Amazon Ad

Monday, February 28, 2005

I reconsidered the GB/BB/1912 design

I would like to think that it would be fair game to allow for a higher speed for the GB/BB/1912 design, while the nominal speed is 22 knots, to allow for 25 knots. The "natural speed", according to Springsharp, is 26.46 knots, so 25 knots is still "underperforming". I also have been vascillating about my reading of the sketch records from 1971, and decided that my original estimate of the secondary armament as 12-6in QF guns was more likely to be correct, and that the one spot where there was a 14/6 reference, that it was Belt/Deck armor. Eventually, the deck armor was 7in, as my cross sectional drawing indicates. This is the revised Springsharp report:
GB/BB/1912 a2, Great Britain Battleship laid down 1912 (Engine 1917)

Displacement:
 37,282 t light; 38,970 t standard; 42,620 t normal; 45,539 t full load

Dimensions: Length overall / water x beam x draught
 700.00 ft / 700.00 ft x 105.00 ft x 33.00 ft (normal load)
 213.36 m / 213.36 m x 32.00 m  x 10.06 m

Armament:
      9 - 15.00" / 381 mm guns (3x3 guns), 1,687.50lbs / 765.44kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, all raised mounts - superfiring
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 16,484 lbs / 7,477 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 460.00 ft / 140.21 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 460.00 ft / 140.21 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 8.00" / 203 mm  13.0" / 330 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 7.00" / 178 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 80,283 shp / 59,891 Kw = 25.00 kts
 Range 9,600nm at 15.00 kts
 Bunker at max displacement = 6,569 tons

Complement:
 1,483 - 1,928

Cost:
 £3.448 million / $13.791 million

Distribution of weights at normal displacement:
 Armament: 2,060 tons, 4.8 %
 Armour: 16,317 tons, 38.3 %
    - Belts: 4,483 tons, 10.5 %
    - Torpedo bulkhead: 919 tons, 2.2 %
    - Armament: 3,619 tons, 8.5 %
    - Armour Deck: 7,060 tons, 16.6 %
    - Conning Tower: 237 tons, 0.6 %
 Machinery: 2,943 tons, 6.9 %
 Hull, fittings & equipment: 15,963 tons, 37.5 %
 Fuel, ammunition & stores: 5,337 tons, 12.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   63,315 lbs / 28,719 Kg = 37.5 x 15.0 " / 381 mm shells or 10.8 torpedoes
 Stability (Unstable if below 1.00): 1.03
 Metacentric height 5.7 ft / 1.7 m
 Roll period: 18.4 seconds
 Steadiness - As gun platform (Average = 50 %): 70 %
   - Recoil effect (Restricted arc if above 1.00): 0.74
 Seaboat quality  (Average = 1.00): 1.55

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.615
 Length to Beam Ratio: 6.67 : 1
 'Natural speed' for length: 26.46 kts
 Power going to wave formation at top speed: 48 %
 Trim (Max stability = 0, Max steadiness = 100): 45
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (67 %): 28.00 ft / 8.53 m
    - Mid (67 %):  28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 26.16 ft / 7.97 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 73.1 %
  - Above water (accommodation/working, high = better): 140.0 %
 Waterplane Area: 54,514 Square feet or 5,064 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 204 lbs/sq ft or 994 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

No comments:

Amazon Context Links