A GB/CB/1915 design study from the early 1970's

I have this sparse specification for what I had hoped would be a fast battlecruiser with 8-15in guns, dating from the early 1970's. I entered a version into Springsharp, and found that all I could achieve was a 33 knot speed. This is my original specification:

Battlecruiser

displacment  35,000 tons light, 36,500 tons normal load, 39,000 tons full load
dimensions: 850ft x 105ft x 25.3ft (48ft hull depth)
armament: 8-15in/45  Speed=35 knots  Speed-length ratio: 1.2
SHP (normal)=154,000   (max.)=184,500

5.05 SHP/ton to reach the speed  max speed=37.3 knots

This is the Springsharp report:

GB/CB/1915 design study, Great Britain Battlecruiser laid down 1915 (Engine 1927)

Displacement:
 35,532 t light; 37,200 t standard; 39,316 t normal; 41,009 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (855.39 ft / 850.00 ft) x 105.00 ft x (26.00 / 26.91 ft)
 (260.72 m / 259.08 m) x 32.00 m  x (7.92 / 8.20 m)

Armament:
      8 - 15.00" / 381 mm 42.0 cal guns - 1,920.00lbs / 870.90kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts , 1915 Model
   4 x Twin mounts on centreline ends, evenly spread
  2 raised mounts - superfiring
      16 - 5.50" / 140 mm 50.0 cal guns - 85.00lbs / 38.56kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts , 1915 Model
   16 x Single mounts on sides, evenly spread
  4 raised mounts
 Weight of broadside 16,720 lbs / 16,720 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 560.00 ft / 170.69 m 16.00 ft / 4.88 m
 Ends: 4.00" / 102 mm 290.00 ft / 88.39 m 12.00 ft / 3.66 m
   Main Belt covers 101 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 560.00 ft / 170.69 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 2.00" / 51 mm  3.00" / 76 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 209,197 shp / 156,061 Kw = 33.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,809 tons

Complement:
 1,395 - 1,814

Cost:
 £5.026 million / $20.105 million

Distribution of weights at normal displacement:
 Armament: 2,446 tons, 6.2 %
 Armour: 9,080 tons, 23.1 %
    - Belts: 2,802 tons, 7.1 %
    - Torpedo bulkhead: 1,077 tons, 2.7 %
    - Armament: 2,601 tons, 6.6 %
    - Armour Deck: 2,399 tons, 6.1 %
    - Conning Tower: 199 tons, 0.5 %
 Machinery: 6,603 tons, 16.8 %
 Hull, fittings & equipment: 18,316 tons, 46.6 %
 Fuel, ammunition & stores: 3,784 tons, 9.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   57,554 lbs / 26,106 Kg = 34.1 x 15.0 " / 381 mm shells or 7.6 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 7.4 ft / 2.3 m
 Roll period: 16.2 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak, raised quarterdeck ,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.593 / 0.598
 Length to Beam Ratio: 8.10 : 1
 'Natural speed' for length: 29.15 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 9.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 25.00 %,  34.00 ft / 10.36 m,  30.00 ft / 9.14 m
    - Forward deck: 38.00 %,  30.00 ft / 9.14 m,  30.00 ft / 9.14 m
    - Aft deck: 22.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Quarter deck: 15.00 %,  23.00 ft / 7.01 m,  24.00 ft / 7.32 m
    - Average freeboard:  27.67 ft / 8.43 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 104.6 %
  - Above water (accommodation/working, high = better): 239.7 %
 Waterplane Area: 64,850 Square feet or 6,025 Square metres
 Displacement factor (Displacement / loading): 114 %
 Structure weight / hull surface area: 203 lbs/sq ft or 990 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.19
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent