The F/BB/1923 design

The main improvements in the F/BB/1923 design are the 29 knot speed and the main armament now being 9-16.5in guns in triple turrets. The freeboard is a foot higher, and this ship is not wet forward. The protection against gunfire seems adequate, while the underwater protection is above-average (if it will take 11 torpedoes, that is how I would rate the design). The AA armament is sub-standard, but in 1923, it matters little. This is the Springsharp report:

F/BB/1923, France Battleship laid down 1923

Displacement:
 47,998 t light; 50,041 t standard; 53,000 t normal; 55,367 t full load

Dimensions: Length overall / water x beam x draught
 789.71 ft / 785.00 ft x 108.00 ft x 33.00 ft (normal load)
 240.70 m / 239.27 m x 32.92 m  x 10.06 m

Armament:
      9 - 16.54" / 420 mm guns (3x3 guns), 2,260.56lbs / 1,025.37kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 5.51" / 140 mm guns (8x2 guns), 83.72lbs / 37.98kg shells, 1923 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, all raised mounts - superfiring
      4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 21,824 lbs / 9,899 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 550.00 ft / 167.64 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 195.00 ft / 59.44 m 12.00 ft / 3.66 m
   40.00 ft / 12.19 m Unarmoured ends
   Main Belt covers 108 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 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: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 159,715 shp / 119,147 Kw = 29.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 5,327 tons

Complement:
 1,746 - 2,270

Cost:
 £13.727 million / $54.910 million

Distribution of weights at normal displacement:
 Armament: 2,728 tons, 5.1 %
 Armour: 20,003 tons, 37.7 %
    - Belts: 5,688 tons, 10.7 %
    - Torpedo bulkhead: 1,832 tons, 3.5 %
    - Armament: 4,763 tons, 9.0 %
    - Armour Deck: 7,295 tons, 13.8 %
    - Conning Tower: 426 tons, 0.8 %
 Machinery: 5,338 tons, 10.1 %
 Hull, fittings & equipment: 19,928 tons, 37.6 %
 Fuel, ammunition & stores: 5,002 tons, 9.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   72,365 lbs / 32,824 Kg = 32.0 x 16.5 " / 420 mm shells or 11.2 torpedoes
 Stability (Unstable if below 1.00): 1.07
 Metacentric height 6.4 ft / 2.0 m
 Roll period: 17.9 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.663
 Length to Beam Ratio: 7.27 : 1
 'Natural speed' for length: 28.02 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 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): 87.5 %
  - Above water (accommodation/working, high = better): 177.7 %
 Waterplane Area: 65,725 Square feet or 6,106 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 218 lbs/sq ft or 1,065 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 drawings at Alt Naval are quite good (Corrected)

Roger, who handles Greece at Wesworld (says Gavin), has some good drawings on his Alt Naval site for the Japanese navy alternate history portion of his site. They are really top quality, and I am impressed. i have tried my hand at this, and it is not easy, although if you work at a large enough scale, it is easier. The main challenge is how to follow scale measurements, and to know the correct size to make things. Gavin, who is the Red Admiral at Wesworld, corrected my misunderstanding.

The French battleship design F/BB/1921

Blogger was down last night, so I am posting this today, instead of yesterday. The next logical step seemed to be to move to a larger caliber gun for French battleships. We are designing ships as if the Washington Naval Treaty didn't exist, so we can go larger and have larger guns than was the case in "real life". This design has 8-16.5in guns in quadruple turrets, 16-5.5in QF guns in twin turrets, and the usual AA armament. The speed is now 28 knots with a range of 7.500nm at 15 knots. The armour basis is 14 inches with a 6 inch deck. This is the Springsharp report:

F/BB/1921, France Battleship laid down 1921

Displacement:
 42,864 t light; 44,697 t standard; 47,500 t normal; 49,743 t full load

Dimensions: Length overall / water x beam x draught
 749.03 ft / 745.00 ft x 102.00 ft x 33.00 ft (normal load)
 228.30 m / 227.08 m x 31.09 m  x 10.06 m

Armament:
      8 - 16.54" / 420 mm guns (2x4 guns), 2,260.56lbs / 1,025.37kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount
      16 - 5.51" / 140 mm guns (8x2 guns), 83.72lbs / 37.98kg shells, 1921 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, all raised mounts - superfiring
      4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 19,564 lbs / 8,874 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 550.00 ft / 167.64 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 195.00 ft / 59.44 m 12.00 ft / 3.66 m
   Main Belt covers 114 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 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: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 131,943 shp / 98,430 Kw = 28.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 5,046 tons

Complement:
 1,608 - 2,091

Cost:
 £10.667 million / $42.667 million

Distribution of weights at normal displacement:
 Armament: 2,445 tons, 5.1 %
 Armour: 17,927 tons, 37.7 %
    - Belts: 5,632 tons, 11.9 %
    - Torpedo bulkhead: 1,832 tons, 3.9 %
    - Armament: 3,529 tons, 7.4 %
    - Armour Deck: 6,539 tons, 13.8 %
    - Conning Tower: 396 tons, 0.8 %
 Machinery: 4,544 tons, 9.6 %
 Hull, fittings & equipment: 17,948 tons, 37.8 %
 Fuel, ammunition & stores: 4,636 tons, 9.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   64,308 lbs / 29,169 Kg = 28.4 x 16.5 " / 420 mm shells or 10.2 torpedoes
 Stability (Unstable if below 1.00): 1.06
 Metacentric height 5.7 ft / 1.7 m
 Roll period: 17.9 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.88
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.663
 Length to Beam Ratio: 7.30 : 1
 'Natural speed' for length: 27.29 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): 86.7 %
  - Above water (accommodation/working, high = better): 166.0 %
 Waterplane Area: 58,907 Square feet or 5,473 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 216 lbs/sq ft or 1,054 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.40
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Brasseys for 1919, 1920, and 1921

If you are interested in the ships planned but not built due to the Washington Naval Treaty, the 1919, 1920, and 1921 Brassey's Naval Annual volumes are a "must read". One of the features that I particularly was interested in was the lists of guns that were either planned or under develpment by the various nations. If nothing else, you can see the manifestation of what information made its way into the public eye, whether it was correct or not. Copies, when found, are often over $100 (US).

The F/BB/1918 design is a much better ship

The F/BB/1918 design is vastly superior to its predecessor. The main armament now consists of 8-40cm guns (15.75in) in quadruple turrets, on forward and one aft. The armour basis was increased to 14in, with a 5in deck. The speed was increased to 27 knots and the range to 7,500nm at 15 knots. Also, the Springsharp entries are more complete, and more attention was paid to some important details (sadly, the last designs were not so complete). This is the Springsharp report:

F/BB/1918, France Battleship laid down 1918

Displacement:
 35,708 t light; 37,281 t standard; 40,000 t normal; 42,175 t full load

Dimensions: Length overall / water x beam x draught
 685.00 ft / 685.00 ft x 98.00 ft x 31.00 ft (normal load)
 208.79 m / 208.79 m x 29.87 m  x 9.45 m

Armament:
      8 - 15.75" / 400 mm guns (2x4 guns), 1,952.76lbs / 885.76kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount
      16 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, all raised mounts - superfiring
      4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 17,101 lbs / 7,757 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 520.00 ft / 158.50 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 165.00 ft / 50.29 m 12.00 ft / 3.66 m
   Main Belt covers 117 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 520.00 ft / 158.50 m 30.00 ft / 9.14 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: 5.00" / 127 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 107,116 shp / 79,909 Kw = 27.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 4,894 tons

Complement:
 1,413 - 1,838

Cost:
 £7.173 million / $28.691 million

Distribution of weights at normal displacement:
 Armament: 2,138 tons, 5.3 %
 Armour: 14,904 tons, 37.3 %
    - Belts: 5,276 tons, 13.2 %
    - Torpedo bulkhead: 1,732 tons, 4.3 %
    - Armament: 2,687 tons, 6.7 %
    - Armour Deck: 4,857 tons, 12.1 %
    - Conning Tower: 353 tons, 0.9 %
 Machinery: 3,864 tons, 9.7 %
 Hull, fittings & equipment: 14,802 tons, 37.0 %
 Fuel, ammunition & stores: 4,292 tons, 10.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   54,648 lbs / 24,788 Kg = 28.0 x 15.7 " / 400 mm shells or 8.7 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 5.9 ft / 1.8 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.673
 Length to Beam Ratio: 6.99 : 1
 'Natural speed' for length: 26.17 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  28.00 ft / 8.53 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (67 %):  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: 22.60 ft / 6.89 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 89.7 %
  - Above water (accommodation/working, high = better): 161.3 %
 Waterplane Area: 52,503 Square feet or 4,878 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 201 lbs/sq ft or 983 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.49
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The French F/BB/1916 battleship design

Compared to some of the other designs that I have produced for this date, this seems to be an under-achiever, although it seems reasonable, given contemporary French ideas. I was able to raise the speed to 25 knots, and the armament to 16-13.4in guns (34cm). The design seems very suitable for Mediterranean naval warfare. Ships with this armament were actually planned. Perhaps the caliber should have been increased to 14.6in, but that will have to wait, if it happens at all. This is the Springsharp report:

F/BB/1916, France Battleship laid down 1916

Displacement:
 30,831 t light; 31,507 t standard; 33,800 t normal; 35,635 t full load

Dimensions: Length overall / water x beam x draught
 635.00 ft / 635.00 ft x 95.00 ft x 30.00 ft (normal load)
 193.55 m / 193.55 m x 28.96 m  x 9.14 m

Armament:
      16 - 13.39" / 340 mm guns (4x4 guns), 1,199.24lbs / 543.97kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, evenly spread, 1 raised mount
   Main guns limited to end-on fire
   Aft Main mounts separated by engine room
      16 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, all raised mounts - superfiring
      4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 20,667 lbs / 9,374 kg
 Shells per gun, main battery: 0

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 480.00 ft / 146.30 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 110.00 ft / 33.53 m 12.00 ft / 3.66 m
   45.00 ft / 13.72 m Unarmoured ends
   Main Belt covers 116 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 480.00 ft / 146.30 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 9.00" / 229 mm  13.0" / 330 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 73,019 shp / 54,472 Kw = 25.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,128 tons

Complement:
 1,246 - 1,620

Cost:
 £5.940 million / $23.760 million

Distribution of weights at normal displacement:
 Armament: 2,583 tons, 7.6 %
 Armour: 12,077 tons, 35.7 %
    - Belts: 4,468 tons, 13.2 %
    - Torpedo bulkhead: 959 tons, 2.8 %
    - Armament: 3,784 tons, 11.2 %
    - Armour Deck: 2,573 tons, 7.6 %
    - Conning Tower: 293 tons, 0.9 %
 Machinery: 2,721 tons, 8.0 %
 Hull, fittings & equipment: 13,450 tons, 39.8 %
 Fuel, ammunition & stores: 2,969 tons, 8.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   39,754 lbs / 18,032 Kg = 33.1 x 13.4 " / 340 mm shells or 5.9 torpedoes
 Stability (Unstable if below 1.00): 1.03
 Metacentric height 4.9 ft / 1.5 m
 Roll period: 18.1 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 1.09
 Seaboat quality  (Average = 1.00): 1.14

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.654
 Length to Beam Ratio: 6.68 : 1
 'Natural speed' for length: 25.20 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  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: 21.60 ft / 6.58 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 101.1 %
  - Above water (accommodation/working, high = better): 154.4 %
 Waterplane Area: 46,369 Square feet or 4,308 Square metres
 Displacement factor (Displacement / loading): 89 %
 Structure weight / hull surface area: 207 lbs/sq ft or 1,010 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.57
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

The J/DD/1941 is disappointing

I had hoped that the J/DD/1941 could have a speed of 36 knots, but the cost is too great. Springsharp continues to be a problem because the power required is greater than it should be. I had to be content to raise the range to 7,200nm at 15 knots. This is the Springsharp report:

J/DD/1941, Japan Destroyer laid down 1941 (Engine 1950)

Displacement:
 1,980 t light; 2,061 t standard; 2,390 t normal; 2,653 t full load

Dimensions: Length overall / water x beam x draught
 377.36 ft / 375.00 ft x 36.00 ft x 13.00 ft (normal load)
 115.02 m / 114.30 m x 10.97 m  x 3.96 m

Armament:
      6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 465 lbs / 211 kg
 Shells per gun, main battery: 120
 10 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 62,044 shp / 46,285 Kw = 35.00 kts
 Range 7,200nm at 15.00 kts
 Bunker at max displacement = 592 tons

Complement:
 170 - 222

Cost:
 £1.794 million / $7.174 million

Distribution of weights at normal displacement:
 Armament: 58 tons, 2.4 %
 Machinery: 1,228 tons, 51.4 %
 Hull, fittings & equipment: 693 tons, 29.0 %
 Fuel, ammunition & stores: 410 tons, 17.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   592 lbs / 269 Kg = 9.5 x 5.0 " / 127 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.33
 Metacentric height 1.8 ft / 0.5 m
 Roll period: 11.3 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak, raised quarterdeck 
 Block coefficient: 0.477
 Length to Beam Ratio: 10.42 : 1
 'Natural speed' for length: 19.36 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (37 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m (14.00 ft / 4.27 m before break)
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 17.96 ft / 5.47 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 184.2 %
  - Above water (accommodation/working, high = better): 55.0 %
 Waterplane Area: 8,809 Square feet or 818 Square metres
 Displacement factor (Displacement / loading): 70 %
 Structure weight / hull surface area: 36 lbs/sq ft or 173 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.44
  - Longitudinal: 2.58
  - Overall: 0.53
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

The J/DD/1937 design

The J/DD/1937 design is a more substantial ship than her predecessors. The normal displacement is now 2,300 tons. The range is extended to 6,000nm at 15 knots. The maximum speed and main armament are unchanged. 35 knots is about all that is feasible with Springsharp in its present state where it overstates the power needed for smaller ships. This is the Springsharp report:

J/DD/1937, Japan Destroyer laid down 1937 (Engine 1945)

Displacement:
 1,939 t light; 2,019 t standard; 2,300 t normal; 2,525 t full load

Dimensions: Length overall / water x beam x draught
 372.36 ft / 370.00 ft x 35.00 ft x 13.00 ft (normal load)
 113.50 m / 112.78 m x 10.67 m  x 3.96 m

Armament:
      6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 465 lbs / 211 kg
 Shells per gun, main battery: 120
 10 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 60,930 shp / 45,454 Kw = 35.00 kts
 Range 6,000nm at 15.00 kts
 Bunker at max displacement = 506 tons

Complement:
 165 - 215

Cost:
 £1.567 million / $6.269 million

Distribution of weights at normal displacement:
 Armament: 58 tons, 2.5 %
 Machinery: 1,219 tons, 53.0 %
 Hull, fittings & equipment: 663 tons, 28.8 %
 Fuel, ammunition & stores: 361 tons, 15.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   515 lbs / 234 Kg = 8.2 x 5.0 " / 127 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.29
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 11.5 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.64
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak, raised quarterdeck 
 Block coefficient: 0.478
 Length to Beam Ratio: 10.57 : 1
 'Natural speed' for length: 19.24 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (37 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m (14.00 ft / 4.27 m before break)
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 17.96 ft / 5.47 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 190.0 %
  - Above water (accommodation/working, high = better): 49.8 %
 Waterplane Area: 8,461 Square feet or 786 Square metres
 Displacement factor (Displacement / loading): 65 %
 Structure weight / hull surface area: 34 lbs/sq ft or 167 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.72
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is extremely poor

The J/DD/1933 design

The J/DD/1933 design is larger, has dual-purpose 5in guns and 10-24in TT. The range is increased to 5,400nm at 15 knots. Admittedly, this is not trying to much different than the real Japanese destroyers. This is the Springsharp report:

J/DD/1933, Japan Destroyer laid down 1933 (Engine 1940)

Displacement:
 1,825 t light; 1,868 t standard; 2,120 t normal; 2,322 t full load

Dimensions: Length overall / water x beam x draught
 367.31 ft / 365.00 ft x 34.00 ft x 13.00 ft (normal load)
 111.96 m / 111.25 m x 10.36 m  x 3.96 m

Armament:
      6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1933 Model
   Dual purpose guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      12 - 2.24" / 57.0 mm guns (6x2 guns), 5.65lbs / 2.56kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 443 lbs / 201 kg
 Shells per gun, main battery: 0
 10 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 57,477 shp / 42,878 Kw = 35.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 454 tons

Complement:
 156 - 203

Cost:
 £1.282 million / $5.127 million

Distribution of weights at normal displacement:
 Armament: 55 tons, 2.6 %
 Machinery: 1,148 tons, 54.2 %
 Hull, fittings & equipment: 622 tons, 29.3 %
 Fuel, ammunition & stores: 295 tons, 13.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   450 lbs / 204 Kg = 7.2 x 5.0 " / 127 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 1.5 ft / 0.4 m
 Roll period: 11.8 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.69
 Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.460
 Length to Beam Ratio: 10.74 : 1
 'Natural speed' for length: 19.10 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 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 (37 %):  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: 17.20 ft / 5.24 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 192.8 %
  - Above water (accommodation/working, high = better): 43.1 %
 Waterplane Area: 7,982 Square feet or 742 Square metres
 Displacement factor (Displacement / loading): 60 %
 Structure weight / hull surface area: 34 lbs/sq ft or 167 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.61
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is extremely poor

The J/DD/1927 design

The J/DD/1927 design is a great improvement over its smaller predecessors. The armament is now 6-4.7in QF guns, in twin mounts, and 9-24in TT. The speed and range are the same as the 1921 design, 35 knots maximum speed with a 4,500nm range at 15 knots. This ship suffers from the fact that the Springsharp power calculation overstates what a destroyer would need to make particular speed. This is the Springsharp report:

J/DD/1927, Japan Destroyer laid down 1927 (Engine 1937)

Displacement:
 1,741 t light; 1,780 t standard; 1,990 t normal; 2,158 t full load

Dimensions: Length overall / water x beam x draught
 357.31 ft / 355.00 ft x 33.00 ft x 13.00 ft (normal load)
 108.91 m / 108.20 m x 10.06 m  x 3.96 m

Armament:
      6 - 4.70" / 119 mm guns (3x2 guns), 51.91lbs / 23.55kg shells, 1927 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1927 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships, 1 raised gun
      8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 2 raised mounts - superfiring
 Weight of broadside 370 lbs / 168 kg
 Shells per gun, main battery: 0
 9 - 24.0" / 609.6 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 56,041 shp / 41,806 Kw = 35.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 377 tons

Complement:
 148 - 193

Cost:
 £0.928 million / $3.712 million

Distribution of weights at normal displacement:
 Armament: 46 tons, 2.3 %
 Machinery: 1,110 tons, 55.8 %
 Hull, fittings & equipment: 584 tons, 29.4 %
 Fuel, ammunition & stores: 249 tons, 12.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   408 lbs / 185 Kg = 7.9 x 4.7 " / 119 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.25
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 11.7 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.66
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.457
 Length to Beam Ratio: 10.76 : 1
 'Natural speed' for length: 18.84 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 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 (37 %):  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: 17.20 ft / 5.24 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 196.0 %
  - Above water (accommodation/working, high = better): 48.0 %
 Waterplane Area: 7,518 Square feet or 698 Square metres
 Displacement factor (Displacement / loading): 57 %
 Structure weight / hull surface area: 33 lbs/sq ft or 160 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.90
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is extremely poor

The J/DD/1921 design

The J/DD/1921 design really indicates a problem with how Springsharp computes the speed and power for small ships. The real Japanese destroyers from 1918 to 1921 achieved much higher speeds with less power for similar dimensions and displacement. The J/DD/1921 is having to compensate for that by going to lighter weight machinery, because a power that is too high is required to reach only 35 knots. The J/DD/1921 design has a greater range than its predecessor, 4,500nm at 15 knots. Otherwise, the armament and overall design is the same. This is the Springsharp report:

J/DD/1921, Japan Destroyer laid down 1921 (Engine 1937)

Displacement:
 1,429 t light; 1,462 t standard; 1,650 t normal; 1,800 t full load

Dimensions: Length overall / water x beam x draught
 337.26 ft / 335.00 ft x 31.00 ft x 13.00 ft (normal load)
 102.80 m / 102.11 m x 9.45 m  x 3.96 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1921 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1921 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships, 1 raised gun
      8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 2 raised mounts - superfiring
 Weight of broadside 266 lbs / 121 kg
 Shells per gun, main battery: 0
 6 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 50,513 shp / 37,683 Kw = 35.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 338 tons

Complement:
 129 - 168

Cost:
 £0.528 million / $2.112 million

Distribution of weights at normal displacement:
 Armament: 33 tons, 2.0 %
 Machinery: 924 tons, 56.0 %
 Hull, fittings & equipment: 472 tons, 28.6 %
 Fuel, ammunition & stores: 221 tons, 13.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   348 lbs / 158 Kg = 6.7 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.39
 Metacentric height 1.5 ft / 0.5 m
 Roll period: 10.5 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.50
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.428
 Length to Beam Ratio: 10.81 : 1
 'Natural speed' for length: 18.30 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 21.00 ft / 6.40 m
    - Mid (37 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 16.20 ft / 4.94 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.6 %
  - Above water (accommodation/working, high = better): 87.3 %
 Waterplane Area: 6,511 Square feet or 605 Square metres
 Displacement factor (Displacement / loading): 54 %
 Structure weight / hull surface area: 30 lbs/sq ft or 146 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.41
  - Longitudinal: 2.97
  - Overall: 0.50
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

The J/DD/1918 design

The J/DD/1918 design doesn't seem to have a lot to commend it. The armament is unimproved over its predecessor, except that the light AA armament is now 8-57mm. The speed is now 34 knots, which was expensive, and the range is 3,750nm at 15 knots. For a 1918 ship, I was not willing to pay more in size to achieve a better design. This is the Springsharp report:

J/DD/1918, Japan Destroyer laid down 1918 (Engine 1927)

Displacement:
 1,416 t light; 1,449 t standard; 1,620 t normal; 1,757 t full load

Dimensions: Length overall / water x beam x draught
 327.26 ft / 325.00 ft x 32.00 ft x 13.00 ft (normal load)
 99.75 m / 99.06 m x 9.75 m  x 3.96 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1918 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships, 1 raised gun
      8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 2 raised mounts - superfiring
 Weight of broadside 266 lbs / 121 kg
 Shells per gun, main battery: 0
 6 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 45,088 shp / 33,636 Kw = 34.00 kts
 Range 3,750nm at 15.00 kts
 Bunker at max displacement = 308 tons

Complement:
 126 - 165

Cost:
 £0.411 million / $1.645 million

Distribution of weights at normal displacement:
 Armament: 33 tons, 2.1 %
 Machinery: 915 tons, 56.5 %
 Hull, fittings & equipment: 468 tons, 28.9 %
 Fuel, ammunition & stores: 204 tons, 12.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   351 lbs / 159 Kg = 6.8 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.41
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 10.5 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.46
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.419
 Length to Beam Ratio: 10.16 : 1
 'Natural speed' for length: 18.03 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 21.00 ft / 6.40 m
    - Mid (37 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 16.20 ft / 4.94 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 196.4 %
  - Above water (accommodation/working, high = better): 89.1 %
 Waterplane Area: 6,481 Square feet or 602 Square metres
 Displacement factor (Displacement / loading): 52 %
 Structure weight / hull surface area: 31 lbs/sq ft or 150 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.42
  - Longitudinal: 3.05
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

The J/DD/1916 design

The J/DD/1916 design has a higher speed, although only 33 knots, and a faster cruising speed, so that the range is now 3,500nm at 15 knots. The armament was increased with two more torpedo tubes, so that the armament is 4-4.7in QF guns, 1-3in AA, and 2-57mm AA guns, and 6-21in TT. This is the Springsharp report:

J/DD/1916, Japan Destroyer laid down 1916 (Engine 1921)

Displacement:
 1,207 t light; 1,234 t standard; 1,390 t normal; 1,515 t full load

Dimensions: Length overall / water x beam x draught
 310.21 ft / 308.00 ft x 31.00 ft x 12.00 ft (normal load)
 94.55 m / 93.88 m x 9.45 m  x 3.66 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships, 1 raised gun
      4 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 244 lbs / 111 kg
 Shells per gun, main battery: 0
 6 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 37,386 shp / 27,890 Kw = 33.00 kts
 Range 3,500nm at 15.00 kts
 Bunker at max displacement = 280 tons

Complement:
 113 - 147

Cost:
 £0.288 million / $1.152 million

Distribution of weights at normal displacement:
 Armament: 30 tons, 2.2 %
 Machinery: 773 tons, 55.6 %
 Hull, fittings & equipment: 403 tons, 29.0 %
 Fuel, ammunition & stores: 183 tons, 13.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   310 lbs / 141 Kg = 6.0 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.40
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 10.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.46
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.425
 Length to Beam Ratio: 9.94 : 1
 'Natural speed' for length: 17.55 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 20.00 ft / 6.10 m
    - Mid (37 %):  20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break)
    - Quarterdeck (15 %): 12.00 ft / 3.66 m
    - Stern:  12.00 ft / 3.66 m
    - Average freeboard: 15.20 ft / 4.63 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.5 %
  - Above water (accommodation/working, high = better): 80.4 %
 Waterplane Area: 5,972 Square feet or 555 Square metres
 Displacement factor (Displacement / loading): 49 %
 Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.83
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

The J/DD/1914 design

The J/DD/1914 design is very conservative for a large destroyer designed in 1914. The design worked immediately in Springsharp, although I tweaked the design so that I could add an AA armament. The design has a gun armament of 4-4.7in QF, 1-3in AA, and 4-57mm AA. The torpedo armament is 4-21in TT. The speed is a conservative 32 knots. This is the Springsharp report:

J/DD/1914, Japan Destroyer laid down 1914

Displacement:
 1,050 t light; 1,074 t standard; 1,180 t normal; 1,265 t full load

Dimensions: Length overall / water x beam x draught
 299.15 ft / 297.00 ft x 30.00 ft x 10.00 ft (normal load)
 91.18 m / 90.53 m x 9.14 m  x 3.05 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships, 1 raised gun
      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, all raised mounts - superfiring
 Weight of broadside 244 lbs / 111 kg
 Shells per gun, main battery: 0
 4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 30,954 shp / 23,091 Kw = 32.00 kts
 Range 3,500nm at 12.00 kts
 Bunker at max displacement = 191 tons

Complement:
 99 - 130

Cost:
 £0.195 million / $0.778 million

Distribution of weights at normal displacement:
 Armament: 30 tons, 2.6 %
 Machinery: 647 tons, 54.8 %
 Hull, fittings & equipment: 373 tons, 31.6 %
 Fuel, ammunition & stores: 130 tons, 11.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   288 lbs / 131 Kg = 5.5 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.35
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 10.7 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.59
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.464
 Length to Beam Ratio: 9.90 : 1
 'Natural speed' for length: 17.23 kts
 Power going to wave formation at top speed: 71 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 1.00 ft / 0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m (11.00 ft / 3.35 m aft of break)
    - Quarterdeck (15 %): 11.00 ft / 3.35 m
    - Stern:  11.00 ft / 3.35 m
    - Average freeboard: 15.24 ft / 4.65 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.6 %
  - Above water (accommodation/working, high = better): 112.2 %
 Waterplane Area: 5,748 Square feet or 534 Square metres
 Displacement factor (Displacement / loading): 45 %
 Structure weight / hull surface area: 29 lbs/sq ft or 142 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 3.06
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

The (online) International Journal of Naval History

The International Journal of Naval History has been around long enough that the first issue was published in 2002. If I have seen the journal previously, I had forgotten, but it seems worth a read, as they lastest issue, from December 2005, has a good article about the American monitor Miantonomoh visiting Britain in the summer of 1866. Particularly interesting were the pictures in the PowerPoint presentation (best seen with a PowerPoint reader, not OpenOffice) (Photo Gallery).

The J/CL/1941 light cruiser design

The J/CL/1941 light cruiser design now has 15-6.1in QF guns, 12-5in DP, and 48-57mm AA guns in twin mounts. The torpedo armament has stayed at 8-24in TT. The speed is 37 knots, so the design is the embodiment of the original Mogami design, except that much more is required to achieve that then the original, too small displacement (to have been 8,500 tons standard). My main criticism of this design is that the armour basis is too light at 3in with a 2in deck. The roll period is now a very good 14.1 seconds and with the seakeeping ability, the result is a good, fast ship. The range might have been increased, but that would have required additional size. This is the Springsharp report:

J/CL/1941, Japan Light Cruiser laid down 1941 (Engine 1950)

Displacement:
 12,778 t light; 13,365 t standard; 14,400 t normal; 15,228 t full load

Dimensions: Length overall / water x beam x draught
 666.89 ft / 662.00 ft x 64.00 ft x 21.00 ft (normal load)
 203.27 m / 201.78 m x 19.51 m  x 6.40 m

Armament:
      15 - 6.10" / 155 mm guns (5x3 guns), 113.62lbs / 51.54kg shells, 1941 Model
   Quick firing 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, 12 raised mounts - superfiring
 Weight of broadside 2,726 lbs / 1,236 kg
 Shells per gun, main battery: 180
 8 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 110 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m

   - 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, 
 Geared drive, 4 shafts, 188,126 shp / 140,342 Kw = 37.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 1,862 tons

Complement:
 656 - 854

Cost:
 £8.429 million / $33.715 million

Distribution of weights at normal displacement:
 Armament: 341 tons, 2.4 %
 Armour: 1,925 tons, 13.4 %
    - Belts: 701 tons, 4.9 %
    - Torpedo bulkhead: 334 tons, 2.3 %
    - Armament: 296 tons, 2.1 %
    - Armour Deck: 556 tons, 3.9 %
    - Conning Tower: 38 tons, 0.3 %
 Machinery: 4,501 tons, 31.3 %
 Hull, fittings & equipment: 6,011 tons, 41.7 %
 Fuel, ammunition & stores: 1,622 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   13,566 lbs / 6,154 Kg = 119.4 x 6.1 " / 155 mm shells or 1.7 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.6 ft / 1.1 m
 Roll period: 14.1 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.566
 Length to Beam Ratio: 10.34 : 1
 'Natural speed' for length: 25.73 kts
 Power going to wave formation at top speed: 62 %
 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:  33.00 ft / 10.06 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: 24.84 ft / 7.57 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 174.8 %
  - Above water (accommodation/working, high = better): 179.4 %
 Waterplane Area: 30,029 Square feet or 2,790 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 116 lbs/sq ft or 567 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.71
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1937 design is a 37-knot ship

The only improvement in the J/CL/1937 design is that the maximum speed is now 37 knots. The other changes are more beam, a foot more draft, and a small increase in length, which improved seakeeping and lowered the power required for the extra knot. I considered increasing the main armament to 15-6.1in guns, but decided to defer that for the next interation. This is the Springsharp report:

J/CL/1937, Japan Light Cruiser laid down 1937 (Engine 1947)

Displacement:
 12,084 t light; 12,579 t standard; 13,600 t normal; 14,417 t full load

Dimensions: Length overall / water x beam x draught
 663.80 ft / 659.00 ft x 62.00 ft x 21.00 ft (normal load)
 202.33 m / 200.86 m x 18.90 m  x 6.40 m

Armament:
      12 - 6.10" / 155 mm guns (4x3 guns), 113.62lbs / 51.54kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      32 - 2.24" / 57.0 mm guns (16x2 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 2,044 lbs / 927 kg
 Shells per gun, main battery: 180
 8 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 111 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m

   - 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, 
 Geared drive, 4 shafts, 179,924 shp / 134,223 Kw = 37.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 1,839 tons

Complement:
 629 - 818

Cost:
 £6.872 million / $27.488 million

Distribution of weights at normal displacement:
 Armament: 256 tons, 1.9 %
 Armour: 1,839 tons, 13.5 %
    - Belts: 699 tons, 5.1 %
    - Torpedo bulkhead: 334 tons, 2.5 %
    - Armament: 239 tons, 1.8 %
    - Armour Deck: 530 tons, 3.9 %
    - Conning Tower: 37 tons, 0.3 %
 Machinery: 4,445 tons, 32.7 %
 Hull, fittings & equipment: 5,545 tons, 40.8 %
 Fuel, ammunition & stores: 1,516 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   12,534 lbs / 5,685 Kg = 110.3 x 6.1 " / 155 mm shells or 1.6 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): 0.49
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.555
 Length to Beam Ratio: 10.63 : 1
 'Natural speed' for length: 25.67 kts
 Power going to wave formation at top speed: 62 %
 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:  32.00 ft / 9.75 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: 23.84 ft / 7.27 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 178.6 %
  - Above water (accommodation/working, high = better): 169.9 %
 Waterplane Area: 28,642 Square feet or 2,661 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 112 lbs/sq ft or 546 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.62
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1933 is a great advancement

The J/CL/1937 design is much more capable than its immediate predecessor. The armament was greatly improved with four triple 6.1in turrets and 8-5in DP guns in twin mounts. The light AA armament was slightly increased, as well. The displacement was not much changed, as the normal displacement was 12,900 tons. The freeboard and beam were increased, and that improved the hull strength. That is sufficient for a 36-knot ships with a 7,500nm range at 15 knots. This is the Springsharp report:

J/CL/1933, Japan Light Cruiser laid down 1933 (Engine 1943)

Displacement:
 11,303 t light; 11,781 t standard; 12,800 t normal; 13,615 t full load

Dimensions: Length overall / water x beam x draught
 656.71 ft / 652.00 ft x 61.00 ft x 20.00 ft (normal load)
 200.17 m / 198.73 m x 18.59 m  x 6.10 m

Armament:
      12 - 6.10" / 155 mm guns (4x3 guns), 113.62lbs / 51.54kg shells, 1933 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1933 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      32 - 2.24" / 57.0 mm guns (16x2 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 2,044 lbs / 927 kg
 Shells per gun, main battery: 180
 8 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 112 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m

   - 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, 
 Geared drive, 4 shafts, 156,021 shp / 116,391 Kw = 36.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 1,833 tons

Complement:
 601 - 782

Cost:
 £5.552 million / $22.206 million

Distribution of weights at normal displacement:
 Armament: 256 tons, 2.0 %
 Armour: 1,820 tons, 14.2 %
    - Belts: 698 tons, 5.5 %
    - Torpedo bulkhead: 334 tons, 2.6 %
    - Armament: 233 tons, 1.8 %
    - Armour Deck: 520 tons, 4.1 %
    - Conning Tower: 35 tons, 0.3 %
 Machinery: 4,029 tons, 31.5 %
 Hull, fittings & equipment: 5,198 tons, 40.6 %
 Fuel, ammunition & stores: 1,497 tons, 11.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   12,433 lbs / 5,639 Kg = 109.4 x 6.1 " / 155 mm shells or 1.6 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 13.6 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.50
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.563
 Length to Beam Ratio: 10.69 : 1
 'Natural speed' for length: 25.53 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: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (67 %):  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: 22.84 ft / 6.96 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 175.6 %
  - Above water (accommodation/working, high = better): 166.2 %
 Waterplane Area: 28,103 Square feet or 2,611 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 110 lbs/sq ft or 536 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.46
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

There are two improvements in the J/CL/1927 design

The J/CL/1927 design is still too large for the armament, but the design does incorporate two improvements over the 1923 design: a 36 knot speed and twin 4.7in AA guns. The size growth was moderated by lighter weight machinery. I considered using triple 6.1in guns, but decided that was still inappropriate for 1927. The ships do have good strategic mobility and are well-suited to run with aircraft carriers. The US found in WWII that they really wanted faster cruisers and destroyers for that purposed. In the 1920's, prior to much experience with aircraft carriers, the US authorities decided that aviation eliminated the need for speed, and that slower ships were perfectly acceptable. The Japanese tended to want higher speed for cruisers, while the generally accepted 34 knot destroyers, because they wanted a powerful gun and torpedo armament. The original design for the Mogami class is a case in point, as they wanted a 37-knot speed. This is the Springsharp report for the J/CL/1927:

J/CL/1927, Japan Light Cruiser laid down 1927 (Engine 1937)

Displacement:
 10,754 t light; 11,159 t standard; 12,200 t normal; 13,033 t full load

Dimensions: Length overall / water x beam x draught
 651.54 ft / 647.00 ft x 57.00 ft x 20.00 ft (normal load)
 198.59 m / 197.21 m x 17.37 m  x 6.10 m

Armament:
      8 - 6.10" / 155 mm guns (4x2 guns), 113.62lbs / 51.54kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns (4x2 guns), 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, 8 raised mounts - superfiring
 Weight of broadside 1,460 lbs / 662 kg
 Shells per gun, main battery: 180
 8 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 113 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m

   - 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, 
 Geared drive, 4 shafts, 151,489 shp / 113,011 Kw = 36.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 1,874 tons

Complement:
 579 - 754

Cost:
 £4.064 million / $16.255 million

Distribution of weights at normal displacement:
 Armament: 182 tons, 1.5 %
 Armour: 1,734 tons, 14.2 %
    - Belts: 695 tons, 5.7 %
    - Torpedo bulkhead: 334 tons, 2.7 %
    - Armament: 181 tons, 1.5 %
    - Armour Deck: 489 tons, 4.0 %
    - Conning Tower: 34 tons, 0.3 %
 Machinery: 4,199 tons, 34.4 %
 Hull, fittings & equipment: 4,639 tons, 38.0 %
 Fuel, ammunition & stores: 1,446 tons, 11.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   10,603 lbs / 4,810 Kg = 93.3 x 6.1 " / 155 mm shells or 1.4 torpedoes
 Stability (Unstable if below 1.00): 1.28
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 13.1 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.41
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.579
 Length to Beam Ratio: 11.35 : 1
 'Natural speed' for length: 25.44 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: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.00 ft / 8.84 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  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: 21.76 ft / 6.63 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 190.3 %
  - Above water (accommodation/working, high = better): 152.5 %
 Waterplane Area: 26,445 Square feet or 2,457 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 102 lbs/sq ft or 497 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.37
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1923 is a lot of ship for the armament

The J/CL/1923 is quite large, although there are improvements over its predecessor. The freeboard was increased by a foot, the range was increased dramatically to 7,500nm at 15 knots, and the armament was slightly increased. The 21in TT were replaced by 24in TT, while the main armament was increased from 6in QF guns to 155m (6.1in) QF guns. Otherwise, there were no changes, but the roll period was increased to 13.1 seconds. This is the Springsharp report:

J/CL/1923, Japan Light Cruiser laid down 1923 (Engine 1933)

Displacement:
 10,085 t light; 10,463 t standard; 11,500 t normal; 12,329 t full load

Dimensions: Length overall / water x beam x draught
 629.54 ft / 625.00 ft x 57.00 ft x 20.00 ft (normal load)
 191.88 m / 190.50 m x 17.37 m  x 6.10 m

Armament:
      8 - 6.10" / 155 mm guns (4x2 guns), 113.62lbs / 51.54kg shells, 1923 Model
   Quick firing 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, 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, 8 raised mounts - superfiring
 Weight of broadside 1,356 lbs / 615 kg
 Shells per gun, main battery: 180
 8 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 117 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m

   - 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, 
 Geared drive, 2 shafts, 131,907 shp / 98,403 Kw = 35.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 1,866 tons

Complement:
 554 - 721

Cost:
 £3.006 million / $12.026 million

Distribution of weights at normal displacement:
 Armament: 170 tons, 1.5 %
 Armour: 1,708 tons, 14.8 %
    - Belts: 693 tons, 6.0 %
    - Torpedo bulkhead: 334 tons, 2.9 %
    - Armament: 181 tons, 1.6 %
    - Armour Deck: 466 tons, 4.1 %
    - Conning Tower: 33 tons, 0.3 %
 Machinery: 3,843 tons, 33.4 %
 Hull, fittings & equipment: 4,364 tons, 38.0 %
 Fuel, ammunition & stores: 1,415 tons, 12.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   10,608 lbs / 4,812 Kg = 93.4 x 6.1 " / 155 mm shells or 1.4 torpedoes
 Stability (Unstable if below 1.00): 1.27
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 13.1 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.40
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.565
 Length to Beam Ratio: 10.96 : 1
 'Natural speed' for length: 25.00 kts
 Power going to wave formation at top speed: 60 %
 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:  29.00 ft / 8.84 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  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: 21.76 ft / 6.63 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 185.2 %
  - Above water (accommodation/working, high = better): 150.7 %
 Waterplane Area: 25,213 Square feet or 2,342 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 100 lbs/sq ft or 488 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.47
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1921 design

The J/CL/1921 design has a top speed of 35 knots, which is its main improvement over its predecessor. There is also a slightly improved AA armament, with 6-4.7in AA, and 24-57mm AA. The torpedo armament is increased to 8-21in TT. This is the Springsharp report:

J/CL/1921, Japan Light Cruiser laid down 1921 (Engine 1931)

Displacement:
 9,389 t light; 9,742 t standard; 10,500 t normal; 11,106 t full load

Dimensions: Length overall / water x beam x draught
 618.42 ft / 615.00 ft x 56.00 ft x 20.00 ft (normal load)
 188.49 m / 187.45 m x 17.07 m  x 6.10 m

Armament:
      8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      6 - 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, 8 raised mounts - superfiring
 Weight of broadside 1,311 lbs / 595 kg
 Shells per gun, main battery: 180
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 119 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 475.00 ft / 144.78 m 18.00 ft / 5.49 m

   - 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, 
 Geared drive, 2 shafts, 123,623 shp / 92,222 Kw = 35.00 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 1,364 tons

Complement:
 518 - 674

Cost:
 £2.504 million / $10.017 million

Distribution of weights at normal displacement:
 Armament: 164 tons, 1.6 %
 Armour: 1,559 tons, 14.8 %
    - Belts: 691 tons, 6.6 %
    - Torpedo bulkhead: 316 tons, 3.0 %
    - Armament: 83 tons, 0.8 %
    - Armour Deck: 438 tons, 4.2 %
    - Conning Tower: 31 tons, 0.3 %
 Machinery: 3,697 tons, 35.2 %
 Hull, fittings & equipment: 3,969 tons, 37.8 %
 Fuel, ammunition & stores: 1,111 tons, 10.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   8,735 lbs / 3,962 Kg = 80.9 x 6.0 " / 152 mm shells or 1.3 torpedoes
 Stability (Unstable if below 1.00): 1.31
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 12.8 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.38
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.534
 Length to Beam Ratio: 10.98 : 1
 'Natural speed' for length: 24.80 kts
 Power going to wave formation at top speed: 60 %
 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 (67 %):  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: 20.68 ft / 6.30 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 196.9 %
  - Above water (accommodation/working, high = better): 151.9 %
 Waterplane Area: 23,668 Square feet or 2,199 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 98 lbs/sq ft or 476 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.41
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1918 design

I felt like the 5.5in gun was insufficient for a ship of this size, so the J/CL/1918 has 8-6in QF guns. The size is much larger so that the range can be greater and a torpedo bulkhead could be added. The speed is still 33 knots, which is probably sufficient for 1918. This is the Springsharp report:

J/CL/1918, Japan Light Cruiser laid down 1918 (Engine 1927)

Displacement:
 7,889 t light; 8,192 t standard; 8,900 t normal; 9,466 t full load

Dimensions: Length overall / water x beam x draught
 568.36 ft / 565.00 ft x 53.00 ft x 19.00 ft (normal load)
 173.24 m / 172.21 m x 16.15 m  x 5.79 m

Armament:
      8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 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
      16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships
 Weight of broadside 1,162 lbs / 527 kg
 Shells per gun, main battery: 180
 6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 455.00 ft / 138.68 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 124 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 455.00 ft / 138.68 m 17.00 ft / 5.18 m

   - 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, 
 Geared drive, 2 shafts, 92,046 shp / 68,666 Kw = 33.00 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 1,274 tons

Complement:
 457 - 595

Cost:
 £1.610 million / $6.439 million

Distribution of weights at normal displacement:
 Armament: 145 tons, 1.6 %
 Armour: 1,442 tons, 16.2 %
    - Belts: 659 tons, 7.4 %
    - Torpedo bulkhead: 286 tons, 3.2 %
    - Armament: 83 tons, 0.9 %
    - Armour Deck: 386 tons, 4.3 %
    - Conning Tower: 28 tons, 0.3 %
 Machinery: 2,905 tons, 32.6 %
 Hull, fittings & equipment: 3,397 tons, 38.2 %
 Fuel, ammunition & stores: 1,011 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   8,434 lbs / 3,826 Kg = 78.1 x 6.0 " / 152 mm shells or 1.3 torpedoes
 Stability (Unstable if below 1.00): 1.26
 Metacentric height 2.9 ft / 0.9 m
 Roll period: 13.0 seconds
 Steadiness - As gun platform (Average = 50 %): 59 %
   - Recoil effect (Restricted arc if above 1.00): 0.46
 Seaboat quality  (Average = 1.00): 1.17

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.547
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 23.77 kts
 Power going to wave formation at top speed: 59 %
 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:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  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: 20.60 ft / 6.28 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 191.0 %
  - Above water (accommodation/working, high = better): 155.7 %
 Waterplane Area: 20,849 Square feet or 1,937 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 92 lbs/sq ft or 450 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.68
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The J/CL/1916 design

The goal of the J/CL/1916 design was to reach 33 knots. This design probably needs lighter weight machinery than it currently has. The armament is still the modest 6-5.5in QF guns but with 4-4in AA and 12-57mm AA guns. The torpedo armament is now 6-21in TT. The belt is still 3in and the deck is 1in. This is the Springsharp report:

J/CL/1916, Japan Light Cruiser laid down 1916 (Engine 1923)

Displacement:
 6,595 t light; 6,817 t standard; 7,350 t normal; 7,776 t full load

Dimensions: Length overall / water x beam x draught
 518.36 ft / 515.00 ft x 46.00 ft x 19.00 ft (normal load)
 158.00 m / 156.97 m x 14.02 m  x 5.79 m

Armament:
      6 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread
      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
      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, all amidships
 Weight of broadside 695 lbs / 315 kg
 Shells per gun, main battery: 180
 6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 405.00 ft / 123.44 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 121 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - 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, 
 Geared drive, 2 shafts, 85,627 shp / 63,877 Kw = 33.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 959 tons

Complement:
 396 - 515

Cost:
 £1.153 million / $4.611 million

Distribution of weights at normal displacement:
 Armament: 87 tons, 1.2 %
 Armour: 989 tons, 13.5 %
    - Belts: 588 tons, 8.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 65 tons, 0.9 %
    - Armour Deck: 312 tons, 4.2 %
    - Conning Tower: 24 tons, 0.3 %
 Machinery: 2,862 tons, 38.9 %
 Hull, fittings & equipment: 2,657 tons, 36.1 %
 Fuel, ammunition & stores: 755 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,216 lbs / 2,366 Kg = 62.7 x 5.5 " / 140 mm shells or 0.8 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 2.3 ft / 0.7 m
 Roll period: 12.8 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.42
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.572
 Length to Beam Ratio: 11.20 : 1
 'Natural speed' for length: 22.69 kts
 Power going to wave formation at top speed: 62 %
 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:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  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: 20.60 ft / 6.28 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 135.5 %
  - Above water (accommodation/working, high = better): 139.2 %
 Waterplane Area: 16,870 Square feet or 1,567 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 79 lbs/sq ft or 385 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.90
  - Longitudinal: 2.40
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

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