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Thursday, January 31, 2008

The GB/CL/1912 design

This is my 1912 version of my proposal for British light cruisers. These are designed from the beginning, like the old Town class, for overseas service, as well as with the fleet. This has three guns on the centerline, two aft and one forward, and six guns on the sidess. They have a six gun broadside that way. The main improvement is side armour to go with a 2in deck, although they have a much stronger gun armament, as well. This is the Springsharp report:
GB/CL/1912, Great Britain Light Cruiser laid down 1912 (Engine 1917)

Displacement:
 4,833 t light; 5,014 t standard; 5,626 t normal; 6,115 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (467.00 ft / 462.00 ft) x 46.00 ft x (17.00 / 18.16 ft)
 (142.34 m / 140.82 m) x 14.02 m  x (5.18 / 5.53 m)

Armament:
      7 - 6.00" / 152 mm 45.0 cal guns - 108.92lbs / 49.41kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1912 Model
   3 x Single mounts on centreline ends, evenly spread
   4 x Single mounts on sides, forward deck aft
      Weight of broadside 762 lbs / 346 kg
      4 - 21.0" / 533 mm, 20.00 ft / 6.10 m torpedoes - 1.271 t each, 5.084 t total
 In 2 sets of deck mounted side rotating tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 3.00" / 76 mm 280.00 ft / 85.34 m 8.00 ft / 2.44 m
   Main Belt covers 133 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  0.70" / 18 mm 400.00 ft / 121.92 m 17.00 ft / 5.18 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Protected deck - single deck: 2.00" / 51 mm For and Aft decks
 Forecastle: 2.00" / 51 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 4.00" / 102 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 33,615 shp / 25,077 Kw = 27.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 1,100 tons

Complement:
 324 - 422

Cost:
 £0.414 million / $1.655 million

Distribution of weights at normal displacement:
 Armament: 208 tons, 3.7 %
    - Guns: 202 tons, 3.6 %
    - Torpedoes: 5 tons, 0.1 %
 Armour: 1,584 tons, 28.2 %
    - Belts: 656 tons, 11.7 %
    - Torpedo bulkhead: 176 tons, 3.1 %
    - Armament: 174 tons, 3.1 %
    - Armour Deck: 551 tons, 9.8 %
    - Conning Tower: 27 tons, 0.5 %
 Machinery: 1,232 tons, 21.9 %
 Hull, fittings & equipment: 1,809 tons, 32.2 %
 Fuel, ammunition & stores: 792 tons, 14.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   7,811 lbs / 3,543 Kg = 72.3 x 6.0 " / 152 mm shells or 1.6 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 1.9 ft / 0.6 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 66 %
   - Recoil effect (Restricted arc if above 1.00): 0.45
 Seaboat quality  (Average = 1.00): 1.32

Hull form characteristics:
 Hull has rise forward of midbreak,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.545 / 0.555
 Length to Beam Ratio: 10.04 : 1
 'Natural speed' for length: 21.49 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 9.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  23.00 ft / 7.01 m,  22.00 ft / 6.71 m
    - Forward deck: 17.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Aft deck: 48.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Quarter deck: 15.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Average freeboard:  17.04 ft / 5.19 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 147.9 %
  - Above water (accommodation/working, high = better): 136.2 %
 Waterplane Area: 14,762 Square feet or 1,371 Square metres
 Displacement factor (Displacement / loading): 119 %
 Structure weight / hull surface area: 75 lbs/sq ft or 368 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.55
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Monday, January 21, 2008

The GB/CL/1908 design

This is my design that is a larger cruiser for overseas operations. It has a mixed 6in and 4.7 in armament. The speed is the same 27 knots and the protection is a 2in deck with a 0.7in torpedo bulkhead. The layout is the same as my 1905 design. They both depend on lightweight machinery. This is the Springsharp report:
GB/CL/1908, Great Britain Light Cruiser laid down 1908 (Engine 1911)

Displacement:
 4,049 t light; 4,210 t standard; 5,242 t normal; 6,068 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (458.00 ft / 450.00 ft) x 45.00 ft x (17.00 / 19.08 ft)
 (139.60 m / 137.16 m) x 13.72 m  x (5.18 / 5.81 m)

Armament:
      2 - 6.00" / 152 mm 45.0 cal guns - 108.92lbs / 49.41kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1908 Model
   2 x Single mounts on centreline ends, evenly spread
      8 - 4.70" / 119 mm 45.0 cal guns - 52.35lbs / 23.75kg shells, 150 per gun
   Quick firing guns in casemate mounts, 1908 Model
   8 x Single mounts on sides amidships
      Weight of broadside 637 lbs / 289 kg
      4 - 18.0" / 457 mm, 20.00 ft / 6.10 m torpedoes - 0.941 t each, 3.764 t total
 In 4 sets of deck mounted side rotating tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Ends: Unarmoured

   - Torpedo Bulkhead:
  0.70" / 18 mm 330.00 ft / 100.58 m 17.00 ft / 5.18 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm
 2nd: 3.00" / 76 mm 2.00" / 51 mm  3.00" / 76 mm

   - Protected deck - single deck: 2.00" / 51 mm For and Aft decks
 Forecastle: 2.00" / 51 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 4.00" / 102 mm,  Aft 0.00" / 0 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 2 shafts, 32,371 shp / 24,149 Kw = 27.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 1,858 tons (100% coal)

Complement:
 307 - 400

Cost:
 £0.385 million / $1.538 million

Distribution of weights at normal displacement:
 Armament: 135 tons, 2.6 %
    - Guns: 131 tons, 2.5 %
    - Torpedoes: 4 tons, 0.1 %
 Armour: 808 tons, 15.4 %
    - Torpedo bulkhead: 145 tons, 2.8 %
    - Armament: 118 tons, 2.3 %
    - Armour Deck: 519 tons, 9.9 %
    - Conning Tower: 26 tons, 0.5 %
 Machinery: 1,445 tons, 27.6 %
 Hull, fittings & equipment: 1,660 tons, 31.7 %
 Fuel, ammunition & stores: 1,194 tons, 22.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   6,871 lbs / 3,116 Kg = 63.6 x 6.0 " / 152 mm shells or 1.3 torpedoes
 Stability (Unstable if below 1.00): 1.33
 Metacentric height 2.5 ft / 0.8 m
 Roll period: 12.0 seconds
 Steadiness - As gun platform (Average = 50 %): 73 %
   - Recoil effect (Restricted arc if above 1.00): 0.26
 Seaboat quality  (Average = 1.00): 1.46

Hull form characteristics:
 Hull has rise forward of midbreak,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.533 / 0.550
 Length to Beam Ratio: 10.00 : 1
 'Natural speed' for length: 21.21 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  23.00 ft / 7.01 m,  22.00 ft / 6.71 m
    - Forward deck: 17.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Aft deck: 48.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Quarter deck: 15.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Average freeboard:  17.04 ft / 5.19 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 175.4 %
  - Above water (accommodation/working, high = better): 135.6 %
 Waterplane Area: 13,909 Square feet or 1,292 Square metres
 Displacement factor (Displacement / loading): 128 %
 Structure weight / hull surface area: 71 lbs/sq ft or 346 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.76
  - 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
 Good seaboat, rides out heavy weather easily

Sunday, January 20, 2008

A British 1905 light cruiser

I thought that exploring what could have been done with a British light cruiser laid down in 1905 would be a good exercise. Such a ship would have certainly had coal-fired boilers and steam turbines. I don't understand the fixation on the 4in gun. Perfectly good 4.7in guns had been produced for many years and were widely used and had seen combat. At this date, there would have not been any side armour, just a protective deck. This is the Springsharp report:
GB/CL/1905, Great Britain Light Cruiser laid down 1905 (Engine 1911)

Displacement:
 3,658 t light; 3,787 t standard; 4,586 t normal; 5,225 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (436.00 ft / 428.00 ft) x 41.00 ft x (17.00 / 18.85 ft)
 (132.89 m / 130.45 m) x 12.50 m  x (5.18 / 5.74 m)

Armament:
      8 - 4.70" / 119 mm 45.0 cal guns - 50.00lbs / 22.68kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1905 Model
   2 x Single mounts on centreline ends, evenly spread
   6 x Single mounts on sides, evenly spread
      Weight of broadside 400 lbs / 181 kg
      4 - 18.0" / 457 mm, 20.00 ft / 6.10 m torpedoes - 0.865 t each, 3.459 t total
 In 4 sets of deck mounted side rotating tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Ends: Unarmoured

   - Torpedo Bulkhead:
  0.60" / 15 mm 300.00 ft / 91.44 m 17.00 ft / 5.18 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 3.00" / 76 mm 2.00" / 51 mm  3.00" / 76 mm

   - Protected deck - single deck: 2.00" / 51 mm For and Aft decks
 Forecastle: 2.00" / 51 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 4.00" / 102 mm,  Aft 0.00" / 0 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 2 shafts, 30,308 shp / 22,610 Kw = 27.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 1,438 tons (100% coal)

Complement:
 278 - 362

Cost:
 £0.357 million / $1.430 million

Distribution of weights at normal displacement:
 Armament: 117 tons, 2.6 %
    - Guns: 114 tons, 2.5 %
    - Torpedoes: 3 tons, 0.1 %
 Armour: 704 tons, 15.4 %
    - Torpedo bulkhead: 113 tons, 2.5 %
    - Armament: 115 tons, 2.5 %
    - Armour Deck: 452 tons, 9.9 %
    - Conning Tower: 24 tons, 0.5 %
 Machinery: 1,353 tons, 29.5 %
 Hull, fittings & equipment: 1,484 tons, 32.4 %
 Fuel, ammunition & stores: 927 tons, 20.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,076 lbs / 2,303 Kg = 97.8 x 4.7 " / 119 mm shells or 1.0 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 1.8 ft / 0.5 m
 Roll period: 12.9 seconds
 Steadiness - As gun platform (Average = 50 %): 74 %
   - Recoil effect (Restricted arc if above 1.00): 0.36
 Seaboat quality  (Average = 1.00): 1.48

Hull form characteristics:
 Hull has rise forward of midbreak,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.538 / 0.553
 Length to Beam Ratio: 10.44 : 1
 'Natural speed' for length: 20.69 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  23.00 ft / 7.01 m,  22.00 ft / 6.71 m
    - Forward deck: 17.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Aft deck: 48.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Quarter deck: 15.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
    - Average freeboard:  17.04 ft / 5.19 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 203.3 %
  - Above water (accommodation/working, high = better): 129.9 %
 Waterplane Area: 12,110 Square feet or 1,125 Square metres
 Displacement factor (Displacement / loading): 121 %
 Structure weight / hull surface area: 67 lbs/sq ft or 325 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.92
  - Longitudinal: 2.00
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is extremely poor
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Monday, January 14, 2008

A big British dreadnought cruiser: the GB/CB/1905

This is the cruiser variant of the battleship-cruiser design. The side armour is thinner and the speed is raised to 26 knots. The armament is 8-12in/45 on the centerline, with a super-firing turret aft. The secondary armament is the same 16-4in QF guns in casemates. The belt is 10in on the waterline. The design depends on lightweight machinery. This is the Springsharp report:
GB/BB/1905, Great Britain Dreadnought Cruiser laid down 1905 (Engine 1917)

Displacement:
 20,213 t light; 21,073 t standard; 23,413 t normal; 25,286 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (625.00 ft / 618.00 ft) x 85.00 ft x (26.00 / 27.71 ft)
 (190.50 m / 188.37 m) x 25.91 m  x (7.92 / 8.44 m)

Armament:
      8 - 12.00" / 305 mm 45.0 cal guns - 871.37lbs / 395.24kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts, 1905 Model
   3 x Twin mounts on centreline ends, evenly spread
  1 raised mount aft - superfiring
   1 x Twin mount on centreline, forward deck aft
      16 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 150 per gun
   Quick firing guns in casemate mounts, 1905 Model
   16 x Single mounts on sides, evenly spread
  8 raised mounts
      Weight of broadside 7,487 lbs / 3,396 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 405.00 ft / 123.44 m 9.00 ft / 2.74 m
 Ends: 4.00" / 102 mm 170.00 ft / 51.82 m 12.00 ft / 3.66 m
   43.00 ft / 13.11 m Unarmoured ends
 Upper: 7.00" / 178 mm 405.00 ft / 123.44 m 8.00 ft / 2.44 m
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 395.00 ft / 120.40 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 10.0" / 254 mm 7.00" / 178 mm  10.0" / 254 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 3.00" / 76 mm For and Aft decks
 Forecastle: 3.00" / 76 mm  Quarter deck: 3.00" / 76 mm

   - Conning towers: Forward 10.00" / 254 mm,  Aft 0.00" / 0 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 66,702 shp / 49,760 Kw = 26.00 kts
 Range 5,400nm at 16.00 kts
 Bunker at max displacement = 4,213 tons (100% coal)

Complement:
 946 - 1,230

Cost:
 £1.760 million / $7.039 million

Distribution of weights at normal displacement:
 Armament: 1,331 tons, 5.7 %
 Armour: 7,921 tons, 33.8 %
    - Belts: 2,836 tons, 12.1 %
    - Torpedo bulkhead: 760 tons, 3.2 %
    - Armament: 2,004 tons, 8.6 %
    - Armour Deck: 2,145 tons, 9.2 %
    - Conning Tower: 176 tons, 0.8 %
 Machinery: 2,690 tons, 11.5 %
 Hull, fittings & equipment: 8,271 tons, 35.3 %
 Fuel, ammunition & stores: 3,200 tons, 13.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   43,692 lbs / 19,818 Kg = 50.6 x 12.0 " / 305 mm shells or 6.9 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 5.2 ft / 1.6 m
 Roll period: 15.7 seconds
 Steadiness - As gun platform (Average = 50 %): 71 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.41

Hull form characteristics:
 Hull has low quarterdeck ,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.600 / 0.608
 Length to Beam Ratio: 7.27 : 1
 'Natural speed' for length: 24.86 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 27.00 %,  28.00 ft / 8.53 m,  26.00 ft / 7.92 m
    - Forward deck: 30.00 %,  26.00 ft / 7.92 m,  26.00 ft / 7.92 m
    - Aft deck: 10.00 %,  26.00 ft / 7.92 m,  26.00 ft / 7.92 m
    - Quarter deck: 33.00 %,  18.00 ft / 5.49 m,  18.00 ft / 5.49 m
    - Average freeboard:  23.58 ft / 7.19 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 83.6 %
  - Above water (accommodation/working, high = better): 201.1 %
 Waterplane Area: 38,420 Square feet or 3,569 Square metres
 Displacement factor (Displacement / loading): 119 %
 Structure weight / hull surface area: 156 lbs/sq ft or 761 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.64
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Saturday, January 12, 2008

The battleship-cruiser with steam turbines

I thought that we would be interested to see the effects of switching from reciprocating engines to steam turbines. The effects are dramatic for the battleship-cruiser design. The armour basis is increased from 11in to 12in and the displacement is lowered. The armour at the ends is increased to 5in. I also raised the freeboard to reduce the effects of the flush-decked hull. The armament is still 12-12in/45 BL and 16-4in/45 QF guns. This is the Springsharp report:
GB/BB/1905, Great Britain Battleship-Cruiser laid down 1905 (Engine 1917)

Displacement:
 22,807 t light; 23,887 t standard; 25,736 t normal; 27,215 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (602.00 ft / 595.00 ft) x 90.00 ft x (27.00 / 28.29 ft)
 (183.49 m / 181.36 m) x 27.43 m  x (8.23 / 8.62 m)

Armament:
      12 - 12.00" / 305 mm 45.0 cal guns - 871.37lbs / 395.24kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts, 1905 Model
   4 x Twin mounts on sides, forward deck aft
  2 raised mounts - superfiring
      16 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 150 per gun
   Quick firing guns in casemate mounts, 1905 Model
   16 x Single mounts on sides, evenly spread
  8 raised mounts
      Weight of broadside 10,973 lbs / 4,977 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 395.00 ft / 120.40 m 9.00 ft / 2.74 m
 Ends: 5.00" / 127 mm 170.00 ft / 51.82 m 12.00 ft / 3.66 m
   30.00 ft / 9.14 m Unarmoured ends
 Upper: 9.00" / 229 mm 395.00 ft / 120.40 m 8.00 ft / 2.44 m
   Main Belt covers 102 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 395.00 ft / 120.40 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 7.00" / 178 mm  12.0" / 305 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 3.00" / 76 mm For and Aft decks
 Forecastle: 3.00" / 76 mm  Quarter deck: 3.00" / 76 mm

   - Conning towers: Forward 12.00" / 305 mm,  Aft 0.00" / 0 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 53,383 shp / 39,824 Kw = 24.00 kts
 Range 5,400nm at 14.00 kts
 Bunker at max displacement = 3,328 tons (100% coal)

Complement:
 1,015 - 1,320

Cost:
 £2.101 million / $8.402 million

Distribution of weights at normal displacement:
 Armament: 1,951 tons, 7.6 %
 Armour: 9,594 tons, 37.3 %
    - Belts: 3,455 tons, 13.4 %
    - Torpedo bulkhead: 848 tons, 3.3 %
    - Armament: 2,832 tons, 11.0 %
    - Armour Deck: 2,234 tons, 8.7 %
    - Conning Tower: 225 tons, 0.9 %
 Machinery: 2,153 tons, 8.4 %
 Hull, fittings & equipment: 9,109 tons, 35.4 %
 Fuel, ammunition & stores: 2,929 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   43,125 lbs / 19,561 Kg = 49.9 x 12.0 " / 305 mm shells or 7.4 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 5.2 ft / 1.6 m
 Roll period: 16.6 seconds
 Steadiness - As gun platform (Average = 50 %): 72 %
   - Recoil effect (Restricted arc if above 1.00): 0.82
 Seaboat quality  (Average = 1.00): 1.45

Hull form characteristics:
 Hull has a flush deck,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.623 / 0.629
 Length to Beam Ratio: 6.61 : 1
 'Natural speed' for length: 24.39 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 27.00 %,  25.00 ft / 7.62 m,  23.00 ft / 7.01 m
    - Forward deck: 30.00 %,  23.00 ft / 7.01 m,  22.00 ft / 6.71 m
    - Aft deck: 10.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Quarter deck: 33.00 %,  22.00 ft / 6.71 m,  22.00 ft / 6.71 m
    - Average freeboard:  22.64 ft / 6.90 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 80.6 %
  - Above water (accommodation/working, high = better): 168.0 %
 Waterplane Area: 40,013 Square feet or 3,717 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 173 lbs/sq ft or 846 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.80
  - 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
 Good seaboat, rides out heavy weather easily

Friday, January 11, 2008

A 1903 battleship-cruiser

In my opinion, a ship similar to what Colonel Cuniberti proposed in 1903 would need to be much larger and less capable. My design has the superfiring guns on the beam, so that the fire ahead could be as much as 10 guns, when firing directly ahead and accepting some blast damage. The broadside would be 8 guns. That seemed to be along the lines of what 1903 thought was reasonable, although not what I would want. I used coal-fired boilers and reciprocating engines, to be consistent with the times. The machinery has to be quite lightweight for this to be feasible. This is my Springsharp report:
GB/BB/1903, Great Britain Battleship-Cruiser laid down 1903 (Engine 1917)

Displacement:
 23,257 t light; 24,355 t standard; 26,622 t normal; 28,436 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (602.00 ft / 595.00 ft) x 90.00 ft x (29.00 / 30.62 ft)
 (183.49 m / 181.36 m) x 27.43 m  x (8.84 / 9.33 m)

Armament:
      12 - 12.00" / 305 mm 45.0 cal guns - 871.37lbs / 395.24kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts, 1903 Model
   4 x Twin mounts on sides, forward deck aft
  2 raised mounts - superfiring
      16 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 150 per gun
   Quick firing guns in casemate mounts, 1903 Model
   16 x Single mounts on sides, evenly spread
  8 raised mounts
      Weight of broadside 10,973 lbs / 4,977 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 400.00 ft / 121.92 m 9.00 ft / 2.74 m
 Ends: 4.00" / 102 mm 150.00 ft / 45.72 m 12.00 ft / 3.66 m
   45.00 ft / 13.72 m Unarmoured ends
 Upper: 8.00" / 203 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 400.00 ft / 121.92 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 7.00" / 178 mm  11.0" / 279 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 3.00" / 76 mm For and Aft decks
 Forecastle: 3.00" / 76 mm  Quarter deck: 3.00" / 76 mm

   - Conning towers: Forward 11.00" / 279 mm,  Aft 0.00" / 0 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 4 shafts, 53,830 ihp / 40,157 Kw = 24.00 kts
 Range 5,400nm at 14.00 kts
 Bunker at max displacement = 4,081 tons (100% coal)

Complement:
 1,041 - 1,354

Cost:
 £2.306 million / $9.224 million

Distribution of weights at normal displacement:
 Armament: 1,951 tons, 7.3 %
 Armour: 8,899 tons, 33.4 %
    - Belts: 3,082 tons, 11.6 %
    - Torpedo bulkhead: 858 tons, 3.2 %
    - Armament: 2,561 tons, 9.6 %
    - Armour Deck: 2,187 tons, 8.2 %
    - Conning Tower: 211 tons, 0.8 %
 Machinery: 3,507 tons, 13.2 %
 Hull, fittings & equipment: 8,900 tons, 33.4 %
 Fuel, ammunition & stores: 3,365 tons, 12.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   35,059 lbs / 15,903 Kg = 40.6 x 12.0 " / 305 mm shells or 5.4 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 5.5 ft / 1.7 m
 Roll period: 16.2 seconds
 Steadiness - As gun platform (Average = 50 %): 70 %
   - Recoil effect (Restricted arc if above 1.00): 0.75
 Seaboat quality  (Average = 1.00): 1.41

Hull form characteristics:
 Hull has a flush deck,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.600 / 0.607
 Length to Beam Ratio: 6.61 : 1
 'Natural speed' for length: 24.39 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 27.00 %,  24.00 ft / 7.32 m,  22.00 ft / 6.71 m
    - Forward deck: 30.00 %,  22.00 ft / 6.71 m,  21.00 ft / 6.40 m
    - Aft deck: 10.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
    - Quarter deck: 33.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
    - Average freeboard:  21.64 ft / 6.59 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 98.9 %
  - Above water (accommodation/working, high = better): 153.2 %
 Waterplane Area: 39,166 Square feet or 3,639 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 171 lbs/sq ft or 836 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.76
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Thursday, January 03, 2008

A British fast battleship

I was dismayed at the size of ship that was necessary to have a 32 knot British battleship with 9-16in/45 guns. The side armour is substantial, as it is 17ft high and a uniform 16in, inclined outward at 16 degrees. To do that in Springsharp took a ship that is 59,061 tons Standard displacement. This is the Springsharp report:
GB/BB/1939, Great Britain Battleship laid down 1939 (Engine 1950)

Displacement:
 56,457 t light; 59,061 t standard; 62,990 t normal; 66,133 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (869.23 ft / 862.00 ft) x 118.00 ft x (33.50 / 34.88 ft)
 (264.94 m / 262.74 m) x 35.97 m  x (10.21 / 10.63 m)

Armament:
      9 - 16.00" / 406 mm 45.0 cal guns - 2,100.00lbs / 952.54kg shells, 120 per gun
   Breech loading guns in turret on barbette mounts, 1939 Model
   3 x Triple mounts on centreline ends, majority forward
  1 raised mount - superfiring
      20 - 4.50" / 114 mm 45.0 cal guns - 45.95lbs / 20.84kg shells, 150 per gun
   Dual purpose guns in turret on barbette mounts, 1939 Model
   10 x Twin mounts on sides, evenly spread
  4 raised mounts
      48 - 1.57" / 40.0 mm 45.0 cal guns - 2.00lbs / 0.91kg shells, 150 per gun
   Anti-air guns in deck mounts, 1939 Model
   8 x 2 row sextuple mounts on sides, evenly spread
  8 raised mounts
      Weight of broadside 19,915 lbs / 9,033 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 16.0" / 406 mm 565.00 ft / 172.21 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  6.00" / 152 mm 565.00 ft / 172.21 m 33.50 ft / 10.21 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 12.0" / 305 mm  16.0" / 406 mm
 2nd: 3.00" / 76 mm 2.00" / 51 mm  3.00" / 76 mm

   - Armoured deck - multiple decks: 7.00" / 178 mm For and Aft decks
 Forecastle: 7.00" / 178 mm  Quarter deck: 7.00" / 178 mm

   - Conning towers: Forward 12.00" / 305 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 233,559 shp / 174,235 Kw = 32.00 kts
 Range 8,500nm at 17.00 kts
 Bunker at max displacement = 7,071 tons

Complement:
 1,987 - 2,584

Cost:
 £26.676 million / $106.702 million

Distribution of weights at normal displacement:
 Armament: 3,267 tons, 5.2 %
 Armour: 26,305 tons, 41.8 %
    - Belts: 6,629 tons, 10.5 %
    - Torpedo bulkhead: 4,202 tons, 6.7 %
    - Armament: 4,657 tons, 7.4 %
    - Armour Deck: 10,408 tons, 16.5 %
    - Conning Tower: 409 tons, 0.6 %
 Machinery: 5,588 tons, 8.9 %
 Hull, fittings & equipment: 21,297 tons, 33.8 %
 Fuel, ammunition & stores: 6,533 tons, 10.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   117,729 lbs / 53,401 Kg = 57.5 x 16.0 " / 406 mm shells or 25.4 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 9.4 ft / 2.9 m
 Roll period: 16.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.44
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck,
   an extended bulbous bow and small transom stern
 Block coefficient (normal/deep): 0.647 / 0.652
 Length to Beam Ratio: 7.31 : 1
 'Natural speed' for length: 31.67 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 12.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  34.00 ft / 10.36 m,  27.00 ft / 8.23 m
    - Forward deck: 30.00 %,  27.00 ft / 8.23 m,  24.00 ft / 7.32 m
    - Aft deck: 35.00 %,  24.00 ft / 7.32 m,  24.00 ft / 7.32 m
    - Quarter deck: 15.00 %,  24.00 ft / 7.32 m,  24.00 ft / 7.32 m
    - Average freeboard:  25.61 ft / 7.81 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 67.7 %
  - Above water (accommodation/working, high = better): 188.7 %
 Waterplane Area: 79,722 Square feet or 7,406 Square metres
 Displacement factor (Displacement / loading): 115 %
 Structure weight / hull surface area: 210 lbs/sq ft or 1,026 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.20
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

Tuesday, January 01, 2008

A 36 knot heavy cruiser

This is the heavy cruiser counterpart to the 37 knot light cruiser. The heavy cruiser has 4in side armour and 10-8in/50 guns. The speed had to be reduced to 36 knots, which is still comparable to the big Japanese cruisers. This is the Springsharp report:
GB/CA/1932, Great Britain Heavy Cruiser laid down 1932 (Engine 1950)

Displacement:
 14,068 t light; 14,656 t standard; 15,974 t normal; 17,029 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (671.00 ft / 665.00 ft) x 68.00 ft x (22.00 / 23.11 ft)
 (204.52 m / 202.69 m) x 20.73 m  x (6.71 / 7.04 m)

Armament:
      10 - 8.00" / 203 mm 50.0 cal guns - 250.00lbs / 113.40kg shells, 150 per gun
   Breech loading guns in turret on barbette mounts, 1932 Model
   5 x Twin mounts on centreline ends, majority forward
  2 raised mounts - superfiring
      12 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 150 per gun
   Anti-air guns in deck and hoist mounts, 1932 Model
   6 x Twin mounts on sides, forward deck aft
      24 - 1.57" / 40.0 mm 45.0 cal guns - 1.97lbs / 0.89kg shells, 150 per gun
   Anti-air guns in deck mounts, 1932 Model
   4 x 2 row sextuple mounts on sides, aft deck forward
  4 raised mounts
      Weight of broadside 2,935 lbs / 1,331 kg
      16 - 21.0" / 533 mm, 22.00 ft / 6.71 m torpedoes - 1.469 t each, 23.507 t total
 In 4 sets of deck mounted side rotating tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 460.00 ft / 140.21 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 106 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  0.90" / 23 mm 460.00 ft / 140.21 m 22.00 ft / 6.71 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 2.00" / 51 mm For and Aft decks
 Forecastle: 2.00" / 51 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 4.00" / 102 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 155,091 shp / 115,698 Kw = 36.00 kts
 Range 6,500nm at 17.00 kts
 Bunker at max displacement = 2,374 tons

Complement:
 709 - 923

Cost:
 £6.067 million / $24.267 million

Distribution of weights at normal displacement:
 Armament: 797 tons, 5.0 %
    - Guns: 773 tons, 4.8 %
    - Torpedoes: 24 tons, 0.1 %
 Armour: 3,392 tons, 21.2 %
    - Belts: 1,207 tons, 7.6 %
    - Torpedo bulkhead: 337 tons, 2.1 %
    - Armament: 555 tons, 3.5 %
    - Armour Deck: 1,239 tons, 7.8 %
    - Conning Tower: 55 tons, 0.3 %
 Machinery: 3,710 tons, 23.2 %
 Hull, fittings & equipment: 6,169 tons, 38.6 %
 Fuel, ammunition & stores: 1,906 tons, 11.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   21,782 lbs / 9,880 Kg = 85.1 x 8.0 " / 203 mm shells or 2.7 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 15.7 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak,
   an extended bulbous bow and large transom stern
 Block coefficient (normal/deep): 0.562 / 0.570
 Length to Beam Ratio: 9.78 : 1
 'Natural speed' for length: 29.28 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 10.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 32.00 %,  34.00 ft / 10.36 m,  28.00 ft / 8.53 m
    - Forward deck: 30.00 %,  28.00 ft / 8.53 m,  28.00 ft / 8.53 m
    - Aft deck: 23.00 %,  20.00 ft / 6.10 m,  20.00 ft / 6.10 m
    - Quarter deck: 15.00 %,  20.00 ft / 6.10 m,  20.00 ft / 6.10 m
    - Average freeboard:  25.73 ft / 7.84 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 133.5 %
  - Above water (accommodation/working, high = better): 215.5 %
 Waterplane Area: 33,236 Square feet or 3,088 Square metres
 Displacement factor (Displacement / loading): 115 %
 Structure weight / hull surface area: 120 lbs/sq ft or 586 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

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