The "Super Blonde" concept, from 1912, works in Springsharp

Apparently, the original plan for the Super Blonde, which evolved into the Arethusa class of 1912, was to have machinery that weighed but 800 tons. The power required was about 40,000 SHP. That would required 50 SHP/ton machinery. They proposed to achieve that by constantly running in a state that would have previously been considered as "overload". The Super Blonde apparently would have been a 3,500 ton ship with a speed of 30 knots, with an armament of 10-4in QF guns. I assume that there would have been pairs of guns in the forecastle and quarterdeck. My Springsharp design uses about 36 SHP/ton machinery, so it is more conservative that that actually planned! This is my Super Blonde photo:

This is the Springsharp report:

GB/CL/1912 Super Blonde, Great Britain Light Cruiser laid down 1912 (Engine 1941)

Displacement:
    3,335 t light; 3,428 t standard; 3,860 t normal; 4,206 t full load

Dimensions: Length overall / water x beam x draught
    431.68 ft / 430.00 ft x 39.00 ft x 14.00 ft (normal load)
    131.58 m / 131.06 m x 11.89 m  x 4.27 m

Armament:
      10 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1912 Model
      Quick firing guns in deck mounts with hoists
      on side, evenly spread
    Weight of broadside 320 lbs / 145 kg
    Shells per gun, main battery: 90

Armour:
   - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    3.00" / 76 mm    250.00 ft / 76.20 m    12.00 ft / 3.66 m
    Ends:    1.00" / 25 mm    180.00 ft / 54.86 m    8.00 ft / 2.44 m
      Main Belt covers 89 % of normal length
      Main belt does not fully cover magazines and engineering spaces

   - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    3.00" / 76 mm    3.00" / 76 mm        3.00" / 76 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm

Machinery:
    Oil fired boilers, steam turbines,
    Direct drive, 2 shafts, 42,290 shp / 31,549 Kw = 30.00 kts
    Range 6,500nm at 15.00 kts
    Bunker at max displacement = 778 tons

Complement:
    244 - 318

Cost:
    £0.307 million / $1.227 million

Distribution of weights at normal displacement:
    Armament: 40 tons, 1.0 %
    Armour: 765 tons, 19.8 %
       - Belts: 432 tons, 11.2 %
       - Torpedo bulkhead: 0 tons, 0.0 %
       - Armament: 96 tons, 2.5 %
       - Armour Deck: 222 tons, 5.7 %
       - Conning Tower: 16 tons, 0.4 %
    Machinery: 1,118 tons, 29.0 %
    Hull, fittings & equipment: 1,412 tons, 36.6 %
    Fuel, ammunition & stores: 525 tons, 13.6 %
    Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      4,742 lbs / 2,151 Kg = 148.2 x 4.0 " / 102 mm shells or 0.9 torpedoes
    Stability (Unstable if below 1.00): 1.19
    Metacentric height 1.7 ft / 0.5 m
    Roll period: 12.6 seconds
    Steadiness    - As gun platform (Average = 50 %): 56 %
            - Recoil effect (Restricted arc if above 1.00): 0.29
    Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
    Hull has rise forward of midbreak
    Block coefficient: 0.575
    Length to Beam Ratio: 11.03 : 1
    'Natural speed' for length: 20.74 kts
    Power going to wave formation at top speed: 61 %
    Trim (Max stability = 0, Max steadiness = 100): 50
    Bow angle (Positive = bow angles forward): 4.00 degrees
    Stern overhang: -2.00 ft / -0.61 m
    Freeboard (% = measuring location as a percentage of overall length):
       - Stem:        24.00 ft / 7.32 m
       - Forecastle (20 %):    22.00 ft / 6.71 m
       - Mid (29 %):        22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
       - Quarterdeck (15 %):    14.00 ft / 4.27 m
       - Stern:        14.00 ft / 4.27 m
       - Average freeboard:    16.48 ft / 5.02 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 102.0 %
        - Above water (accommodation/working, high = better): 141.4 %
    Waterplane Area: 11,986 Square feet or 1,114 Square metres
    Displacement factor (Displacement / loading): 116 %
    Structure weight / hull surface area: 63 lbs/sq ft or 310 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.94
        - Longitudinal: 1.84
        - Overall: 1.00
    Hull space for machinery, storage, compartmentation is adequate
    Room for accommodation and workspaces is excellent