 %
 Hull, fittings & equipment: 18,028 tons, 42.2 %
 Fuel, ammunition & stores: 6,182 tons, 14.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   62,135 lbs / 28,184 Kg = 27.5 x 16.5 " / 420 mm shells or 9.2 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 6.8 ft / 2.1 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.44

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.612
 Length to Beam Ratio: 7.50 : 1
 'Natural speed' for length: 28.06 kts
 Power going to wave formation at top speed: 46 %
 Trim (Max stability = 0, Max steadiness = 100): 44
 Bow angle (Positive = bow angles forward): 1.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.17 ft / 9.50 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (60 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 25.72 ft / 7.84 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 92.8 %
  - Above water (accommodation/working, high = better): 202.1 %
 Waterplane Area: 61,157 Square feet or 5,682 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 211 lbs/sq ft or 1,028 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.28
  - 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

The German L20e battleship design

The next ship that I designed from Deutsche Grosskampschiffe 1915-1918 was the L20e battleship. the L20e has dimensions 778ft x 105ft x 29.5ft. The armament is 8-16.5in BLR, 12-5.9in QF, and 8-88mm AA guns. The speed is 25 knots with a cruising speed of 13 knots for 10,500 nm. The belt is 13.8in maximum with a 1.97in armoured deck. The torpedo bulkhead is 2.36in. This is the Springsharp report:

L20e, Germany Battleship laid down 1916

Displacement:
 35,429 t light; 37,246 t standard; 41,500 t normal; 44,903 t full load

Dimensions: Length overall / water x beam x draught
 778.10 ft / 777.56 ft x 104.99 ft x 29.53 ft (normal load)
 237.17 m / 237.00 m x 32.00 m  x 9.00 m

Armament:
      8 - 16.54" / 420 mm guns (4x2 guns), 2,260.56lbs / 1,025.37kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 19,487 lbs / 8,839 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 574.15 ft / 175.00 m 9.84 ft / 3.00 m
 Ends: 5.12" / 130 mm 196.85 ft / 60.00 m 9.84 ft / 3.00 m
   6.56 ft / 2.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 574.15 ft / 175.00 m 0.00 ft / 0.00 m
   Main Belt covers 114 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 574.15 ft / 175.00 m 29.53 ft / 9.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.8" / 350 mm 9.84" / 250 mm  13.8" / 350 mm
 2nd: 6.69" / 170 mm 1.18" / 30 mm  1.18" / 30 mm

   - Armour deck: 1.97" / 50 mm, Conning tower: 13.78" / 350 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 76,118 shp / 56,784 Kw = 25.00 kts
 Range 10,700nm at 13.00 kts
 Bunker at max displacement = 7,657 tons (100% coal)

Complement:
 1,453 - 1,889

Cost:
 £6.092 million / $24.368 million

Distribution of weights at normal displacement:
 Armament: 2,436 tons, 5.9 %
 Armour: 12,038 tons, 29.0 %
    - Belts: 3,638 tons, 8.8 %
    - Torpedo bulkhead: 1,482 tons, 3.6 %
    - Armament: 4,382 tons, 10.6 %
    - Armour Deck: 2,180 tons, 5.3 %
    - Conning Tower: 356 tons, 0.9 %
 Machinery: 3,120 tons, 7.5 %
 Hull, fittings & equipment: 17,836 tons, 43.0 %
 Fuel, ammunition & stores: 6,071 tons, 14.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   64,082 lbs / 29,067 Kg = 28.3 x 16.5 " / 420 mm shells or 10.0 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 6.7 ft / 2.0 m
 Roll period: 17.1 seconds
 Steadiness - As gun platform (Average = 50 %): 66 %
   - Recoil effect (Restricted arc if above 1.00): 0.87
 Seaboat quality  (Average = 1.00): 1.51

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.603
 Length to Beam Ratio: 7.41 : 1
 'Natural speed' for length: 27.88 kts
 Power going to wave formation at top speed: 43 %
 Trim (Max stability = 0, Max steadiness = 100): 44
 Bow angle (Positive = bow angles forward): 1.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.17 ft / 9.50 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (60 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 25.72 ft / 7.84 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 87.3 %
  - Above water (accommodation/working, high = better): 202.0 %
 Waterplane Area: 59,850 Square feet or 5,560 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 212 lbs/sq ft or 1,037 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.35
  - Overall: 1.01
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

German Grosse Kreuzer I design from 1916

The Grosse Kreuzer 1 (GK-1) was the first of the really big, fast German battlecruiser designs. I based my Springsharp design on the diagram and data from Forstmeier and Breyer's book Deutsche Grosskampschiffe 1915-1918. The ship has 8-15in BLR, 14-5.9in, 8-88mm AA guns and 5-60cm TT. The dimensions are 771ft x 99.74ft x 28.87ft. The speed is 29.25 knots with a range of 10,000nm at 13 knots. This is the Springsharp report:

GK-1, Germany Battlecruiser laid down 1916

Displacement:
 33,887 t light; 35,437 t standard; 39,300 t normal; 42,390 t full load

Dimensions: Length overall / water x beam x draught
 771.00 ft / 771.00 ft x 99.74 ft x 28.87 ft (normal load)
 235.00 m / 235.00 m x 30.40 m  x 8.80 m

Armament:
      8 - 14.96" / 380 mm guns (4x2 guns), 1,674.25lbs / 759.43kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   14 guns in hull casemates - Limited use in heavy seas
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 15,002 lbs / 6,805 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.8" / 300 mm 492.13 ft / 150.00 m 9.84 ft / 3.00 m
 Ends: 3.94" / 100 mm 278.87 ft / 85.00 m 9.84 ft / 3.00 m
 Upper: 9.45" / 240 mm 492.13 ft / 150.00 m 9.84 ft / 3.00 m
   Main Belt covers 98 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.97" / 50 mm 492.13 ft / 150.00 m 28.87 ft / 8.80 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.6" / 320 mm 7.87" / 200 mm  11.4" / 290 mm
 2nd: 5.91" / 150 mm 5.91" / 150 mm  1.97" / 50 mm

   - Armour deck: 1.18" / 30 mm, Conning tower: 12.60" / 320 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 135,373 shp / 100,988 Kw = 29.25 kts
 Range 10,000nm at 13.00 kts
 Bunker at max displacement = 6,953 tons (100% coal)

Complement:
 1,395 - 1,814

Cost:
 £5.789 million / $23.158 million

Distribution of weights at normal displacement:
 Armament: 1,875 tons, 4.8 %
 Armour: 10,756 tons, 27.4 %
    - Belts: 4,835 tons, 12.3 %
    - Torpedo bulkhead: 1,035 tons, 2.6 %
    - Armament: 3,322 tons, 8.5 %
    - Armour Deck: 1,251 tons, 3.2 %
    - Conning Tower: 314 tons, 0.8 %
 Machinery: 5,548 tons, 14.1 %
 Hull, fittings & equipment: 15,707 tons, 40.0 %
 Fuel, ammunition & stores: 5,413 tons, 13.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   53,092 lbs / 24,082 Kg = 31.7 x 15.0 " / 380 mm shells or 7.0 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 6.1 ft / 1.8 m
 Roll period: 17.0 seconds
 Steadiness - As gun platform (Average = 50 %): 62 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.25

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.620
 Length to Beam Ratio: 7.73 : 1
 'Natural speed' for length: 27.77 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -9.84 ft / -3.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.09 ft / 11.00 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (64 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 26.51 ft / 8.08 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 102.2 %
  - Above water (accommodation/working, high = better): 206.1 %
 Waterplane Area: 57,276 Square feet or 5,321 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 192 lbs/sq ft or 935 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.31
  - 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

Wikipedia has a page about the German Mackensen class battlecruisers

I was interested to see that Wikipedia has a page about the German Mackensen class battlecruisers. I suspect that my Springsharp design would have worked better if I had allowed for lighter machinery than I used. To achieve adequate strength, I had to increase the displacement considerably.

The German L1 battleship design from1916

I thought that I would try the German L1 battleship design in Springsharp. I tried to get the parameters as close as I could to what is in Forstmeier and Breyer's book Deutsche Grosskampschipffe 1915-1918. The ship has 8-15in guns and 16-5.9in guns. The dimensions are roughly 728ft x 98.4ft x 28.2ft. The armour belt is about 13.8in at the thickest part. The speed is 26 knots. This is the Springsharp report:

L1, Germany Battleship laid down 1916 (Engine 1917)

Displacement:
 32,598 t light; 34,119 t standard; 37,200 t normal; 39,665 t full load

Dimensions: Length overall / water x beam x draught
 728.35 ft / 721.78 ft x 98.43 ft x 28.22 ft (normal load)
 222.00 m / 220.00 m x 30.00 m  x 8.60 m

Armament:
      8 - 14.96" / 380 mm guns (4x2 guns), 1,674.25lbs / 759.43kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   16 guns in hull casemates - Limited use in heavy seas
      8 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 15,208 lbs / 6,898 kg
 Shells per gun, main battery: 90
 5 - 23.6" / 600 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 429.79 ft / 131.00 m 9.84 ft / 3.00 m
 Ends: 5.51" / 140 mm 219.82 ft / 67.00 m 9.84 ft / 3.00 m
   72.18 ft / 22.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 429.79 ft / 131.00 m 9.84 ft / 3.00 m
   Main Belt covers 92 % of normal length

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.84" / 250 mm 7.87" / 200 mm  13.8" / 350 mm
 2nd: 6.69" / 170 mm 6.69" / 170 mm  1.97" / 50 mm

   - Armour deck: 3.54" / 90 mm, Conning tower: 15.75" / 400 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 85,947 shp / 64,116 Kw = 26.00 kts
 Range 8,500nm at 13.00 kts
 Bunker at max displacement = 5,546 tons (100% coal)

Complement:
 1,339 - 1,741

Cost:
 £5.274 million / $21.096 million

Distribution of weights at normal displacement:
 Armament: 1,901 tons, 5.1 %
 Armour: 12,529 tons, 33.7 %
    - Belts: 4,834 tons, 13.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 3,751 tons, 10.1 %
    - Armour Deck: 3,566 tons, 9.6 %
    - Conning Tower: 378 tons, 1.0 %
 Machinery: 3,466 tons, 9.3 %
 Hull, fittings & equipment: 14,703 tons, 39.5 %
 Fuel, ammunition & stores: 4,602 tons, 12.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   58,786 lbs / 26,665 Kg = 35.1 x 15.0 " / 380 mm shells or 4.5 torpedoes
 Stability (Unstable if below 1.00): 1.05
 Metacentric height 5.4 ft / 1.6 m
 Roll period: 17.8 seconds
 Steadiness - As gun platform (Average = 50 %): 75 %
   - Recoil effect (Restricted arc if above 1.00): 1.00
 Seaboat quality  (Average = 1.00): 1.51

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.650
 Length to Beam Ratio: 7.33 : 1
 'Natural speed' for length: 26.87 kts
 Power going to wave formation at top speed: 48 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 6.56 ft / 2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.17 ft / 9.50 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (69 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 26.61 ft / 8.11 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 68.9 %
  - Above water (accommodation/working, high = better): 196.9 %
 Waterplane Area: 54,400 Square feet or 5,054 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 190 lbs/sq ft or 926 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

My attempt at the German Mackensen class battlecruiser design

The German Mackensen class battlecruiser design seemed like a good candidate to try in Springsharp. The ship has 8-13.4in BLR, 14-5.9in QF, and 8-88mm AA guns. The ship also has 5-23.6in TT, underwater. The belt is 13.8in at the thickest part. The speed is 28.75 knots. The dimensions, in feet, are: 735ft x 99.75ft x 27.5ft. This is the Springsharp report:

Mackensen class, Germany Battlecruiser laid down 1914 (Engine 1915)

Displacement:
 30,237 t light; 31,568 t standard; 35,200 t normal; 38,106 t full load

Dimensions: Length overall / water x beam x draught
 734.91 ft / 734.91 ft x 99.74 ft x 27.56 ft (normal load)
 224.00 m / 224.00 m x 30.40 m  x 8.40 m

Armament:
      8 - 13.39" / 340 mm guns (4x2 guns), 1,199.24lbs / 543.97kg shells, 1914 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1914 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   14 guns in hull casemates - Limited use in heavy seas
      8 - 0.35" / 8.8 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 4 raised mounts
 Weight of broadside 11,036 lbs / 5,006 kg
 Shells per gun, main battery: 100
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 413.39 ft / 126.00 m 9.84 ft / 3.00 m
 Ends: 5.91" / 150 mm 278.87 ft / 85.00 m 9.84 ft / 3.00 m
   42.65 ft / 13.00 m Unarmoured ends
 Upper: 8.66" / 220 mm 413.39 ft / 126.00 m 9.84 ft / 3.00 m
   Main Belt covers 87 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.36" / 60 mm 413.39 ft / 126.00 m 27.56 ft / 8.40 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.6" / 320 mm 7.09" / 180 mm  11.4" / 290 mm
 2nd: 7.87" / 200 mm 5.91" / 150 mm  1.97" / 50 mm

   - Armour deck: 1.18" / 30 mm, Conning tower: 11.81" / 300 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 120,745 shp / 90,076 Kw = 28.75 kts
 Range 9,700nm at 13.00 kts
 Bunker at max displacement = 6,538 tons (100% coal)

Complement:
 1,284 - 1,670

Cost:
 £3.718 million / $14.873 million

Distribution of weights at normal displacement:
 Armament: 1,379 tons, 3.9 %
 Armour: 10,217 tons, 29.0 %
    - Belts: 4,657 tons, 13.2 %
    - Torpedo bulkhead: 996 tons, 2.8 %
    - Armament: 3,109 tons, 8.8 %
    - Armour Deck: 1,182 tons, 3.4 %
    - Conning Tower: 273 tons, 0.8 %
 Machinery: 5,031 tons, 14.3 %
 Hull, fittings & equipment: 13,609 tons, 38.7 %
 Fuel, ammunition & stores: 4,963 tons, 14.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   51,441 lbs / 23,333 Kg = 42.9 x 13.4 " / 340 mm shells or 7.2 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 6.5 ft / 2.0 m
 Roll period: 16.5 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.610
 Length to Beam Ratio: 7.37 : 1
 'Natural speed' for length: 27.11 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.17 ft / 9.50 m
    - Forecastle (20 %): 26.25 ft / 8.00 m
    - Mid (63 %):  26.25 ft / 8.00 m
    - Quarterdeck (15 %): 26.25 ft / 8.00 m
    - Stern:  26.25 ft / 8.00 m
    - Average freeboard: 26.64 ft / 8.12 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 98.6 %
  - Above water (accommodation/working, high = better): 210.7 %
 Waterplane Area: 54,106 Square feet or 5,027 Square metres
 Displacement factor (Displacement / loading): 112 %
 Structure weight / hull surface area: 177 lbs/sq ft or 863 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.35
  - 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

My attempt at a German L20b battleship

I own the book Deutsche Grosskampfschiffe 1915-1918, by Friedrich Forstmeier and Siegfried Breyer. That book has inboard profiles, dimensions, and armour specifications for the various German capital ship projects in the Dreadnought era. One interesting ship is the L20b design with 8-16.5in guns. This is my attempt at the design in Springsharp, although the displacement is greatly inflated and the draft increased to achieve adequate strength:

L20b, Germany Battleship laid down 1918

Displacement:
 41,346 t light; 43,380 t standard; 46,500 t normal; 48,996 t full load

Dimensions: Length overall / water x beam x draught
 772.25 ft / 771.00 ft x 104.99 ft x 31.17 ft (normal load)
 235.38 m / 235.00 m x 32.00 m  x 9.50 m

Armament:
      8 - 16.54" / 420 mm guns (4x2 guns), 2,260.56lbs / 1,025.37kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 19,603 lbs / 8,892 kg
 Shells per gun, main battery: 100
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 577.43 ft / 176.00 m 9.84 ft / 3.00 m
 Ends: 5.12" / 130 mm 114.83 ft / 35.00 m 9.84 ft / 3.00 m
   78.74 ft / 24.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 577.43 ft / 176.00 m 9.84 ft / 3.00 m
   Main Belt covers 115 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 577.43 ft / 176.00 m 29.53 ft / 9.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.8" / 350 mm 9.84" / 250 mm  13.8" / 350 mm
 2nd: 6.69" / 170 mm 6.69" / 170 mm  1.50" / 38 mm

   - Armour deck: 5.91" / 150 mm, Conning tower: 15.75" / 400 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 55,778 shp / 41,610 Kw = 22.50 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 5,616 tons (100% coal)

Complement:
 1,583 - 2,058

Cost:
 £7.631 million / $30.522 million

Distribution of weights at normal displacement:
 Armament: 2,450 tons, 5.3 %
 Armour: 18,908 tons, 40.7 %
    - Belts: 5,852 tons, 12.6 %
    - Torpedo bulkhead: 1,490 tons, 3.2 %
    - Armament: 4,383 tons, 9.4 %
    - Armour Deck: 6,744 tons, 14.5 %
    - Conning Tower: 439 tons, 0.9 %
 Machinery: 2,213 tons, 4.8 %
 Hull, fittings & equipment: 17,774 tons, 38.2 %
 Fuel, ammunition & stores: 5,154 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   84,648 lbs / 38,396 Kg = 37.4 x 16.5 " / 420 mm shells or 14.6 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 6.6 ft / 2.0 m
 Roll period: 17.1 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.65

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.645
 Length to Beam Ratio: 7.34 : 1
 'Natural speed' for length: 27.77 kts
 Power going to wave formation at top speed: 39 %
 Trim (Max stability = 0, Max steadiness = 100): 39
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (60 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 26.11 ft / 7.96 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 70.9 %
  - Above water (accommodation/working, high = better): 191.2 %
 Waterplane Area: 61,730 Square feet or 5,735 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 204 lbs/sq ft or 997 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.42
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Sorry, I couldn't resist creating a radical design: GB/CB/1941 36 knots

Just because I could, I created a 36-knot version of the GB/CB/1941 design with 9-16in BLR, 20-4.5in DP, and 52-2pdr AA guns. The armour is greatly reduced, so the belt is just 9in. The power involved requires six shafts. This is the Springsharp report:

GB/CB/1941 36 knots, Great Britain Battlecruiser laid down 1941 (Engine 1945)

Displacement:
 53,427 t light; 55,692 t standard; 58,500 t normal; 60,746 t full load

Dimensions: Length overall / water x beam x draught
 915.15 ft / 912.00 ft x 110.00 ft x 35.00 ft (normal load)
 278.94 m / 277.98 m x 33.53 m  x 10.67 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      20 - 4.50" / 114 mm guns (10x2 guns), 45.56lbs / 20.67kg shells, 1941 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 1.95lbs / 0.88kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 7 raised mounts
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.88kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
 Weight of broadside 19,445 lbs / 8,820 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 590.00 ft / 179.83 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 590.00 ft / 179.83 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 8.00" / 203 mm  12.0" / 305 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 311,983 shp / 232,739 Kw = 36.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 5,054 tons

Complement:
 1,880 - 2,445

Cost:
 £30.999 million / $123.998 million

Distribution of weights at normal displacement:
 Armament: 2,431 tons, 4.2 %
 Armour: 19,747 tons, 33.8 %
    - Belts: 3,616 tons, 6.2 %
    - Torpedo bulkhead: 2,969 tons, 5.1 %
    - Armament: 4,421 tons, 7.6 %
    - Armour Deck: 8,352 tons, 14.3 %
    - Conning Tower: 390 tons, 0.7 %
 Machinery: 7,878 tons, 13.5 %
 Hull, fittings & equipment: 23,371 tons, 40.0 %
 Fuel, ammunition & stores: 5,073 tons, 8.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   85,413 lbs / 38,743 Kg = 41.7 x 16.0 " / 406 mm shells or 12.9 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 6.9 ft / 2.1 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.583
 Length to Beam Ratio: 8.29 : 1
 'Natural speed' for length: 34.66 kts
 Power going to wave formation at top speed: 57 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 30.00 ft / 9.14 m
    - Mid (50 %):  30.00 ft / 9.14 m
    - Quarterdeck (15 %): 30.00 ft / 9.14 m
    - Stern:  30.00 ft / 9.14 m
    - Average freeboard: 30.48 ft / 9.29 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 92.1 %
  - Above water (accommodation/working, high = better): 228.7 %
 Waterplane Area: 75,245 Square feet or 6,991 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 215 lbs/sq ft or 1,049 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.40
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Finally, I did the 33-knot GB/BB/1941 fast battleship

My attempt at a British 33-knot fast battleship is pretty heavy. The actual displacement for the Iowa class ships was above 45,000 tons, so maybe this is not so bad. This is the Springsharp report:

GB/BB/1941 33 knost, Great Britain Battleship laid down 1941 (Engine 1945)

Displacement:
 50,392 t light; 52,587 t standard; 55,000 t normal; 56,930 t full load

Dimensions: Length overall / water x beam x draught
 878.89 ft / 876.00 ft x 110.00 ft x 33.00 ft (normal load)
 267.88 m / 267.00 m x 33.53 m  x 10.06 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      20 - 4.50" / 114 mm guns (10x2 guns), 45.56lbs / 20.67kg shells, 1941 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 7 raised mounts
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
 Weight of broadside 19,445 lbs / 8,820 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 580.00 ft / 176.78 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 580.00 ft / 176.78 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 9.00" / 229 mm  14.0" / 356 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 220,141 shp / 164,225 Kw = 33.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 4,343 tons

Complement:
 1,795 - 2,334

Cost:
 £28.336 million / $113.343 million

Distribution of weights at normal displacement:
 Armament: 2,431 tons, 4.4 %
 Armour: 21,303 tons, 38.7 %
    - Belts: 5,535 tons, 10.1 %
    - Torpedo bulkhead: 2,747 tons, 5.0 %
    - Armament: 4,390 tons, 8.0 %
    - Armour Deck: 8,195 tons, 14.9 %
    - Conning Tower: 436 tons, 0.8 %
 Machinery: 5,559 tons, 10.1 %
 Hull, fittings & equipment: 21,100 tons, 38.4 %
 Fuel, ammunition & stores: 4,608 tons, 8.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   85,766 lbs / 38,903 Kg = 41.9 x 16.0 " / 406 mm shells or 14.6 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 7.2 ft / 2.2 m
 Roll period: 17.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.59
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.605
 Length to Beam Ratio: 7.96 : 1
 'Natural speed' for length: 34.00 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  33.00 ft / 10.06 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: 25.64 ft / 7.82 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 81.4 %
  - Above water (accommodation/working, high = better): 195.9 %
 Waterplane Area: 73,829 Square feet or 6,859 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 209 lbs/sq ft or 1,020 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.18
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The GB/BB/1941 is sort of a British analog to the US Iowa class ships

The GB/BB/1941 fast battleship is a British answer to the American Iowa class ships. The one drawback is that the ship does not take advantage of its length to reach a higher speed, such as 33 or 34 knots. I will experiment to see what might be done to increase the speed of the GB/BB/1941 design up to something comparable to the Iowas. The natural speed for the length is something like 33.89 knots, so at 31 knots, the GB/BB/1941 is underachieving.

The GB/BB/1941 fast battleship

The GB/BB/1941 is a 31-knot battleship with 9-16in BLR, 20-4.5in DP, and 52-2pdr AA guns. The armour basis is 14in. This is the Springsharp report:

GB/BB/1941 Fast Battleship, Great Britain Battleship laid down 1941 (Engine 1945)

Displacement:
 48,387 t light; 50,534 t standard; 52,600 t normal; 54,253 t full load

Dimensions: Length overall / water x beam x draught
 866.80 ft / 864.00 ft x 112.00 ft x 32.00 ft (normal load)
 264.20 m / 263.35 m x 34.14 m  x 9.75 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      20 - 4.50" / 114 mm guns (10x2 guns), 45.56lbs / 20.67kg shells, 1941 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 7 raised mounts
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
 Weight of broadside 19,445 lbs / 8,820 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 580.00 ft / 176.78 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 580.00 ft / 176.78 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 9.00" / 229 mm  14.0" / 356 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 169,042 shp / 126,106 Kw = 31.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,720 tons

Complement:
 1,736 - 2,257

Cost:
 £26.785 million / $107.140 million

Distribution of weights at normal displacement:
 Armament: 2,431 tons, 4.6 %
 Armour: 21,121 tons, 40.2 %
    - Belts: 5,535 tons, 10.5 %
    - Torpedo bulkhead: 2,747 tons, 5.2 %
    - Armament: 4,270 tons, 8.1 %
    - Armour Deck: 8,145 tons, 15.5 %
    - Conning Tower: 423 tons, 0.8 %
 Machinery: 4,269 tons, 8.1 %
 Hull, fittings & equipment: 20,567 tons, 39.1 %
 Fuel, ammunition & stores: 4,214 tons, 8.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   88,821 lbs / 40,288 Kg = 43.4 x 16.0 " / 406 mm shells or 16.6 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 7.6 ft / 2.3 m
 Roll period: 17.1 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.14

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.595
 Length to Beam Ratio: 7.71 : 1
 'Natural speed' for length: 33.89 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  32.00 ft / 9.75 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (50 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.64 ft / 7.51 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 75.1 %
  - Above water (accommodation/working, high = better): 193.2 %
 Waterplane Area: 73,378 Square feet or 6,817 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 209 lbs/sq ft or 1,020 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.17
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The 29-knot GB/CB/1937 with a 12in belt

The 29-knot version of the GB/CB/1937, with a 12in belt and a 4.5in deck works very well. As well, the turret faces, barbettes, and conning tower are 13in. The design is very close to being a fast battleship, rather than a battlecruiser. This is the Springsharp report:

GB/CB/1937, Great Britain Battlecruiser laid down 1937 (Engine 1941)

Displacement:
 42,055 t light; 44,145 t standard; 46,100 t normal; 47,664 t full load

Dimensions: Length overall / water x beam x draught
 852.17 ft / 850.00 ft x 108.00 ft x 31.00 ft (normal load)
 259.74 m / 259.08 m x 32.92 m  x 9.45 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread, 4 raised mounts
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
      16 - 1.57" / 40.0 mm guns (2x8 guns), 1.95lbs / 0.88kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 1 raised mount - superfiring
      8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1937 Model
   Anti-aircraft guns in deck mount 
   on side, evenly spread, all raised mounts
 Weight of broadside 20,622 lbs / 9,354 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 570.00 ft / 173.74 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 570.00 ft / 173.74 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 8.00" / 203 mm  13.0" / 330 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 4.50" / 114 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 120,571 shp / 89,946 Kw = 29.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,518 tons

Complement:
 1,572 - 2,044

Cost:
 £22.273 million / $89.091 million

Distribution of weights at normal displacement:
 Armament: 2,578 tons, 5.6 %
 Armour: 16,664 tons, 36.1 %
    - Belts: 4,647 tons, 10.1 %
    - Torpedo bulkhead: 1,961 tons, 4.3 %
    - Armament: 4,051 tons, 8.8 %
    - Armour Deck: 5,644 tons, 12.2 %
    - Conning Tower: 360 tons, 0.8 %
 Machinery: 3,186 tons, 6.9 %
 Hull, fittings & equipment: 19,627 tons, 42.6 %
 Fuel, ammunition & stores: 4,045 tons, 8.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   72,969 lbs / 33,098 Kg = 35.6 x 16.0 " / 406 mm shells or 12.6 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 6.7 ft / 2.0 m
 Roll period: 17.5 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.28

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.567
 Length to Beam Ratio: 7.87 : 1
 'Natural speed' for length: 33.66 kts
 Power going to wave formation at top speed: 47 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (50 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.64 ft / 7.21 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 79.7 %
  - Above water (accommodation/working, high = better): 188.9 %
 Waterplane Area: 67,795 Square feet or 6,298 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 215 lbs/sq ft or 1,048 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.17
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

The 31-knot version of the GB/CB/1937

I thought that 29 knots was too slow for the GB/CB/1937, so I increased the draft and displacement to make 31 knots possible. at 29 knots, the battlecruiser did not have a sufficient advantage over the 27-knot battleship. If we had a 29-knot battlecruiser, we should increase the belt thickness to more than 11 inches. This is the Springsharp report for the 31-knot version with a 11in belt:

GB/CB/1937, Great Britain Battlecruiser laid down 1937 (Engine 1941)

Displacement:
 41,675 t light; 43,757 t standard; 45,700 t normal; 47,254 t full load

Dimensions: Length overall / water x beam x draught
 852.17 ft / 850.00 ft x 108.00 ft x 31.00 ft (normal load)
 259.74 m / 259.08 m x 32.92 m  x 9.45 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread, 4 raised mounts
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
      16 - 1.57" / 40.0 mm guns (2x8 guns), 1.95lbs / 0.88kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 1 raised mount - superfiring
      8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1937 Model
   Anti-aircraft guns in deck mount 
   on side, evenly spread, all raised mounts
 Weight of broadside 20,622 lbs / 9,354 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 570.00 ft / 173.74 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 570.00 ft / 173.74 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 8.00" / 203 mm  12.0" / 305 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 153,523 shp / 114,528 Kw = 31.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,498 tons

Complement:
 1,562 - 2,031

Cost:
 £22.865 million / $91.461 million

Distribution of weights at normal displacement:
 Armament: 2,578 tons, 5.6 %
 Armour: 15,399 tons, 33.7 %
    - Belts: 4,259 tons, 9.3 %
    - Torpedo bulkhead: 1,961 tons, 4.3 %
    - Armament: 3,855 tons, 8.4 %
    - Armour Deck: 4,993 tons, 10.9 %
    - Conning Tower: 330 tons, 0.7 %
 Machinery: 4,057 tons, 8.9 %
 Hull, fittings & equipment: 19,641 tons, 43.0 %
 Fuel, ammunition & stores: 4,025 tons, 8.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   66,100 lbs / 29,982 Kg = 32.3 x 16.0 " / 406 mm shells or 10.7 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 6.9 ft / 2.1 m
 Roll period: 17.3 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.68
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.562
 Length to Beam Ratio: 7.87 : 1
 'Natural speed' for length: 33.68 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (50 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.64 ft / 7.21 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 87.9 %
  - Above water (accommodation/working, high = better): 189.2 %
 Waterplane Area: 67,475 Square feet or 6,269 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 216 lbs/sq ft or 1,053 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.16
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

This is the battleship in the design pair: the GB/BB/1937

This is the battleship from my 1980's designs: the GB/BB/1937 with 9-16in guns and a length of 750ft. This is the Springsharp report:

GB/BB/1937, Great Britain Battlecruiser laid down 1937 (Engine 1941)

Displacement:
 40,099 t light; 42,143 t standard; 43,800 t normal; 45,126 t full load

Dimensions: Length overall / water x beam x draught
 752.17 ft / 750.00 ft x 108.00 ft x 29.00 ft (normal load)
 229.26 m / 228.60 m x 32.92 m  x 8.84 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread, 4 raised mounts
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
      16 - 1.57" / 40.0 mm guns (2x8 guns), 1.95lbs / 0.89kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 1 raised mount - superfiring
      8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1937 Model
   Anti-aircraft guns in deck mount 
   on side, evenly spread, all raised mounts
 Weight of broadside 20,622 lbs / 9,354 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 470.00 ft / 143.26 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 96 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 470.00 ft / 143.26 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 9.00" / 229 mm  14.0" / 356 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 96,022 shp / 71,632 Kw = 27.00 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 2,982 tons

Complement:
 1,513 - 1,967

Cost:
 £21.404 million / $85.616 million

Distribution of weights at normal displacement:
 Armament: 2,578 tons, 5.9 %
 Armour: 16,827 tons, 38.4 %
    - Belts: 4,616 tons, 10.5 %
    - Torpedo bulkhead: 1,513 tons, 3.5 %
    - Armament: 4,321 tons, 9.9 %
    - Armour Deck: 6,003 tons, 13.7 %
    - Conning Tower: 375 tons, 0.9 %
 Machinery: 2,538 tons, 5.8 %
 Hull, fittings & equipment: 18,157 tons, 41.5 %
 Fuel, ammunition & stores: 3,701 tons, 8.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   71,208 lbs / 32,300 Kg = 34.8 x 16.0 " / 406 mm shells or 12.3 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 6.7 ft / 2.0 m
 Roll period: 17.5 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.19

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.653
 Length to Beam Ratio: 6.94 : 1
 'Natural speed' for length: 31.67 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (50 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.64 ft / 7.21 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 78.0 %
  - Above water (accommodation/working, high = better): 187.9 %
 Waterplane Area: 64,896 Square feet or 6,029 Square metres
 Displacement factor (Displacement / loading): 103 %
 Structure weight / hull surface area: 214 lbs/sq ft or 1,044 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.34
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

This is one of my 1980 designs: GB/CB/1937

This is part of a design pair (battleship and battlecruiser) that I did in the 1980's. This is the battlecruiser in the pair, the GB/CB/1937. This is 850ft long ship (on the waterline), with 9-16in guns. This is the Springsharp report:

GB/CB/1937, Great Britain Battlecruiser laid down 1937 (Engine 1941)

Displacement:
 40,705 t light; 42,767 t standard; 44,700 t normal; 46,246 t full load

Dimensions: Length overall / water x beam x draught
 852.17 ft / 850.00 ft x 108.00 ft x 29.00 ft (normal load)
 259.74 m / 259.08 m x 32.92 m  x 8.84 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread, 4 raised mounts
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread
      16 - 1.57" / 40.0 mm guns (2x8 guns), 1.95lbs / 0.89kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 1 raised mount - superfiring
      8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1937 Model
   Anti-aircraft guns in deck mount 
   on side, evenly spread, all raised mounts
 Weight of broadside 20,622 lbs / 9,354 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 570.00 ft / 173.74 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 570.00 ft / 173.74 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 8.00" / 203 mm  12.0" / 305 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 119,919 shp / 89,459 Kw = 29.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,479 tons

Complement:
 1,536 - 1,998

Cost:
 £22.002 million / $88.007 million

Distribution of weights at normal displacement:
 Armament: 2,578 tons, 5.8 %
 Armour: 15,397 tons, 34.4 %
    - Belts: 4,265 tons, 9.5 %
    - Torpedo bulkhead: 1,835 tons, 4.1 %
    - Armament: 3,855 tons, 8.6 %
    - Armour Deck: 5,117 tons, 11.4 %
    - Conning Tower: 326 tons, 0.7 %
 Machinery: 3,169 tons, 7.1 %
 Hull, fittings & equipment: 19,561 tons, 43.8 %
 Fuel, ammunition & stores: 3,995 tons, 8.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   71,227 lbs / 32,308 Kg = 34.8 x 16.0 " / 406 mm shells or 12.1 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 7.0 ft / 2.1 m
 Roll period: 17.2 seconds
 Steadiness - As gun platform (Average = 50 %): 61 %
   - Recoil effect (Restricted arc if above 1.00): 0.71
 Seaboat quality  (Average = 1.00): 1.23

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.588
 Length to Beam Ratio: 7.87 : 1
 'Natural speed' for length: 33.59 kts
 Power going to wave formation at top speed: 47 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (50 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.64 ft / 7.21 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 82.0 %
  - Above water (accommodation/working, high = better): 197.2 %
 Waterplane Area: 69,155 Square feet or 6,425 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 214 lbs/sq ft or 1,043 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.11
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

The GB/DL/1927 design

This version of a British super destroyer, the GB/DL/1927, is incrementally better, although the armament is now 4.7in QF guns, but there are 8 of them. The speed is now 37.5 knots with a maximum range of 4,250 nm at 15 knots. This is the Springsharp report:

GB/DL/1927, Great Britain Destroyer Leader laid down 1927 (Engine 1941)

Displacement:
 2,378 t light; 2,472 t standard; 2,690 t normal; 2,864 t full load

Dimensions: Length overall / water x beam x draught
 409.82 ft / 408.00 ft x 38.00 ft x 13.00 ft (normal load)
 124.91 m / 124.36 m x 11.58 m  x 3.96 m

Armament:
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1927 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 1 raised mount - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1927 Model
   Anti-aircraft gun in a deck mount with hoist
   on centreline amidships, 1 raised gun
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.89kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread, all raised mounts
 Weight of broadside 471 lbs / 214 kg
 Shells per gun, main battery: 150
 8 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 71,057 shp / 53,009 Kw = 37.50 kts
 Range 4,250nm at 15.00 kts
 Bunker at max displacement = 392 tons

Complement:
 186 - 242

Cost:
 £1.258 million / $5.033 million

Distribution of weights at normal displacement:
 Armament: 59 tons, 2.2 %
 Machinery: 1,524 tons, 56.7 %
 Hull, fittings & equipment: 795 tons, 29.5 %
 Fuel, ammunition & stores: 312 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   598 lbs / 271 Kg = 11.5 x 4.7 " / 119 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.40
 Metacentric height 2.1 ft / 0.6 m
 Roll period: 11.0 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.52
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.467
 Length to Beam Ratio: 10.74 : 1
 'Natural speed' for length: 23.01 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (33 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 18.80 ft / 5.73 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 199.5 %
  - Above water (accommodation/working, high = better): 100.6 %
 Waterplane Area: 10,426 Square feet or 969 Square metres
 Displacement factor (Displacement / loading): 64 %
 Structure weight / hull surface area: 36 lbs/sq ft or 176 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.30
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

I wondered if a smaller large destroyer would still work

I decided that I needed to see if a smaller ship could be designed that would still reach 37 knots and have a decent armament. The result is a GB/DL/1921 with a normal displacement of 2,200 tons. The armament is 6-13cm (5.1in) QF guns, 2-3in AA, and 12-2pdr AA guns, with 8-24in TT. The range is reduced to 4,100 nm at 15 knots. This is the Springsharp report:

GB/DL/1921, Great Britain Destroyer Leader laid down 1921 (Engine 1941)

Displacement:
 1,978 t light; 2,063 t standard; 2,250 t normal; 2,400 t full load

Dimensions: Length overall / water x beam x draught
 385.00 ft / 385.00 ft x 37.00 ft x 13.00 ft (normal load)
 117.35 m / 117.35 m x 11.28 m  x 3.96 m

Armament:
      6 - 5.10" / 130 mm guns (3x2 guns), 66.33lbs / 30.08kg shells, 1921 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority forward, 1 raised mount - superfiring
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.89kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on centreline, evenly spread, all raised mounts
 Weight of broadside 448 lbs / 203 kg
 Shells per gun, main battery: 150
 8 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 60,010 shp / 44,768 Kw = 37.00 kts
 Range 4,100nm at 15.00 kts
 Bunker at max displacement = 337 tons

Complement:
 163 - 212

Cost:
 £0.731 million / $2.925 million

Distribution of weights at normal displacement:
 Armament: 56 tons, 2.5 %
 Machinery: 1,221 tons, 54.3 %
 Hull, fittings & equipment: 701 tons, 31.2 %
 Fuel, ammunition & stores: 272 tons, 12.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   521 lbs / 236 Kg = 7.9 x 5.1 " / 130 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.36
 Metacentric height 1.9 ft / 0.6 m
 Roll period: 11.2 seconds
 Steadiness - As gun platform (Average = 50 %): 50 %
   - Recoil effect (Restricted arc if above 1.00): 0.57
 Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.425
 Length to Beam Ratio: 10.41 : 1
 'Natural speed' for length: 22.54 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (33 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 17.88 ft / 5.45 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.1 %
  - Above water (accommodation/working, high = better): 88.8 %
 Waterplane Area: 9,255 Square feet or 860 Square metres
 Displacement factor (Displacement / loading): 62 %
 Structure weight / hull surface area: 36 lbs/sq ft or 175 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.43
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped