The J/CL/1914 design

From the beginning the Japanese light cruiser design depends on lightweight machinery. The J/CL/1914 design is pretty conservative with just a 30-knot speed and 6-5.5in QF guns. The armour basis is 3in with a 1in deck. The displacement is driven in part by the 30-knot speed and the desire to have a substantial freeboard for good seakeeping. This is the Springsharp report:

J/CL/1914, Japan Light Cruiser laid down 1914 (Engine 1921)

Displacement:
 4,727 t light; 4,891 t standard; 5,340 t normal; 5,699 t full load

Dimensions: Length overall / water x beam x draught
 458.31 ft / 455.00 ft x 42.00 ft x 16.00 ft (normal load)
 139.69 m / 138.68 m x 12.80 m  x 4.88 m

Armament:
      6 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      4 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1914 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships
 Weight of broadside 549 lbs / 249 kg
 Shells per gun, main battery: 180
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 385.00 ft / 117.35 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 130 % of normal length

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 3.00" / 76 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 51,336 shp / 38,297 Kw = 30.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 809 tons

Complement:
 312 - 406

Cost:
 £0.599 million / $2.396 million

Distribution of weights at normal displacement:
 Armament: 69 tons, 1.3 %
 Armour: 901 tons, 16.9 %
    - Belts: 555 tons, 10.4 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 65 tons, 1.2 %
    - Armour Deck: 261 tons, 4.9 %
    - Conning Tower: 20 tons, 0.4 %
 Machinery: 1,768 tons, 33.1 %
 Hull, fittings & equipment: 1,990 tons, 37.3 %
 Fuel, ammunition & stores: 613 tons, 11.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,212 lbs / 2,364 Kg = 62.7 x 5.5 " / 140 mm shells or 0.9 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 1.8 ft / 0.6 m
 Roll period: 13.0 seconds
 Steadiness - As gun platform (Average = 50 %): 72 %
   - Recoil effect (Restricted arc if above 1.00): 0.52
 Seaboat quality  (Average = 1.00): 1.43

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.611
 Length to Beam Ratio: 10.83 : 1
 'Natural speed' for length: 21.33 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  25.00 ft / 7.62 m
    - Forecastle (20 %): 22.00 ft / 6.71 m
    - Mid (67 %):  22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
    - Quarterdeck (15 %): 14.00 ft / 4.27 m
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 19.60 ft / 5.97 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 117.7 %
  - Above water (accommodation/working, high = better): 146.0 %
 Waterplane Area: 14,124 Square feet or 1,312 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 71 lbs/sq ft or 345 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.90
  - Longitudinal: 2.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

The J/CA/1941 has just a very small improvements

The feature of the J/CA/1941 is an improved AA armament. The secondary armament is now 12-5in DP guns in twin mounts. The light AA armament is a non-standard 48-57mm AA in twin mounts. The rest is the same as the J/CA/1937 with still lighter machinery. This is the Springsharp report:

J/CA/1941, Japan Heavy Cruiser laid down 1941 (Engine 1947)

Displacement:
 14,851 t light; 15,454 t standard; 17,300 t normal; 18,777 t full load

Dimensions: Length overall / water x beam x draught
 687.89 ft / 682.00 ft x 64.00 ft x 23.00 ft (normal load)
 209.67 m / 207.87 m x 19.51 m  x 7.01 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      48 - 2.24" / 57.0 mm guns (24x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 16 raised mounts - superfiring
 Weight of broadside 3,581 lbs / 1,624 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 187,554 shp / 139,915 Kw = 36.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 3,323 tons

Complement:
 753 - 980

Cost:
 £9.548 million / $38.190 million

Distribution of weights at normal displacement:
 Armament: 448 tons, 2.6 %
 Armour: 3,048 tons, 17.6 %
    - Belts: 1,045 tons, 6.0 %
    - Torpedo bulkhead: 333 tons, 1.9 %
    - Armament: 428 tons, 2.5 %
    - Armour Deck: 1,185 tons, 6.8 %
    - Conning Tower: 58 tons, 0.3 %
 Machinery: 4,633 tons, 26.8 %
 Hull, fittings & equipment: 6,722 tons, 38.9 %
 Fuel, ammunition & stores: 2,449 tons, 14.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   18,902 lbs / 8,574 Kg = 73.8 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.6 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.81
 Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.603
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 26.12 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 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): 155.3 %
  - Above water (accommodation/working, high = better): 135.7 %
 Waterplane Area: 32,017 Square feet or 2,975 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 119 lbs/sq ft or 579 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.74
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The improvements in the J/CA/1937 design

The J/CA/1937 design has two improvements. They are an increased range to 12,000nm at 15 knots and a change to twin 5in DP guns, instead of twin 4.7in AA guns. The machiney is lighter-weight, so the modest increase in capabilities just adds 300 tons to the normal displacement. This is the Springsharp report:

J/CA/1937, Japan Heavy Cruiser laid down 1937 (Engine 1945)

Displacement:
 14,847 t light; 15,423 t standard; 17,300 t normal; 18,802 t full load

Dimensions: Length overall / water x beam x draught
 687.89 ft / 682.00 ft x 64.00 ft x 23.00 ft (normal load)
 209.67 m / 207.87 m x 19.51 m  x 7.01 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      36 - 2.24" / 57.0 mm guns (18x2 guns), 5.65lbs / 2.56kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 12 raised mounts - superfiring
 Weight of broadside 3,263 lbs / 1,480 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 187,554 shp / 139,915 Kw = 36.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 3,379 tons

Complement:
 753 - 980

Cost:
 £8.320 million / $33.281 million

Distribution of weights at normal displacement:
 Armament: 408 tons, 2.4 %
 Armour: 3,035 tons, 17.5 %
    - Belts: 1,045 tons, 6.0 %
    - Torpedo bulkhead: 333 tons, 1.9 %
    - Armament: 415 tons, 2.4 %
    - Armour Deck: 1,185 tons, 6.8 %
    - Conning Tower: 58 tons, 0.3 %
 Machinery: 4,736 tons, 27.4 %
 Hull, fittings & equipment: 6,668 tons, 38.5 %
 Fuel, ammunition & stores: 2,453 tons, 14.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   18,998 lbs / 8,617 Kg = 74.2 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.5 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.74
 Seaboat quality  (Average = 1.00): 1.14

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.603
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 26.12 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 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): 155.6 %
  - Above water (accommodation/working, high = better): 135.7 %
 Waterplane Area: 32,017 Square feet or 2,975 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 118 lbs/sq ft or 574 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.74
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CA/1933 design

The J/CA/1933 design was converted to be flush-decked with a higher speed (36 knots). The range is still 10,000nm at 15 knots, although I experimented with lowering the range to 9,500nm and then to 9,000nm. The light AA armament is increased with the non-standard twin 57mm AA guns. The ship is now a much better seaboat and has a 14.5 second roll period, which is better. This is the Springsharp report:

J/CA/1933, Japan Heavy Cruiser laid down 1933 (Engine 1942)

Displacement:
 14,836 t light; 15,400 t standard; 17,000 t normal; 18,280 t full load

Dimensions: Length overall / water x beam x draught
 687.89 ft / 682.00 ft x 64.00 ft x 23.00 ft (normal load)
 209.67 m / 207.87 m x 19.51 m  x 7.01 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1933 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1933 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 2.24" / 57.0 mm guns (18x2 guns), 5.65lbs / 2.56kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 12 raised mounts - superfiring
 Weight of broadside 3,179 lbs / 1,442 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 184,611 shp / 137,720 Kw = 36.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,881 tons

Complement:
 743 - 967

Cost:
 £7.224 million / $28.897 million

Distribution of weights at normal displacement:
 Armament: 397 tons, 2.3 %
 Armour: 2,995 tons, 17.6 %
    - Belts: 1,044 tons, 6.1 %
    - Torpedo bulkhead: 333 tons, 2.0 %
    - Armament: 388 tons, 2.3 %
    - Armour Deck: 1,173 tons, 6.9 %
    - Conning Tower: 57 tons, 0.3 %
 Machinery: 4,823 tons, 28.4 %
 Hull, fittings & equipment: 6,621 tons, 38.9 %
 Fuel, ammunition & stores: 2,164 tons, 12.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,723 lbs / 8,039 Kg = 69.2 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.5 seconds
 Steadiness - As gun platform (Average = 50 %): 58 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.593
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 26.12 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 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): 160.0 %
  - Above water (accommodation/working, high = better): 136.2 %
 Waterplane Area: 31,706 Square feet or 2,946 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 117 lbs/sq ft or 573 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.75
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CA/1927 design has small improvements

The J/CA/1927 design has two improvements. One is the increase in torpedo armament to 16-24in TT. The other improvement is an increase in range to 10,000nm at 15 knots. The real Japanese cruisers were smaller with similar characteristics. The Atago class had a range of 8,500nm at 14 knots. The real Japanese cruisers had less deck armour and thicker side armour. This is the Springsharp report:

J/CA/1927, Japan Heavy Cruiser laid down 1927 (Engine 1939)

Displacement:
 13,236 t light; 13,759 t standard; 15,300 t normal; 16,533 t full load

Dimensions: Length overall / water x beam x draught
 680.80 ft / 675.00 ft x 62.00 ft x 22.00 ft (normal load)
 207.51 m / 205.74 m x 18.90 m  x 6.71 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1927 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      24 - 2.24" / 57.0 mm guns (12x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 6 raised mounts - superfiring
 Weight of broadside 3,111 lbs / 1,411 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 153,387 shp / 114,427 Kw = 35.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,774 tons

Complement:
 687 - 894

Cost:
 £4.985 million / $19.940 million

Distribution of weights at normal displacement:
 Armament: 389 tons, 2.5 %
 Armour: 2,895 tons, 18.9 %
    - Belts: 1,040 tons, 6.8 %
    - Torpedo bulkhead: 333 tons, 2.2 %
    - Armament: 356 tons, 2.3 %
    - Armour Deck: 1,113 tons, 7.3 %
    - Conning Tower: 53 tons, 0.3 %
 Machinery: 4,150 tons, 27.1 %
 Hull, fittings & equipment: 5,801 tons, 37.9 %
 Fuel, ammunition & stores: 2,064 tons, 13.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   16,116 lbs / 7,310 Kg = 63.0 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.20
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.66
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.582
 Length to Beam Ratio: 10.89 : 1
 'Natural speed' for length: 25.98 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  32.00 ft / 9.75 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (50 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 22.48 ft / 6.85 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 158.7 %
  - Above water (accommodation/working, high = better): 118.7 %
 Waterplane Area: 30,086 Square feet or 2,795 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 115 lbs/sq ft or 563 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.29
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

Perhaps I was too ambitious with the J/CA/1923 design

I wanted to have a speed of 35 knots for the J/CA/1923 design, and to achieve that at this date required lighter weight machinery and a deeper draft. The higher speed is the only change between this design and its predecessor. The length, draft, freeboard, and displacement needed to grow to satisfy Springsharp. Perhaps, 34 knots would have been more reasonable, so that the range could have been increased. This is the Springsharp report:

J/CA/1923, Japan Heavy Cruiser laid down 1923 (Engine 1937)

Displacement:
 13,116 t light; 13,630 t standard; 14,800 t normal; 15,736 t full load

Dimensions: Length overall / water x beam x draught
 680.80 ft / 675.00 ft x 62.00 ft x 22.00 ft (normal load)
 207.51 m / 205.74 m x 18.90 m  x 6.71 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      24 - 2.24" / 57.0 mm guns (12x2 guns), 5.65lbs / 2.56kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 6 raised mounts - superfiring
 Weight of broadside 3,111 lbs / 1,411 kg
 Shells per gun, main battery: 120
 12 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 148,942 shp / 111,111 Kw = 35.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,107 tons

Complement:
 670 - 872

Cost:
 £3.967 million / $15.868 million

Distribution of weights at normal displacement:
 Armament: 389 tons, 2.6 %
 Armour: 2,874 tons, 19.4 %
    - Belts: 1,040 tons, 7.0 %
    - Torpedo bulkhead: 333 tons, 2.3 %
    - Armament: 356 tons, 2.4 %
    - Armour Deck: 1,094 tons, 7.4 %
    - Conning Tower: 52 tons, 0.4 %
 Machinery: 4,128 tons, 27.9 %
 Hull, fittings & equipment: 5,726 tons, 38.7 %
 Fuel, ammunition & stores: 1,684 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,745 lbs / 6,688 Kg = 57.6 x 8.0 " / 203 mm shells or 1.8 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.68
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.563
 Length to Beam Ratio: 10.89 : 1
 'Natural speed' for length: 25.98 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  32.00 ft / 9.75 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (50 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 22.48 ft / 6.85 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 163.3 %
  - Above water (accommodation/working, high = better): 135.2 %
 Waterplane Area: 29,554 Square feet or 2,746 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 115 lbs/sq ft or 562 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.30
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CA/1921 design

The J/CA/1921 design in an incremental improvement over its predecessor. The main differences are an increase to 10-8in guns, to 8-4.7in AA guns, and to 12-24in TT, instead of 16-21in TT. The speed and range are unchanged. The displacement was only slightly increased. The roll is still snappier than I would like with a roll period of 13.8 seconds. This is the Springsharp report:

J/CA/1921, Japan Heavy Cruiser laid down 1921 (Engine 1931)

Displacement:
 12,109 t light; 12,602 t standard; 13,800 t normal; 14,758 t full load

Dimensions: Length overall / water x beam x draught
 660.10 ft / 655.00 ft x 62.00 ft x 19.00 ft (normal load)
 201.20 m / 199.64 m x 18.90 m  x 5.79 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      24 - 2.24" / 57.0 mm guns (12x2 guns), 5.65lbs / 2.56kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 6 raised mounts - superfiring
 Weight of broadside 3,111 lbs / 1,411 kg
 Shells per gun, main battery: 120
 12 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 106 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 18.00 ft / 5.49 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 117,999 shp / 88,027 Kw = 33.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,156 tons

Complement:
 636 - 827

Cost:
 £3.168 million / $12.671 million

Distribution of weights at normal displacement:
 Armament: 389 tons, 2.8 %
 Armour: 2,862 tons, 20.7 %
    - Belts: 1,040 tons, 7.5 %
    - Torpedo bulkhead: 300 tons, 2.2 %
    - Armament: 347 tons, 2.5 %
    - Armour Deck: 1,126 tons, 8.2 %
    - Conning Tower: 50 tons, 0.4 %
 Machinery: 3,529 tons, 25.6 %
 Hull, fittings & equipment: 5,329 tons, 38.6 %
 Fuel, ammunition & stores: 1,691 tons, 12.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   16,101 lbs / 7,304 Kg = 62.9 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 3.6 ft / 1.1 m
 Roll period: 13.8 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.64
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.626
 Length to Beam Ratio: 10.56 : 1
 'Natural speed' for length: 25.59 kts
 Power going to wave formation at top speed: 57 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  30.00 ft / 9.14 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break)
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 21.40 ft / 6.52 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 154.4 %
  - Above water (accommodation/working, high = better): 138.4 %
 Waterplane Area: 30,428 Square feet or 2,827 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 113 lbs/sq ft or 550 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.08
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The Japanese J/CA/1918 cruiser design

The J/CA/1918 design has a snappier roll than I would like, but Springsharp is happy with the result, except that the belt might not cover the machinery and magazines completely! This design, like its predecessor, depends on light-weight machinery (of 32.1 SHP/ton, not very light-weight). The speed is now 33 knots with a somewhat better AA armament. The torpedo armament is increased to 16-21in TT. The date is too early to go with the 24in size. This is the Springsharp report:

J/CA/1918, Japan Heavy Cruiser laid down 1918 (Engine 1928)

Displacement:
 11,749 t light; 12,192 t standard; 13,400 t normal; 14,367 t full load

Dimensions: Length overall / water x beam x draught
 650.10 ft / 645.00 ft x 61.00 ft x 19.00 ft (normal load)
 198.15 m / 196.60 m x 18.59 m  x 5.79 m

Armament:
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      24 - 2.24" / 57.0 mm guns (12x2 guns), 5.65lbs / 2.56kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 6 raised mounts - superfiring
 Weight of broadside 2,495 lbs / 1,132 kg
 Shells per gun, main battery: 120
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 107 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 18.00 ft / 5.49 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 116,627 shp / 87,004 Kw = 33.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,175 tons

Complement:
 622 - 809

Cost:
 £2.363 million / $9.452 million

Distribution of weights at normal displacement:
 Armament: 312 tons, 2.3 %
 Armour: 2,764 tons, 20.6 %
    - Belts: 1,038 tons, 7.7 %
    - Torpedo bulkhead: 300 tons, 2.2 %
    - Armament: 286 tons, 2.1 %
    - Armour Deck: 1,092 tons, 8.2 %
    - Conning Tower: 49 tons, 0.4 %
 Machinery: 3,631 tons, 27.1 %
 Hull, fittings & equipment: 5,042 tons, 37.6 %
 Fuel, ammunition & stores: 1,651 tons, 12.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   15,326 lbs / 6,952 Kg = 59.9 x 8.0 " / 203 mm shells or 1.9 torpedoes
 Stability (Unstable if below 1.00): 1.25
 Metacentric height 3.6 ft / 1.1 m
 Roll period: 13.6 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.55
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.627
 Length to Beam Ratio: 10.57 : 1
 'Natural speed' for length: 25.40 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  30.00 ft / 9.14 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break)
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 21.40 ft / 6.52 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 157.5 %
  - Above water (accommodation/working, high = better): 134.6 %
 Waterplane Area: 29,519 Square feet or 2,742 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 108 lbs/sq ft or 530 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.13
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Japanese cruiser design J/CA/1916

The J/CA/1916 design has lighter weight machinery, as the power output was too low with what Springsharp judges to be the normal weight for machinery in 1916. This design has 8-8in guns in twin turrets with an AA armament and torpedo tubes. The speed is now 32 knots and the range is 7,500nm at 15 knots. This is the Springsharp report:

J/CA/1916, Japan Heavy Cruiser laid down 1916 (Engine 1924)

Displacement:
 10,712 t light; 11,114 t standard; 12,300 t normal; 13,249 t full load

Dimensions: Length overall / water x beam x draught
 639.96 ft / 635.00 ft x 61.00 ft x 19.00 ft (normal load)
 195.06 m / 193.55 m x 18.59 m  x 5.79 m

Armament:
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 2,266 lbs / 1,028 kg
 Shells per gun, main battery: 120
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 430.00 ft / 131.06 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 104 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 430.00 ft / 131.06 m 16.00 ft / 4.88 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 96,590 shp / 72,056 Kw = 32.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,134 tons

Complement:
 583 - 759

Cost:
 £1.732 million / $6.927 million

Distribution of weights at normal displacement:
 Armament: 283 tons, 2.3 %
 Armour: 2,596 tons, 21.1 %
    - Belts: 996 tons, 8.1 %
    - Torpedo bulkhead: 255 tons, 2.1 %
    - Armament: 266 tons, 2.2 %
    - Armour Deck: 1,034 tons, 8.4 %
    - Conning Tower: 46 tons, 0.4 %
 Machinery: 3,181 tons, 25.9 %
 Hull, fittings & equipment: 4,652 tons, 37.8 %
 Fuel, ammunition & stores: 1,588 tons, 12.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   15,122 lbs / 6,859 Kg = 59.1 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.26
 Metacentric height 3.6 ft / 1.1 m
 Roll period: 13.5 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.49
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.585
 Length to Beam Ratio: 10.41 : 1
 'Natural speed' for length: 25.20 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  28.00 ft / 8.53 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (50 %):  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: 20.32 ft / 6.19 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 151.3 %
  - Above water (accommodation/working, high = better): 141.4 %
 Waterplane Area: 27,934 Square feet or 2,595 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 108 lbs/sq ft or 525 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.05
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CA/1914 design

The J/CA/1914 design seems to work fairly well. The main reason that the displacement is so high and the speed so low (30 knots) is that the machinery is heavy for the power produced. The machinery used here is very conservative and produces about 26 SHP per ton of machinery. This design has an archaic armament layout with 5-8in guns on the centerline and two on either side on the broadside. We have also burdened the design with a torpedo bulkhead, although havin a torpedo bulkhead means that the protection scheme is good, as rated by Springsharp:

J/CA/1914, Japan Heavy Cruiser laid down 1914

Displacement:
 9,454 t light; 9,843 t standard; 11,100 t normal; 12,106 t full load

Dimensions: Length overall / water x beam x draught
 598.42 ft / 595.00 ft x 57.00 ft x 18.00 ft (normal load)
 182.40 m / 181.36 m x 17.37 m  x 5.49 m

Armament:
      5 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority forward, 2 raised mounts - superfiring
      4 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 2,358 lbs / 1,070 kg
 Shells per gun, main battery: 120
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 400.00 ft / 121.92 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 103 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 400.00 ft / 121.92 m 16.00 ft / 4.88 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 73,320 shp / 54,697 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,263 tons

Complement:
 539 - 702

Cost:
 £1.239 million / $4.958 million

Distribution of weights at normal displacement:
 Armament: 295 tons, 2.7 %
 Armour: 2,329 tons, 21.0 %
    - Belts: 929 tons, 8.4 %
    - Torpedo bulkhead: 237 tons, 2.1 %
    - Armament: 172 tons, 1.5 %
    - Armour Deck: 949 tons, 8.6 %
    - Conning Tower: 43 tons, 0.4 %
 Machinery: 2,824 tons, 25.4 %
 Hull, fittings & equipment: 4,005 tons, 36.1 %
 Fuel, ammunition & stores: 1,646 tons, 14.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   13,245 lbs / 6,008 Kg = 51.7 x 8.0 " / 203 mm shells or 1.8 torpedoes
 Stability (Unstable if below 1.00): 1.28
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 13.0 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.58
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.636
 Length to Beam Ratio: 10.44 : 1
 'Natural speed' for length: 24.39 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (50 %):  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: 19.32 ft / 5.89 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 158.7 %
  - Above water (accommodation/working, high = better): 155.7 %
 Waterplane Area: 25,658 Square feet or 2,384 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 101 lbs/sq ft or 493 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.07
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Photo of a J/CB/1941 battlecruiser

This is a photo of one of the J/CB/1941 battlecruisers.

The Ultimate Japanese Battlecruiser: J/CB/1941

The J/CB/1941 is a very large ship that is still extremely capable. I would argue that the large battlecruiser of this type, that is well-protected, is analogous to the Iowa class battleships. They are fast, well-armed, adequately protected, and have great strategic mobility. This design is significant in that it uses the 21in gun for the main armament. This is the Springsharp report:

J/CB/1941, Japan Battlecruiser laid down 1941

Displacement:
 92,016 t light; 96,104 t standard; 102,200 t normal; 107,077 t full load

Dimensions: Length overall / water x beam x draught
 1,041.78 ft / 1,035.00 ft x 128.00 ft x 35.00 ft (normal load)
 317.54 m / 315.47 m x 39.01 m  x 10.67 m

Armament:
      8 - 21.00" / 533 mm guns (4x2 guns), 4,630.50lbs / 2,100.36kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1941 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      64 - 2.24" / 57.0 mm guns (32x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 40,202 lbs / 18,235 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 15.0" / 381 mm 680.00 ft / 207.26 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 680.00 ft / 207.26 m 8.00 ft / 2.44 m
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 680.00 ft / 207.26 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 12.0" / 305 mm  15.0" / 381 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 15.00" / 381 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 374,336 shp / 279,255 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,972 tons

Complement:
 2,857 - 3,715

Cost:
 £54.565 million / $218.260 million

Distribution of weights at normal displacement:
 Armament: 5,025 tons, 4.9 %
 Armour: 38,598 tons, 37.8 %
    - Belts: 6,730 tons, 6.6 %
    - Torpedo bulkhead: 6,844 tons, 6.7 %
    - Armament: 7,591 tons, 7.4 %
    - Armour Deck: 16,726 tons, 16.4 %
    - Conning Tower: 706 tons, 0.7 %
 Machinery: 9,893 tons, 9.7 %
 Hull, fittings & equipment: 38,501 tons, 37.7 %
 Fuel, ammunition & stores: 10,184 tons, 10.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   152,591 lbs / 69,214 Kg = 33.0 x 21.0 " / 533 mm shells or 29.8 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 9.3 ft / 2.8 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.771
 Length to Beam Ratio: 8.09 : 1
 'Natural speed' for length: 32.17 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.56 ft / 9.01 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 81.3 %
  - Above water (accommodation/working, high = better): 218.5 %
 Waterplane Area: 113,017 Square feet or 10,500 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 255 lbs/sq ft or 1,246 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.04
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The J/CB/1937 design is huge

The J/CB/1937 design is huge. If I had not reduced the armour basis to 14in, it would have been even larger. I guess that a ship that has 12-18in guns, a speed of 33 knots, and a range of 12,000nm at 15 knots needs to be large to do all that. That is especially true when the 8in armour deck and 8in anti-torpedo bulkhead are considered. the design is extremely well-protected against underwater attack. The defence against gunfire is less effective, but is adequate for a battlecruiser. Consider that the battleship counterpart has an 18in armour basis. This is the Springsharp report:

J/CB/1937, Japan Battlecruiser laid down 1937

Displacement:
 87,795 t light; 91,693 t standard; 97,800 t normal; 102,686 t full load

Dimensions: Length overall / water x beam x draught
 1,031.78 ft / 1,025.00 ft x 125.00 ft x 35.00 ft (normal load)
 314.49 m / 312.42 m x 38.10 m  x 10.67 m

Armament:
      12 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      64 - 2.24" / 57.0 mm guns (32x2 guns), 5.65lbs / 2.56kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 38,150 lbs / 17,304 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 680.00 ft / 207.26 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 680.00 ft / 207.26 m 8.00 ft / 2.44 m
   Main Belt covers 102 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 680.00 ft / 207.26 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 13.0" / 330 mm  14.0" / 356 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 363,186 shp / 270,936 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,993 tons

Complement:
 2,764 - 3,594

Cost:
 £46.297 million / $185.189 million

Distribution of weights at normal displacement:
 Armament: 4,769 tons, 4.9 %
 Armour: 37,331 tons, 38.2 %
    - Belts: 6,446 tons, 6.6 %
    - Torpedo bulkhead: 6,844 tons, 7.0 %
    - Armament: 7,336 tons, 7.5 %
    - Armour Deck: 16,065 tons, 16.4 %
    - Conning Tower: 640 tons, 0.7 %
 Machinery: 10,066 tons, 10.3 %
 Hull, fittings & equipment: 35,630 tons, 36.4 %
 Fuel, ammunition & stores: 10,005 tons, 10.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   142,830 lbs / 64,787 Kg = 49.0 x 18.0 " / 457 mm shells or 27.1 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 9.2 ft / 2.8 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.75
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.763
 Length to Beam Ratio: 8.20 : 1
 'Natural speed' for length: 32.02 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.56 ft / 9.01 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 83.7 %
  - Above water (accommodation/working, high = better): 216.9 %
 Waterplane Area: 108,545 Square feet or 10,084 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 243 lbs/sq ft or 1,188 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.02
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1933 design

This design has ballooned to 90,800 tons, normal displacement. The reason is that the ship is well-armed, moderately well-protected, and has a high speed (well, relatively high speed) of 33 knots. This is the Springsharp report:

J/CB/1933, Japan Battlecruiser laid down 1933

Displacement:
 81,822 t light; 85,270 t standard; 90,800 t normal; 95,224 t full load

Dimensions: Length overall / water x beam x draught
 980.78 ft / 975.00 ft x 124.00 ft x 35.00 ft (normal load)
 298.94 m / 297.18 m x 37.80 m  x 10.67 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1933 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1933 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      20 - 5.00" / 127 mm guns (10x2 guns), 62.50lbs / 28.35kg shells, 1933 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      56 - 2.24" / 57.0 mm guns (28x2 guns), 5.65lbs / 2.56kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 32,022 lbs / 14,525 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 15.0" / 381 mm 640.00 ft / 195.07 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 640.00 ft / 195.07 m 8.00 ft / 2.44 m
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  7.00" / 178 mm 640.00 ft / 195.07 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 15.0" / 381 mm 13.0" / 330 mm  15.0" / 381 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 15.00" / 381 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 353,975 shp / 264,065 Kw = 33.01 kts
 Range 11,000nm at 15.00 kts
 Bunker at max displacement = 9,955 tons

Complement:
 2,614 - 3,399

Cost:
 £36.259 million / $145.034 million

Distribution of weights at normal displacement:
 Armament: 4,003 tons, 4.4 %
 Armour: 35,433 tons, 39.0 %
    - Belts: 6,354 tons, 7.0 %
    - Torpedo bulkhead: 5,636 tons, 6.2 %
    - Armament: 7,792 tons, 8.6 %
    - Armour Deck: 14,999 tons, 16.5 %
    - Conning Tower: 653 tons, 0.7 %
 Machinery: 10,314 tons, 11.4 %
 Hull, fittings & equipment: 32,072 tons, 35.3 %
 Fuel, ammunition & stores: 8,978 tons, 9.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   132,264 lbs / 59,994 Kg = 45.4 x 18.0 " / 457 mm shells or 24.3 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 8.7 ft / 2.7 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.68
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.751
 Length to Beam Ratio: 7.86 : 1
 'Natural speed' for length: 31.22 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.56 ft / 9.01 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 83.8 %
  - Above water (accommodation/working, high = better): 214.2 %
 Waterplane Area: 101,347 Square feet or 9,415 Square metres
 Displacement factor (Displacement / loading): 103 %
 Structure weight / hull surface area: 233 lbs/sq ft or 1,140 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.00
  - Longitudinal: 1.04
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1927 design

The J/CB/1927 design is better protected than the previous version. The armour basis is now 14 inches. Otherwise, the design is very similar to the corresponding battleship. The speed is 33 knots, still, and the range is 12,000nm at 15 knots. The seakeeping is not quite as good as the preceding design, but is adequate. This is the Springsharp report:

J/CB/1927, Japan Battlecruiser laid down 1927

Displacement:
 75,199 t light; 78,484 t standard; 84,500 t normal; 89,313 t full load

Dimensions: Length overall / water x beam x draught
 970.68 ft / 965.00 ft x 122.00 ft x 35.00 ft (normal load)
 295.86 m / 294.13 m x 37.19 m  x 10.67 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1927 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
      42 - 2.24" / 57.0 mm guns (21x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 31,443 lbs / 14,262 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 640.00 ft / 195.07 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 640.00 ft / 195.07 m 8.00 ft / 2.44 m
   Main Belt covers 102 % of normal length

   - Torpedo Bulkhead:
  5.00" / 127 mm 640.00 ft / 195.07 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 12.0" / 305 mm  14.0" / 356 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 16.00" / 406 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 334,570 shp / 249,589 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,828 tons

Complement:
 2,477 - 3,221

Cost:
 £26.953 million / $107.811 million

Distribution of weights at normal displacement:
 Armament: 3,930 tons, 4.7 %
 Armour: 30,083 tons, 35.6 %
    - Belts: 6,084 tons, 7.2 %
    - Torpedo bulkhead: 3,789 tons, 4.5 %
    - Armament: 7,132 tons, 8.4 %
    - Armour Deck: 12,414 tons, 14.7 %
    - Conning Tower: 664 tons, 0.8 %
 Machinery: 10,561 tons, 12.5 %
 Hull, fittings & equipment: 30,624 tons, 36.2 %
 Fuel, ammunition & stores: 9,301 tons, 11.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   113,026 lbs / 51,268 Kg = 38.8 x 18.0 " / 457 mm shells or 18.0 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 8.4 ft / 2.6 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.69
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.718
 Length to Beam Ratio: 7.91 : 1
 'Natural speed' for length: 31.06 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (67 %):  28.00 ft / 8.53 m
    - Quarterdeck (15 %): 28.00 ft / 8.53 m
    - Stern:  28.00 ft / 8.53 m
    - Average freeboard: 28.56 ft / 8.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 90.5 %
  - Above water (accommodation/working, high = better): 206.4 %
 Waterplane Area: 95,861 Square feet or 8,906 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 234 lbs/sq ft or 1,143 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.00
  - Longitudinal: 1.04
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1923 design

The J/CB/1923 design ballooned considerably over the corresponding battleship design. That was mostly driven by the desire for a 33-knot speed. Very likely, the design is not very well-protected against gunfire, but it is a battlecruiser so we would accept that as the price for speed and gunpower. The armour design is somewhat different from the J/BB/1923 design in that the deck is thicker. The range was also extended to 12,000nm at 15 knots, as befitted a ship that would be a fast wing of the battlefleet, able to make long strategic moves. This is the Springsharp report:

J/CB/1923, Japan Battlecruiser laid down 1923

Displacement:
 72,137 t light; 75,354 t standard; 81,455 t normal; 86,337 t full load

Dimensions: Length overall / water x beam x draught
 978.06 ft / 975.00 ft x 118.00 ft x 35.00 ft (normal load)
 298.11 m / 297.18 m x 35.97 m  x 10.67 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1923 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 8 raised mounts - superfiring
      12 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      32 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 31,295 lbs / 14,195 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 660.00 ft / 201.17 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 10.0" / 254 mm 660.00 ft / 201.17 m 8.00 ft / 2.44 m
   Main Belt covers 104 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 660.00 ft / 201.17 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 11.0" / 279 mm  14.0" / 356 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 322,007 shp / 240,217 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,983 tons

Complement:
 2,410 - 3,134

Cost:
 £21.287 million / $85.149 million

Distribution of weights at normal displacement:
 Armament: 3,912 tons, 4.8 %
 Armour: 27,829 tons, 34.2 %
    - Belts: 5,520 tons, 6.8 %
    - Torpedo bulkhead: 3,321 tons, 4.1 %
    - Armament: 6,435 tons, 7.9 %
    - Armour Deck: 12,027 tons, 14.8 %
    - Conning Tower: 526 tons, 0.6 %
 Machinery: 10,762 tons, 13.2 %
 Hull, fittings & equipment: 29,634 tons, 36.4 %
 Fuel, ammunition & stores: 9,318 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   102,797 lbs / 46,628 Kg = 35.3 x 18.0 " / 457 mm shells or 15.1 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 8.1 ft / 2.5 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.708
 Length to Beam Ratio: 8.26 : 1
 'Natural speed' for length: 31.22 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (67 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.64 ft / 8.42 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 95.2 %
  - Above water (accommodation/working, high = better): 198.2 %
 Waterplane Area: 92,874 Square feet or 8,628 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 232 lbs/sq ft or 1,132 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.02
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1921 is a faster version of the battleship

Apparently, the J/BB/1921 is under-protected, and the J/CB/1921 uses that same protection scheme with a 33-knot speed for a reasonable battlecruiser design. The armament and protection are identical, but the battlcruiser has greater dimensions and a higher freeboard. An interesting phenomenon was that the seakeeping improved as the beam was increased. In many smaller ships, decreasing the beam improves seakeeping. The resulting ship is rather lightly protected, but seems to be more capable than I would have expected for the size. This is the Springsharp report:

J/CB/1921, Japan Battlecruiser laid down 1921

Displacement:
 57,727 t light; 60,303 t standard; 64,800 t normal; 68,398 t full load

Dimensions: Length overall / water x beam x draught
 914.97 ft / 912.00 ft x 116.00 ft x 34.00 ft (normal load)
 278.88 m / 277.98 m x 35.36 m  x 10.36 m

Armament:
      8 - 18.00" / 457 mm guns (4x2 guns), 2,916.00lbs / 1,322.68kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1921 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 8 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      24 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 25,210 lbs / 11,435 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 570.00 ft / 173.74 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 10.0" / 254 mm 570.00 ft / 173.74 m 8.00 ft / 2.44 m
   Main Belt covers 96 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  4.00" / 102 mm 570.00 ft / 173.74 m 30.00 ft / 9.14 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 10.0" / 254 mm  13.0" / 330 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 279,915 shp / 208,816 Kw = 33.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 8,094 tons

Complement:
 2,029 - 2,639

Cost:
 £15.316 million / $61.263 million

Distribution of weights at normal displacement:
 Armament: 3,151 tons, 4.9 %
 Armour: 19,928 tons, 30.8 %
    - Belts: 4,845 tons, 7.5 %
    - Torpedo bulkhead: 2,531 tons, 3.9 %
    - Armament: 4,738 tons, 7.3 %
    - Armour Deck: 7,363 tons, 11.4 %
    - Conning Tower: 452 tons, 0.7 %
 Machinery: 9,639 tons, 14.9 %
 Hull, fittings & equipment: 25,009 tons, 38.6 %
 Fuel, ammunition & stores: 7,073 tons, 10.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   80,058 lbs / 36,314 Kg = 27.5 x 18.0 " / 457 mm shells or 11.2 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 8.0 ft / 2.4 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): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.631
 Length to Beam Ratio: 7.86 : 1
 'Natural speed' for length: 30.20 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: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  34.00 ft / 10.36 m
    - Forecastle (20 %): 30.00 ft / 9.14 m
    - Mid (67 %):  30.00 ft / 9.14 m (21.00 ft / 6.40 m aft of break)
    - Quarterdeck (15 %): 21.00 ft / 6.40 m
    - Stern:  21.00 ft / 6.40 m
    - Average freeboard: 27.35 ft / 8.34 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 102.5 %
  - Above water (accommodation/working, high = better): 205.6 %
 Waterplane Area: 79,603 Square feet or 7,395 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 225 lbs/sq ft or 1,099 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.14
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1918 design has ended up being a fast battleship

The J/CB/1918 design is a fast battleship, although the armour basis is just 12in. It has the same armament as its battleship counterpart, but has a much higher speed at 32 knots. That speed was a challenge, as I struggled to reach adequate seakeeping with this design. I kept raising the freeboard and increasing the draft, almost without effect. What finally made the difference was increasing the length. By the way, for the Japanese battlecruiser series, I will be starting from the corresponding battleship and modifying the design to be a battlecruiser, rather than having a continuous series of battlecruisers. This is the Springsharp report:

J/CB/1918, Japan Battleship laid down 1918

Displacement:
 48,367 t light; 50,611 t standard; 55,800 t normal; 59,951 t full load

Dimensions: Length overall / water x beam x draught
 837.38 ft / 835.00 ft x 108.00 ft x 34.00 ft (normal load)
 255.23 m / 254.51 m x 32.92 m  x 10.36 m

Armament:
      10 - 16.00" / 406 mm guns (5x2 guns), 2,048.00lbs / 928.96kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 6 raised mounts - superfiring
      6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
      16 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 22,213 lbs / 10,076 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 620.00 ft / 188.98 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 9.00" / 229 mm 620.00 ft / 188.98 m 8.00 ft / 2.44 m
   Main Belt covers 114 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 620.00 ft / 188.98 m 30.00 ft / 9.14 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 9.00" / 229 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, 233,965 shp / 174,538 Kw = 32.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 9,341 tons

Complement:
 1,814 - 2,359

Cost:
 £10.414 million / $41.655 million

Distribution of weights at normal displacement:
 Armament: 2,777 tons, 5.0 %
 Armour: 16,658 tons, 29.9 %
    - Belts: 4,675 tons, 8.4 %
    - Torpedo bulkhead: 2,065 tons, 3.7 %
    - Armament: 4,490 tons, 8.0 %
    - Armour Deck: 5,051 tons, 9.1 %
    - Conning Tower: 378 tons, 0.7 %
 Machinery: 8,440 tons, 15.1 %
 Hull, fittings & equipment: 20,492 tons, 36.7 %
 Fuel, ammunition & stores: 7,433 tons, 13.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   65,894 lbs / 29,889 Kg = 32.2 x 16.0 " / 406 mm shells or 8.8 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 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.77
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.637
 Length to Beam Ratio: 7.73 : 1
 'Natural speed' for length: 28.90 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  34.00 ft / 10.36 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m (21.00 ft / 6.40 m aft of break)
    - Quarterdeck (15 %): 21.00 ft / 6.40 m
    - Stern:  21.00 ft / 6.40 m
    - Average freeboard: 26.76 ft / 8.16 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 106.1 %
  - Above water (accommodation/working, high = better): 192.0 %
 Waterplane Area: 68,260 Square feet or 6,342 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 210 lbs/sq ft or 1,025 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.25
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

This is bigger than I would have thought necessary: J/CB/1916

The J/CB/1916 has 8-16in guns and a speed of 30 knots. The armour basis is 11 inches. One reason for the size might be the deck armour being 4in, rather than the 3.5in I had considered. The speed is another reason, along with size needed to obtain the necessary hull strength. This is the Springsharp report:

J/CB/1916, Japan Battlecruiser laid down 1916

Displacement:
 40,755 t light; 42,597 t standard; 46,800 t normal; 50,162 t full load

Dimensions: Length overall / water x beam x draught
 767.17 ft / 765.00 ft x 102.00 ft x 32.00 ft (normal load)
 233.83 m / 233.17 m x 31.09 m  x 9.75 m

Armament:
      8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 8 raised mounts - superfiring
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 2 raised mounts
      12 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 17,837 lbs / 8,091 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 630.00 ft / 192.02 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 127 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 630.00 ft / 192.02 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 9.00" / 229 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, 169,734 shp / 126,621 Kw = 30.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 7,565 tons

Complement:
 1,590 - 2,068

Cost:
 £6.848 million / $27.390 million

Distribution of weights at normal displacement:
 Armament: 2,230 tons, 4.8 %
 Armour: 15,398 tons, 32.9 %
    - Belts: 4,855 tons, 10.4 %
    - Torpedo bulkhead: 2,168 tons, 4.6 %
    - Armament: 3,592 tons, 7.7 %
    - Armour Deck: 4,448 tons, 9.5 %
    - Conning Tower: 336 tons, 0.7 %
 Machinery: 6,324 tons, 13.5 %
 Hull, fittings & equipment: 16,803 tons, 35.9 %
 Fuel, ammunition & stores: 6,045 tons, 12.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   59,507 lbs / 26,992 Kg = 29.1 x 16.0 " / 406 mm shells or 8.8 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 6.5 ft / 2.0 m
 Roll period: 16.8 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.656
 Length to Beam Ratio: 7.50 : 1
 'Natural speed' for length: 27.66 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (67 %):  27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break)
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 24.68 ft / 7.52 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 99.2 %
  - Above water (accommodation/working, high = better): 178.5 %
 Waterplane Area: 60,105 Square feet or 5,584 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 197 lbs/sq ft or 964 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.29
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/CB/1914 battlecruiser design

The J/CB/1914 battlecruiser design is analogous to the J/BB/1914, except the battlecruiser version. One turret was sacrificed, but the armament is still 10-14in guns, as 8-14in is too light for such a large ship. Post 1918, "in the real world", they planned battlecruisers with 10-16in guns, so five turrets is not unprecedented for Japanese battlecruisers. The speed is rather low at 28 knots, but we can improve on that in later versions. This is the Springsharp report:

J/CB/1914, Japan Battlecruiser laid down 1914

Displacement:
 31,787 t light; 33,301 t standard; 37,200 t normal; 40,319 t full load

Dimensions: Length overall / water x beam x draught
 707.03 ft / 705.00 ft x 102.00 ft x 31.00 ft (normal load)
 215.50 m / 214.88 m x 31.09 m  x 9.45 m

Armament:
      10 - 14.00" / 356 mm guns (5x2 guns), 1,372.00lbs / 622.33kg shells, 1914 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1914 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 8 raised mounts - superfiring
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
      8 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1914 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 15,123 lbs / 6,860 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 590.00 ft / 179.83 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 129 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 590.00 ft / 179.83 m 30.00 ft / 9.14 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 8.00" / 203 mm  10.0" / 254 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 113,280 shp / 84,507 Kw = 28.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 7,018 tons

Complement:
 1,339 - 1,741

Cost:
 £4.215 million / $16.858 million

Distribution of weights at normal displacement:
 Armament: 1,890 tons, 5.1 %
 Armour: 11,664 tons, 31.4 %
    - Belts: 4,121 tons, 11.1 %
    - Torpedo bulkhead: 1,310 tons, 3.5 %
    - Armament: 3,094 tons, 8.3 %
    - Armour Deck: 2,876 tons, 7.7 %
    - Conning Tower: 264 tons, 0.7 %
 Machinery: 4,364 tons, 11.7 %
 Hull, fittings & equipment: 13,869 tons, 37.3 %
 Fuel, ammunition & stores: 5,413 tons, 14.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   50,666 lbs / 22,982 Kg = 36.9 x 14.0 " / 356 mm shells or 7.7 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 6.6 ft / 2.0 m
 Roll period: 16.7 seconds
 Steadiness - As gun platform (Average = 50 %): 61 %
   - Recoil effect (Restricted arc if above 1.00): 0.65
 Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.584
 Length to Beam Ratio: 6.91 : 1
 'Natural speed' for length: 26.55 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.00 ft / 8.84 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (67 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 23.60 ft / 7.19 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 95.0 %
  - Above water (accommodation/working, high = better): 175.3 %
 Waterplane Area: 51,815 Square feet or 4,814 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 189 lbs/sq ft or 924 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.47
  - 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

Super ship: J/BB/1941

The J/BB/1941 is really a super ship. It has 8-21in guns and has a speed of 30 knots with a 12,000nm range at 15 knots. The armour basis is only 18in, but that is probably adequate. I had thought that I would just move to 8-20in guns, but it was possible to move to the 21in caliber, so I did. This is the Springsharp report:

J/BB/1941, Japan Battleship laid down 1941

Displacement:
 84,147 t light; 88,067 t standard; 93,800 t normal; 98,386 t full load

Dimensions: Length overall / water x beam x draught
 934.68 ft / 928.00 ft x 129.00 ft x 35.00 ft (normal load)
 284.89 m / 282.85 m x 39.32 m  x 10.67 m

Armament:
      8 - 21.00" / 533 mm guns (4x2 guns), 4,630.50lbs / 2,100.36kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1941 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      64 - 2.24" / 57.0 mm guns (32x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 40,202 lbs / 18,235 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 18.0" / 457 mm 650.00 ft / 198.12 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 650.00 ft / 198.12 m 8.00 ft / 2.44 m
   Main Belt covers 108 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 650.00 ft / 198.12 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 18.0" / 457 mm 13.0" / 330 mm  18.0" / 457 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 18.00" / 457 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 258,205 shp / 192,621 Kw = 30.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,319 tons

Complement:
 2,679 - 3,483

Cost:
 £50.206 million / $200.826 million

Distribution of weights at normal displacement:
 Armament: 5,025 tons, 5.4 %
 Armour: 38,353 tons, 40.9 %
    - Belts: 7,198 tons, 7.7 %
    - Torpedo bulkhead: 6,542 tons, 7.0 %
    - Armament: 8,542 tons, 9.1 %
    - Armour Deck: 15,271 tons, 16.3 %
    - Conning Tower: 801 tons, 0.9 %
 Machinery: 6,824 tons, 7.3 %
 Hull, fittings & equipment: 33,946 tons, 36.2 %
 Fuel, ammunition & stores: 9,653 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   144,681 lbs / 65,626 Kg = 31.2 x 21.0 " / 533 mm shells or 30.9 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 9.0 ft / 2.7 m
 Roll period: 18.1 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.77
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.784
 Length to Beam Ratio: 7.19 : 1
 'Natural speed' for length: 30.46 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (67 %):  28.00 ft / 8.53 m
    - Quarterdeck (15 %): 28.00 ft / 8.53 m
    - Stern:  28.00 ft / 8.53 m
    - Average freeboard: 28.56 ft / 8.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 75.9 %
  - Above water (accommodation/working, high = better): 205.4 %
 Waterplane Area: 103,180 Square feet or 9,586 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 249 lbs/sq ft or 1,216 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.13
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The J/BB/1937 design

The J/BB/1937 design is rather like some of the "what if" designs that I have seen, such as at Alt Naval. This design escalates things further by going with 12-18in guns in triple turrets. The armour basis is expanded to 18in with an 8in torpedo bulkhead. This is a supership, in that it has such positives characteristics. Springsharp seems to have nothing bad to say about this design. This is the report:

J/BB/1937, Japan Battleship laid down 1937

Displacement:
 82,462 t light; 86,245 t standard; 92,100 t normal; 96,784 t full load

Dimensions: Length overall / water x beam x draught
 922.30 ft / 915.00 ft x 128.00 ft x 35.00 ft (normal load)
 281.12 m / 278.89 m x 39.01 m  x 10.67 m

Armament:
      12 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      64 - 2.24" / 57.0 mm guns (32x2 guns), 5.65lbs / 2.56kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 38,150 lbs / 17,304 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 18.0" / 457 mm 650.00 ft / 198.12 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 650.00 ft / 198.12 m 8.00 ft / 2.44 m
   Main Belt covers 109 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 650.00 ft / 198.12 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 18.0" / 457 mm 13.0" / 330 mm  18.0" / 457 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 18.00" / 457 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 256,964 shp / 191,695 Kw = 30.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,538 tons

Complement:
 2,642 - 3,436

Cost:
 £43.031 million / $172.123 million

Distribution of weights at normal displacement:
 Armament: 4,769 tons, 5.2 %
 Armour: 38,083 tons, 41.3 %
    - Belts: 7,181 tons, 7.8 %
    - Torpedo bulkhead: 6,542 tons, 7.1 %
    - Armament: 8,594 tons, 9.3 %
    - Armour Deck: 14,976 tons, 16.3 %
    - Conning Tower: 791 tons, 0.9 %
 Machinery: 7,122 tons, 7.7 %
 Hull, fittings & equipment: 32,489 tons, 35.3 %
 Fuel, ammunition & stores: 9,638 tons, 10.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   143,042 lbs / 64,883 Kg = 49.1 x 18.0 " / 457 mm shells or 30.4 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 9.1 ft / 2.8 m
 Roll period: 17.8 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.71
 Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.786
 Length to Beam Ratio: 7.15 : 1
 'Natural speed' for length: 30.25 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 7.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (67 %):  28.00 ft / 8.53 m
    - Quarterdeck (15 %): 28.00 ft / 8.53 m
    - Stern:  28.00 ft / 8.53 m
    - Average freeboard: 28.56 ft / 8.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 76.2 %
  - Above water (accommodation/working, high = better): 204.3 %
 Waterplane Area: 101,187 Square feet or 9,401 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 243 lbs/sq ft or 1,184 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.15
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The J/BB/1933 design almost seems too capable

The J/BB/1933 design is so capable, that it almost seems to be unrealistic. You have an armament of 10-18in BLR, 12-6in QG, 20-5in DP, and 56-57mm AA guns. The speed is 30 knots with a range of 12,000nm at 15 knots. The armour basis is 17in with 8in deck and a 7in torpedo bulkhead. This is the Springsharp report:

J/BB/1933, Japan Battleship laid down 1933

Displacement:
 76,740 t light; 80,090 t standard; 85,900 t normal; 90,548 t full load

Dimensions: Length overall / water x beam x draught
 900.57 ft / 895.00 ft x 127.00 ft x 34.00 ft (normal load)
 274.49 m / 272.80 m x 38.71 m  x 10.36 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1933 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1933 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      20 - 5.00" / 127 mm guns (10x2 guns), 62.50lbs / 28.35kg shells, 1933 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      56 - 2.24" / 57.0 mm guns (28x2 guns), 5.65lbs / 2.56kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 32,022 lbs / 14,525 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 17.0" / 432 mm 640.00 ft / 195.07 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 640.00 ft / 195.07 m 8.00 ft / 2.44 m
   Main Belt covers 110 % of normal length

   - Torpedo Bulkhead:
  7.00" / 178 mm 640.00 ft / 195.07 m 33.00 ft / 10.06 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 17.0" / 432 mm 13.0" / 330 mm  17.0" / 432 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 17.00" / 432 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 248,345 shp / 185,266 Kw = 30.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,459 tons

Complement:
 2,508 - 3,261

Cost:
 £33.381 million / $133.523 million

Distribution of weights at normal displacement:
 Armament: 4,003 tons, 4.7 %
 Armour: 35,561 tons, 41.4 %
    - Belts: 6,822 tons, 7.9 %
    - Torpedo bulkhead: 5,470 tons, 6.4 %
    - Armament: 8,125 tons, 9.5 %
    - Armour Deck: 14,431 tons, 16.8 %
    - Conning Tower: 713 tons, 0.8 %
 Machinery: 7,236 tons, 8.4 %
 Hull, fittings & equipment: 29,940 tons, 34.9 %
 Fuel, ammunition & stores: 9,160 tons, 10.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   137,151 lbs / 62,211 Kg = 47.0 x 18.0 " / 457 mm shells or 28.9 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 9.2 ft / 2.8 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.778
 Length to Beam Ratio: 7.05 : 1
 'Natural speed' for length: 29.92 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  34.00 ft / 10.36 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (67 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.56 ft / 8.40 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 74.5 %
  - Above water (accommodation/working, high = better): 199.9 %
 Waterplane Area: 97,505 Square feet or 9,059 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 234 lbs/sq ft or 1,141 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.12
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

The J/BB/1927 Design: a ship that finally has adequate protection

The size needed to balloon considerably, but the J/BB/1927 design finally has adequate protection against gunfire, unlike its predecessors. Having a 6in secondary battery is rather a retrograde move, but is historically accurate. The tertiary armament now has 5in DP guns in twin mounts. I am using the odd 57mm AA guns, which is not historically accurate. This is the Springsharp report:

J/BB/1927, Japan Battleship laid down 1927

Displacement:
 70,439 t light; 73,605 t standard; 78,500 t normal; 82,416 t full load

Dimensions: Length overall / water x beam x draught
 900.57 ft / 895.00 ft x 122.00 ft x 33.00 ft (normal load)
 274.49 m / 272.80 m x 37.19 m  x 10.06 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1927 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
      42 - 2.24" / 57.0 mm guns (21x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 31,443 lbs / 14,262 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 16.0" / 406 mm 640.00 ft / 195.07 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 640.00 ft / 195.07 m 8.00 ft / 2.44 m
   Main Belt covers 110 % of normal length

   - Torpedo Bulkhead:
  5.00" / 127 mm 640.00 ft / 195.07 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 12.0" / 305 mm  16.0" / 406 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 16.00" / 406 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 232,185 shp / 173,210 Kw = 30.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 8,811 tons

Complement:
 2,344 - 3,048

Cost:
 £24.702 million / $98.807 million

Distribution of weights at normal displacement:
 Armament: 3,930 tons, 5.0 %
 Armour: 30,600 tons, 39.0 %
    - Belts: 6,547 tons, 8.3 %
    - Torpedo bulkhead: 3,789 tons, 4.8 %
    - Armament: 7,661 tons, 9.8 %
    - Armour Deck: 11,971 tons, 15.2 %
    - Conning Tower: 632 tons, 0.8 %
 Machinery: 7,329 tons, 9.3 %
 Hull, fittings & equipment: 28,580 tons, 36.4 %
 Fuel, ammunition & stores: 8,061 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   115,996 lbs / 52,615 Kg = 39.8 x 18.0 " / 457 mm shells or 20.8 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 8.3 ft / 2.5 m
 Roll period: 17.8 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.71
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.763
 Length to Beam Ratio: 7.34 : 1
 'Natural speed' for length: 29.92 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  34.00 ft / 10.36 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (67 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.56 ft / 8.40 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 81.5 %
  - Above water (accommodation/working, high = better): 202.8 %
 Waterplane Area: 92,439 Square feet or 8,588 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 233 lbs/sq ft or 1,136 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.09
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent