Now, let us try well-protected battlecruisers

Now, let us see what might be done for a well-protected British battlecruiser for 1906, as an alternative to the Invincibles, but still a cruiser, not a fast battleship. This version is rather strange, as the dimensions are reduced to achieve adequate strength without ballooning the displacement unnecessarily. Part of the strangeness is that this version embraces the 25.5 knot speed, rather than 25 knots. The 25.5 knot speed was a feature of some design studies during the 1906-1908 period, and we are using that for this design. "Better protection" means a 9in belt. This design abandons the 16ft high thick belt for a thicker lower belt and a thinner upper belt, again to keep the displacement from undue increases. One of the two 12in gun turrets aft is superfiring. All turrets are on the centerline, with one amidships, although you would not necessarily know it from the Springsharp report:

GB/CB/1906, Great Britain Battlecruiser laid down 1906

Displacement:
 17,560 t light; 18,299 t standard; 20,150 t normal; 21,631 t full load

Dimensions: Length overall / water x beam x draught
 545.00 ft / 545.00 ft x 77.00 ft x 27.00 ft (normal load)
 166.12 m / 166.12 m x 23.47 m  x 8.23 m

Armament:
      8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount aft - superfiring
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1906 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 80
 4 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 6.00" / 152 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
   Main Belt covers 130 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 460.00 ft / 140.21 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 59,493 shp / 44,382 Kw = 25.50 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 3,332 tons

Complement:
 845 - 1,099

Cost:
 £1.935 million / $7.740 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.6 %
 Armour: 5,834 tons, 29.0 %
    - Belts: 2,266 tons, 11.2 %
    - Torpedo bulkhead: 664 tons, 3.3 %
    - Armament: 1,601 tons, 7.9 %
    - Armour Deck: 1,160 tons, 5.8 %
    - Conning Tower: 144 tons, 0.7 %
 Machinery: 3,863 tons, 19.2 %
 Hull, fittings & equipment: 6,935 tons, 34.4 %
 Fuel, ammunition & stores: 2,590 tons, 12.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,343 lbs / 9,227 Kg = 23.5 x 12.0 " / 305 mm shells or 2.8 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 4.0 ft / 1.2 m
 Roll period: 16.1 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.622
 Length to Beam Ratio: 7.08 : 1
 'Natural speed' for length: 23.35 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 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 space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 134.9 %
  - Above water (accommodation/working, high = better): 146.8 %
 Waterplane Area: 31,340 Square feet or 2,912 Square metres
 Displacement factor (Displacement / loading): 96 %
 Structure weight / hull surface area: 148 lbs/sq ft or 722 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.65
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent