Extreme measures: the Super Swift

Given my experience in the last month with Springsharp, I thought I was ready to try a "Super Swift" design. In Vol.I of The World Crisis, Winston Churchill and Admiral Fisher discussed ideas for a new light cruiser for the British navy. One alternative was an enlarged version of the super destroyer Swift. That concept has caught my imagination for a long time. The ship was to carry 6-4in QF guns and I would expect that it would have had 4-21in TT. The speed was to be 37 knots with no armour protection. I had to resort to "extreme measures" to make the design work in Springsharp, such as having a very high freeboard. Admiral Fisher really liked the idea. It was his ideal for a scout that would work with aircraft and submarines. This is the Springsharp report:

Super Swift, Great Britain Scout laid down 1912 (Engine 1950)
Armoured gunboat

Displacement:
 1,857 t light; 1,922 t standard; 2,104 t normal; 2,251 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (374.73 ft / 372.00 ft) x 36.00 ft x (12.50 / 13.08 ft)
 (114.22 m / 113.39 m) x 10.97 m  x (3.81 / 3.99 m)

Armament:
      6 - 4.00" / 102 mm 50.0 cal guns - 33.88lbs / 15.37kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1912 Model
   2 x Single mounts on sides, forward deck forward
   4 x Single mounts on sides, aft deck aft
   Main guns limited to end-on fire
      Weight of broadside 203 lbs / 92 kg
      4 - 21.0" / 533 mm, 22.00 ft / 6.71 m torpedoes - 1.389 t each, 5.557 t total
 In 2 sets of deck mounted centre rotating tubes

Armour:
   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 59,333 shp / 44,263 Kw = 37.00 kts
 Range 4,500nm at 14.00 kts
 Bunker at max displacement = 329 tons

Complement:
 154 - 201

Cost:
 £0.246 million / $0.984 million

Distribution of weights at normal displacement:
 Armament: 68 tons, 3.2 %
    - Guns: 62 tons, 3.0 %
    - Torpedoes: 6 tons, 0.3 %
 Armour: 43 tons, 2.0 %
    - Armament: 43 tons, 2.0 %
 Machinery: 1,136 tons, 54.0 %
 Hull, fittings & equipment: 610 tons, 29.0 %
 Fuel, ammunition & stores: 247 tons, 11.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   559 lbs / 254 Kg = 17.5 x 4.0 " / 102 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 11.9 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.31
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak,
   a normal bow and large transom stern
 Block coefficient (normal/deep): 0.440 / 0.450
 Length to Beam Ratio: 10.33 : 1
 'Natural speed' for length: 22.12 kts
 Power going to wave formation at top speed: 71 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 17.00 %,  26.00 ft / 7.92 m,  24.00 ft / 7.32 m
    - Forward deck: 15.00 %,  24.00 ft / 7.32 m,  24.00 ft / 7.32 m
    - Aft deck: 53.00 %,  16.00 ft / 4.88 m,  16.00 ft / 4.88 m
    - Quarter deck: 15.00 %,  16.00 ft / 4.88 m,  16.00 ft / 4.88 m
    - Average freeboard:  18.70 ft / 5.70 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 183.7 %
  - Above water (accommodation/working, high = better): 158.0 %
 Waterplane Area: 8,801 Square feet or 818 Square metres
 Displacement factor (Displacement / loading): 68 %
 Structure weight / hull surface area: 33 lbs/sq ft or 160 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 2.92
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent