The USS Topeka, unarmoured cruiser

Over at "My Victorian Navy", I have posted a rare photograph of the unarmoured cruiser USS Topeka. The photograph was taken in 1898, when the Topeka was painted gray. I thought that I would try the Topeka in Springsharp. One issue that the exact mean draft is in dispute. The source for the photograph gives the mean draft as only 15ft-6in. I have seen other sources that give the draft as over 17ft. The primary problem with my Springsharp design is that the roll period is too short. I had to experiment to get the roll period over a short 11 seconds. The Topeka originally carried 8-4in guns, but later had the guns reduced to 6-4in. The speed was 16 knots. A sister ship lasted a long time in the Peruvian navy as the Lima. This is the Springsharp report:

USS Topeka, United States Cruiser laid down 1881

Displacement:
 1,558 t light; 1,626 t standard; 2,414 t normal; 3,044 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (271.00 ft / 259.00 ft) x 35.00 ft x (17.75 / 21.32 ft)
 (82.60 m / 78.94 m) x 10.67 m  x (5.41 / 6.50 m)

Armament:
      2 - 4.00" / 102 mm 40.0 cal guns - 28.00lbs / 12.70kg shells, 150 per gun
   Breech loading guns in deck and hoist mounts, 1881 Model
   2 x Single mounts on centreline ends, evenly spread
      6 - 4.00" / 102 mm 40.0 cal guns - 28.00lbs / 12.70kg shells, 150 per gun
   Breech loading guns in casemate mounts, 1881 Model
   6 x Single mounts on sides, forward deck aft
  6 hull mounts in casemates- Limited use in all but light seas
      2 - 2.24" / 57.0 mm 40.0 cal guns - 6.00lbs / 2.72kg shells, 150 per gun
   Breech loading guns in deck mounts, 1881 Model
   2 x Single mounts on sides, aft deck forward
      Weight of broadside 236 lbs / 107 kg

Machinery:
 Coal fired boilers, simple reciprocating steam engines, 
 Direct drive, 2 shafts, 3,519 ihp / 2,625 Kw = 16.00 kts
 Range 5,600nm at 12.00 kts
 Bunker at max displacement = 1,418 tons (100% coal)

Complement:
 171 - 223

Cost:
 £0.168 million / $0.671 million

Distribution of weights at normal displacement:
 Armament: 40 tons, 1.6 %
 Machinery: 717 tons, 29.7 %
 Hull, fittings & equipment: 801 tons, 33.2 %
 Fuel, ammunition & stores: 855 tons, 35.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   2,382 lbs / 1,080 Kg = 86.0 x 4.0 " / 102 mm shells or 0.6 torpedoes
 Stability (Unstable if below 1.00): 1.27
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 11.7 seconds
 Steadiness - As gun platform (Average = 50 %): 100 %
   - Recoil effect (Restricted arc if above 1.00): 0.25
 Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
 Hull has a flush deck,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.525 / 0.551
 Length to Beam Ratio: 7.40 : 1
 'Natural speed' for length: 16.09 kts
 Power going to wave formation at top speed: 46 %
 Trim (Max stability = 0, Max steadiness = 100): 75
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 12.00 ft / 3.66 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 25.00 %,  18.00 ft / 5.49 m,  16.00 ft / 4.88 m
    - Forward deck: 30.00 %,  16.00 ft / 4.88 m,  15.00 ft / 4.57 m
    - Aft deck: 30.00 %,  15.00 ft / 4.57 m,  15.00 ft / 4.57 m
    - Quarter deck: 15.00 %,  15.00 ft / 4.57 m,  15.00 ft / 4.57 m
    - Average freeboard:  15.60 ft / 4.75 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 102.1 %
  - Above water (accommodation/working, high = better): 105.0 %
 Waterplane Area: 6,180 Square feet or 574 Square metres
 Displacement factor (Displacement / loading): 155 %
 Structure weight / hull surface area: 63 lbs/sq ft or 305 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.84
  - Longitudinal: 5.23
  - Overall: 1.01
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather