My concept for a big, fast, heavy cruiser: GB/CA/1921

This is another example of the sort of big, fast, heavy cruiser for the 1921 timeframe. This time, the design is intended for the British: the GB/CA/1921. It is sort of a melding of the armored cruiser with the Japanese concept for big, fast heavy cruisers. One twist is that the guns are 9.2in. I did want the 35 knots and for the ship to carry torpedoes. I also wanted 10,000 nm mile range for the Pacific theater. An odd feature is that the main armament is in two quadruple 9.2in turrets, one superfiring over the over, and arranged forward. A nasty feature is that the size has gotten very large. At least Springsharp largely reports in glowing terms, except that the machinery spaces are somewhat cramped.

GB/CA/1921, Great Britain Heavy Cruiser laid down 1921

Displacement:
	20,596 t light; 21,394 t standard; 23,793 t normal; 25,712 t full load

Dimensions: Length overall / water x beam x draught
	718.78 ft / 715.00 ft x 76.00 ft x 25.00 ft (normal load)
	219.08 m / 217.93 m x 23.16 m  x 7.62 m

Armament:
      8 - 9.20" / 234 mm guns (2x4 guns), 389.34lbs / 176.60kg shells, 1921 Model
	  Breech loading guns in turrets (on barbettes)
	  on centreline, all forward, all raised mounts - superfiring
      12 - 4.70" / 119 mm guns (6x2 guns), 51.91lbs / 23.55kg shells, 1921 Model
	  Dual purpose guns in deck mounts with hoists
	  on side, all amidships, all raised mounts - superfiring
	Weight of broadside 3,738 lbs / 1,695 kg
	Shells per gun, main battery: 150
	12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	4.00" / 102 mm	450.00 ft / 137.16 m	15.00 ft / 4.57 m
	Ends:	Unarmoured
	  Main Belt covers 97 % of normal length
	  Main belt does not fully cover magazines and engineering spaces

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	5.00" / 127 mm	3.00" / 76 mm		4.00" / 102 mm
	2nd:	2.00" / 51 mm	1.00" / 25 mm		1.00" / 25 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 4.00" / 102 mm

Machinery:
	Oil fired boilers, steam turbines, 
	Geared drive, 4 shafts, 204,375 shp / 152,464 Kw = 35.00 kts
	Range 10,000nm at 15.00 kts
	Bunker at max displacement = 4,318 tons

Complement:
	957 - 1,245

Cost:
	£5.342 million / $21.367 million

Distribution of weights at normal displacement:
	Armament: 467 tons, 2.0 %
	Armour: 3,984 tons, 16.7 %
	   - Belts: 1,141 tons, 4.8 %
	   - Torpedo bulkhead: 0 tons, 0.0 %
	   - Armament: 539 tons, 2.3 %
	   - Armour Deck: 2,233 tons, 9.4 %
	   - Conning Tower: 71 tons, 0.3 %
	Machinery: 7,038 tons, 29.6 %
	Hull, fittings & equipment: 9,107 tons, 38.3 %
	Fuel, ammunition & stores: 3,197 tons, 13.4 %
	Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  24,517 lbs / 11,121 Kg = 63.0 x 9.2 " / 234 mm shells or 1.9 torpedoes
	Stability (Unstable if below 1.00): 1.19
	Metacentric height 4.5 ft / 1.4 m
	Roll period: 15.0 seconds
	Steadiness	- As gun platform (Average = 50 %): 61 %
			- Recoil effect (Restricted arc if above 1.00): 0.62
	Seaboat quality  (Average = 1.00): 1.23

Hull form characteristics:
	Hull has a flush deck
	Block coefficient: 0.613
	Length to Beam Ratio: 9.41 : 1
	'Natural speed' for length: 26.74 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:		34.00 ft / 10.36 m
	   - Forecastle (20 %):	28.00 ft / 8.53 m
	   - Mid (50 %):		28.00 ft / 8.53 m
	   - Quarterdeck (15 %):	28.00 ft / 8.53 m
	   - Stern:		28.00 ft / 8.53 m
	   - Average freeboard:	28.48 ft / 8.68 m

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 111.3 %
		- Above water (accommodation/working, high = better): 190.1 %
	Waterplane Area: 40,228 Square feet or 3,737 Square metres
	Displacement factor (Displacement / loading): 109 %
	Structure weight / hull surface area: 136 lbs/sq ft or 665 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 0.93
		- Longitudinal: 1.88
		- 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