Amazon Ad

Saturday, January 21, 2006

My American heavy cruiser for 1914

This is my attempt at a heavy cruiser design for 1914 for the US (US/CA/1914). This is prior to the existence of such a type, although the British were already doing design studies that would produce such a ship. This design works reasonably well, although the broadside has only 5-8in guns, as there are four broadside guns and five on the centerline, with two forward and three aft. This is the Springsharp report:
US/CA/1914, United States Heavy Cruiser laid down 1914

Displacement:
 9,070 t light; 9,456 t standard; 10,950 t normal; 12,146 t full load

Dimensions: Length overall / water x beam x draught
 568.47 ft / 565.00 ft x 57.00 ft x 21.00 ft (normal load)
 173.27 m / 172.21 m x 17.37 m  x 6.40 m

Armament:
      5 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority aft, 2 raised mounts - superfiring
      4 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on centreline, all amidships
      8 - 0.40" / 10.2 mm guns in single mounts, 0.03lbs / 0.01kg shells, 1914 Model
   Machine guns in deck mounts 
   on centreline, all amidships, all raised mounts - superfiring
 Weight of broadside 2,358 lbs / 1,070 kg
 Shells per gun, main battery: 120
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 530.00 ft / 161.54 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 144 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 530.00 ft / 161.54 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 63,038 shp / 47,026 Kw = 29.00 kts
 Range 8,000nm at 15.00 kts
 Bunker at max displacement = 2,690 tons

Complement:
 534 - 695

Cost:
 £1.152 million / $4.607 million

Distribution of weights at normal displacement:
 Armament: 295 tons, 2.7 %
 Armour: 2,329 tons, 21.3 %
    - Belts: 878 tons, 8.0 %
    - Torpedo bulkhead: 392 tons, 3.6 %
    - Armament: 172 tons, 1.6 %
    - Armour Deck: 845 tons, 7.7 %
    - Conning Tower: 42 tons, 0.4 %
 Machinery: 2,428 tons, 22.2 %
 Hull, fittings & equipment: 4,017 tons, 36.7 %
 Fuel, ammunition & stores: 1,880 tons, 17.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,641 lbs / 6,641 Kg = 57.2 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.1 ft / 0.9 m
 Roll period: 13.7 seconds
 Steadiness - As gun platform (Average = 50 %): 71 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.42

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.567
 Length to Beam Ratio: 9.91 : 1
 'Natural speed' for length: 23.77 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  28.00 ft / 8.53 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.09 ft / 6.43 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 143.0 %
  - Above water (accommodation/working, high = better): 156.8 %
 Waterplane Area: 22,830 Square feet or 2,121 Square metres
 Displacement factor (Displacement / loading): 115 %
 Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.69
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

No comments:

Amazon Context Links