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Tuesday, October 31, 2006

HMS Incomparable

I found a page with the specification for the HMS Incomparable design project on Bob Henneman's site. The basic concept was for a 1000ft-long ship with 6-20in guns and a good speed. I tried to implement that in Springsharp, but was not very successful for a number of reasons. One is that Springsharp would only give a speed of 29 knots for a little over 180,000 SHP. Another was the due to the shallow draft, I had to greatly increase the displacement, which only made the powering situation worse. This is the Springsharp report, for what it is worth:
HMS Incomparable, Great Britain Battlecruiser laid down 1916

Displacement:
 60,067 t light; 62,631 t standard; 66,500 t normal; 69,595 t full load

Dimensions: Length overall / water x beam x draught
 1,001.73 ft / 1,000.00 ft x 104.00 ft x 25.00 ft (normal load)
 305.33 m / 304.80 m x 31.70 m  x 7.62 m

Armament:
      6 - 20.00" / 508 mm guns (3x2 guns), 4,000.00lbs / 1,814.37kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      9 - 4.00" / 102 mm guns (3x3 guns), 32.00lbs / 14.51kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority aft, 2 raised mounts - superfiring
      6 - 4.00" / 102 mm guns (2x3 guns), 32.00lbs / 14.51kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline, all amidships, all raised mounts - superfiring
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 24,534 lbs / 11,128 kg
 Shells per gun, main battery: 90
 8 - 21.0" / 533.4 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 620.00 ft / 188.98 m 8.00 ft / 2.44 m
 Ends: 5.00" / 127 mm 300.00 ft / 91.44 m 8.00 ft / 2.44 m
   80.00 ft / 24.38 m Unarmoured ends
 Upper: 7.00" / 178 mm 620.00 ft / 188.98 m 8.00 ft / 2.44 m
   Main Belt covers 95 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 620.00 ft / 188.98 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 9.00" / 229 mm  14.0" / 356 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 10.00" / 254 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 183,292 shp / 136,736 Kw = 29.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 6,965 tons

Complement:
 2,069 - 2,691

Cost:
 £9.220 million / $36.880 million

Distribution of weights at normal displacement:
 Armament: 3,067 tons, 4.6 %
 Armour: 16,804 tons, 25.3 %
    - Belts: 4,027 tons, 6.1 %
    - Torpedo bulkhead: 1,101 tons, 1.7 %
    - Armament: 4,058 tons, 6.1 %
    - Armour Deck: 7,264 tons, 10.9 %
    - Conning Tower: 354 tons, 0.5 %
 Machinery: 6,829 tons, 10.3 %
 Hull, fittings & equipment: 33,367 tons, 50.2 %
 Fuel, ammunition & stores: 6,433 tons, 9.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   108,217 lbs / 49,087 Kg = 27.1 x 20.0 " / 508 mm shells or 13.3 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 7.0 ft / 2.1 m
 Roll period: 16.5 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.93
 Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.895
 Length to Beam Ratio: 9.62 : 1
 'Natural speed' for length: 31.62 kts
 Power going to wave formation at top speed: 45 %
 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:  33.00 ft / 10.06 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m (21.00 ft / 6.40 m aft of break)
    - Quarterdeck (15 %): 21.00 ft / 6.40 m
    - Stern:  21.00 ft / 6.40 m
    - Average freeboard: 26.68 ft / 8.13 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 87.4 %
  - Above water (accommodation/working, high = better): 242.1 %
 Waterplane Area: 98,168 Square feet or 9,120 Square metres
 Displacement factor (Displacement / loading): 121 %
 Structure weight / hull surface area: 260 lbs/sq ft or 1,271 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.33
  - Longitudinal: 0.91
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Monday, October 30, 2006

An extremely shallow draft fast battleship: GB/BB/1915 Design A

John Roberts, in his Battlecruisers book, has the specifications for the design studies for a fast battleship to be built in 1915 or 1916. The ship would have been the length of the Renown, with a greater beam, but an extremely shallow draft. That was to reduce the risk of torpedo attack. The armament was 8-15in and 12-5in guns. The armour basis was 10in. I gave the ship a 3in deck armour, as the deck armour was not specified. 3in may have been greater than the design was actually given. When I implemented Design A in Springsharp, I had to increase the displacement to achieve an adequate strength. This is the Springsharp report:
GB/BB/1915 Design A, Great Britain Fast Battleship laid down 1915

Displacement:
 31,754 t light; 33,182 t standard; 35,400 t normal; 37,175 t full load

Dimensions: Length overall / water x beam x draught
 796.17 ft / 794.00 ft x 104.00 ft x 23.50 ft (normal load)
 242.67 m / 242.01 m x 31.70 m  x 7.16 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 1,687.50lbs / 765.44kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1915 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 14,250 lbs / 6,464 kg
 Shells per gun, main battery: 90
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 535.00 ft / 163.07 m 8.00 ft / 2.44 m
 Ends: 5.00" / 127 mm 240.00 ft / 73.15 m 8.00 ft / 2.44 m
   19.00 ft / 5.79 m Unarmoured ends
 Upper: 7.00" / 178 mm 535.00 ft / 163.07 m 8.00 ft / 2.44 m
   Main Belt covers 104 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 535.00 ft / 163.07 m 23.50 ft / 7.16 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 9.00" / 229 mm  10.0" / 254 mm
 2nd: 5.00" / 127 mm 2.00" / 51 mm  5.00" / 127 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 88,293 shp / 65,866 Kw = 26.50 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 3,993 tons

Complement:
 1,289 - 1,677

Cost:
 £4.474 million / $17.896 million

Distribution of weights at normal displacement:
 Armament: 1,781 tons, 5.0 %
 Armour: 10,896 tons, 30.8 %
    - Belts: 3,461 tons, 9.8 %
    - Torpedo bulkhead: 930 tons, 2.6 %
    - Armament: 2,775 tons, 7.8 %
    - Armour Deck: 3,474 tons, 9.8 %
    - Conning Tower: 256 tons, 0.7 %
 Machinery: 3,344 tons, 9.4 %
 Hull, fittings & equipment: 15,733 tons, 44.4 %
 Fuel, ammunition & stores: 3,646 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   61,481 lbs / 27,887 Kg = 36.4 x 15.0 " / 381 mm shells or 9.6 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 7.2 ft / 2.2 m
 Roll period: 16.3 seconds
 Steadiness - As gun platform (Average = 50 %): 65 %
   - Recoil effect (Restricted arc if above 1.00): 0.62
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.638
 Length to Beam Ratio: 7.63 : 1
 'Natural speed' for length: 28.18 kts
 Power going to wave formation at top speed: 45 %
 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:  31.00 ft / 9.45 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (67 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 23.76 ft / 7.24 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 85.1 %
  - Above water (accommodation/working, high = better): 212.6 %
 Waterplane Area: 62,592 Square feet or 5,815 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 191 lbs/sq ft or 931 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.00
  - Longitudinal: 1.02
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Saturday, October 28, 2006

The GB/CA/1913 Design E2

The E2 design study from 1913 is interesting, as an example of a 9.2in gun armoured cruiser with a good speed. There are no dimensions, just a displacement and weights, in the specifcation in D. K. Brown's book, The Grand Fleet (1999). These are the specified weights:
Hull      5500 tons
Armament  1900 tons
Armour    3560 tons
Machinery 2700 tons

This is the Springsharp report:
GB/CA/1913 Design E2, Enter country Enter ship type laid down 1913

Displacement:
 13,603 t light; 14,186 t standard; 17,250 t normal; 19,701 t full load

Dimensions: Length overall / water x beam x draught
 550.00 ft / 550.00 ft x 78.00 ft x 25.00 ft (normal load)
 167.64 m / 167.64 m x 23.77 m  x 7.62 m

Armament:
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1913 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1913 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      8 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1913 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   8 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 3,979 lbs / 1,805 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 370.00 ft / 112.78 m 8.00 ft / 2.44 m
 Ends: 3.00" / 76 mm 120.00 ft / 36.58 m 8.00 ft / 2.44 m
   60.00 ft / 18.29 m Unarmoured ends
 Upper: 4.00" / 102 mm 370.00 ft / 112.78 m 8.00 ft / 2.44 m
   Main Belt covers 103 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 370.00 ft / 112.78 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 3rd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 76,885 shp / 57,356 Kw = 28.00 kts
 Range 5,500nm at 18.00 kts
 Bunker at max displacement = 5,514 tons (100% coal)

Complement:
 752 - 978

Cost:
 £1.481 million / $5.925 million

Distribution of weights at normal displacement:
 Armament: 497 tons, 2.9 %
 Armour: 3,983 tons, 23.1 %
    - Belts: 1,376 tons, 8.0 %
    - Torpedo bulkhead: 513 tons, 3.0 %
    - Armament: 886 tons, 5.1 %
    - Armour Deck: 1,121 tons, 6.5 %
    - Conning Tower: 86 tons, 0.5 %
 Machinery: 3,314 tons, 19.2 %
 Hull, fittings & equipment: 5,809 tons, 33.7 %
 Fuel, ammunition & stores: 3,647 tons, 21.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   24,308 lbs / 11,026 Kg = 62.4 x 9.2 " / 234 mm shells or 3.5 torpedoes
 Stability (Unstable if below 1.00): 1.30
 Metacentric height 5.5 ft / 1.7 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.33
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.563
 Length to Beam Ratio: 7.05 : 1
 'Natural speed' for length: 23.45 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 55
 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 space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 113.7 %
  - Above water (accommodation/working, high = better): 167.2 %
 Waterplane Area: 30,305 Square feet or 2,815 Square metres
 Displacement factor (Displacement / loading): 118 %
 Structure weight / hull surface area: 128 lbs/sq ft or 626 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.78
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Friday, October 27, 2006

The GB/CB/1907 Design E from 5 December 1906

Design E would have been a very good ship, as were some of the earlier versions. Design E had a 9in armour basis and had a maximum speed of 25 knots. The armament was the usual 8-12in guns and 16-4in QF guns. Design E would have been more costly, as the design displacement was 21,400 tons. This is the Springsharp report:
GB/CB/1907 Design E-5 Dec 1906, Great Britain Battlecruiser laid down 1907

Displacement:
 18,350 t light; 19,190 t standard; 22,400 t normal; 24,968 t full load

Dimensions: Length overall / water x beam x draught
 590.00 ft / 590.00 ft x 83.00 ft x 27.00 ft (normal load)
 179.83 m / 179.83 m x 25.30 m  x 8.23 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90
 5 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm   80.00 ft / 24.38 m 8.00 ft / 2.44 m
   120.00 ft / 36.58 m Unarmoured ends
 Upper: 5.00" / 127 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 390.00 ft / 118.87 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 2nd: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 56,375 shp / 42,056 Kw = 25.00 kts
 Range 5,700nm at 15.00 kts
 Bunker at max displacement = 5,778 tons (100% coal)

Complement:
 915 - 1,190

Cost:
 £1.915 million / $7.660 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.1 %
 Armour: 5,692 tons, 25.4 %
    - Belts: 1,978 tons, 8.8 %
    - Torpedo bulkhead: 584 tons, 2.6 %
    - Armament: 1,659 tons, 7.4 %
    - Armour Deck: 1,316 tons, 5.9 %
    - Conning Tower: 154 tons, 0.7 %
 Machinery: 3,523 tons, 15.7 %
 Hull, fittings & equipment: 8,206 tons, 36.6 %
 Fuel, ammunition & stores: 4,050 tons, 18.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   29,018 lbs / 13,162 Kg = 33.6 x 12.0 " / 305 mm shells or 4.0 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 5.1 ft / 1.6 m
 Roll period: 15.4 seconds
 Steadiness - As gun platform (Average = 50 %): 73 %
   - Recoil effect (Restricted arc if above 1.00): 0.64
 Seaboat quality  (Average = 1.00): 1.45

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.593
 Length to Beam Ratio: 7.11 : 1
 'Natural speed' for length: 24.29 kts
 Power going to wave formation at top speed: 51 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (68 %):  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: 22.68 ft / 6.91 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 112.7 %
  - Above water (accommodation/working, high = better): 169.7 %
 Waterplane Area: 35,581 Square feet or 3,306 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 155 lbs/sq ft or 758 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.76
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Thursday, October 26, 2006

The GB/CB/1907 Design B 21 November 1906 version

The 21 November 1906 version of Design B for the GB/CB/1907 battlecruiser was extremely well-protected. The lower belt was 10in thick. The other characteristics are the same, with a speed of 24.5 knots. This is so much better than the Indefatigable that we have a hard time understanding why the 1907-1908 battlecruisers were not built to this design. This design was proteced on a similar scale to the German Von der Tann. This is the Springsharp report:
GB/CB/1907  Design B 21 November 1906, Great Britain Battlecruiser laid down 1907

Displacement:
 18,438 t light; 19,274 t standard; 22,200 t normal; 24,541 t full load

Dimensions: Length overall / water x beam x draught
 585.00 ft / 585.00 ft x 81.00 ft x 27.00 ft (normal load)
 178.31 m / 178.31 m x 24.69 m  x 8.23 m

Armament:
     4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
     4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
     16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Quick firing guns in casemate mounts
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90
 5 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
  - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 100.00 ft / 30.48 m 8.00 ft / 2.44 m
   85.00 ft / 25.91 m Unarmoured ends
 Upper: 6.00" / 152 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
   Main Belt covers 105 % of normal length
   Main belt does not fully cover magazines and engineering spaces

  - Torpedo Bulkhead:
  1.50" / 38 mm 400.00 ft / 121.92 m 26.50 ft / 8.08 m

  - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 10.0" / 254 mm 6.00" / 152 mm  10.0" / 254 mm
 2nd: 10.0" / 254 mm 6.00" / 152 mm  10.0" / 254 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

  - Armour deck: 2.00" / 51 mm, Conning tower: 10.00" / 254 mm

Machinery:
 Coal fired boilers, steam turbines,
 Direct drive, 4 shafts, 52,089 shp / 38,858 Kw = 24.50 kts
 Range 5,200nm at 15.00 kts
 Bunker at max displacement = 5,266 tons (100% coal)

Complement:
 909 - 1,182

Cost:
 £1.881 million / $7.523 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.2 %
 Armour: 6,151 tons, 27.7 %
    - Belts: 2,307 tons, 10.4 %
    - Torpedo bulkhead: 588 tons, 2.7 %
    - Armament: 1,794 tons, 8.1 %
    - Armour Deck: 1,291 tons, 5.8 %
    - Conning Tower: 170 tons, 0.8 %
 Machinery: 3,256 tons, 14.7 %
 Hull, fittings & equipment: 8,104 tons, 36.5 %
 Fuel, ammunition & stores: 3,762 tons, 16.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   29,314 lbs / 13,297 Kg = 33.9 x 12.0 " / 305 mm shells or 4.1 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 4.7 ft / 1.4 m
 Roll period: 15.8 seconds
 Steadiness - As gun platform (Average = 50 %): 74 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.48

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.607
 Length to Beam Ratio: 7.22 : 1
 'Natural speed' for length: 24.19 kts
 Power going to wave formation at top speed: 50 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (70 %):  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: 22.84 ft / 6.96 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 109.4 %
  - Above water (accommodation/working, high = better): 169.3 %
 Waterplane Area: 34,894 Square feet or 3,242 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 155 lbs/sq ft or 756 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.78
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Wednesday, October 25, 2006

The GB/CB/1907 Design B

I had no difficulty in making Design B for the GB/CB/1907 ship work in Springsharp. This is so much better than the Indefatigable, that you have to wonder why they built that ship, when they could have done better. Design B has a 9in armour basis, although only a 24.5-knot speed. The ship, of course, has 8-12in BLR and 16-4in QF guns. The boilers are coal-fired and the ship is propelled by turbines. This is the Springsharp report:
GB/CB/1907  Design B, Great Britain Battlecruiser laid down 1907

Displacement:
 17,800 t light; 18,622 t standard; 21,500 t normal; 23,802 t full load

Dimensions: Length overall / water x beam x draught
 575.00 ft / 575.00 ft x 79.00 ft x 26.50 ft (normal load)
 175.26 m / 175.26 m x 24.08 m  x 8.08 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90
 3 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 100.00 ft / 30.48 m 8.00 ft / 2.44 m
   75.00 ft / 22.86 m Unarmoured ends
 Upper: 6.00" / 152 mm 400.00 ft / 121.92 m 8.00 ft / 2.44 m
   Main Belt covers 107 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 400.00 ft / 121.92 m 26.50 ft / 8.08 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 2nd: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 51,677 shp / 38,551 Kw = 24.50 kts
 Range 5,200nm at 15.00 kts
 Bunker at max displacement = 5,181 tons (100% coal)

Complement:
 887 - 1,154

Cost:
 £1.855 million / $7.419 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.3 %
 Armour: 5,823 tons, 27.1 %
    - Belts: 2,163 tons, 10.1 %
    - Torpedo bulkhead: 588 tons, 2.7 %
    - Armament: 1,663 tons, 7.7 %
    - Armour Deck: 1,258 tons, 5.9 %
    - Conning Tower: 150 tons, 0.7 %
 Machinery: 3,230 tons, 15.0 %
 Hull, fittings & equipment: 7,819 tons, 36.4 %
 Fuel, ammunition & stores: 3,700 tons, 17.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   28,150 lbs / 12,769 Kg = 32.6 x 12.0 " / 305 mm shells or 3.9 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 4.5 ft / 1.4 m
 Roll period: 15.7 seconds
 Steadiness - As gun platform (Average = 50 %): 73 %
   - Recoil effect (Restricted arc if above 1.00): 0.79
 Seaboat quality  (Average = 1.00): 1.45

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.625
 Length to Beam Ratio: 7.28 : 1
 'Natural speed' for length: 23.98 kts
 Power going to wave formation at top speed: 51 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (70 %):  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: 22.84 ft / 6.96 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 111.6 %
  - Above water (accommodation/working, high = better): 169.1 %
 Waterplane Area: 34,009 Square feet or 3,160 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 153 lbs/sq ft or 746 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.80
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Tuesday, October 24, 2006

The Design "X4" Fast Battleship from 2 December 1905

I thought that I would make another attempt at making the Design "X4" fast battleship specification work in Springsharp. John Roberts has the summary specification on page 26 of his Battlecruisers book. This is basically the Dreadnought, with the size increased so that 25 knots is possible. This is the Springsharp report:
Design X4  2 December 1905, Great Britain Fast Battleship laid down 1906 (Engine 1908)

Displacement:
 20,687 t light; 21,657 t standard; 24,200 t normal; 26,234 t full load

Dimensions: Length overall / water x beam x draught
 623.00 ft / 623.00 ft x 83.00 ft x 27.00 ft (normal load)
 189.89 m / 189.89 m x 25.30 m  x 8.23 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      2 - 12.00" / 305 mm guns (1x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
   Breech loading guns in a turret (on a barbette)
   on centreline amidships
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      8 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1906 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, all raised mounts
      18 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1906 Model
   Breech loading guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 9,139 lbs / 4,145 kg
 Shells per gun, main battery: 90
 3 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 385.00 ft / 117.35 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 238.00 ft / 72.54 m 8.00 ft / 2.44 m
 Upper: 7.00" / 178 mm 385.00 ft / 117.35 m 8.00 ft / 2.44 m
   Main Belt covers 95 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 385.00 ft / 117.35 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 8.00" / 203 mm  11.0" / 279 mm
 2nd: 11.0" / 279 mm 8.00" / 203 mm  11.0" / 279 mm
 3rd: 11.0" / 279 mm 8.00" / 203 mm  11.0" / 279 mm
 4th: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm
 5th: 1.00" / 25 mm       -   1.00" / 25 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 11.00" / 279 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 57,989 shp / 43,259 Kw = 25.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 4,577 tons (100% coal)

Complement:
 969 - 1,261

Cost:
 £2.135 million / $8.539 million

Distribution of weights at normal displacement:
 Armament: 1,142 tons, 4.7 %
 Armour: 7,360 tons, 30.4 %
    - Belts: 2,689 tons, 11.1 %
    - Torpedo bulkhead: 769 tons, 3.2 %
    - Armament: 2,296 tons, 9.5 %
    - Armour Deck: 1,408 tons, 5.8 %
    - Conning Tower: 198 tons, 0.8 %
 Machinery: 3,222 tons, 13.3 %
 Hull, fittings & equipment: 8,963 tons, 37.0 %
 Fuel, ammunition & stores: 3,513 tons, 14.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   28,928 lbs / 13,121 Kg = 33.5 x 12.0 " / 305 mm shells or 4.4 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 4.8 ft / 1.4 m
 Roll period: 16.0 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.607
 Length to Beam Ratio: 7.51 : 1
 'Natural speed' for length: 24.96 kts
 Power going to wave formation at top speed: 49 %
 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:  27.00 ft / 8.23 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (37 %):  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: 19.20 ft / 5.85 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 106.2 %
  - Above water (accommodation/working, high = better): 135.3 %
 Waterplane Area: 38,055 Square feet or 3,535 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 165 lbs/sq ft or 804 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.30
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Monday, October 23, 2006

My attempt at a battlecruiser analog to the Queen Elizabeth class

The initial plan was to build a battlecruiser in 1912 to go with the battleships to be built. In the event, only the four battleships were built, with a fifth funded by Malaya. This is my concept of what a battlecruiser laid down in 1912, with 8-15in BLR and 16-6in QF guns, with a 9in armour basis and a 29 knot speed might be like:
GB/CB/1912, Great Britain Battlecruiser laid down 1912

Displacement:
 28,447 t light; 29,872 t standard; 32,500 t normal; 34,602 t full load

Dimensions: Length overall / water x beam x draught
 765.00 ft / 765.00 ft x 94.00 ft x 27.00 ft (normal load)
 233.17 m / 233.17 m x 28.65 m  x 8.23 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 1,687.50lbs / 765.44kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 15,228 lbs / 6,907 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 485.00 ft / 147.83 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 280.00 ft / 85.34 m 8.00 ft / 2.44 m
 Upper: 6.00" / 152 mm 485.00 ft / 147.83 m 8.00 ft / 2.44 m
   Main Belt covers 98 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 485.00 ft / 147.83 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 7.00" / 178 mm  9.00" / 229 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 114,576 shp / 85,474 Kw = 29.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,730 tons

Complement:
 1,209 - 1,573

Cost:
 £3.234 million / $12.937 million

Distribution of weights at normal displacement:
 Armament: 1,904 tons, 5.9 %
 Armour: 8,209 tons, 25.3 %
    - Belts: 2,822 tons, 8.7 %
    - Torpedo bulkhead: 727 tons, 2.2 %
    - Armament: 2,542 tons, 7.8 %
    - Armour Deck: 1,920 tons, 5.9 %
    - Conning Tower: 197 tons, 0.6 %
 Machinery: 4,568 tons, 14.1 %
 Hull, fittings & equipment: 13,766 tons, 42.4 %
 Fuel, ammunition & stores: 4,053 tons, 12.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   39,535 lbs / 17,933 Kg = 23.4 x 15.0 " / 381 mm shells or 5.0 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 5.8 ft / 1.8 m
 Roll period: 16.4 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.80
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.586
 Length to Beam Ratio: 8.14 : 1
 'Natural speed' for length: 27.66 kts
 Power going to wave formation at top speed: 50 %
 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:  28.00 ft / 8.53 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: 22.60 ft / 6.89 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 113.6 %
  - Above water (accommodation/working, high = better): 186.3 %
 Waterplane Area: 51,903 Square feet or 4,822 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 188 lbs/sq ft or 920 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.10
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, October 22, 2006

Is there something wrong with this? It looks too good: GB/CB/1908 design study

I just ran a design study in Springsharp for a GB/CB/1908 battlecruiser. I wanted to use something like the better data that was erroneously reported in Jane's Fighting Ships, with an 8in belt. This came out better than I expected, so I wondered if I did something wrong that I am not recognizing?:
GB/CB/1908 design study, Great Britain Battlecruiser laid down 1908

Displacement:
 17,177 t light; 17,987 t standard; 20,900 t normal; 23,230 t full load

Dimensions: Length overall / water x beam x draught
 580.00 ft / 580.00 ft x 80.00 ft x 26.50 ft (normal load)
 176.78 m / 176.78 m x 24.38 m  x 8.08 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1908 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1908 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1908 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 190.00 ft / 57.91 m 8.00 ft / 2.44 m
 Upper: 5.00" / 127 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
   Main Belt covers 103 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 390.00 ft / 118.87 m 26.50 ft / 8.08 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

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

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 58,660 shp / 43,760 Kw = 25.50 kts
 Range 5,700nm at 15.00 kts
 Bunker at max displacement = 5,243 tons (100% coal)

Complement:
 868 - 1,129

Cost:
 £1.837 million / $7.348 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.4 %
 Armour: 5,349 tons, 25.6 %
    - Belts: 1,963 tons, 9.4 %
    - Torpedo bulkhead: 574 tons, 2.7 %
    - Armament: 1,432 tons, 6.8 %
    - Armour Deck: 1,250 tons, 6.0 %
    - Conning Tower: 131 tons, 0.6 %
 Machinery: 3,259 tons, 15.6 %
 Hull, fittings & equipment: 7,641 tons, 36.6 %
 Fuel, ammunition & stores: 3,723 tons, 17.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   27,005 lbs / 12,249 Kg = 31.3 x 12.0 " / 305 mm shells or 3.8 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 4.9 ft / 1.5 m
 Roll period: 15.2 seconds
 Steadiness - As gun platform (Average = 50 %): 65 %
   - Recoil effect (Restricted arc if above 1.00): 0.66
 Seaboat quality  (Average = 1.00): 1.31

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.595
 Length to Beam Ratio: 7.25 : 1
 'Natural speed' for length: 24.08 kts
 Power going to wave formation at top speed: 52 %
 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:  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 space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 112.2 %
  - Above water (accommodation/working, high = better): 161.5 %
 Waterplane Area: 33,775 Square feet or 3,138 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 152 lbs/sq ft or 742 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.69
  - 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

Friday, October 20, 2006

My GB/CB/1905 design study

This is my design study for a British 1905 battlecruiser with 8-12in guns, 16-4in QF guns, and a 25.5 knot speed. The armour basis is 6in with a 2in deck. The main issue is caused by Springsharp requiring too much power to reach 25.5 knots (over 50,000 SHP). I used turbine machinery with direct drive and coal-fired boilers. This is the Springsharp report:
GB/CB/1905 design study, Great Britain Battlecruiser laid down 1905 (Engine 1907)

Displacement:
 16,457 t light; 17,249 t standard; 19,991 t normal; 22,184 t full load

Dimensions: Length overall / water x beam x draught
 567.00 ft / 567.00 ft x 78.00 ft x 26.50 ft (normal load)
 172.82 m / 172.82 m x 23.77 m  x 8.08 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 340.00 ft / 103.63 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 220.00 ft / 67.06 m 8.00 ft / 2.44 m
   7.00 ft / 2.13 m Unarmoured ends
 Upper: 4.00" / 102 mm 340.00 ft / 103.63 m 8.00 ft / 2.44 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 340.00 ft / 103.63 m 26.50 ft / 8.08 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 57,545 shp / 42,929 Kw = 25.50 kts
 Range 5,200nm at 15.00 kts
 Bunker at max displacement = 4,935 tons (100% coal)

Complement:
 839 - 1,092

Cost:
 £1.859 million / $7.436 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.6 %
 Armour: 4,564 tons, 22.8 %
    - Belts: 1,454 tons, 7.3 %
    - Torpedo bulkhead: 500 tons, 2.5 %
    - Armament: 1,306 tons, 6.5 %
    - Armour Deck: 1,193 tons, 6.0 %
    - Conning Tower: 111 tons, 0.6 %
 Machinery: 3,597 tons, 18.0 %
 Hull, fittings & equipment: 7,368 tons, 36.9 %
 Fuel, ammunition & stores: 3,533 tons, 17.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,414 lbs / 10,621 Kg = 27.1 x 12.0 " / 305 mm shells or 3.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 4.7 ft / 1.4 m
 Roll period: 15.1 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.70
 Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.597
 Length to Beam Ratio: 7.27 : 1
 'Natural speed' for length: 23.81 kts
 Power going to wave formation at top speed: 53 %
 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): 125.4 %
  - Above water (accommodation/working, high = better): 159.5 %
 Waterplane Area: 32,256 Square feet or 2,997 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 152 lbs/sq ft or 742 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Thursday, October 19, 2006

Two issues with Springsharp

In trying the British battlecruiser design studies with reciprocating engines and coal-fired boilers, I noticed that Springsharp attributed heavier machinery weight to the reciprocating engines than was actually the case. I also have already noted that Springsharp required over 50,000 ihp to reach 25.5 knots, while the actual design studies were just over 40,000 ihp. I suspect that part of the reason is that my Springsharp designs were heavy, in order to achieve adequate hull strength. I let the weights given by John Roberts drive what I was trying to achieve in Springsharp. Because of the higher power requirements, that meant that I needed lighter machinery to have near the specified machinery weight of about 3,500 tons.

Wednesday, October 18, 2006

The original concept for Design A from January 1905

On page 21 of John Roberts' book, Battlecruisers, he has sketches of the various designs considered for the first battlecruisers, built as armoured cruisers. He shows the original concept for Design A, from January 1905, that is much more reasonable than what is in British Battleships. The design has a ram bow and only two levels. This is the Springsharp report:
GB/CB/1905 Design A-4 January 1905, Great Britain Battlecruiser laid down 1905 (Engine 1916)

Displacement:
 15,810 t light; 16,586 t standard; 19,200 t normal; 21,291 t full load

Dimensions: Length overall / water x beam x draught
 564.00 ft / 564.00 ft x 77.00 ft x 26.50 ft (normal load)
 171.91 m / 171.91 m x 23.47 m  x 8.08 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side, all forward
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 310.00 ft / 94.49 m 12.00 ft / 3.66 m
 Ends: 4.00" / 102 mm 154.00 ft / 46.94 m 12.00 ft / 3.66 m
   100.00 ft / 30.48 m Unarmoured ends
   Main Belt covers 85 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 310.00 ft / 94.49 m 26.50 ft / 8.08 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 4 shafts, 55,875 ihp / 41,683 Kw = 25.50 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,706 tons (100% coal)

Complement:
 815 - 1,060

Cost:
 £1.844 million / $7.377 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.8 %
 Armour: 3,988 tons, 20.8 %
    - Belts: 1,270 tons, 6.6 %
    - Torpedo bulkhead: 456 tons, 2.4 %
    - Armament: 1,286 tons, 6.7 %
    - Armour Deck: 868 tons, 4.5 %
    - Conning Tower: 108 tons, 0.6 %
 Machinery: 3,652 tons, 19.0 %
 Hull, fittings & equipment: 7,242 tons, 37.7 %
 Fuel, ammunition & stores: 3,390 tons, 17.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,602 lbs / 9,345 Kg = 23.8 x 12.0 " / 305 mm shells or 2.8 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 4.6 ft / 1.4 m
 Roll period: 15.2 seconds
 Steadiness - As gun platform (Average = 50 %): 60 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.584
 Length to Beam Ratio: 7.32 : 1
 'Natural speed' for length: 23.75 kts
 Power going to wave formation at top speed: 53 %
 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 %): 23.00 ft / 7.01 m
    - Mid (62 %):  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: 20.20 ft / 6.16 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 132.3 %
  - Above water (accommodation/working, high = better): 147.5 %
 Waterplane Area: 31,288 Square feet or 2,907 Square metres
 Displacement factor (Displacement / loading): 103 %
 Structure weight / hull surface area: 155 lbs/sq ft or 755 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.70
  - 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

Tuesday, October 17, 2006

The 1905 Battlecruiser "Design A" works very badly in Springsharp

The 1905 British battlecruiser "Design A" was to have a low quarterdeck and a raised forecastle above the middle of the ship. There were two turrets next to each other on the forecastle, with two turrets aft, one superfiring. The 25.5 knot speed with reciprocating engines and coal-fired boilers makes the design difficult to implement in Springsharp. Part of the problem is that Springsharp wants over 50,000 ihp to reach 25.5 knots,not 41,000 ihp. The specification is very sketchy. I followed the specification in John Robert's battlecruiser book, and used the sketch in Dr. Oscar Parkes' British Battleship book to judge the belt length. I tried to achieve the weights in the specification in John Roberts' book. This is the Springsharp report:
GB/CB/1905 Design A, Great Britain Battlecruiser laid down 1907 (Engine 1917)

Displacement:
 17,535 t light; 18,327 t standard; 20,000 t normal; 21,338 t full load

Dimensions: Length overall / water x beam x draught
 568.10 ft / 564.00 ft x 77.00 ft x 26.50 ft (normal load)
 173.16 m / 171.91 m x 23.47 m  x 8.08 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on side, all forward
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 325.00 ft / 99.06 m 12.00 ft / 3.66 m
 Ends: 4.00" / 102 mm 140.00 ft / 42.67 m 12.00 ft / 3.66 m
   99.00 ft / 30.18 m Unarmoured ends
   Main Belt covers 89 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 325.00 ft / 99.06 m 26.50 ft / 8.08 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 4 shafts, 57,863 ihp / 43,166 Kw = 25.50 kts
 Range 4,000nm at 15.00 kts
 Bunker at max displacement = 3,011 tons (100% coal)

Complement:
 840 - 1,093

Cost:
 £1.921 million / $7.684 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.6 %
 Armour: 4,008 tons, 20.0 %
    - Belts: 1,284 tons, 6.4 %
    - Torpedo bulkhead: 478 tons, 2.4 %
    - Armament: 1,247 tons, 6.2 %
    - Armour Deck: 888 tons, 4.4 %
    - Conning Tower: 111 tons, 0.6 %
 Machinery: 3,770 tons, 18.8 %
 Hull, fittings & equipment: 8,830 tons, 44.1 %
 Fuel, ammunition & stores: 2,465 tons, 12.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   19,370 lbs / 8,786 Kg = 22.4 x 12.0 " / 305 mm shells or 2.8 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 4.0 ft / 1.2 m
 Roll period: 16.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.62
 Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
 Hull has raised forecastle, rise forward of midbreak, raised quarterdeck 
 Block coefficient: 0.608
 Length to Beam Ratio: 7.32 : 1
 'Natural speed' for length: 23.75 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 26
 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 (37 %): 30.00 ft / 9.14 m (22.00 ft / 6.71 m aft of break)
    - Mid (50 %):  22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
    - Quarterdeck (30 %): 155.00 ft / 47.24 m (14.00 ft / 4.27 m before break)
    - Stern:  14.00 ft / 4.27 m
    - Average freeboard: 42.11 ft / 12.84 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 129.6 %
  - Above water (accommodation/working, high = better): 124.5 %
 Waterplane Area: 32,008 Square feet or 2,974 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 122 lbs/sq ft or 597 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.79
  - Longitudinal: 8.50
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Monday, October 16, 2006

Another attempt at the HMS Unapproachable concept

This version of the HMS Unapproachable differs from what I have been doing in having reciprocating engines, rather than turbines. This version also has coal-fired boilers. I have tried to achieve the weights in the specification, but there is an issue in that it takes more than 40,000 ihp to reach 25.5 knots, with Springsharp. I punted on the armament layout, and assume the 9.2in guns are all on the same level. The 4in QF guns are mounted above them, in casemates. This is the Springsharp report:
HMS Unapproachable October 1904, Great Britain Armoured Cruiser laid down 1904 (Engine 1912)

Displacement:
    16,340 t light; 17,075 t standard; 18,700 t normal; 20,000 t full load

Dimensions: Length overall / water x beam x draught
    554.00 ft / 554.00 ft x 75.00 ft x 26.50 ft (normal load)
    168.86 m / 168.86 m x 22.86 m  x 8.08 m

Armament:
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1904 Model
      Breech loading guns in turrets (on barbettes)
      on centreline ends, evenly spread
      12 - 9.20" / 234 mm guns (6x2 guns), 389.34lbs / 176.60kg shells, 1904 Model
      Breech loading guns in turrets (on barbettes)
      on side, all amidships
      12 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1904 Model
      Quick firing guns in casemate mounts
      on side, evenly spread, all raised mounts
    Weight of broadside 6,614 lbs / 3,000 kg
    Shells per gun, main battery: 90

Armour:
   - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    6.00" / 152 mm    360.00 ft / 109.73 m    8.00 ft / 2.44 m
    Ends:    4.00" / 102 mm    194.00 ft / 59.13 m    8.00 ft / 2.44 m
    Upper:    4.00" / 102 mm    360.00 ft / 109.73 m    8.00 ft / 2.44 m
      Main Belt covers 100 % of normal length
      Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
        1.50" / 38 mm    360.00 ft / 109.73 m    26.50 ft / 8.08 m

   - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    8.00" / 203 mm    5.00" / 127 mm        8.00" / 203 mm
    2nd:    8.00" / 203 mm    5.00" / 127 mm        8.00" / 203 mm
    3rd:    4.00" / 102 mm    4.00" / 102 mm        4.00" / 102 mm

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

Machinery:
    Coal fired boilers, complex reciprocating steam engines,
    Direct drive, 4 shafts, 55,488 ihp / 41,394 Kw = 25.50 kts
    Range 3,800nm at 15.00 kts
    Bunker at max displacement = 2,925 tons (100% coal)

Complement:
    799 - 1,039

Cost:
    £1.781 million / $7.123 million

Distribution of weights at normal displacement:
    Armament: 827 tons, 4.4 %
    Armour: 5,233 tons, 28.0 %
       - Belts: 1,468 tons, 7.9 %
       - Torpedo bulkhead: 529 tons, 2.8 %
       - Armament: 1,995 tons, 10.7 %
       - Armour Deck: 1,119 tons, 6.0 %
       - Conning Tower: 121 tons, 0.6 %
    Machinery: 3,675 tons, 19.7 %
    Hull, fittings & equipment: 6,606 tons, 35.3 %
    Fuel, ammunition & stores: 2,360 tons, 12.6 %
    Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      19,743 lbs / 8,955 Kg = 50.7 x 9.2 " / 234 mm shells or 2.7 torpedoes
    Stability (Unstable if below 1.00): 1.09
    Metacentric height 3.8 ft / 1.2 m
    Roll period: 16.2 seconds
    Steadiness    - As gun platform (Average = 50 %): 59 %
            - Recoil effect (Restricted arc if above 1.00): 0.75
    Seaboat quality  (Average = 1.00): 1.17

Hull form characteristics:
    Hull has a flush deck
    Block coefficient: 0.594
    Length to Beam Ratio: 7.39 : 1
    'Natural speed' for length: 23.54 kts
    Power going to wave formation at top speed: 54 %
    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:        24.00 ft / 7.32 m
       - Forecastle (20 %):    21.00 ft / 6.40 m
       - Mid (50 %):        21.00 ft / 6.40 m
       - Quarterdeck (15 %):    21.00 ft / 6.40 m
       - Stern:        21.00 ft / 6.40 m
       - Average freeboard:    21.24 ft / 6.47 m
    Ship tends to be wet forward

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 132.3 %
        - Above water (accommodation/working, high = better): 151.3 %
    Waterplane Area: 30,231 Square feet or 2,809 Square metres
    Displacement factor (Displacement / loading): 97 %
    Structure weight / hull surface area: 143 lbs/sq ft or 699 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.95
        - Longitudinal: 1.57
        - Overall: 1.00
    Hull space for machinery, storage, compartmentation is cramped
    Room for accommodation and workspaces is excellent

Sunday, October 15, 2006

The lightly-armed battleship design from 1902

Along with the heavily-armed battleship design from the senior officers' course in 1902, John Roberts has a less complete description of the lightly-armed battleship design, which was the alternative to the former. Naturally, I wanted to try that ship in Springsharp, as well. I had less to go on, but I made an attempt, anyway. This is the Springsharp report:
GB/BB/1902 Lighly Armed, Great Britain Battleship laid down 1902

Displacement:
 13,513 t light; 14,055 t standard; 15,961 t normal; 17,485 t full load

Dimensions: Length overall / water x beam x draught
 490.00 ft / 490.00 ft x 78.00 ft x 24.00 ft (normal load)
 149.35 m / 149.35 m x 23.77 m  x 7.32 m

Armament:
      4 - 10.00" / 254 mm guns (2x2 guns), 500.00lbs / 226.80kg shells, 1902 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      16 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1902 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 3,728 lbs / 1,691 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 370.00 ft / 112.78 m 8.00 ft / 2.44 m
 Ends: 5.00" / 127 mm 120.00 ft / 36.58 m 8.00 ft / 2.44 m
 Upper: 5.00" / 127 mm 370.00 ft / 112.78 m 8.00 ft / 2.44 m
   Main Belt covers 116 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 370.00 ft / 112.78 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.50" / 241 mm 6.00" / 152 mm  9.50" / 241 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 9.50" / 241 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 30,225 ihp / 22,548 Kw = 22.00 kts
 Range 4,200nm at 15.00 kts
 Bunker at max displacement = 3,430 tons (100% coal)

Complement:
 709 - 923

Cost:
 £1.506 million / $6.022 million

Distribution of weights at normal displacement:
 Armament: 466 tons, 2.9 %
 Armour: 3,820 tons, 23.9 %
    - Belts: 1,558 tons, 9.8 %
    - Torpedo bulkhead: 493 tons, 3.1 %
    - Armament: 857 tons, 5.4 %
    - Armour Deck: 782 tons, 4.9 %
    - Conning Tower: 130 tons, 0.8 %
 Machinery: 4,580 tons, 28.7 %
 Hull, fittings & equipment: 4,647 tons, 29.1 %
 Fuel, ammunition & stores: 2,448 tons, 15.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,027 lbs / 6,362 Kg = 28.1 x 10.0 " / 254 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.49
 Metacentric height 6.8 ft / 2.1 m
 Roll period: 12.6 seconds
 Steadiness - As gun platform (Average = 50 %): 75 %
   - Recoil effect (Restricted arc if above 1.00): 0.22
 Seaboat quality  (Average = 1.00): 1.50

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.609
 Length to Beam Ratio: 6.28 : 1
 'Natural speed' for length: 22.14 kts
 Power going to wave formation at top speed: 51 %
 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:  22.00 ft / 6.71 m
    - Forecastle (20 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.32 ft / 5.58 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 154.7 %
  - Above water (accommodation/working, high = better): 136.3 %
 Waterplane Area: 28,189 Square feet or 2,619 Square metres
 Displacement factor (Displacement / loading): 96 %
 Structure weight / hull surface area: 116 lbs/sq ft or 568 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.58
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Saturday, October 14, 2006

The Heavily-Armed Battleship from the January 1902 Senior Officer's War Course

On page 15 of John Robert's book, Battlecruisers (about British battlecruisers), he has the high-level specification for a heavily-armed battleship and a lightly-armed battleship that were used in the "Senior Officers' War Course, January 1902". There are no dimensions, just a displacement, speed, armament, and armour. I extrapolated from that description to create a Springsharp design:
GB/BB/1902 Heavily Armed, Great Britain Battleship laid down 1902

Displacement:
 14,614 t light; 15,372 t standard; 17,604 t normal; 19,390 t full load

Dimensions: Length overall / water x beam x draught
 480.00 ft / 480.00 ft x 78.00 ft x 25.00 ft (normal load)
 146.30 m / 146.30 m x 23.77 m  x 7.62 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1902 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1902 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      12 - 7.00" / 178 mm guns in single mounts, 171.50lbs / 77.79kg shells, 1902 Model
   Breech loading guns in casemate mounts 
   on side, evenly spread
   12 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 7,562 lbs / 3,430 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 360.00 ft / 109.73 m 8.00 ft / 2.44 m
 Ends: 8.00" / 203 mm 120.00 ft / 36.58 m 8.00 ft / 2.44 m
 Upper: 6.00" / 152 mm 360.00 ft / 109.73 m 8.00 ft / 2.44 m
   Main Belt covers 115 % of normal length

   - Torpedo Bulkhead:
  1.50" / 38 mm 360.00 ft / 109.73 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 7.00" / 178 mm  11.0" / 279 mm
 2nd: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 3rd: 7.00" / 178 mm 7.00" / 178 mm  7.00" / 178 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 11.00" / 279 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 15,182 ihp / 11,326 Kw = 18.00 kts
 Range 4,600nm at 15.00 kts
 Bunker at max displacement = 4,018 tons (100% coal)

Complement:
 763 - 993

Cost:
 £1.628 million / $6.510 million

Distribution of weights at normal displacement:
 Armament: 945 tons, 5.4 %
 Armour: 5,618 tons, 31.9 %
    - Belts: 2,251 tons, 12.8 %
    - Torpedo bulkhead: 500 tons, 2.8 %
    - Armament: 1,905 tons, 10.8 %
    - Armour Deck: 802 tons, 4.6 %
    - Conning Tower: 160 tons, 0.9 %
 Machinery: 2,300 tons, 13.1 %
 Hull, fittings & equipment: 5,750 tons, 32.7 %
 Fuel, ammunition & stores: 2,990 tons, 17.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   21,422 lbs / 9,717 Kg = 24.8 x 12.0 " / 305 mm shells or 3.4 torpedoes
 Stability (Unstable if below 1.00): 1.20
 Metacentric height 4.8 ft / 1.5 m
 Roll period: 14.9 seconds
 Steadiness - As gun platform (Average = 50 %): 85 %
   - Recoil effect (Restricted arc if above 1.00): 0.65
 Seaboat quality  (Average = 1.00): 1.70

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.658
 Length to Beam Ratio: 6.15 : 1
 'Natural speed' for length: 21.91 kts
 Power going to wave formation at top speed: 43 %
 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:  22.00 ft / 6.71 m
    - Forecastle (20 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.32 ft / 5.58 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 111.4 %
  - Above water (accommodation/working, high = better): 129.9 %
 Waterplane Area: 28,899 Square feet or 2,685 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 141 lbs/sq ft or 687 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Friday, October 13, 2006

Springsharp and survivability

I have not tried to look closely at how Springsharp determines how survivable a ship is. I like the fact that relatively lightly armoured ships have what I would consider to be good survivability ratings. A ship with better protection, such as the fast battleship version of the Super Lion concept has very good survivability. I guess that the more lightly protected ships still show a good resistence to torpedo attack, even if the number of large caliber hits is not that large. Even the Super Lion fast battleship will only take 32.9 15in hits, but will resist up to 7.6 torpedoes. I guess that 8 torpedoes would sink the ship, while it might survive 7 hits, just barely. The GB/CA/1921d design will still resist 4.3 torpedoes, and 77.8 1oin hits. The GB/CA/1921d design only has a 5in belt, but does have a 3in deck, as does the Super Lion fast battleship. They both do have a 2in torpedo bulkhead, so that they are relatively well-protected by 1905 to 1921 standards. By 1939, typical practice for large armoured ships was to have much thicker torpedo bulkheads.

Thursday, October 12, 2006

I am struggling to describe turret positions for Colonel Cuniberti's "Ideal Battleship"

The current version of the Ross-Gowan's Springsharp program seems to have limited ability to describe the vertical position of turrets. This is a significant issue for Colonel Cuniberti's "Ideal Battleship", described in a seminal article in the 1903 Jane's All the World's Fighting Ships. The gun layout is very typical of Colonel Cuniberti's Italian designs that were actually built, particularly the Roma class. There is this diagrammatic drawing that I drew in April 2005:

There are also some photos, of varying quality, that I put together, as well:

Here is a shot from a higher elevation, from a distance:

Here is a photo from the port quarter:

The design has four twin 12in turrets and four single 12in turrets. There are also 12-12pdr QF guns in a battery below the forecastle level, but amidships. The 12in belt is complete, also in the Continental style of the period. The speed was to be a very great 24 knots. In Springsharp, the way I have been describing the 12in gun turret positions is not working well, as there are recoil and stability issues, when the layout really should work. The problem is with the concept of how Springsharp describes superfiring guns. If the upper 12in wing turrets are desribed as superfiring, there is a problem. Does anyone have a suggested solution?

Wednesday, October 11, 2006

An attempt at the fast battleship version of the Super Lion

I thought that I would make another attempt to do the Super Lion as a fast battleship in Springsharp. I have this rather large set of dimensions mind, and the ship demands the use of lightweight machinery (31.7 SHP/ton, which is asking a lot for 1912). You may or may not recall that this is a 30-knot ship with 10-15in guns. The fast battleship version needs a 13in lower belt. This is the photo of the Super Lion with the large dimensions:

This is the Springsharp report:
GB/BB/1912 Super Lion, Great Britain Fast Battleship laid down 1912 (Engine 1927)

Displacement:
 38,525 t light; 40,318 t standard; 42,500 t normal; 44,245 t full load

Dimensions: Length overall / water x beam x draught
 812.00 ft / 812.00 ft x 97.00 ft x 30.00 ft (normal load)
 247.50 m / 247.50 m x 29.57 m  x 9.14 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 1,687.51lbs / 765.44kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 15.00" / 381 mm guns (1x2 guns), 1,687.51lbs / 765.44kg shells, 1912 Model
   Breech loading guns in a turret (on a barbette)
   on centreline amidships
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 18,387 lbs / 8,340 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 585.00 ft / 178.31 m 8.00 ft / 2.44 m
 Ends: 5.00" / 127 mm 200.00 ft / 60.96 m 16.00 ft / 4.88 m
   27.00 ft / 8.23 m Unarmoured ends
 Upper: 9.00" / 229 mm 585.00 ft / 178.31 m 8.00 ft / 2.44 m
   Main Belt covers 111 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 585.00 ft / 178.31 m 30.00 ft / 9.14 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: 13.0" / 330 mm 9.00" / 229 mm  13.0" / 330 mm
 3rd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 152,772 shp / 113,968 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,927 tons

Complement:
 1,479 - 1,923

Cost:
 £3.954 million / $15.817 million

Distribution of weights at normal displacement:
 Armament: 2,298 tons, 5.4 %
 Armour: 14,062 tons, 33.1 %
    - Belts: 4,891 tons, 11.5 %
    - Torpedo bulkhead: 1,299 tons, 3.1 %
    - Armament: 4,245 tons, 10.0 %
    - Armour Deck: 3,286 tons, 7.7 %
    - Conning Tower: 341 tons, 0.8 %
 Machinery: 4,822 tons, 11.3 %
 Hull, fittings & equipment: 17,342 tons, 40.8 %
 Fuel, ammunition & stores: 3,975 tons, 9.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   55,460 lbs / 25,156 Kg = 32.9 x 15.0 " / 381 mm shells or 7.6 torpedoes
 Stability (Unstable if below 1.00): 1.05
 Metacentric height 5.3 ft / 1.6 m
 Roll period: 17.7 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.92
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.630
 Length to Beam Ratio: 8.37 : 1
 'Natural speed' for length: 28.50 kts
 Power going to wave formation at top speed: 51 %
 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:  30.00 ft / 9.14 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (72 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 24.08 ft / 7.34 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 97.7 %
  - Above water (accommodation/working, high = better): 186.1 %
 Waterplane Area: 59,210 Square feet or 5,501 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 205 lbs/sq ft or 1,002 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.12
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Calculating power for a speed for a ship

The modern computative approach to calculating the power that is needed to move a ship at a certain speed uses a database of ships and then interpolates from the known values. In the past, to get a rough idea of the power required, the British navy used an empirical formula. They knew that they would need to do model trials to get a better power figure and to be able to generate a tentative power-speed curve. A third approach, developed by David Taylor, was to look up values from graphs from The Speed and Power of Ships, and then generate the data to provide a power curve. The U.S. Navy apparently had classified factors that they used to improve the results from the Taylor calculations, based on hull form. I have a program that runs in a game engine scripting language (which is unfortunate), that uses some data that both summarizes and extends what is in The Speed and Power of Ships. I also use, on the advice of Frank Fox, friction data from Gertler's book, A Reanalysis of the Original Test Data for the Taylor Standard Series (1954). This page has a picture of Morton Gertler with towing model of the submarine Albacore.

Tuesday, October 10, 2006

At cut at the "Super Fast" battlecruiser

I don't know if this qualifies as "Super Fast", but I have a Springsharp design for the "Super Fast" battlecruiser that can make 36 knots. The machinery is 41.8 SHP/ton. This is trying to be faithful to the original sketch design from 18 July 1973. I took the liberty of increasing the draft from 29.7ft to 30ft, and the Standard displacement is a bit more than the original 32,000 tons. I had hoped for, can you believe it, 52 knots! I know now that was based on erroneous extrapolation from speed and power curves. This is the Springsharp report:
GB/CB/1918 "Super Fast", Great Britain Battlecruiser laid down 1918 (Engine 1950)

Displacement:
 31,782 t light; 32,930 t standard; 34,500 t normal; 35,756 t full load

Dimensions: Length overall / water x beam x draught
 801.29 ft / 800.00 ft x 85.00 ft x 30.00 ft (normal load)
 244.23 m / 243.84 m x 25.91 m  x 9.14 m

Armament:
      4 - 17.00" / 432 mm guns (2x2 guns), 2,456.50lbs / 1,114.25kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 0.00" / 0.0 mm guns (2x2 guns), 0.00lbs / 0.00kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, all raised mounts
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 10,210 lbs / 4,631 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 430.00 ft / 131.06 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 5.00" / 127 mm 230.00 ft / 70.10 m 8.00 ft / 2.44 m
   Main Belt covers 83 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 430.00 ft / 131.06 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm
 3rd: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 271,404 shp / 202,467 Kw = 36.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 2,826 tons

Complement:
 1,265 - 1,645

Cost:
 £6.187 million / $24.747 million

Distribution of weights at normal displacement:
 Armament: 1,276 tons, 3.7 %
 Armour: 5,598 tons, 16.2 %
    - Belts: 1,802 tons, 5.2 %
    - Torpedo bulkhead: 461 tons, 1.3 %
    - Armament: 1,326 tons, 3.8 %
    - Armour Deck: 1,826 tons, 5.3 %
    - Conning Tower: 183 tons, 0.5 %
 Machinery: 6,493 tons, 18.8 %
 Hull, fittings & equipment: 18,415 tons, 53.4 %
 Fuel, ammunition & stores: 2,718 tons, 7.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   43,152 lbs / 19,573 Kg = 17.6 x 17.0 " / 432 mm shells or 4.5 torpedoes
 Stability (Unstable if below 1.00): 1.07
 Metacentric height 4.5 ft / 1.4 m
 Roll period: 16.8 seconds
 Steadiness - As gun platform (Average = 50 %): 50 %
   - Recoil effect (Restricted arc if above 1.00): 0.85
 Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.592
 Length to Beam Ratio: 9.41 : 1
 'Natural speed' for length: 28.28 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  37.00 ft / 11.28 m
    - Forecastle (20 %): 33.00 ft / 10.06 m
    - Mid (44 %):  33.00 ft / 10.06 m (25.00 ft / 7.62 m aft of break)
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 28.84 ft / 8.79 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.1 %
  - Above water (accommodation/working, high = better): 207.8 %
 Waterplane Area: 49,359 Square feet or 4,586 Square metres
 Displacement factor (Displacement / loading): 120 %
 Structure weight / hull surface area: 233 lbs/sq ft or 1,135 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.30
  - Longitudinal: 2.11
  - Overall: 1.36
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Very fast ships with a few big guns

While I did not conceive of the GB/CB/1905 design, I have evidently bought into the basic concept: accept light protection and just a few guns, in exchange for very high speed (in excess of 32 knots). My ultimate expression of the concept was designed in 1973, when I conceived of what I optimistically called the "Super Fast Battlecruiser". The idea was to have a short citadel, 4-17in guns, and maybe an 8 inch lower belt. The ship had "soft ends", similar to the "all-or-nothing" ships, except that the lower belt was thicker than the upper belt (I believe). This is a photo of one of the "Super Fast Battlecruisers" steaming at moderate speed:

Monday, October 09, 2006

Another try at the GB/CA/1921d design

The GB/CA/1921d design is only viable with extremely lightweight machinery. The machinery is 39.6 SHP/ton. The ship is heavier than the original Standard displacement of 24,500 tons. The ship ended up at 27,287 tons Standard. The armament is 9-10in BLR, 12-5.5in QF, and 6-4.7in AA guns. The speed is great, at 37 knots. This is the Springsharp report:
GB/CA/1921d, Great Britain Armoured Cruiser laid down 1921 (Engine 1945)

Displacement:
 26,355 t light; 27,287 t standard; 29,800 t normal; 31,810 t full load

Dimensions: Length overall / water x beam x draught
 838.32 ft / 835.00 ft x 82.00 ft x 25.50 ft (normal load)
 255.52 m / 254.51 m x 24.99 m  x 7.77 m

Armament:
      9 - 10.00" / 254 mm guns (3x3 guns), 500.00lbs / 226.80kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 5.50" / 140 mm guns (6x2 guns), 83.19lbs / 37.73kg shells, 1921 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, all raised mounts - superfiring
      6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 5,810 lbs / 2,635 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 5.00" / 127 mm 405.00 ft / 123.44 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 75 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 405.00 ft / 123.44 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 7.00" / 178 mm 4.00" / 102 mm  7.00" / 178 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm
 3rd: 2.00" / 51 mm       -         -

   - Armour deck: 3.00" / 76 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 270,562 shp / 201,839 Kw = 37.00 kts
 Range 7,500nm at 18.00 kts
 Bunker at max displacement = 4,523 tons

Complement:
 1,133 - 1,474

Cost:
 £6.336 million / $25.342 million

Distribution of weights at normal displacement:
 Armament: 726 tons, 2.4 %
 Armour: 6,841 tons, 23.0 %
    - Belts: 1,505 tons, 5.1 %
    - Torpedo bulkhead: 749 tons, 2.5 %
    - Armament: 1,670 tons, 5.6 %
    - Armour Deck: 2,772 tons, 9.3 %
    - Conning Tower: 145 tons, 0.5 %
 Machinery: 6,832 tons, 22.9 %
 Hull, fittings & equipment: 11,955 tons, 40.1 %
 Fuel, ammunition & stores: 3,445 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   38,887 lbs / 17,639 Kg = 77.8 x 10.0 " / 254 mm shells or 4.3 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 4.7 ft / 1.4 m
 Roll period: 15.9 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.597
 Length to Beam Ratio: 10.18 : 1
 'Natural speed' for length: 28.90 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  38.00 ft / 11.58 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (50 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.88 ft / 8.50 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 123.1 %
  - Above water (accommodation/working, high = better): 226.8 %
 Waterplane Area: 49,955 Square feet or 4,641 Square metres
 Displacement factor (Displacement / loading): 113 %
 Structure weight / hull surface area: 153 lbs/sq ft or 749 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.13
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, October 08, 2006

The coal-fired boiler version of the Ger/CB/1911

The Ger/CB/1911 was so over-specified, when I made the specification in 1971, that the ship easily uses coal-fired boilers and is still a very capable ship, except for being under-armed. The ship is 750ft x 100ft x 30ft, with 6-12in guns in triple turrets, forward. The secondary armament is an inadequate 8-6in QF guns in shields. The side armour is 6in with a thick 5in deck. The turret faces and barbettes are 8in thick. The torpedo bulkhead is 2in. The speed is 30 knots, with a cruising speed of 18 knots for a range of 10,000 miles. This is the Springsharp report:
Ger/CB/1911 Coal-fired boilers, Germany Battlecruiser laid down 1911 (Engine 1917)

Displacement:
 26,995 t light; 28,005 t standard; 35,000 t normal; 40,596 t full load

Dimensions: Length overall / water x beam x draught
 752.00 ft / 750.00 ft x 100.00 ft x 30.00 ft (normal load)
 229.21 m / 228.60 m x 30.48 m  x 9.14 m

