So just how high a speed could the Repulse make?

I still remember reading in the 1919 Jane's Fighting Ships about the Renown and Repulse type hitting 40 knots. It seemed incredible, and I am sure that it was not possible. I have already written about this, but I wanted to try the Repulse, suitably lightened, might have been able to make. I am assuming that the power plant would be dangerously stressed to achieve maximum power. The ammunition would be mostly unloaded and the fuel supply would be reduced to the minimum. I was able to achieve 35 knots in the condition with Springsharp 3.0b2 Beta. The seakeeping ability is poor, but we could accept that in a trial condition in fair weather. Frank Fox says that the WWII American battleships were generally in this condition, all the time. They were not able to fight in bad weather. This is a photo of the Repulse, as originally completed, with equal-height funnels. The fore funnel was later raised:

This is the Springsharp report:

Repulse, lightened, Great Britain Battlecruiser laid down 1915 (Engine 1919)

Displacement:
 29,031 t light; 29,666 t standard; 29,952 t normal; 30,181 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (800.00 ft / 794.00 ft) x 89.00 ft x (29.67 / 29.84 ft)
 (243.84 m / 242.01 m) x 27.13 m  x (9.04 / 9.10 m)

Armament:
      6 - 15.00" / 381 mm 42.0 cal guns - 1,920.00lbs / 870.90kg shells, 5 per gun
   Breech loading guns in turret on barbette mounts, 1915 Model
   3 x Twin mounts on centreline ends, evenly spread
  1 raised mount - superfiring
      17 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 15 per gun
   Quick firing guns in deck and hoist mounts, 1915 Model
   4 x Twin mounts on sides, evenly spread
   3 x Single mounts on centreline, aft deck forward
  2 raised mounts - superfiring
      Weight of broadside 12,069 lbs / 5,474 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 490.00 ft / 149.35 m 16.00 ft / 4.88 m
 Ends: 4.00" / 102 mm 300.00 ft / 91.44 m 12.00 ft / 3.66 m
   4.00 ft / 1.22 m Unarmoured ends
   Main Belt covers 95 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 490.00 ft / 149.35 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 3.00" / 76 mm       -   2.00" / 51 mm

   - Protected deck - single deck: 3.00" / 76 mm For and Aft decks

   - Conning towers: Forward 9.00" / 229 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 214,934 shp / 160,341 Kw = 35.00 kts
 Range 500nm at 15.00 kts
 Bunker at max displacement = 514 tons

Complement:
 1,137 - 1,479

Cost:
 £4.352 million / $17.408 million

Distribution of weights at normal displacement:
 Armament: 1,655 tons, 5.5 %
 Armour: 6,624 tons, 22.1 %
    - Belts: 2,503 tons, 8.4 %
    - Torpedo bulkhead: 789 tons, 2.6 %
    - Armament: 1,450 tons, 4.8 %
    - Armour Deck: 1,695 tons, 5.7 %
    - Conning Tower: 187 tons, 0.6 %
 Machinery: 7,633 tons, 25.5 %
 Hull, fittings & equipment: 13,119 tons, 43.8 %
 Fuel, ammunition & stores: 921 tons, 3.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   30,176 lbs / 13,688 Kg = 17.9 x 15.0 " / 381 mm shells or 3.5 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 5.2 ft / 1.6 m
 Roll period: 16.4 seconds
 Steadiness - As gun platform (Average = 50 %): 49 %
   - Recoil effect (Restricted arc if above 1.00): 0.93
 Seaboat quality  (Average = 1.00): 0.97

Hull form characteristics:
 Hull has low quarterdeck ,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.500 / 0.501
 Length to Beam Ratio: 8.92 : 1
 'Natural speed' for length: 28.18 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: -4.00 ft / -1.22 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  31.00 ft / 9.45 m,  28.00 ft / 8.53 m
    - Forward deck: 30.00 %,  28.00 ft / 8.53 m,  27.00 ft / 8.23 m
    - Aft deck: 18.00 %,  27.00 ft / 8.23 m,  27.00 ft / 8.23 m
    - Quarter deck: 32.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Average freeboard:  25.03 ft / 7.63 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 139.5 %
  - Above water (accommodation/working, high = better): 215.4 %
 Waterplane Area: 47,083 Square feet or 4,374 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 189 lbs/sq ft or 923 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.38
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Poor seaboat, wet and uncomfortable, reduced performance in heavy weather