Amazon Ad

Wednesday, January 04, 2006

Distortions by Springsharp? US/BB/1921

The next logical step was to have an American battleship with 12-16in guns. That is what the US/BB?1921 has. The odd thing is that to satisfy Springsharp, it was necessary to shorten the length to achieve strength. I guess that I should be thankful to only have a 31ft draft, as the American designs probably had a deeper draft. I was able to increase the armor basis to 15in and the deck armor to 5in. This is the Springsharp report:
US/BB/1921, United States Battleship laid down 1921

Displacement:
 39,845 t light; 42,082 t standard; 44,500 t normal; 46,434 t full load

Dimensions: Length overall / water x beam x draught
 642.45 ft / 640.00 ft x 108.00 ft x 31.00 ft (normal load)
 195.82 m / 195.07 m x 32.92 m  x 9.45 m

Armament:
      12 - 16.00" / 406 mm guns (4 mounts), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 4 raised mounts - superfiring
      8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 2 raised mounts
      24 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1921 Model
   Machine guns in deck mounts 
   on side, evenly spread, 12 raised mounts
 Weight of broadside 26,590 lbs / 12,061 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 15.0" / 381 mm 440.00 ft / 134.11 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 106 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 440.00 ft / 134.11 m 30.00 ft / 9.14 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 15.0" / 381 mm 11.0" / 279 mm  15.0" / 381 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 15.00" / 381 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 65,118 shp / 48,578 Kw = 23.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,352 tons

Complement:
 1,531 - 1,991

Cost:
 £11.456 million / $45.822 million

Distribution of weights at normal displacement:
 Armament: 3,324 tons, 7.5 %
 Armour: 17,359 tons, 39.0 %
    - Belts: 4,929 tons, 11.1 %
    - Torpedo bulkhead: 1,954 tons, 4.4 %
    - Armament: 4,822 tons, 10.8 %
    - Armour Deck: 5,248 tons, 11.8 %
    - Conning Tower: 406 tons, 0.9 %
 Machinery: 2,242 tons, 5.0 %
 Hull, fittings & equipment: 16,920 tons, 38.0 %
 Fuel, ammunition & stores: 4,655 tons, 10.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   57,993 lbs / 26,305 Kg = 28.3 x 16.0 " / 406 mm shells or 10.0 torpedoes
 Stability (Unstable if below 1.00): 1.06
 Metacentric height 6.3 ft / 1.9 m
 Roll period: 18.0 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.96
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.727
 Length to Beam Ratio: 5.93 : 1
 'Natural speed' for length: 25.30 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 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 %): 25.00 ft / 7.62 m
    - Mid (67 %):  25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break)
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 22.60 ft / 6.89 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 88.7 %
  - Above water (accommodation/working, high = better): 160.8 %
 Waterplane Area: 56,735 Square feet or 5,271 Square metres
 Displacement factor (Displacement / loading): 92 %
 Structure weight / hull surface area: 223 lbs/sq ft or 1,091 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.65
  - 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

1 comment:

Chris Moonbeams said...

Hello, Just wandering the blogosphere and happened on your blog. I like the way how you have put it all together. I'll be coming back again.

Regards,

mini treadmill

Amazon Context Links