I struggled with Springsharp to try and get an anachronistic Viper to work

A reader asked if I had ever thought about doing an anachronistic destroyer. I thought I would attempt my favorite 1890's destroyer, HMS Viper. I ran into the usual problem with Springsharp, in that the empirical equation for powering destroyers does not perform well. I had to settle for a 30.5 knot ship with too deep a draft. Unlike the designers of the early destroyers, I was not willing to settle for inadequate seakeeping. That perjudice on my part just aggravated the other Springsharp problem. The resulting design has too short a roll period and too high freeboard, in addition to a draft that is too deep. I guess that I should be happy to have a coal-burning turbine destroyer that can even make 30.5 knots, much less 33 or 36 knots. This is my painting of the original HMS Viper making 36 knots on trials:

The anachronistic Viper doesn't look anything like that. It looks like a WWII small destroyer or torpedo boat. The 18in TT are in a twin mount. The 3in QF gun is superfiring over the 6pdr QF forward. There is a twin 6pdr amidships and another twin 6pdr aft, on a bandstand, as is the midships 6pdr mount. The hull is flush-decked with a flared bow and twin funnels. This is the Springsharp report:

Viper, Great Britain Destroyer laid down 1912 (Engine 1950)

Displacement:
 352 t light; 365 t standard; 415 t normal; 455 t full load

Dimensions: Length overall / water x beam x draught
 213.31 ft / 210.00 ft x 21.00 ft x 11.00 ft (normal load)
 65.02 m / 64.01 m x 6.40 m  x 3.35 m

Armament:
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing gun in a deck mount with hoist
   on centreline forward, 1 raised gun
      2 - 2.24" / 57.0 mm guns (1x2 guns), 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading guns in deck mount 
   on centreline amidships, all raised guns - superfiring
      2 - 2.24" / 57.0 mm guns (1x2 guns), 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading guns in deck mount 
   on centreline aft, all raised guns - superfiring
      1 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading gun in deck mount 
   on centreline forward
 Weight of broadside 42 lbs / 19 kg
 Shells per gun, main battery: 150
 2 - 18.0" / 457.2 mm above water torpedoes

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 2 shafts, 14,242 shp / 10,625 Kw = 30.50 kts
 Range 3,500nm at 12.00 kts
 Bunker at max displacement = 90 tons (100% coal)

Complement:
 45 - 59

Cost:
 £0.046 million / $0.186 million

Distribution of weights at normal displacement:
 Armament: 5 tons, 1.3 %
 Machinery: 212 tons, 51.2 %
 Hull, fittings & equipment: 135 tons, 32.4 %
 Fuel, ammunition & stores: 63 tons, 15.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   131 lbs / 59 Kg = 9.7 x 3.0 " / 76 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.42
 Metacentric height 0.9 ft / 0.3 m
 Roll period: 9.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.25
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has low forecastle
 Block coefficient: 0.299
 Length to Beam Ratio: 10.00 : 1
 'Natural speed' for length: 14.49 kts
 Power going to wave formation at top speed: 68 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  15.00 ft / 4.57 m
    - Forecastle (20 %): 0.00 ft / 0.00 m (11.00 ft / 3.35 m aft of break)
    - Mid (50 %):  11.00 ft / 3.35 m
    - Quarterdeck (15 %): 11.00 ft / 3.35 m
    - Stern:  11.00 ft / 3.35 m
    - Average freeboard: 10.00 ft / 3.05 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 175.2 %
  - Above water (accommodation/working, high = better): 101.8 %
 Waterplane Area: 2,839 Square feet or 264 Square metres
 Displacement factor (Displacement / loading): 52 %
 Structure weight / hull surface area: 21 lbs/sq ft or 104 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.41
  - Longitudinal: 3.88
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate