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Monday, March 19, 2007

An anachronistic Cressy design

One of my alternate looks is rather 1930's Italian-looking (I fancy). This is another drawing dating from the 1980's:

The ship works pretty well in Springsharp 3.0b1 Beta. I used coal-fired boilers and reciprocating machinery. I used something similar to the original armament, except arranged differently. I omitted any guns smaller than 6in. This is the Springsharp report:
Cressy class, Great Britain Armoured Cruiser laid down 1911 (Engine 1914)

Displacement:
 9,675 t light; 10,080 t standard; 12,000 t normal; 13,536 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (477.48 ft / 472.00 ft) x 69.00 ft x (26.00 / 28.49 ft)
 (145.54 m / 143.87 m) x 21.03 m  x (7.92 / 8.68 m)

Armament:
      2 - 9.20" / 234 mm 45.0 cal guns - 392.66lbs / 178.11kg shells, 150 per gun
   Breech loading guns in turret on barbette mount , 1911 Model
   1 x Twin mount on centreline, forward deck forward
      12 - 6.00" / 152 mm 45.0 cal guns - 100.00lbs / 45.36kg shells, 150 per gun
   Quick firing guns in turret on barbette mounts , 1911 Model
   2 x Triple mounts on centreline ends, evenly spread
  1 raised mount - superfiring
   2 x Triple mounts on sides, forward deck aft
 Weight of broadside 1,985 lbs / 1,985 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 300.00 ft / 91.44 m 16.00 ft / 4.88 m
 Ends: 4.00" / 102 mm 172.00 ft / 52.43 m 16.00 ft / 4.88 m
   Main Belt covers 98 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 300.00 ft / 91.44 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 5.00" / 127 mm 4.00" / 102 mm  5.00" / 127 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 34,142 ihp / 25,470 Kw = 24.00 kts
 Range 6,200nm at 15.00 kts
 Bunker at max displacement = 3,455 tons (100% coal)

Complement:
 573 - 745

Cost:
 £0.850 million / $3.400 million

Distribution of weights at normal displacement:
 Armament: 473 tons, 3.9 %
 Armour: 3,399 tons, 28.3 %
    - Belts: 1,655 tons, 13.8 %
    - Torpedo bulkhead: 289 tons, 2.4 %
    - Armament: 588 tons, 4.9 %
    - Armour Deck: 800 tons, 6.7 %
    - Conning Tower: 68 tons, 0.6 %
 Machinery: 2,246 tons, 18.7 %
 Hull, fittings & equipment: 3,795 tons, 31.6 %
 Fuel, ammunition & stores: 2,325 tons, 19.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   16,829 lbs / 7,633 Kg = 43.2 x 9.2 " / 234 mm shells or 2.9 torpedoes
 Stability (Unstable if below 1.00): 1.30
 Metacentric height 4.6 ft / 1.4 m
 Roll period: 13.6 seconds
 Steadiness - As gun platform (Average = 50 %): 65 %
   - Recoil effect (Restricted arc if above 1.00): 0.26
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has a flush deck,
   a normal bow and a round stern
 Block coefficient (normal/deep): 0.496 / 0.511
 Length to Beam Ratio: 6.84 : 1
 'Natural speed' for length: 21.73 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 9.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  22.00 ft / 6.71 m,  18.00 ft / 5.49 m
    - Forward deck: 30.00 %,  18.00 ft / 5.49 m,  17.00 ft / 5.18 m
    - Aft deck: 35.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
    - Quarter deck: 15.00 %,  17.00 ft / 5.18 m,  18.00 ft / 5.49 m
    - Average freeboard:  17.75 ft / 5.41 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 107.9 %
  - Above water (accommodation/working, high = better): 123.8 %
 Waterplane Area: 21,621 Square feet or 2,009 Square metres
 Displacement factor (Displacement / loading): 123 %
 Structure weight / hull surface area: 113 lbs/sq ft or 551 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.88
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

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