Another attempt to calculate the GB/PG/1914 fast gunboat

I have a (moderately) successful Springsharp report for the GB/PG/1914 design for a fast gunboat (36 knots). The proportions are somewhat strange, as the draft is too deep, but it is what is necessary to get an acceptable Springsharp report. The armament is 3-5in/50 QF guns, with two guns forward and one aft. The forecastle is raised and there are two funnels, with three boilers, with two trunked into the first funnel. I suspect that the strangeness is due to the inability of Springsharp to have a high-enough SHP/ton, plus the empirical power calculation equation wants to high a power for the speed. This is the report:

GB/PG/1914, Great Britain Fast Gunboat laid down 1914 (Engine 1945)

Displacement:
 1,087 t light; 1,137 t standard; 1,189 t normal; 1,231 t full load

Dimensions: Length overall / water x beam x draught
 275.80 ft / 275.00 ft x 29.00 ft x 15.00 ft (normal load)
 84.06 m / 83.82 m x 8.84 m  x 4.57 m

Armament:
    3 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward
 Weight of broadside 188 lbs / 85 kg
 Shells per gun, main battery: 250

Machinery:
 Oil fired boilers, steam turbines,
 Geared drive, 2 shafts, 51,135 shp / 38,147 Kw = 36.00 kts
 Range 2,500nm at 12.00 kts
 Bunker at max displacement = 95 tons

Complement:
 100 - 131

Cost:
 £0.194 million / $0.777 million

Distribution of weights at normal displacement:
 Armament: 23 tons, 2.0 %
 Machinery: 678 tons, 57.0 %
 Hull, fittings & equipment: 386 tons, 32.4 %
 Fuel, ammunition & stores: 102 tons, 8.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   213 lbs / 97 Kg = 3.4 x 5.0 " / 127 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.27
 Metacentric height 1.2 ft / 0.4 m
 Roll period: 11.1 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.47
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.348
 Length to Beam Ratio: 9.48 : 1
 'Natural speed' for length: 16.58 kts
 Power going to wave formation at top speed: 74 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (34 %): 21.00 ft / 6.40 m
    - Mid (34 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 15.99 ft / 4.87 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 199.8 %
  - Above water (accommodation/working, high = better): 119.9 %
 Waterplane Area: 4,843 Square feet or 450 Square metres
 Displacement factor (Displacement / loading): 43 %
 Structure weight / hull surface area: 30 lbs/sq ft or 145 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.38
  - Longitudinal: 5.81
  - Overall: 0.50
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate