The 35-knot battlecruiser with 9-15in guns

The next step seemed to be to increase the armament of the 35-knot battlecruiser (GB/CB/1921) to 9-15in guns. I decreased the belt to 6in and reduced the turret faces, barbettes, and conning tower to 8in. The deck is still the thick 4in. The Standard displacement has ballooned to 37,664 tons. Still, the ship is much more potent, and the roll period is still a quite long 16.9 seconds. If anything, the roll period was increased further. This is the Springsharp report:

GB/CB/1921 15in guns 35 knots, Great Britain Battlecruiser laid down 1921 (Engine 1937)

Displacement:
 36,017 t light; 37,664 t standard; 40,700 t normal; 43,129 t full load

Dimensions: Length overall / water x beam x draught
 829.31 ft / 827.00 ft x 104.00 ft x 31.00 ft (normal load)
 252.77 m / 252.07 m x 31.70 m  x 9.45 m

Armament:
      9 - 15.00" / 381 mm guns (3x3 guns), 1,687.50lbs / 765.44kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 4.70" / 119 mm guns (6 mounts), 51.91lbs / 23.55kg shells, 1921 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, 4 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, all raised mounts - superfiring
      24 - 1.57" / 40.0 mm guns (6x4 guns), 1.95lbs / 0.89kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 16,376 lbs / 7,428 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 530.00 ft / 161.54 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 99 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 530.00 ft / 161.54 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 6.00" / 152 mm  8.00" / 203 mm
 2nd: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 226,229 shp / 168,767 Kw = 35.00 kts
 Range 7,500nm at 18.00 kts
 Bunker at max displacement = 5,465 tons

Complement:
 1,432 - 1,862

Cost:
 £9.820 million / $39.281 million

Distribution of weights at normal displacement:
 Armament: 2,047 tons, 5.0 %
 Armour: 9,483 tons, 23.3 %
    - Belts: 1,630 tons, 4.0 %
    - Torpedo bulkhead: 569 tons, 1.4 %
    - Armament: 2,526 tons, 6.2 %
    - Armour Deck: 4,555 tons, 11.2 %
    - Conning Tower: 204 tons, 0.5 %
 Machinery: 6,270 tons, 15.4 %
 Hull, fittings & equipment: 18,217 tons, 44.8 %
 Fuel, ammunition & stores: 4,683 tons, 11.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   53,385 lbs / 24,215 Kg = 31.6 x 15.0 " / 381 mm shells or 6.2 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 6.7 ft / 2.0 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.71
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.534
 Length to Beam Ratio: 7.95 : 1
 'Natural speed' for length: 33.30 kts
 Power going to wave formation at top speed: 57 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 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 (35 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.48 ft / 8.38 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 108.6 %
  - Above water (accommodation/working, high = better): 221.1 %
 Waterplane Area: 61,556 Square feet or 5,719 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 208 lbs/sq ft or 1,014 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.47
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent