GB/CB/1908, Great Britain Battlecruiser laid down 1908 (Engine 1921)
Displacement:
23,883 t light; 24,753 t standard; 27,400 t normal; 29,518 t full load
Dimensions: Length overall / water x beam x draught
750.00 ft / 750.00 ft x 80.00 ft x 28.00 ft (normal load)
228.60 m / 228.60 m x 24.38 m x 8.53 m
Armament:
6 - 12.00" / 305 mm guns (3x2 guns), 864.00lbs / 391.90kg shells, 1908 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
10 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1908 Model
Quick firing guns in deck mounts with hoists
on side, all amidships
Weight of broadside 6,264 lbs / 2,841 kg
Shells per gun, main battery: 90
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 6.00" / 152 mm 465.00 ft / 141.73 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 4.00" / 102 mm 465.00 ft / 141.73 m 8.00 ft / 2.44 m
Main Belt covers 95 % of normal length
Main belt does not fully cover magazines and engineering spaces
- Torpedo Bulkhead:
2.00" / 51 mm 465.00 ft / 141.73 m 28.00 ft / 8.53 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 6.00" / 152 mm 4.00" / 102 mm 6.00" / 152 mm
2nd: 3.00" / 76 mm 3.00" / 76 mm 3.00" / 76 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 6.00" / 152 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 201,582 shp / 150,380 Kw = 34.50 kts
Range 6,700nm at 18.00 kts
Bunker at max displacement = 4,765 tons
Complement:
1,064 - 1,384
Cost:
£2.465 million / $9.862 million
Distribution of weights at normal displacement:
Armament: 783 tons, 2.9 %
Armour: 6,098 tons, 22.3 %
- Belts: 1,574 tons, 5.7 %
- Torpedo bulkhead: 963 tons, 3.5 %
- Armament: 1,073 tons, 3.9 %
- Armour Deck: 2,370 tons, 8.6 %
- Conning Tower: 117 tons, 0.4 %
Machinery: 6,942 tons, 25.3 %
Hull, fittings & equipment: 10,060 tons, 36.7 %
Fuel, ammunition & stores: 3,517 tons, 12.8 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
29,848 lbs / 13,539 Kg = 34.5 x 12.0 " / 305 mm shells or 3.4 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 4.9 ft / 1.5 m
Roll period: 15.1 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.61
Seaboat quality (Average = 1.00): 1.04
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.571
Length to Beam Ratio: 9.38 : 1
'Natural speed' for length: 27.39 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 50
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: 32.00 ft / 9.75 m
- Forecastle (20 %): 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: 25.68 ft / 7.83 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 138.3 %
- Above water (accommodation/working, high = better): 197.1 %
Waterplane Area: 42,700 Square feet or 3,967 Square metres
Displacement factor (Displacement / loading): 104 %
Structure weight / hull surface area: 149 lbs/sq ft or 728 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.31
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
This is a forum for discussion of topics relating to the Dreadnought era, prior to the ascendency of naval aviation. We will be discussing history, ship design, and naval wargaming.
Thursday, July 20, 2006
The GB/CB/1908 design for a fast battlecruiser (Corrected)
As usual, the GB/CB/1908 design for a fast battlecruiser with 6-12in guns depends on lightweight machinery. The specification is minimal, giving the Standard displacement as 25,000 tons and the armament as 6-12in guns. The dimensions are only referenced by the displacement calculation. Otherwise, I would have only known the length (750ft). I went with a secondary armament of 10-6in QF guns, as there was nothing given. I suspect that my friend Cliff, who conceived the design, would have had fewer 6in guns. The specification specified 4in-6in armour, so I used that for the upper and lower belt. (The freeboard is higher, still, but corrected to reflect the long forecastle and lower quarterdeck)
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