Amazon Ad

Monday, September 25, 2006

How about a coal-fired boiler version of the 33-knot GB/CB/1905 design

I find it amazing that even with light-weight machinery, I was able to have a 33-knot GB/CB/1905 battlecruiser with coal-fired boilers. The Standard displacement is almost exactly the original 25,000 tons. Obviously, the secret is having lightweight machinery. The plant is designed to a 20 SHP/ton basis, which is not out of line for a fast ship. You may or may not know that this was my friend Cliff's fast battlecruiser that sacrificed armament and armour to achieve a high speed for 1905. The armament is 4-12in/45 and 9-6in QF guns and the armour basis is 4in, with a 2in deck. This is the Springsharp report:
GB/CB/1905 Coal-fired boilers, Great Britain Battlecruiser laid down 1905 (Engine 1909)

Displacement:
 24,101 t light; 24,919 t standard; 29,400 t normal; 32,985 t full load

Dimensions: Length overall / water x beam x draught
 770.00 ft / 770.00 ft x 85.00 ft x 27.00 ft (normal load)
 234.70 m / 234.70 m x 25.91 m  x 8.23 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      8 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1905 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread
      1 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1905 Model
   Quick firing gun in a deck mount with hoist
   on centreline aft, 1 raised gun
 Weight of broadside 4,428 lbs / 2,009 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 460.00 ft / 140.21 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 4.00" / 102 mm 340.00 ft / 103.63 m 8.00 ft / 2.44 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - 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: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 176,101 shp / 131,371 Kw = 33.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 8,067 tons (100% coal)

Complement:
 1,122 - 1,459

Cost:
 £2.541 million / $10.165 million

Distribution of weights at normal displacement:
 Armament: 554 tons, 1.9 %
 Armour: 4,883 tons, 16.6 %
    - Belts: 1,200 tons, 4.1 %
    - Torpedo bulkhead: 919 tons, 3.1 %
    - Armament: 858 tons, 2.9 %
    - Armour Deck: 1,742 tons, 5.9 %
    - Conning Tower: 164 tons, 0.6 %
 Machinery: 8,805 tons, 29.9 %
 Hull, fittings & equipment: 9,859 tons, 33.5 %
 Fuel, ammunition & stores: 5,299 tons, 18.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   27,971 lbs / 12,687 Kg = 32.4 x 12.0 " / 305 mm shells or 3.2 torpedoes
 Stability (Unstable if below 1.00): 1.28
 Metacentric height 6.1 ft / 1.9 m
 Roll period: 14.5 seconds
 Steadiness - As gun platform (Average = 50 %): 75 %
   - Recoil effect (Restricted arc if above 1.00): 0.33
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.582
 Length to Beam Ratio: 9.06 : 1
 'Natural speed' for length: 27.75 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 65
 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 (20 %): 26.00 ft / 7.92 m
    - Mid (67 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 23.76 ft / 7.24 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 145.6 %
  - Above water (accommodation/working, high = better): 190.1 %
 Waterplane Area: 47,082 Square feet or 4,374 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 141 lbs/sq ft or 686 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.08
  - 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

No comments:

Amazon Context Links