Amazon Ad

Tuesday, November 08, 2005

A "nice" 1912 British light cruiser

By using rather light machinery (although not excessively so, at 29 SHP/ton), a 30-knot British light cruiser for 1912 with 6-6in guns on the broadside is possible. The displacement is about that of a Town class and the machinery weight is not as agressive as that of the Arethusa class (47 SHP/ton desired). Admittedly, this looks a lot like a D-class ship, except earlier in time. This is the Springsharp report:
GB/CS/1912, Great Britain Scout Cruiser laid down 1912 (Engine 1921)

Displacement:
 4,784 t light; 4,969 t standard; 5,390 t normal; 5,727 t full load

Dimensions: Length overall / water x beam x draught
 476.31 ft / 475.00 ft x 45.00 ft x 16.00 ft (normal load)
 145.18 m / 144.78 m x 13.72 m  x 4.88 m

Armament:
      6 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1912 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      12 - 1.57" / 40.0 mm guns (6x2 guns), 2.00lbs / 0.91kg shells, 1912 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 736 lbs / 334 kg
 Shells per gun, main battery: 180
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 360.00 ft / 109.73 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 117 % of normal length

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 49,462 shp / 36,899 Kw = 30.00 kts
 Range 4,200nm at 15.00 kts
 Bunker at max displacement = 758 tons

Complement:
 313 - 408

Cost:
 £0.483 million / $1.932 million

Distribution of weights at normal displacement:
 Armament: 92 tons, 1.7 %
 Armour: 1,028 tons, 19.1 %
    - Belts: 527 tons, 9.8 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 60 tons, 1.1 %
    - Armour Deck: 415 tons, 7.7 %
    - Conning Tower: 26 tons, 0.5 %
 Machinery: 1,703 tons, 31.6 %
 Hull, fittings & equipment: 1,961 tons, 36.4 %
 Fuel, ammunition & stores: 606 tons, 11.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,028 lbs / 2,281 Kg = 46.6 x 6.0 " / 152 mm shells or 0.9 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 2.2 ft / 0.7 m
 Roll period: 12.6 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.43
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.552
 Length to Beam Ratio: 10.56 : 1
 'Natural speed' for length: 21.79 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  25.00 ft / 7.62 m
    - Forecastle (20 %): 22.00 ft / 6.71 m
    - Mid (36 %):  22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
    - Quarterdeck (15 %): 14.00 ft / 4.27 m
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 17.12 ft / 5.22 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.1 %
  - Above water (accommodation/working, high = better): 107.7 %
 Waterplane Area: 14,940 Square feet or 1,388 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 75 lbs/sq ft or 368 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.61
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

No comments:

Amazon Context Links