Armament:
      6 - 12.00" / 305 mm guns (2x3 guns), 864.00lbs / 391.90kg shells, 1911 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all forward, 1 raised mount - superfiring
      8 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1911 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, 2 raised mounts - superfiring
 Weight of broadside 6,048 lbs / 2,743 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 400.00 ft / 121.92 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 82 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 400.00 ft / 121.92 m 30.00 ft / 9.14 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 136,555 shp / 101,870 Kw = 30.00 kts
 Range 10,000nm at 18.00 kts
 Bunker at max displacement = 12,592 tons (100% coal)

Complement:
 1,279 - 1,663

Cost:
 £2.351 million / $9.403 million

Distribution of weights at normal displacement:
 Armament: 756 tons, 2.2 %
 Armour: 8,711 tons, 24.9 %
    - Belts: 1,823 tons, 5.2 %
    - Torpedo bulkhead: 888 tons, 2.5 %
    - Armament: 1,000 tons, 2.9 %
    - Armour Deck: 4,816 tons, 13.8 %
    - Conning Tower: 184 tons, 0.5 %
 Machinery: 5,506 tons, 15.7 %
 Hull, fittings & equipment: 12,021 tons, 34.3 %
 Fuel, ammunition & stores: 8,005 tons, 22.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   61,630 lbs / 27,955 Kg = 71.3 x 12.0 " / 305 mm shells or 9.0 torpedoes
 Stability (Unstable if below 1.00): 1.35
 Metacentric height 8.5 ft / 2.6 m
 Roll period: 14.4 seconds
 Steadiness - As gun platform (Average = 50 %): 74 %
   - Recoil effect (Restricted arc if above 1.00): 0.29
 Seaboat quality  (Average = 1.00): 1.47

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.544
 Length to Beam Ratio: 7.50 : 1
 'Natural speed' for length: 27.39 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 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: 25.80 ft / 7.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 85.0 %
  - Above water (accommodation/working, high = better): 193.9 %
 Waterplane Area: 52,070 Square feet or 4,837 Square metres
 Displacement factor (Displacement / loading): 136 %
 Structure weight / hull surface area: 159 lbs/sq ft or 774 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.50
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Saturday, October 07, 2006

The GB/CA/1905 design with coal-fired boilers

By concept for a 1905 British armoured cruiser that uses coal-fired boilers has 12-9.2in guns arranged in the lozenge pattern. There is one turret at each end, and two turrets on each beam. The secondary armament consists of 12-4in QF guns in casemates on the upper deck, with four elevated one level above that. The speed is aggressive for the time, with 26 knots. The armour basis is 6in with a 2in deck. The turret faces and barbettes are 7in. The machinery, while lightweight, is just 22.4 SHP/ton. This is the Springsharp report:
GB/CA/1905, Great Britain Armoured Cruiser laid down 1905 (Engine 1911)

Displacement:
 15,642 t light; 16,561 t standard; 18,800 t normal; 20,591 t full load

Dimensions: Length overall / water x beam x draught
 560.00 ft / 560.00 ft x 78.00 ft x 25.50 ft (normal load)
 170.69 m / 170.69 m x 23.77 m  x 7.77 m

Armament:
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      8 - 9.20" / 234 mm guns (4x2 guns), 389.34lbs / 176.60kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1905 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 4 raised mounts
 Weight of broadside 5,968 lbs / 2,707 kg
 Shells per gun, main battery: 150

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 390.00 ft / 118.87 m 16.00 ft / 4.88 m
 Ends: 4.00" / 102 mm 250.00 ft / 76.20 m 16.00 ft / 4.88 m
   Main Belt covers 107 % of normal length

   - Torpedo Bulkhead:
  1.50" / 38 mm 390.00 ft / 118.87 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 7.00" / 178 mm 5.00" / 127 mm  7.00" / 178 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 60,178 shp / 44,893 Kw = 26.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 4,030 tons (100% coal)

Complement:
 802 - 1,043

Cost:
 £1.550 million / $6.201 million

Distribution of weights at normal displacement:
 Armament: 746 tons, 4.0 %
 Armour: 5,517 tons, 29.3 %
    - Belts: 2,186 tons, 11.6 %
    - Torpedo bulkhead: 563 tons, 3.0 %
    - Armament: 1,490 tons, 7.9 %
    - Armour Deck: 1,172 tons, 6.2 %
    - Conning Tower: 107 tons, 0.6 %
 Machinery: 2,687 tons, 14.3 %
 Hull, fittings & equipment: 6,692 tons, 35.6 %
 Fuel, ammunition & stores: 3,158 tons, 16.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   27,569 lbs / 12,505 Kg = 70.8 x 9.2 " / 234 mm shells or 4.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 4.7 ft / 1.4 m
 Roll period: 15.1 seconds
 Steadiness - As gun platform (Average = 50 %): 62 %
   - Recoil effect (Restricted arc if above 1.00): 0.58
 Seaboat quality  (Average = 1.00): 1.24

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.591
 Length to Beam Ratio: 7.18 : 1
 'Natural speed' for length: 23.66 kts
 Power going to wave formation at top speed: 54 %
 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 %): 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: 22.44 ft / 6.84 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 104.7 %
  - Above water (accommodation/working, high = better): 171.4 %
 Waterplane Area: 31,672 Square feet or 2,942 Square metres
 Displacement factor (Displacement / loading): 112 %
 Structure weight / hull surface area: 140 lbs/sq ft or 685 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.69
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

Friday, October 06, 2006

The HMS Unapproachable with coal-fired boilers

This is my attempt at the HMS Unapproachable design with 4-9.2in, 12-7.5in, and 12-4in QF guns, with coal-fired boilers. To make this work requires pretty lightweight machinery. The speed is agressive at 25.5 knots. The armour basis is 6in with a 2in deck. This is the photo of one of these ships:

This is the Springsharp report:
HMS Unapproachable, Great Britain Armoured Cruiser laid down 1905 (Engine 1910)

Displacement:
 14,696 t light; 15,454 t standard; 17,700 t normal; 19,497 t full load

Dimensions: Length overall / water x beam x draught
 554.00 ft / 554.00 ft x 75.00 ft x 26.50 ft (normal load)
 168.86 m / 168.86 m x 22.86 m  x 8.08 m

Armament:
      8 - 7.50" / 191 mm guns (4x2 guns), 210.94lbs / 95.68kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side ends, evenly spread
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, all raised mounts
      4 - 7.50" / 191 mm guns in single mounts, 210.94lbs / 95.68kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side, evenly spread, all raised mounts
      12 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 4,473 lbs / 2,029 kg
 Shells per gun, main battery: 150

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 390.00 ft / 118.87 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 108 % of normal length

   - Torpedo Bulkhead:
  1.50" / 38 mm 390.00 ft / 118.87 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 3rd: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 4th: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

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

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 52,957 shp / 39,506 Kw = 25.50 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 4,043 tons (100% coal)

Complement:
 766 - 997

Cost:
 £1.321 million / $5.284 million

Distribution of weights at normal displacement:
 Armament: 559 tons, 3.2 %
 Armour: 5,258 tons, 29.7 %
    - Belts: 1,584 tons, 8.9 %
    - Torpedo bulkhead: 563 tons, 3.2 %
    - Armament: 1,908 tons, 10.8 %
    - Armour Deck: 1,086 tons, 6.1 %
    - Conning Tower: 117 tons, 0.7 %
 Machinery: 2,407 tons, 13.6 %
 Hull, fittings & equipment: 6,472 tons, 36.6 %
 Fuel, ammunition & stores: 3,004 tons, 17.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   25,021 lbs / 11,349 Kg = 118.6 x 7.5 " / 191 mm shells or 4.2 torpedoes
 Stability (Unstable if below 1.00): 1.02
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 17.2 seconds
 Steadiness - As gun platform (Average = 50 %): 59 %
   - Recoil effect (Restricted arc if above 1.00): 0.64
 Seaboat quality  (Average = 1.00): 1.19

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.563
 Length to Beam Ratio: 7.39 : 1
 'Natural speed' for length: 23.54 kts
 Power going to wave formation at top speed: 53 %
 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:  22.00 ft / 6.71 m
    - Forecastle (20 %): 20.00 ft / 6.10 m
    - Mid (50 %):  20.00 ft / 6.10 m
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 20.16 ft / 6.14 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 94.7 %
  - Above water (accommodation/working, high = better): 145.9 %
 Waterplane Area: 29,343 Square feet or 2,726 Square metres
 Displacement factor (Displacement / loading): 122 %
 Structure weight / hull surface area: 145 lbs/sq ft or 708 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.62
  - Overall: 1.02
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

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