My American very large battleship design: US/BB/1937a1

I tried out a very large American battleship design: US/BB/1937a1, that has 12-21in guns in quadruple turrets, with 25-5in QF guns in turrets. The speed was pretty modest: 29 knots.

US/BB/1937a1, United States Battleship laid down 1937

Displacement:
	129,983 t light; 137,684 t standard; 145,600 t normal; 151,933 t full load

Dimensions: Length overall / water x beam x draught
	1,254.33 ft / 1,250.00 ft x 160.00 ft x 40.00 ft (normal load)
	382.32 m / 381.00 m x 48.77 m  x 12.19 m

Armament:
      12 - 21.00" / 533 mm guns (3x4 guns), 4,630.50lbs / 2,100.36kg shells, 1937 Model
	  Breech loading guns in turrets (on barbettes)
	  on centreline ends, majority forward, all raised mounts - superfiring
      24 - 5.10" / 130 mm guns (12x2 guns), 66.33lbs / 30.08kg shells, 1937 Model
	  Breech loading guns in turrets (on barbettes)
	  on side, all amidships, all raised mounts - superfiring
	Weight of broadside 57,158 lbs / 25,926 kg
	Shells per gun, main battery: 150

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	18.0" / 457 mm	815.00 ft / 248.41 m	20.00 ft / 6.10 m
	Ends:	Unarmoured
	  Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
		3.00" / 76 mm	815.00 ft / 248.41 m	35.00 ft / 10.67 m

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	18.0" / 457 mm	11.0" / 279 mm		18.0" / 457 mm
	2nd:	4.00" / 102 mm	4.00" / 102 mm		4.00" / 102 mm

   - Armour deck: 9.00" / 229 mm, Conning tower: 12.00" / 305 mm

Machinery:
	Oil fired boilers, steam turbines, 
	Geared drive, 6 shafts, 258,658 shp / 192,959 Kw = 29.00 kts
	Range 12,000nm at 15.00 kts
	Bunker at max displacement = 14,249 tons

Complement:
	3,726 - 4,844

Cost:
	£63.025 million / $252.101 million

Distribution of weights at normal displacement:
	Armament: 7,145 tons, 4.9 %
	Armour: 52,646 tons, 36.2 %
	   - Belts: 12,580 tons, 8.6 %
	   - Torpedo bulkhead: 3,166 tons, 2.2 %
	   - Armament: 10,978 tons, 7.5 %
	   - Armour Deck: 25,207 tons, 17.3 %
	   - Conning Tower: 716 tons, 0.5 %
	Machinery: 7,169 tons, 4.9 %
	Hull, fittings & equipment: 63,023 tons, 43.3 %
	Fuel, ammunition & stores: 15,617 tons, 10.7 %
	Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  280,607 lbs / 127,281 Kg = 60.6 x 21.0 " / 533 mm shells or 57.8 torpedoes
	Stability (Unstable if below 1.00): 1.10
	Metacentric height 12.2 ft / 3.7 m
	Roll period: 19.2 seconds
	Steadiness	- As gun platform (Average = 50 %): 69 %
			- Recoil effect (Restricted arc if above 1.00): 0.77
	Seaboat quality  (Average = 1.00): 1.39

Hull form characteristics:
	Hull has a flush deck
	Block coefficient: 0.637
	Length to Beam Ratio: 7.81 : 1
	'Natural speed' for length: 35.36 kts
	Power going to wave formation at top speed: 39 %
	Trim (Max stability = 0, Max steadiness = 100): 50
	Bow angle (Positive = bow angles forward): 2.00 degrees
	Stern overhang: 3.00 ft / 0.91 m
	Freeboard (% = measuring location as a percentage of overall length):
	   - Stem:		38.00 ft / 11.58 m
	   - Forecastle (20 %):	34.00 ft / 10.36 m
	   - Mid (0 %):		34.00 ft / 10.36 m
	   - Quarterdeck (15 %):	34.00 ft / 10.36 m
	   - Stern:		35.00 ft / 10.67 m
	   - Average freeboard:	34.40 ft / 10.48 m
	Ship tends to be wet forward

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 62.6 %
		- Above water (accommodation/working, high = better): 263.1 %
	Waterplane Area: 151,391 Square feet or 14,065 Square metres
	Displacement factor (Displacement / loading): 117 %
	Structure weight / hull surface area: 314 lbs/sq ft or 1,532 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 0.99
		- Longitudinal: 1.04
		- Overall: 1.00
	Hull space for machinery, storage, compartmentation is excellent
	Room for accommodation and workspaces is excellent
	Good seaboat, rides out heavy weather easily