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Saturday, December 31, 2005

Photo of a British Battlecruiser (tentatively labelled GB/CB/1907)

I have this drawing from 1971 of a British battlecruiser with 8-12in and 12-6in guns. The ship was large, with a 600ft length and a normal displacement perhaps of 21,500 tons. The protection was 6,678 tons. The normal maximum speed was 28.6 knots and the maximum overload would be 30 knots. The normal SHP was hoped to be 80,600. This is the photo of this design:

A photo of the Ger/CL/1919 light cruiser

This is a photo of my radical light cruiser, the Ger/CL/1919 design that I created about 1973.

My photo of the Ger/CL/1920 fleet cruiser design

This is a photo of my Ger/CL/1920 fleet cruiser design. Thiswas intended to be a 6,000 ton standard displacement fast cruiser with 6-6in/55 QF and 8-23.6in TT. The originally intended speed was 37 knots. Protection was to be a scant 675 tons. I had hoped for a 38.4 knot speed on overload.

The next step: US/BB/1916

I may have advanced to the 16in gun too soon, but that is what the US/BB/1916 carries. I increased the armour basis to 14in and the guns to 8-16in BLR. You may not have noticed, but these ships have a 15 knot cruising speed for a range of 6,500nm. I increased the freeboard, as Springsharp complained about being wet forward, which is still the case, even with a one foot increase. The light AA gun for the US seems to have been the 0.50in MG, so that is what these ships have. This is the Springsharp report:
US/BB/1916, United States Battleship laid down 1916

Displacement:
 29,926 t light; 31,497 t standard; 33,800 t normal; 35,643 t full load

Dimensions: Length overall / water x beam x draught
 613.89 ft / 612.00 ft x 98.00 ft x 30.00 ft (normal load)
 187.11 m / 186.54 m x 29.87 m  x 9.14 m

Armament:
      8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
   Main guns limited to end-on fire
      16 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1916 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 4 raised mounts - superfiring
      4 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 17,635 lbs / 7,999 kg
 Shells per gun, main battery: 90
 10 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 14.0" / 356 mm 400.00 ft / 121.92 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 400.00 ft / 121.92 m 28.00 ft / 8.53 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 10.0" / 254 mm  14.0" / 356 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 37,984 shp / 28,336 Kw = 21.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,146 tons

Complement:
 1,246 - 1,620

Cost:
 £5.068 million / $20.273 million

Distribution of weights at normal displacement:
 Armament: 2,204 tons, 6.5 %
 Armour: 13,286 tons, 39.3 %
    - Belts: 4,189 tons, 12.4 %
    - Torpedo bulkhead: 1,658 tons, 4.9 %
    - Armament: 3,701 tons, 10.9 %
    - Armour Deck: 3,423 tons, 10.1 %
    - Conning Tower: 315 tons, 0.9 %
 Machinery: 1,415 tons, 4.2 %
 Hull, fittings & equipment: 13,021 tons, 38.5 %
 Fuel, ammunition & stores: 3,874 tons, 11.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   51,219 lbs / 23,233 Kg = 25.0 x 16.0 " / 406 mm shells or 9.6 torpedoes
 Stability (Unstable if below 1.00): 1.02
 Metacentric height 5.0 ft / 1.5 m
 Roll period: 18.4 seconds
 Steadiness - As gun platform (Average = 50 %): 83 %
   - Recoil effect (Restricted arc if above 1.00): 1.18
 Seaboat quality  (Average = 1.00): 1.65

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.657
 Length to Beam Ratio: 6.24 : 1
 'Natural speed' for length: 24.74 kts
 Power going to wave formation at top speed: 44 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 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: 22.52 ft / 6.86 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 78.8 %
  - Above water (accommodation/working, high = better): 142.6 %
 Waterplane Area: 46,261 Square feet or 4,298 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 202 lbs/sq ft or 986 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.79
  - 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

Friday, December 30, 2005

A new thread: American battleships

This starts a new design thread. Again, the thread starts in 1914. This time, the ship is an American battleship design: US/BB/1914. I must confess to being throughly conventional. I had thought of only having a 9-14in gun main armament, but I went with 12-14in, instead. The result seemed pretty reasonable. This is the Springsharp report:
US/BB/1914, United States Battleship laid down 1914

Displacement:
 28,781 t light; 30,331 t standard; 32,600 t normal; 34,415 t full load

Dimensions: Length overall / water x beam x draught
 600.00 ft / 600.00 ft x 96.00 ft x 29.00 ft (normal load)
 182.88 m / 182.88 m x 29.26 m  x 8.84 m

Armament:
      12 - 14.00" / 356 mm guns (4x3 guns), 1,372.00lbs / 622.33kg shells, 1914 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
   Main guns limited to end-on fire
      16 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1914 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 4 raised mounts - superfiring
      4 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 17,714 lbs / 8,035 kg
 Shells per gun, main battery: 90
 10 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 390.00 ft / 118.87 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 390.00 ft / 118.87 m 28.00 ft / 8.53 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 9.00" / 229 mm  13.0" / 330 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 37,714 shp / 28,135 Kw = 21.00 kts
 Range 6,000nm at 15.00 kts
 Bunker at max displacement = 4,083 tons

Complement:
 1,212 - 1,576

Cost:
 £3.908 million / $15.633 million

Distribution of weights at normal displacement:
 Armament: 2,214 tons, 6.8 %
 Armour: 12,595 tons, 38.6 %
    - Belts: 3,803 tons, 11.7 %
    - Torpedo bulkhead: 1,616 tons, 5.0 %
    - Armament: 3,525 tons, 10.8 %
    - Armour Deck: 3,365 tons, 10.3 %
    - Conning Tower: 286 tons, 0.9 %
 Machinery: 1,453 tons, 4.5 %
 Hull, fittings & equipment: 12,519 tons, 38.4 %
 Fuel, ammunition & stores: 3,819 tons, 11.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   46,932 lbs / 21,288 Kg = 34.2 x 14.0 " / 356 mm shells or 8.6 torpedoes
 Stability (Unstable if below 1.00): 1.03
 Metacentric height 4.9 ft / 1.5 m
 Roll period: 18.1 seconds
 Steadiness - As gun platform (Average = 50 %): 79 %
   - Recoil effect (Restricted arc if above 1.00): 1.17
 Seaboat quality  (Average = 1.00): 1.58

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.683
 Length to Beam Ratio: 6.25 : 1
 'Natural speed' for length: 24.49 kts
 Power going to wave formation at top speed: 45 %
 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:  26.00 ft / 7.92 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.52 ft / 6.56 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 82.8 %
  - Above water (accommodation/working, high = better): 137.1 %
 Waterplane Area: 45,472 Square feet or 4,224 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 200 lbs/sq ft or 976 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.69
  - 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

Thursday, December 29, 2005

The ultimate development: GB/DD/1941

The GB/DD/1941 is a blend of the Tribal class with the Daring class. The speed needed to stay at 37 knots, as the cost of going higher was too great. The armament now includes 8-4.5in DP guns, 2-4in AA (an odd feature), and 16-2pdr AA guns, as well as the usual 10-21in TT. The range is now 6,000nm at 15 knots. This is the Springsharp report:
GB/DD/1941, Great Britain Destroyer laid down 1941

Displacement:
 2,515 t light; 2,629 t standard; 2,950 t normal; 3,206 t full load

Dimensions: Length overall / water x beam x draught
 388.82 ft / 387.00 ft x 37.00 ft x 17.00 ft (normal load)
 118.51 m / 117.96 m x 11.28 m  x 5.18 m

Armament:
      8 - 4.50" / 114 mm guns (4x2 guns), 45.56lbs / 20.67kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 4.00" / 102 mm guns (1x2 guns), 32.00lbs / 14.51kg shells, 1941 Model
   Anti-aircraft guns in a deck mount with hoist
   on centreline amidships, all raised guns - superfiring
      16 - 1.57" / 40.0 mm guns (4x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 2 raised mounts
 Weight of broadside 460 lbs / 209 kg
 Shells per gun, main battery: 200
 10 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 71,252 shp / 53,154 Kw = 37.00 kts
 Range 6,000nm at 15.00 kts
 Bunker at max displacement = 577 tons

Complement:
 199 - 260

Cost:
 £2.249 million / $8.996 million

Distribution of weights at normal displacement:
 Armament: 57 tons, 1.9 %
 Machinery: 1,625 tons, 55.1 %
 Hull, fittings & equipment: 833 tons, 28.2 %
 Fuel, ammunition & stores: 435 tons, 14.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   640 lbs / 290 Kg = 14.0 x 4.5 " / 114 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.36
 Metacentric height 1.9 ft / 0.6 m
 Roll period: 11.2 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.62
 Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.424
 Length to Beam Ratio: 10.46 : 1
 'Natural speed' for length: 22.59 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (36 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 19.04 ft / 5.80 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 193.2 %
  - Above water (accommodation/working, high = better): 82.9 %
 Waterplane Area: 9,296 Square feet or 864 Square metres
 Displacement factor (Displacement / loading): 70 %
 Structure weight / hull surface area: 38 lbs/sq ft or 185 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.44
  - Longitudinal: 3.15
  - Overall: 0.53
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

Wednesday, December 28, 2005

The GB/DD/1937 is big enough to have a 15 knot cruising speed

The GB/DD/1937 is big an fast, and has a range of 5,600nm at 15 knots (finally). This seems a great improvement over the puny 12 knot cruising speeds of its predecessors. I had looked at what could be improved that would give the greatest benefit, and cruising speed seemed to be "it". This is the Springsharp report:
GB/DD/1937, Great Britain Destroyer laid down 1937 (Engine 1947)

Displacement:
2,000 t light; 2,103 t standard; 2,350 t normal; 2,548 t full load

Dimensions: Length overall / water x beam x draught
373.75 ft / 372.00 ft x 36.00 ft x 15.00 ft (normal load)
113.92 m / 113.39 m x 10.97 m  x 4.57 m

Armament:
     8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
  Quick firing guns in deck mounts with hoists
  on centreline ends, evenly spread, 1 raised mount - superfiring
     1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1937 Model
  Anti-aircraft gun in a deck mount with hoist
  on side amidships
     16 - 1.57" / 40.0 mm guns (4x4 guns), 1.95lbs / 0.89kg shells, 1937 Model
  Anti-aircraft guns in deck mounts
  on side, evenly spread, 2 raised mounts
Weight of broadside 479 lbs / 217 kg
Shells per gun, main battery: 200
10 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 2 shafts, 62,213 shp / 46,411 Kw = 37.00 kts
Range 5,600nm at 15.00 kts
Bunker at max displacement = 445 tons

Complement:
168 - 219

Cost:
£1.599 million / $6.395 million

Distribution of weights at normal displacement:
Armament: 60 tons, 2.5 %
Machinery: 1,235 tons, 52.5 %
Hull, fittings & equipment: 705 tons, 30.0 %
Fuel, ammunition & stores: 350 tons, 14.9 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
  539 lbs / 245 Kg = 10.4 x 4.7 " / 119 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 1.8 ft / 0.6 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
  - Recoil effect (Restricted arc if above 1.00): 0.65
Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
Hull has rise forward of midbreak
  and transom stern
Block coefficient: 0.409
Length to Beam Ratio: 10.33 : 1
'Natural speed' for length: 22.22 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 4.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
   - Stem:  25.00 ft / 7.62 m
   - Forecastle (20 %): 23.00 ft / 7.01 m
   - Mid (36 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
   - Quarterdeck (15 %): 15.00 ft / 4.57 m
   - Stern:  15.00 ft / 4.57 m
   - Average freeboard: 18.04 ft / 5.50 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 189.7 %
 - Above water (accommodation/working, high = better): 80.4 %
Waterplane Area: 8,605 Square feet or 799 Square metres
Displacement factor (Displacement / loading): 66 %
Structure weight / hull surface area: 36 lbs/sq ft or 176 Kg/sq metre
Hull strength (Relative):
 - Cross-sectional: 0.42
 - Longitudinal: 2.96
 - Overall: 0.51
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

Tuesday, December 27, 2005

The GB/DD/1931 design

I almost would say that this design is "underperforming", in that while it is good, perhaps the speed could be higher. The armament is increased to 8-4.7in QF, 1-4in AA, 12-2pdr AA, with 10-21in TT. The maximum speed is still 37 knots and the range is 5,000nm at just 12 knots. This is the Springsharp report:
GB/DD/1931, Great Britain Destroyer laid down 1931 (Engine 1941)

Displacement:
 1,912 t light; 2,010 t standard; 2,150 t normal; 2,262 t full load

Dimensions: Length overall / water x beam x draught
 366.75 ft / 365.00 ft x 35.00 ft x 15.00 ft (normal load)
 111.78 m / 111.25 m x 10.67 m  x 4.57 m

Armament:
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1931 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 1 raised mount - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1931 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships
      12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.89kg shells, 1931 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 2 raised mounts
 Weight of broadside 471 lbs / 214 kg
 Shells per gun, main battery: 200
 10 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 58,631 shp / 43,739 Kw = 37.00 kts
 Range 5,000nm at 12.00 kts
 Bunker at max displacement = 253 tons

Complement:
 157 - 205

Cost:
 £1.217 million / $4.867 million

Distribution of weights at normal displacement:
 Armament: 59 tons, 2.7 %
 Machinery: 1,161 tons, 54.0 %
 Hull, fittings & equipment: 692 tons, 32.2 %
 Fuel, ammunition & stores: 238 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   465 lbs / 211 Kg = 9.0 x 4.7 " / 119 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.27
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 11.7 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.393
 Length to Beam Ratio: 10.43 : 1
 'Natural speed' for length: 22.05 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  25.00 ft / 7.62 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (36 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 18.04 ft / 5.50 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 195.8 %
  - Above water (accommodation/working, high = better): 77.1 %
 Waterplane Area: 8,128 Square feet or 755 Square metres
 Displacement factor (Displacement / loading): 60 %
 Structure weight / hull surface area: 36 lbs/sq ft or 177 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.42
  - Longitudinal: 3.38
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

Monday, December 26, 2005

Sort of a British Fubuki class: GB/DD/1927

This has turned out to be sort of a British answer to the Fubuki class, except that there is not the super torpedo armament (perhaps the next version should have that). The armament has not changed, but the speed is now 37 knots. The range is also increased to 4,750nm, but only at 12 knots. This is the Springsharp report:
GB/DD/1927, Great Britain Destroyer laid down 1927 (Engine 1937)

Displacement:
 1,871 t light; 1,954 t standard; 2,090 t normal; 2,198 t full load

Dimensions: Length overall / water x beam x draught
 356.75 ft / 355.00 ft x 34.00 ft x 15.00 ft (normal load)
 108.74 m / 108.20 m x 10.36 m  x 4.57 m

Armament:
      6 - 4.70" / 119 mm guns (3x2 guns), 51.91lbs / 23.55kg shells, 1927 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward, 1 raised mount - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1927 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships
      8 - 1.57" / 40.0 mm guns (2x4 guns), 1.95lbs / 0.89kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 359 lbs / 163 kg
 Shells per gun, main battery: 200
 10 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 59,044 shp / 44,047 Kw = 37.00 kts
 Range 4,750nm at 12.00 kts
 Bunker at max displacement = 244 tons

Complement:
 153 - 200

Cost:
 £0.979 million / $3.917 million

Distribution of weights at normal displacement:
 Armament: 45 tons, 2.1 %
 Machinery: 1,186 tons, 56.8 %
 Hull, fittings & equipment: 640 tons, 30.6 %
 Fuel, ammunition & stores: 219 tons, 10.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   420 lbs / 190 Kg = 8.1 x 4.7 " / 119 mm shells or 0.3 torpedoes
 Stability (Unstable if below 1.00): 1.27
 Metacentric height 1.5 ft / 0.5 m
 Roll period: 11.5 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.66
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.404
 Length to Beam Ratio: 10.44 : 1
 'Natural speed' for length: 21.70 kts
 Power going to wave formation at top speed: 71 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  25.00 ft / 7.62 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (36 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 18.04 ft / 5.50 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 200.0 %
  - Above water (accommodation/working, high = better): 70.1 %
 Waterplane Area: 7,729 Square feet or 718 Square metres
 Displacement factor (Displacement / loading): 58 %
 Structure weight / hull surface area: 34 lbs/sq ft or 166 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.41
  - Longitudinal: 3.59
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is extremely poor
 Room for accommodation and workspaces is cramped

The GB/DD/1923 design

The move to twin mounts in the GB/DD/1923 design may be premature, but it seemed an obvious move to make. The armament is increased to 6-4.7in QF, 1-4in AA, and 8-2pdr AA guns with 10-21in TT. The forecastle is raised and the freeboard was increased further to aid seakeeping. The draft is perhaps to deep, but it is a feature of Springsharp that increasing the draft generally improved seakeeping and strenght. This is the Springsharp report:
GB/DD/1923, Great Britain Destroyer laid down 1923 (Engine 1933)

Displacement:
 1,553 t light; 1,630 t standard; 1,750 t normal; 1,846 t full load

Dimensions: Length overall / water x beam x draught
 346.68 ft / 345.00 ft x 33.00 ft x 14.00 ft (normal load)
 105.67 m / 105.16 m x 10.06 m  x 4.27 m

Armament:
      6 - 4.70" / 119 mm guns (3x2 guns), 51.91lbs / 23.55kg shells, 1923 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward, 1 raised mount - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1923 Model
   Anti-aircraft gun in a deck mount with hoist
   on side amidships
      8 - 1.57" / 40.0 mm guns (2x4 guns), 1.95lbs / 0.89kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 359 lbs / 163 kg
 Shells per gun, main battery: 200
 10 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 46,926 shp / 35,007 Kw = 36.00 kts
 Range 4,500nm at 12.00 kts
 Bunker at max displacement = 215 tons

Complement:
 134 - 175

Cost:
 £0.652 million / $2.609 million

Distribution of weights at normal displacement:
 Armament: 45 tons, 2.6 %
 Machinery: 944 tons, 54.0 %
 Hull, fittings & equipment: 564 tons, 32.3 %
 Fuel, ammunition & stores: 197 tons, 11.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   377 lbs / 171 Kg = 7.3 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 11.7 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.75
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has raised forecastle, rise forward of midbreak
   and transom stern
 Block coefficient: 0.384
 Length to Beam Ratio: 10.45 : 1
 'Natural speed' for length: 21.46 kts
 Power going to wave formation at top speed: 69 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 22.00 ft / 6.71 m (21.00 ft / 6.40 m aft of break)
    - Mid (36 %):  22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
    - Quarterdeck (15 %): 14.00 ft / 4.27 m
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 16.96 ft / 5.17 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.3 %
  - Above water (accommodation/working, high = better): 64.2 %
 Waterplane Area: 7,215 Square feet or 670 Square metres
 Displacement factor (Displacement / loading): 57 %
 Structure weight / hull surface area: 33 lbs/sq ft or 163 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.41
  - Longitudinal: 3.33
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

Sunday, December 25, 2005

The GB/DD/1921 design

I was going to just settle for a modest increase in speed and range, but I decided at the last minute to add a fifth 4.7in QF gun to the GB/DD/1921 design. The maximum speed is now 36 knots with a range of 4,500nm at 12 knots. This is the Springsharp report:
GB/DD/1921, Great Britain Destroyer laid down 1921 (Engine 1931)

Displacement:
 1,348 t light; 1,409 t standard; 1,520 t normal; 1,609 t full load

Dimensions: Length overall / water x beam x draught
 336.21 ft / 335.00 ft x 32.00 ft x 13.00 ft (normal load)
 102.48 m / 102.11 m x 9.75 m  x 3.96 m

Armament:
      5 - 4.70" / 119 mm guns (4 mounts), 51.91lbs / 23.55kg shells, 1921 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 1.57" / 40.0 mm guns (1x4 guns), 1.95lbs / 0.89kg shells, 1921 Model
   Anti-aircraft guns in deck mount 
   on side amidships, all raised guns
 Weight of broadside 267 lbs / 121 kg
 Shells per gun, main battery: 200
 8 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 43,455 shp / 32,417 Kw = 36.00 kts
 Range 4,500nm at 12.00 kts
 Bunker at max displacement = 200 tons

Complement:
 121 - 158

Cost:
 £0.489 million / $1.957 million

Distribution of weights at normal displacement:
 Armament: 33 tons, 2.2 %
 Machinery: 836 tons, 55.0 %
 Hull, fittings & equipment: 479 tons, 31.5 %
 Fuel, ammunition & stores: 172 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   338 lbs / 153 Kg = 6.5 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.31
 Metacentric height 1.5 ft / 0.4 m
 Roll period: 11.1 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.57
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.382
 Length to Beam Ratio: 10.47 : 1
 'Natural speed' for length: 21.15 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 21.00 ft / 6.40 m
    - Mid (35 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 15.96 ft / 4.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 194.7 %
  - Above water (accommodation/working, high = better): 77.0 %
 Waterplane Area: 6,786 Square feet or 630 Square metres
 Displacement factor (Displacement / loading): 53 %
 Structure weight / hull surface area: 31 lbs/sq ft or 153 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.42
  - Longitudinal: 2.94
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

Saturday, December 24, 2005

The GB/DD/1918 design

I had thought that the machinery is too heavy for the power produced, but I was reluctant to make the date any later than 10 years more than the laid-down date. The machinery is 50 SHP/ton, so it is not that bad. I also wondered if the problem was that power to reach 35 knots is greater than would really be needed. I looked at some example ships. The A-class ships had 505 ton machinery that produced 34,000 SHP. The improvements in the GB/DD/1918 design include a 35 knot speed, a 4,200nm range at 12 knots, 8-21in TT, and 4-2pdr AA. This is the Springsharp report:
GB/DD/1918, Great Britain Destroyer laid down 1918 (Engine 1928)

Displacement:
 1,199 t light; 1,251 t standard; 1,350 t normal; 1,429 t full load

Dimensions: Length overall / water x beam x draught
 326.21 ft / 325.00 ft x 31.00 ft x 12.00 ft (normal load)
 99.43 m / 99.06 m x 9.45 m  x 3.66 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 1.57" / 40.0 mm guns (1x4 guns), 2.00lbs / 0.91kg shells, 1918 Model
   Anti-aircraft guns in deck mount 
   on side amidships, all raised guns
 Weight of broadside 216 lbs / 98 kg
 Shells per gun, main battery: 200
 8 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 36,622 shp / 27,320 Kw = 35.00 kts
 Range 4,200nm at 12.00 kts
 Bunker at max displacement = 178 tons

Complement:
 110 - 144

Cost:
 £0.333 million / $1.332 million

Distribution of weights at normal displacement:
 Armament: 27 tons, 2.0 %
 Machinery: 728 tons, 53.9 %
 Hull, fittings & equipment: 444 tons, 32.9 %
 Fuel, ammunition & stores: 151 tons, 11.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   333 lbs / 151 Kg = 6.4 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.28
 Metacentric height 1.3 ft / 0.4 m
 Roll period: 11.2 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.391
 Length to Beam Ratio: 10.48 : 1
 'Natural speed' for length: 20.80 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 21.00 ft / 6.40 m
    - Mid (35 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 15.96 ft / 4.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 189.8 %
  - Above water (accommodation/working, high = better): 74.6 %
 Waterplane Area: 6,404 Square feet or 595 Square metres
 Displacement factor (Displacement / loading): 54 %
 Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.43
  - Longitudinal: 3.25
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped

Friday, December 23, 2005

My GB/DD/1916 design

My GB/DD/1916 design is at least more aggressive, in that the destroyer has 4-4.7in QF guns, with two superfiring. I moderately increased the range (to 3,750nm at 12 knots), as well. This is the Springsharp report:
GB/DD/1916, Great Britain Destroyer laid down 1916 (Engine 1920)

Displacement:
 1,109 t light; 1,159 t standard; 1,250 t normal; 1,323 t full load

Dimensions: Length overall / water x beam x draught
 306.21 ft / 305.00 ft x 31.00 ft x 12.00 ft (normal load)
 93.33 m / 92.96 m x 9.45 m  x 3.66 m

Armament:
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 2.24" / 57.0 mm guns (1x2 guns), 5.65lbs / 2.56kg shells, 1916 Model
   Anti-aircraft guns in deck mount 
   on side amidships
 Weight of broadside 219 lbs / 99 kg
 Shells per gun, main battery: 200
 4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 31,903 shp / 23,800 Kw = 34.00 kts
 Range 3,750nm at 12.00 kts
 Bunker at max displacement = 164 tons

Complement:
 104 - 136

Cost:
 £0.255 million / $1.022 million

Distribution of weights at normal displacement:
 Armament: 27 tons, 2.2 %
 Machinery: 673 tons, 53.9 %
 Hull, fittings & equipment: 408 tons, 32.7 %
 Fuel, ammunition & stores: 141 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   307 lbs / 139 Kg = 5.9 x 4.7 " / 119 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.30
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 11.1 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.57
 Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
 Hull has rise forward of midbreak
   and transom stern
 Block coefficient: 0.386
 Length to Beam Ratio: 9.84 : 1
 'Natural speed' for length: 20.28 kts
 Power going to wave formation at top speed: 70 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 21.00 ft / 6.40 m
    - Mid (35 %):  21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 15.96 ft / 4.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 191.1 %
  - Above water (accommodation/working, high = better): 115.5 %
 Waterplane Area: 5,995 Square feet or 557 Square metres
 Displacement factor (Displacement / loading): 51 %
 Structure weight / hull surface area: 30 lbs/sq ft or 144 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.42
  - Longitudinal: 3.63
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

A new design series starting with the GB/DD/1914

One of my main concerns about Springsharp is that destroyer machinery is too heavy. I believe that this will eventually be corrected, perhaps in the next version. I thought that the next design series should study British destroyers. This is my concept for a 1914 British design: the GB/DD/1914. I wanted 1,000 tons , or so, at least 34 knots, and a 3,500nm range. The armament is not particularly interesting, but reasonable at 4-4in QF, 1-6pdr AA, and 4-21in TT. One gun is superfiring. This is the Springsharp report:
GB/DD/1914, Great Britain Destroyer laid down 1914 (Engine 1918)

Displacement:
    923 t light; 959 t standard; 1,040 t normal; 1,105 t full load

Dimensions: Length overall / water x beam x draught
    280.00 ft / 280.00 ft x 29.00 ft x 12.00 ft (normal load)
    85.34 m / 85.34 m x 8.84 m  x 3.66 m

Armament:
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1914 Model
      Quick firing guns in deck mounts with hoists
      on centreline ends, evenly spread, 1 raised mount
      1 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1914 Model
      Anti-aircraft gun in deck mount
      on side amidships
    Weight of broadside 134 lbs / 61 kg
    Shells per gun, main battery: 200
    4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
    Oil fired boilers, steam turbines,
    Direct drive, 2 shafts, 29,517 shp / 22,020 Kw = 34.00 kts
    Range 3,500nm at 12.00 kts
    Bunker at max displacement = 146 tons

Complement:
    91 - 119

Cost:
    £0.161 million / $0.646 million

Distribution of weights at normal displacement:
    Armament: 17 tons, 1.6 %
    Machinery: 575 tons, 55.3 %
    Hull, fittings & equipment: 331 tons, 31.8 %
    Fuel, ammunition & stores: 117 tons, 11.3 %
    Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      257 lbs / 117 Kg = 8.0 x 4.0 " / 102 mm shells or 0.2 torpedoes
    Stability (Unstable if below 1.00): 1.35
    Metacentric height 1.3 ft / 0.4 m
    Roll period: 10.6 seconds
    Steadiness    - As gun platform (Average = 50 %): 52 %
            - Recoil effect (Restricted arc if above 1.00): 0.37
    Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
    Hull has rise forward of midbreak
      and transom stern
    Block coefficient: 0.374
    Length to Beam Ratio: 9.66 : 1
    'Natural speed' for length: 19.50 kts
    Power going to wave formation at top speed: 72 %
    Trim (Max stability = 0, Max steadiness = 100): 50
    Bow angle (Positive = bow angles forward): 0.00 degrees
    Stern overhang: 0.00 ft / 0.00 m
    Freeboard (% = measuring location as a percentage of overall length):
       - Stem:        22.00 ft / 6.71 m
       - Forecastle (20 %):    20.00 ft / 6.10 m
       - Mid (35 %):        20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break)
       - Quarterdeck (15 %):    12.00 ft / 3.66 m
       - Stern:        12.00 ft / 3.66 m
       - Average freeboard:    14.96 ft / 4.56 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 191.1 %
        - Above water (accommodation/working, high = better): 98.1 %
    Waterplane Area: 5,125 Square feet or 476 Square metres
    Displacement factor (Displacement / loading): 46 %
    Structure weight / hull surface area: 28 lbs/sq ft or 135 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.42
        - Longitudinal: 3.99
        - Overall: 0.53
    Hull space for machinery, storage, compartmentation is cramped
    Room for accommodation and workspaces is adequate

Thursday, December 22, 2005

The final step in this design series: GB/CA/1940

The final step in this design series seemed to demand using 9.2in BLR. For a ship of this size, over 23,000 tons normal, 8in guns seemed to be too small. I suspect that the last design had some shortcomings, brought on by typos. This one is a super-ship, with a speed of 36 knots, a range of 8,500nm at 15 knots and a 5in armour basis. This is the Springsharp report:
GB/CA/1940, Great Britain Heavy Cruiser laid down 1940

Displacement:
 20,903 t light; 21,760 t standard; 23,400 t normal; 24,712 t full load

Dimensions: Length overall / water x beam x draught
 738.00 ft / 738.00 ft x 71.00 ft x 26.50 ft (normal load)
 224.94 m / 224.94 m x 21.64 m  x 8.08 m

Armament:
      9 - 9.20" / 234 mm guns (3x3 guns), 389.34lbs / 176.60kg shells, 1940 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 4.70" / 119 mm guns (8x2 guns), 51.91lbs / 23.55kg shells, 1940 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      48 - 1.57" / 40.0 mm guns (12x4 guns), 1.95lbs / 0.89kg shells, 1940 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 4,428 lbs / 2,009 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 5.00" / 127 mm 670.00 ft / 204.22 m 15.00 ft / 4.57 m
 Ends: Unarmoured
   Main Belt covers 140 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 670.00 ft / 204.22 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 3.00" / 76 mm  6.00" / 152 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm       -         -

   - Armour deck: 4.00" / 102 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 189,933 shp / 141,690 Kw = 36.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,953 tons

Complement:
 945 - 1,229

Cost:
 £11.445 million / $45.781 million

Distribution of weights at normal displacement:
 Armament: 554 tons, 2.4 %
 Armour: 6,680 tons, 28.5 %
    - Belts: 1,993 tons, 8.5 %
    - Torpedo bulkhead: 620 tons, 2.6 %
    - Armament: 1,035 tons, 4.4 %
    - Armour Deck: 2,927 tons, 12.5 %
    - Conning Tower: 106 tons, 0.5 %
 Machinery: 5,078 tons, 21.7 %
 Hull, fittings & equipment: 8,590 tons, 36.7 %
 Fuel, ammunition & stores: 2,497 tons, 10.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   30,570 lbs / 13,866 Kg = 78.5 x 9.2 " / 234 mm shells or 3.5 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 3.7 ft / 1.1 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.66
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.590
 Length to Beam Ratio: 10.39 : 1
 'Natural speed' for length: 30.63 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  33.00 ft / 10.06 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.64 ft / 7.82 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 124.3 %
  - Above water (accommodation/working, high = better): 157.4 %
 Waterplane Area: 39,554 Square feet or 3,675 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 133 lbs/sq ft or 649 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.42
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Wednesday, December 21, 2005

The GB/CA/1937 design

The main goal for the GB/CA/1937 design was to increase the maximum speed to 36 knots. The only other increase was to the secondary armament, which is now 16-4.7in DP guns. The ship is large enough where 8in guns are almost too small. This is the Springsharp report:
GB/CA/1937, Great Britain Heavy Cruiser laid down 1937

Displacement:
 18,661 t light; 19,434 t standard; 21,000 t normal; 22,253 t full load

Dimensions: Length overall / water x beam x draught
 714.00 ft / 714.00 ft x 70.00 ft x 26.50 ft (normal load)
 217.63 m / 217.63 m x 21.34 m  x 8.08 m

Armament:
      12 - 8.00" / 203 mm guns (4x3 guns), 256.00lbs / 116.12kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 4.70" / 119 mm guns (8x2 guns), 51.91lbs / 23.55kg shells, 1937 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      48 - 1.57" / 40.0 mm guns (12x4 guns), 1.95lbs / 0.89kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 3,996 lbs / 1,813 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 5.00" / 127 mm 660.00 ft / 201.17 m 5.00 ft / 1.52 m
 Ends: Unarmoured
   Main Belt covers 142 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 660.00 ft / 201.17 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 3.00" / 76 mm  6.00" / 152 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm       -         -

   - Armour deck: 4.00" / 102 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 176,963 shp / 132,014 Kw = 36.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,820 tons

Complement:
 871 - 1,133

Cost:
 £9.597 million / $38.387 million

Distribution of weights at normal displacement:
 Armament: 500 tons, 2.4 %
 Armour: 5,221 tons, 24.9 %
    - Belts: 652 tons, 3.1 %
    - Torpedo bulkhead: 611 tons, 2.9 %
    - Armament: 1,161 tons, 5.5 %
    - Armour Deck: 2,700 tons, 12.9 %
    - Conning Tower: 98 tons, 0.5 %
 Machinery: 4,905 tons, 23.4 %
 Hull, fittings & equipment: 8,035 tons, 38.3 %
 Fuel, ammunition & stores: 2,339 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   25,896 lbs / 11,746 Kg = 101.2 x 8.0 " / 203 mm shells or 3.0 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 15.9 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.69
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.555
 Length to Beam Ratio: 10.20 : 1
 'Natural speed' for length: 30.27 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  32.00 ft / 9.75 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.56 ft / 7.79 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 132.5 %
  - Above water (accommodation/working, high = better): 155.5 %
 Waterplane Area: 36,486 Square feet or 3,390 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 132 lbs/sq ft or 644 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.51
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Tuesday, December 20, 2005

The GB/CA/1935 design

The GB/CA/1935 design consolidates the progress made up to the previous design. The armour basis is now 5in and the range is 8,500nm at 15 knots. The maximum speed of 35 knots is competitive with the Japanese ships and probably is better, in that a larger ship with a higher freeboard will maintain its speed better in a seaway. This design can also hit harder than the Japanese, except for the torpedo situation. At least this design is said to be good for 3 torpedo hits, although perhaps of the 21in sort. This is the Springsharp report:
GB/CA/1935, Great Britain Heavy Cruiser laid down 1935

Displacement:
 17,212 t light; 17,931 t standard; 19,450 t normal; 20,665 t full load

Dimensions: Length overall / water x beam x draught
 694.00 ft / 694.00 ft x 68.00 ft x 25.00 ft (normal load)
 211.53 m / 211.53 m x 20.73 m  x 7.62 m

Armament:
      12 - 8.00" / 203 mm guns (4x3 guns), 256.00lbs / 116.12kg shells, 1935 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 4.70" / 119 mm guns (6x2 guns), 51.91lbs / 23.55kg shells, 1935 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 1.95lbs / 0.89kg shells, 1935 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 3,773 lbs / 1,711 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 5.00" / 127 mm 640.00 ft / 195.07 m 5.00 ft / 1.52 m
 Ends: Unarmoured
   Main Belt covers 142 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 640.00 ft / 195.07 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 3.00" / 76 mm  6.00" / 152 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm       -         -

   - Armour deck: 4.00" / 102 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 154,269 shp / 115,084 Kw = 35.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,735 tons

Complement:
 823 - 1,070

Cost:
 £8.207 million / $32.829 million

Distribution of weights at normal displacement:
 Armament: 472 tons, 2.4 %
 Armour: 4,962 tons, 25.5 %
    - Belts: 633 tons, 3.3 %
    - Torpedo bulkhead: 568 tons, 2.9 %
    - Armament: 1,063 tons, 5.5 %
    - Armour Deck: 2,604 tons, 13.4 %
    - Conning Tower: 93 tons, 0.5 %
 Machinery: 4,383 tons, 22.5 %
 Hull, fittings & equipment: 7,396 tons, 38.0 %
 Fuel, ammunition & stores: 2,238 tons, 11.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   24,658 lbs / 11,185 Kg = 96.3 x 8.0 " / 203 mm shells or 3.0 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 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.69
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.577
 Length to Beam Ratio: 10.21 : 1
 'Natural speed' for length: 29.78 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (50 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.56 ft / 7.49 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 130.8 %
  - Above water (accommodation/working, high = better): 149.8 %
 Waterplane Area: 35,189 Square feet or 3,269 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 129 lbs/sq ft or 628 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.42
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The GB/CA/1931 design

With the growth in the design series for the British heavy cruiser, I thought that the next obvious step would be to add a fourth triple-8in turret, bringing the main armament up to 12-8in BLR. I tried switching the 8in guns to QF, but Springsharp will not allow QF for 8in guns. Of course, in the 1890's, British armament manufacturers built 8in QF guns for use in Elswick cruisers. This is the Springsharp report:
GB/CA/1931, Great Britain Heavy Cruiser laid down 1931

Displacement:
 16,864 t light; 17,573 t standard; 18,950 t normal; 20,051 t full load

Dimensions: Length overall / water x beam x draught
 687.00 ft / 687.00 ft x 68.00 ft x 25.00 ft (normal load)
 209.40 m / 209.40 m x 20.73 m  x 7.62 m

Armament:
      12 - 8.00" / 203 mm guns (4x3 guns), 256.00lbs / 116.12kg shells, 1931 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 4.70" / 119 mm guns (6x2 guns), 51.91lbs / 23.55kg shells, 1931 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 2.00lbs / 0.91kg shells, 1931 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 3,775 lbs / 1,712 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 640.00 ft / 195.07 m 5.00 ft / 1.52 m
 Ends: Unarmoured
   Main Belt covers 143 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 640.00 ft / 195.07 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm       -         -

   - Armour deck: 4.00" / 102 mm, Conning tower: 5.00" / 127 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 151,776 shp / 113,225 Kw = 35.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,478 tons

Complement:
 806 - 1,049

Cost:
 £7.077 million / $28.309 million

Distribution of weights at normal displacement:
 Armament: 472 tons, 2.5 %
 Armour: 4,646 tons, 24.5 %
    - Belts: 505 tons, 2.7 %
    - Torpedo bulkhead: 568 tons, 3.0 %
    - Armament: 940 tons, 5.0 %
    - Armour Deck: 2,555 tons, 13.5 %
    - Conning Tower: 77 tons, 0.4 %
 Machinery: 4,539 tons, 24.0 %
 Hull, fittings & equipment: 7,208 tons, 38.0 %
 Fuel, ammunition & stores: 2,086 tons, 11.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   22,983 lbs / 10,425 Kg = 89.8 x 8.0 " / 203 mm shells or 2.7 torpedoes
 Stability (Unstable if below 1.00): 1.11
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.69
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.568
 Length to Beam Ratio: 10.10 : 1
 'Natural speed' for length: 29.67 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (50 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.56 ft / 7.49 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 137.9 %
  - Above water (accommodation/working, high = better): 149.6 %
 Waterplane Area: 34,531 Square feet or 3,208 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 127 lbs/sq ft or 622 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.46
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Monday, December 19, 2005

The GB/CA/1927 design

This generation of the design series is somewhat similar to the American Baltimore class. This design suffers from the overweight machinery used by Springsharp. In reality, the machinery should be lighter in weight for the power produced. I did not want to do that for this complete design series, however. The GB/CA/1927 generation mainly increases the speed to 35 knots, and has a secondary armament of 12-4.7in DP guns. The deck armour is also increased to 3.5in. This is the Springsharp report:
GB/CA/1927, Great Britain Heavy Cruiser laid down 1927

Displacement:
 15,789 t light; 16,405 t standard; 17,600 t normal; 18,556 t full load

Dimensions: Length overall / water x beam x draught
 674.10 ft / 672.00 ft x 64.00 ft x 25.00 ft (normal load)
 205.47 m / 204.83 m x 19.51 m  x 7.62 m

Armament:
      9 - 8.00" / 203 mm guns (3x3 guns), 256.00lbs / 116.12kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 4.70" / 119 mm guns (6x2 guns), 51.91lbs / 23.55kg shells, 1927 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      32 - 1.57" / 40.0 mm guns (8x4 guns), 1.95lbs / 0.89kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
      4 - 0.00" / 0.0 mm guns in single mounts, 0.00lbs / 0.00kg shells, 1927 Model
   Breech loading guns in deck mount 
   on side, evenly spread
 Weight of broadside 2,989 lbs / 1,356 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 600.00 ft / 182.88 m 14.00 ft / 4.27 m
 Ends: Unarmoured
   Main Belt covers 137 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 600.00 ft / 182.88 m 23.00 ft / 7.01 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: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 3.50" / 89 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 146,241 shp / 109,096 Kw = 35.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,152 tons

Complement:
 763 - 993

Cost:
 £5.501 million / $22.004 million

Distribution of weights at normal displacement:
 Armament: 374 tons, 2.1 %
 Armour: 4,491 tons, 25.5 %
    - Belts: 1,335 tons, 7.6 %
    - Torpedo bulkhead: 511 tons, 2.9 %
    - Armament: 519 tons, 2.9 %
    - Armour Deck: 2,068 tons, 11.8 %
    - Conning Tower: 58 tons, 0.3 %
 Machinery: 4,616 tons, 26.2 %
 Hull, fittings & equipment: 6,308 tons, 35.8 %
 Fuel, ammunition & stores: 1,811 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,013 lbs / 9,078 Kg = 78.2 x 8.0 " / 203 mm shells or 2.3 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.6 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.573
 Length to Beam Ratio: 10.50 : 1
 'Natural speed' for length: 29.25 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  30.00 ft / 9.14 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.56 ft / 7.18 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 148.2 %
  - Above water (accommodation/working, high = better): 136.4 %
 Waterplane Area: 31,944 Square feet or 2,968 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 118 lbs/sq ft or 574 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.50
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, December 18, 2005

The GB/CA/1923 design

The GB/CA/1923 design works quite well. The ship has a flush deck and a transom stern. The armament is almost the same as the 1921 ship, except that the light AA armament is now 32-2pdr AA. The belt is long enough to satisfy Springsharp, and is still 4in. The deck is increased to 3in. The maximum speed is now 34 knots, with the same 6,500nm range at 15 knots. This is the Springsharp report:
GB/CA/1923, Great Britain Heavy Cruiser laid down 1923

Displacement:
 15,013 t light; 15,591 t standard; 16,800 t normal; 17,767 t full load

Dimensions: Length overall / water x beam x draught
 657.03 ft / 655.00 ft x 64.00 ft x 23.00 ft (normal load)
 200.26 m / 199.64 m x 19.51 m  x 7.01 m

Armament:
      9 - 8.00" / 203 mm guns (3x3 guns), 256.00lbs / 116.12kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1923 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      32 - 1.57" / 40.0 mm guns (8x4 guns), 1.95lbs / 0.89kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
      4 - 0.00" / 0.0 mm guns in single mounts, 0.00lbs / 0.00kg shells, 1923 Model
   Breech loading guns in deck mount 
   on side, evenly spread
 Weight of broadside 2,782 lbs / 1,262 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 640.00 ft / 195.07 m 14.00 ft / 4.27 m
 Ends: Unarmoured
   Main Belt covers 150 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 640.00 ft / 195.07 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
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 130,529 shp / 97,375 Kw = 34.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,176 tons

Complement:
 737 - 959

Cost:
 £4.155 million / $16.620 million

Distribution of weights at normal displacement:
 Armament: 348 tons, 2.1 %
 Armour: 4,258 tons, 25.3 %
    - Belts: 1,398 tons, 8.3 %
    - Torpedo bulkhead: 521 tons, 3.1 %
    - Armament: 492 tons, 2.9 %
    - Armour Deck: 1,790 tons, 10.7 %
    - Conning Tower: 57 tons, 0.3 %
 Machinery: 4,363 tons, 26.0 %
 Hull, fittings & equipment: 6,044 tons, 36.0 %
 Fuel, ammunition & stores: 1,787 tons, 10.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,426 lbs / 9,265 Kg = 79.8 x 8.0 " / 203 mm shells or 2.4 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.3 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.610
 Length to Beam Ratio: 10.23 : 1
 'Natural speed' for length: 28.84 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.00 ft / 8.84 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.48 ft / 7.16 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 146.4 %
  - Above water (accommodation/working, high = better): 141.3 %
 Waterplane Area: 32,256 Square feet or 2,997 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 115 lbs/sq ft or 564 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.45
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The GB/CA/1921 design

I was greatly tempted to switch to light weight machinery, but I did not want to alter the series that way. I probably will try a new series with light weight machinery, to demonstrate the radical difference that I know it makes. The GB/CA/1921 does have a flush deck and triple 8in turrets, along with dual-purpose 4.7in guns. The speed is now 33 knots. The armour basis is still 4in and the deck is 2in. This is the Springsharp report:
GB/CA/1921, Great Britain Heavy Cruiser laid down 1921

Displacement:
 13,824 t light; 14,377 t standard; 15,600 t normal; 16,579 t full load

Dimensions: Length overall / water x beam x draught
 627.03 ft / 625.00 ft x 63.00 ft x 23.00 ft (normal load)
 191.12 m / 190.50 m x 19.20 m  x 7.01 m

Armament:
      9 - 8.00" / 203 mm guns (3x3 guns), 256.00lbs / 116.12kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1921 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      24 - 1.57" / 40.0 mm guns (6x4 guns), 2.00lbs / 0.91kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
      4 - 0.00" / 0.0 mm guns in single mounts, 0.00lbs / 0.00kg shells, 1921 Model
   Breech loading guns in deck mount 
   on side, evenly spread
 Weight of broadside 2,767 lbs / 1,255 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 590.00 ft / 179.83 m 14.00 ft / 4.27 m
 Ends: Unarmoured
   Main Belt covers 145 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 590.00 ft / 179.83 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
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 129,200 shp / 96,383 Kw = 33.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,202 tons

Complement:
 697 - 907

Cost:
 £3.556 million / $14.226 million

Distribution of weights at normal displacement:
 Armament: 346 tons, 2.2 %
 Armour: 3,397 tons, 21.8 %
    - Belts: 1,303 tons, 8.4 %
    - Torpedo bulkhead: 480 tons, 3.1 %
    - Armament: 492 tons, 3.2 %
    - Armour Deck: 1,068 tons, 6.8 %
    - Conning Tower: 54 tons, 0.3 %
 Machinery: 4,449 tons, 28.5 %
 Hull, fittings & equipment: 5,632 tons, 36.1 %
 Fuel, ammunition & stores: 1,776 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   15,545 lbs / 7,051 Kg = 60.7 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.3 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.61
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.603
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 25.00 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.00 ft / 8.84 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 23.48 ft / 7.16 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 161.0 %
  - Above water (accommodation/working, high = better): 130.7 %
 Waterplane Area: 28,876 Square feet or 2,683 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 115 lbs/sq ft or 561 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.59
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Saturday, December 17, 2005

My latest design for a British 8in-gun cruiser laid down in 1918

My opinion is that a satisfactory 8in cruiser design could not be restricted to 10,000 tons, standard. The design I propose hear is much larger, and is pretty well protected, as well as having an 8in gun armament and a 4in armour basis. The maximum speed is 32 knots with a 6,500nm range at 15 knots. I suspect that the ship should have lighter machinery (instead of 27.7 SHP/ton), and that this would cure the complaints about belt length. Contemporary Japanese ships had much lighter machinery. This is the Springsharp report:
GB/CA/1918, Great Britain Heavy Cruiser laid down 1918

Displacement:
 12,720 t light; 13,243 t standard; 14,500 t normal; 15,506 t full load

Dimensions: Length overall / water x beam x draught
 616.96 ft / 615.00 ft x 63.00 ft x 23.00 ft (normal load)
 188.05 m / 187.45 m x 19.20 m  x 7.01 m

Armament:
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
      24 - 1.57" / 40.0 mm guns (6x4 guns), 2.00lbs / 0.91kg shells, 1918 Model
   Breech loading guns in deck mounts 
   on side, evenly spread
 Weight of broadside 2,639 lbs / 1,197 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 570.00 ft / 173.74 m 14.00 ft / 4.27 m
 Ends: Unarmoured
   Main Belt covers 143 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 570.00 ft / 173.74 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
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 108,215 shp / 80,728 Kw = 32.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,263 tons

Complement:
 659 - 858

Cost:
 £2.538 million / $10.150 million

Distribution of weights at normal displacement:
 Armament: 330 tons, 2.3 %
 Armour: 3,299 tons, 22.7 %
    - Belts: 1,263 tons, 8.7 %
    - Torpedo bulkhead: 464 tons, 3.2 %
    - Armament: 502 tons, 3.5 %
    - Armour Deck: 1,019 tons, 7.0 %
    - Conning Tower: 51 tons, 0.4 %
 Machinery: 3,904 tons, 26.9 %
 Hull, fittings & equipment: 5,188 tons, 35.8 %
 Fuel, ammunition & stores: 1,780 tons, 12.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   15,585 lbs / 7,069 Kg = 60.9 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.57
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.569
 Length to Beam Ratio: 9.76 : 1
 'Natural speed' for length: 24.80 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.68 ft / 6.61 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 154.2 %
  - Above water (accommodation/working, high = better): 136.4 %
 Waterplane Area: 27,539 Square feet or 2,558 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 115 lbs/sq ft or 561 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.36
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Friday, December 16, 2005

My quick and dirty GB/CA/1916 design

The main problem with my GB/CA/1916 design has to do with the armament layout. Can 9-8in guns fit on the centerline, even with superfiring guns? Also, Springsharp is behaving strangely with respect to the belt length. I was not able to satisfy the magazine and machinery coverage, despite a long belt and having increased the height to 14ft. The speed is now 30 knots with a range of 6,200nm at 15 knots. I have retained the 4.7in gun secondary armament, and increased the torpedo armament to 8 tubes. The design should be superior to the Raleighs and the Kakos, except for the latter's high speed. This is the Springsharp report:
GB/CA/1916, Great Britain Cruiser laid down 1916

Displacement:
 10,369 t light; 10,854 t standard; 12,000 t normal; 12,917 t full load

Dimensions: Length overall / water x beam x draught
 596.42 ft / 595.00 ft x 60.00 ft x 22.00 ft (normal load)
 181.79 m / 181.36 m x 18.29 m  x 6.71 m

Armament:
      9 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1916 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority forward, 3 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
      16 - 1.57" / 40.0 mm guns (4x4 guns), 2.00lbs / 0.91kg shells, 1916 Model
   Breech loading guns in deck mounts 
   on side, evenly spread
 Weight of broadside 2,815 lbs / 1,277 kg
 Shells per gun, main battery: 150
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 550.00 ft / 167.64 m 14.00 ft / 4.27 m
 Ends: Unarmoured
   Main Belt covers 142 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 550.00 ft / 167.64 m 20.00 ft / 6.10 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: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 73,876 shp / 55,111 Kw = 30.00 kts
 Range 6,200nm at 15.00 kts
 Bunker at max displacement = 2,064 tons

Complement:
 573 - 745

Cost:
 £1.708 million / $6.832 million

Distribution of weights at normal displacement:
 Armament: 352 tons, 2.9 %
 Armour: 2,863 tons, 23.9 %
    - Belts: 1,216 tons, 10.1 %
    - Torpedo bulkhead: 407 tons, 3.4 %
    - Armament: 286 tons, 2.4 %
    - Armour Deck: 909 tons, 7.6 %
    - Conning Tower: 45 tons, 0.4 %
 Machinery: 2,752 tons, 22.9 %
 Hull, fittings & equipment: 4,401 tons, 36.7 %
 Fuel, ammunition & stores: 1,631 tons, 13.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,896 lbs / 6,757 Kg = 58.2 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.2 ft / 1.0 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 62 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.25

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.535
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 24.39 kts
 Power going to wave formation at top speed: 54 %
 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 (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 20.68 ft / 6.30 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 146.2 %
  - Above water (accommodation/working, high = better): 143.5 %
 Waterplane Area: 24,562 Square feet or 2,282 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 108 lbs/sq ft or 527 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.41
  - 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

Thursday, December 15, 2005

Another attempt at an 8in gun cruiser from 1914

I wanted to try again to design a series of 8in gun British cruisers, starting in 1914. I would have liked a higher speed, but 28.5 knots was what was readily achievable. The armour basis is 4in with a 2in deck. This is the Springsharp report:
GB/CA/1914, Great Britain Cruiser laid down 1914

Displacement:
 8,359 t light; 8,747 t standard; 9,700 t normal; 10,462 t full load

Dimensions: Length overall / water x beam x draught
 546.36 ft / 545.00 ft x 56.00 ft x 20.00 ft (normal load)
 166.53 m / 166.12 m x 17.07 m  x 6.10 m

Armament:
      7 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority forward, 3 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 2,234 lbs / 1,013 kg
 Shells per gun, main battery: 150
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 520.00 ft / 158.50 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 147 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 520.00 ft / 158.50 m 18.00 ft / 5.49 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: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 55,251 shp / 41,217 Kw = 28.50 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 1,715 tons

Complement:
 488 - 635

Cost:
 £1.050 million / $4.201 million

Distribution of weights at normal displacement:
 Armament: 279 tons, 2.9 %
 Armour: 2,394 tons, 24.7 %
    - Belts: 980 tons, 10.1 %
    - Torpedo bulkhead: 346 tons, 3.6 %
    - Armament: 236 tons, 2.4 %
    - Armour Deck: 793 tons, 8.2 %
    - Conning Tower: 39 tons, 0.4 %
 Machinery: 2,128 tons, 21.9 %
 Hull, fittings & equipment: 3,557 tons, 36.7 %
 Fuel, ammunition & stores: 1,341 tons, 13.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   12,616 lbs / 5,723 Kg = 49.3 x 8.0 " / 203 mm shells or 1.9 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 2.9 ft / 0.9 m
 Roll period: 13.9 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.28

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.556
 Length to Beam Ratio: 9.73 : 1
 'Natural speed' for length: 23.35 kts
 Power going to wave formation at top speed: 54 %
 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 (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 22.00 ft / 6.71 m
    - Mid (67 %):  22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
    - Quarterdeck (15 %): 14.00 ft / 4.27 m
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 19.68 ft / 6.00 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 146.0 %
  - Above water (accommodation/working, high = better): 150.5 %
 Waterplane Area: 21,424 Square feet or 1,990 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 100 lbs/sq ft or 489 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.47
  - 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

Wednesday, December 14, 2005

The GB/CL/1937 converted to an 8in-gun cruiser: GB/CA/1937

I thought that converting the GB/CL/1937 to have 8-in guns would be interesting, sort of along the lines of the Mogami class. The speed is reduced to 35 knots, which is sufficient, anyway. The new armament is 8-8in BLR, 12-4in AA, 32-2pdr AA, and 16-21in TT. The armour basis is still 4in with a 2in deck. I did decide that a heavy cruiser needed a torpedo bulkhead, and that was a factor in reducing the speed. This is the revised Springsharp report:
GB/CA/1937, Great Britain Heavy Cruiser laid down 1937

Displacement:
 13,882 t light; 14,342 t standard; 15,700 t normal; 16,786 t full load

Dimensions: Length overall / water x beam x draught
 668.96 ft / 665.00 ft x 64.00 ft x 25.00 ft (normal load)
 203.90 m / 202.69 m x 19.51 m  x 7.62 m

Armament:
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1937 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      32 - 1.57" / 40.0 mm guns (8x4 guns), 2.00lbs / 0.91kg shells, 1937 Model
   Breech loading guns in deck mounts 
   on side, evenly spread, 4 raised mounts
 Weight of broadside 2,496 lbs / 1,132 kg
 Shells per gun, main battery: 100
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 560.00 ft / 170.69 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 130 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 560.00 ft / 170.69 m 24.00 ft / 7.32 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: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 153,169 shp / 114,264 Kw = 35.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,444 tons

Complement:
 700 - 911

Cost:
 £7.321 million / $29.283 million

Distribution of weights at normal displacement:
 Armament: 312 tons, 2.0 %
 Armour: 3,220 tons, 20.5 %
    - Belts: 1,075 tons, 6.8 %
    - Torpedo bulkhead: 497 tons, 3.2 %
    - Armament: 529 tons, 3.4 %
    - Armour Deck: 1,065 tons, 6.8 %
    - Conning Tower: 54 tons, 0.3 %
 Machinery: 4,245 tons, 27.0 %
 Hull, fittings & equipment: 6,105 tons, 38.9 %
 Fuel, ammunition & stores: 1,818 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,756 lbs / 8,054 Kg = 69.4 x 8.0 " / 203 mm shells or 2.2 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 3.2 ft / 1.0 m
 Roll period: 15.0 seconds
 Steadiness - As gun platform (Average = 50 %): 59 %
   - Recoil effect (Restricted arc if above 1.00): 0.63
 Seaboat quality  (Average = 1.00): 1.18

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.516
 Length to Beam Ratio: 10.39 : 1
 'Natural speed' for length: 25.79 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 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 %): 24.00 ft / 7.32 m
    - Mid (50 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.32 ft / 7.41 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 149.7 %
  - Above water (accommodation/working, high = better): 139.3 %
 Waterplane Area: 28,788 Square feet or 2,674 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 118 lbs/sq ft or 576 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.71
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Tuesday, December 13, 2005

A really extreme ship: the GB/CL/1937 design

I would call the GB/CL/1937 design extreme due to the ship's size and the high speed. I would never expect that British to build such a fast ship, although it would be very capable. The armour basis is still 4in and the deck is 2in. There is no torpedo bulkhead armour. The speed is 37 knots with a range of 8,500nm at 15 knots. The armament is 12-6in QF, 12-4in AA, 32-2pdr AA guns, and 16-21in TT. This is the Springsharp report:
GB/CL/1937, Great Britain Light Cruiser laid down 1937

Displacement:
 14,150 t light; 14,627 t standard; 16,000 t normal; 17,098 t full load

Dimensions: Length overall / water x beam x draught
 668.96 ft / 665.00 ft x 64.00 ft x 25.00 ft (normal load)
 203.90 m / 202.69 m x 19.51 m  x 7.62 m

Armament:
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1937 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, 4 raised mounts - superfiring
      32 - 1.57" / 40.0 mm guns (8x4 guns), 2.00lbs / 0.91kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side ends, evenly spread, 4 raised mounts - superfiring
 Weight of broadside 1,744 lbs / 791 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 560.00 ft / 170.69 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 130 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 195,898 shp / 146,140 Kw = 37.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,471 tons

Complement:
 710 - 924

Cost:
 £7.846 million / $31.382 million

Distribution of weights at normal displacement:
 Armament: 218 tons, 1.4 %
 Armour: 2,624 tons, 16.4 %
    - Belts: 1,076 tons, 6.7 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 419 tons, 2.6 %
    - Armour Deck: 1,075 tons, 6.7 %
    - Conning Tower: 55 tons, 0.3 %
 Machinery: 5,430 tons, 33.9 %
 Hull, fittings & equipment: 5,879 tons, 36.7 %
 Fuel, ammunition & stores: 1,850 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   13,562 lbs / 6,152 Kg = 125.6 x 6.0 " / 152 mm shells or 1.4 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.6 ft / 1.1 m
 Roll period: 14.1 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.36
 Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.526
 Length to Beam Ratio: 10.39 : 1
 'Natural speed' for length: 25.79 kts
 Power going to wave formation at top speed: 62 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.32 ft / 7.41 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 120.7 %
  - Above water (accommodation/working, high = better): 138.6 %
 Waterplane Area: 29,052 Square feet or 2,699 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 113 lbs/sq ft or 551 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.77
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

The GB/CL/1935 light cruiser design

The GB/CL/1935 design is almost a Mogami-type ship, except that this design has a larger displacement and a deeper draft. The draft is abnormal, as this is a convenient way, in Springsharp, to increase strength. I am sorry to say that I will resort to such measures. The main difference with this design is the 36-knot speed and the 8,500nm range at 15 knots. The armour basis is still 4in with a 2in deck. The armament stayed the same with 12-6in QF, 8-4in AA, 28-2pdr AA, and 16-21in TT. This is the Springsharp report:
GB/CL/1935, Great Britain Light Cruiser laid down 1935

Displacement:
 12,475 t light; 12,901 t standard; 14,200 t normal; 15,239 t full load

Dimensions: Length overall / water x beam x draught
 646.42 ft / 645.00 ft x 62.00 ft x 25.00 ft (normal load)
 197.03 m / 196.60 m x 18.90 m  x 7.62 m

Armament:
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1935 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      8 - 4.00" / 102 mm guns (4x2 guns), 32.00lbs / 14.51kg shells, 1935 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      28 - 1.57" / 40.0 mm guns (7x4 guns), 1.95lbs / 0.89kg shells, 1935 Model
   Anti-aircraft guns in deck mounts 
   on side ends, majority aft, 3 raised mounts - superfiring
 Weight of broadside 1,607 lbs / 729 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 550.00 ft / 167.64 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 131 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 162,325 shp / 121,094 Kw = 36.00 kts
 Range 8,500nm at 15.00 kts
 Bunker at max displacement = 2,338 tons

Complement:
 649 - 845

Cost:
 £6.368 million / $25.474 million

Distribution of weights at normal displacement:
 Armament: 201 tons, 1.4 %
 Armour: 2,471 tons, 17.4 %
    - Belts: 1,053 tons, 7.4 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 384 tons, 2.7 %
    - Armour Deck: 983 tons, 6.9 %
    - Conning Tower: 51 tons, 0.4 %
 Machinery: 4,612 tons, 32.5 %
 Hull, fittings & equipment: 5,192 tons, 36.6 %
 Fuel, ammunition & stores: 1,725 tons, 12.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   12,772 lbs / 5,793 Kg = 118.3 x 6.0 " / 152 mm shells or 1.4 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.36
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.497
 Length to Beam Ratio: 10.40 : 1
 'Natural speed' for length: 25.40 kts
 Power going to wave formation at top speed: 60 %
 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 (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 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: 22.52 ft / 6.86 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.5 %
  - Above water (accommodation/working, high = better): 128.7 %
 Waterplane Area: 26,575 Square feet or 2,469 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 110 lbs/sq ft or 538 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.65
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

A more capable British light cruiser is possible by 1931

By ballooning the displacement even more, a 35-knot light cruiser with 12-6in QF, 8-4in AA, 28-2pdr AA, and 16-21in TT is possible. The armour basis is still 4in and the range is now 8,200nm at 15 knots. This design, the GB/CL/1931, is roughly comparable to the Mogami class prior to being rearmed with 8in guns. This is the Springsharp report:
GB/CL/1931, Great Britain Light Cruiser laid down 1931

Displacement:
 11,644 t light; 12,052 t standard; 13,300 t normal; 14,298 t full load

Dimensions: Length overall / water x beam x draught
 626.42 ft / 625.00 ft x 61.00 ft x 24.00 ft (normal load)
 190.93 m / 190.50 m x 18.59 m  x 7.32 m

Armament:
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1931 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      8 - 4.00" / 102 mm guns (4x2 guns), 32.00lbs / 14.51kg shells, 1931 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      28 - 1.57" / 40.0 mm guns (7x4 guns), 1.95lbs / 0.89kg shells, 1931 Model
   Anti-aircraft guns in deck mounts 
   on side ends, majority aft, 3 raised mounts - superfiring
 Weight of broadside 1,607 lbs / 729 kg
 Shells per gun, main battery: 150
 16 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 550.00 ft / 167.64 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 135 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 141,896 shp / 105,854 Kw = 35.00 kts
 Range 8,200nm at 15.00 kts
 Bunker at max displacement = 2,246 tons

Complement:
 619 - 805

Cost:
 £5.107 million / $20.427 million

Distribution of weights at normal displacement:
 Armament: 201 tons, 1.5 %
 Armour: 2,417 tons, 18.2 %
    - Belts: 1,049 tons, 7.9 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 372 tons, 2.8 %
    - Armour Deck: 947 tons, 7.1 %
    - Conning Tower: 48 tons, 0.4 %
 Machinery: 4,243 tons, 31.9 %
 Hull, fittings & equipment: 4,783 tons, 36.0 %
 Fuel, ammunition & stores: 1,656 tons, 12.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   12,129 lbs / 5,502 Kg = 112.3 x 6.0 " / 152 mm shells or 1.4 torpedoes
 Stability (Unstable if below 1.00): 1.22
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 13.8 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.37
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.509
 Length to Beam Ratio: 10.25 : 1
 'Natural speed' for length: 25.00 kts
 Power going to wave formation at top speed: 60 %
 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 (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.60 ft / 6.58 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 115.4 %
  - Above water (accommodation/working, high = better): 122.0 %
 Waterplane Area: 25,606 Square feet or 2,379 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 108 lbs/sq ft or 527 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

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