Amazon Ad

Sunday, October 23, 2005

My anachronistic design for the Cressy class

My 1910 version of the Cressy class greatly outperforms the original. That seems to be largely due to the later building date and newer technology. I kept the dimensions and displacement, but went with a somewhat heavier armament (4-9.2in and 12-6in guns). The layout is very similar to my other anachronistic designs. This is the Springsharp report:
HMS Cressy, Great Britain Armoured Cruiser laid down 1910

Displacement:
 10,101 t light; 10,582 t standard; 12,000 t normal; 13,135 t full load

Dimensions: Length overall / water x beam x draught
 475.54 ft / 472.00 ft x 69.50 ft x 26.00 ft (normal load)
 144.94 m / 143.87 m x 21.18 m  x 7.92 m

Armament:
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1910 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      12 - 6.00" / 152 mm guns (6x2 guns), 108.00lbs / 48.99kg shells, 1910 Model
   Quick firing guns in turrets (on barbettes)
   on centreline, all forward
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1910 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread, all raised mounts
      8 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1910 Model
   Breech loading guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 3,283 lbs / 1,489 kg
 Shells per gun, main battery: 120

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 350.00 ft / 106.68 m 19.00 ft / 5.79 m
 Ends: Unarmoured
   Main Belt covers 114 % of normal length

   - Torpedo Bulkhead:
  1.50" / 38 mm 350.00 ft / 106.68 m 25.00 ft / 7.62 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: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm
 3rd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 4th: 1.00" / 25 mm       -         -

   - Armour deck: 3.00" / 76 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 34,121 shp / 25,454 Kw = 24.00 kts
 Range 6,000nm at 15.00 kts
 Bunker at max displacement = 2,553 tons

Complement:
 573 - 745

Cost:
 £0.896 million / $3.582 million

Distribution of weights at normal displacement:
 Armament: 410 tons, 3.4 %
 Armour: 4,264 tons, 35.5 %
    - Belts: 1,672 tons, 13.9 %
    - Torpedo bulkhead: 486 tons, 4.0 %
    - Armament: 834 tons, 7.0 %
    - Armour Deck: 1,205 tons, 10.0 %
    - Conning Tower: 68 tons, 0.6 %
 Machinery: 1,410 tons, 11.7 %
 Hull, fittings & equipment: 4,016 tons, 33.5 %
 Fuel, ammunition & stores: 1,899 tons, 15.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,959 lbs / 8,146 Kg = 46.1 x 9.2 " / 234 mm shells or 3.7 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 3.7 ft / 1.1 m
 Roll period: 15.2 seconds
 Steadiness - As gun platform (Average = 50 %): 61 %
   - Recoil effect (Restricted arc if above 1.00): 0.43
 Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.492
 Length to Beam Ratio: 6.79 : 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): 4.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 16.00 ft / 4.88 m
    - Mid (50 %):  16.00 ft / 4.88 m
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 16.48 ft / 5.02 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 91.3 %
  - Above water (accommodation/working, high = better): 115.5 %
 Waterplane Area: 21,707 Square feet or 2,017 Square metres
 Displacement factor (Displacement / loading): 116 %
 Structure weight / hull surface area: 121 lbs/sq ft or 591 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.91
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is adequate
 Good seaboat, rides out heavy weather easily

No comments:

Amazon Context Links