GB/CB/1915, Great Britain Battlecruiser laid down 1915
Displacement:
32,975 t light; 34,446 t standard; 37,750 t normal; 40,393 t full load
Dimensions: Length overall / water x beam x draught
780.00 ft / 780.00 ft x 95.00 ft x 29.00 ft (normal load)
237.74 m / 237.74 m x 28.96 m x 8.84 m
Armament:
8 - 15.00" / 381 mm guns (4x2 guns), 1,920.00lbs / 870.90kg shells, 1915 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1915 Model
Quick firing guns in deck mounts with hoists
on side, evenly spread, 6 raised mounts
2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1915 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
16 - 1.57" / 40.0 mm guns (4x4 guns), 2.00lbs / 0.91kg shells, 1915 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 15,968 lbs / 7,243 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 570.00 ft / 173.74 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 8.00" / 203 mm 570.00 ft / 173.74 m 8.00 ft / 2.44 m
Main Belt covers 112 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 570.00 ft / 173.74 m 28.00 ft / 8.53 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12.0" / 305 mm 9.00" / 229 mm 12.0" / 305 mm
2nd: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 12.00" / 305 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 125,717 shp / 93,785 Kw = 29.00 kts
Range 5,600nm at 18.00 kts
Bunker at max displacement = 5,946 tons
Complement:
1,353 - 1,760
Cost:
£4.803 million / $19.212 million
Distribution of weights at normal displacement:
Armament: 1,763 tons, 4.7 %
Armour: 11,398 tons, 30.2 %
- Belts: 3,807 tons, 10.1 %
- Torpedo bulkhead: 1,181 tons, 3.1 %
- Armament: 3,070 tons, 8.1 %
- Armour Deck: 3,050 tons, 8.1 %
- Conning Tower: 291 tons, 0.8 %
Machinery: 4,762 tons, 12.6 %
Hull, fittings & equipment: 15,051 tons, 39.9 %
Fuel, ammunition & stores: 4,775 tons, 12.7 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
49,031 lbs / 22,240 Kg = 29.1 x 15.0 " / 381 mm shells or 6.9 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 5.4 ft / 1.6 m
Roll period: 17.2 seconds
Steadiness - As gun platform (Average = 50 %): 58 %
- Recoil effect (Restricted arc if above 1.00): 0.90
Seaboat quality (Average = 1.00): 1.16
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.615
Length to Beam Ratio: 8.21 : 1
'Natural speed' for length: 27.93 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: 31.00 ft / 9.45 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: 22.84 ft / 6.96 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 98.8 %
- Above water (accommodation/working, high = better): 176.3 %
Waterplane Area: 54,951 Square feet or 5,105 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 193 lbs/sq ft or 943 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.13
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
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Wednesday, November 30, 2005
A compact analog to the Hood
The next obvious step was a 15in-gun battlecruiser with 12in armour. I continued the practice of reducing dimensions to obtain greater strength. I had to increase the beam due to stability and recoil issues. I kept the soft ends and a thicker lower belt and thinner upper belt. This is sort of a more heavily armed and armoured Renown. I also settled for a lower speed to keep the size reasonable. The secondary armament is transitional, with twin 4in QF mounts. This is the Springsharp report:
Tuesday, November 29, 2005
The "Tiger" version of the more heavily protected battlecruisers
The natural thing is to have a 1911 British battlecruiser that is better protected. The design is Tiger-like, except for the soft ends. For better or worse, I am using reduced dimensions, as that increases the "composite strength" in Springsharp. I thought that this design needed to be 28 knots, at least, so that ballooned the displacement by 1,000 tons. This is the Springsharp report:
GB/CB/1911, Great Britain Battlecruiser laid down 1911
Displacement:
26,702 t light; 27,843 t standard; 31,200 t normal; 33,886 t full load
Dimensions: Length overall / water x beam x draught
690.00 ft / 690.00 ft x 89.00 ft x 29.00 ft (normal load)
210.31 m / 210.31 m x 27.13 m x 8.84 m
Armament:
8 - 13.50" / 343 mm guns (4x2 guns), 1,230.19lbs / 558.00kg shells, 1911 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1911 Model
Quick firing guns in casemate mounts
on side, evenly spread, 4 raised mounts
2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1911 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 11,381 lbs / 5,162 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 8.00" / 203 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
Main Belt covers 103 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 460.00 ft / 140.21 m 28.00 ft / 8.53 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12.0" / 305 mm 9.00" / 229 mm 12.0" / 305 mm
2nd: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 12.00" / 305 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 102,012 shp / 76,101 Kw = 28.00 kts
Range 5,400nm at 18.00 kts
Bunker at max displacement = 6,042 tons
Complement:
1,173 - 1,525
Cost:
£2.709 million / $10.837 million
Distribution of weights at normal displacement:
Armament: 1,423 tons, 4.6 %
Armour: 9,634 tons, 30.9 %
- Belts: 3,142 tons, 10.1 %
- Torpedo bulkhead: 953 tons, 3.1 %
- Armament: 2,759 tons, 8.8 %
- Armour Deck: 2,524 tons, 8.1 %
- Conning Tower: 256 tons, 0.8 %
Machinery: 4,140 tons, 13.3 %
Hull, fittings & equipment: 11,505 tons, 36.9 %
Fuel, ammunition & stores: 4,498 tons, 14.4 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
39,656 lbs / 17,988 Kg = 32.2 x 13.5 " / 343 mm shells or 5.6 torpedoes
Stability (Unstable if below 1.00): 1.07
Metacentric height 4.8 ft / 1.5 m
Roll period: 17.0 seconds
Steadiness - As gun platform (Average = 50 %): 58 %
- Recoil effect (Restricted arc if above 1.00): 0.79
Seaboat quality (Average = 1.00): 1.16
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.613
Length to Beam Ratio: 7.75 : 1
'Natural speed' for length: 26.27 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: 29.00 ft / 8.84 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: 22.68 ft / 6.91 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 102.5 %
- Above water (accommodation/working, high = better): 168.2 %
Waterplane Area: 45,470 Square feet or 4,224 Square metres
Displacement factor (Displacement / loading): 107 %
Structure weight / hull surface area: 174 lbs/sq ft or 848 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.33
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Monday, November 28, 2005
A GB/CB/1909 battlecruiser with 11in armour
Perhaps using oil-fired boilers on a British capital ship in 1909 is "cheating", but having them allows for a very potent ship. This is a small-dimension battlecruiser with 8-13.5 guns with the superfiring guns aft. The lower belt, barbettes, and turret faces are 11in thick. The deck is 3in with a 2in torpedo bulkhead. This design is much more capable than the Lion class, but probably only is due to the oil-fired boilers. I also omit armour at the ends, as the unarmoured length is relatively small. This is the Springsharp report:
GB/CB/1909, Great Britain Battlecruiser laid down 1909
Displacement:
24,493 t light; 25,541 t standard; 29,100 t normal; 31,947 t full load
Dimensions: Length overall / water x beam x draught
670.00 ft / 670.00 ft x 87.00 ft x 28.00 ft (normal load)
204.22 m / 204.22 m x 26.52 m x 8.53 m
Armament:
8 - 13.50" / 343 mm guns (4x2 guns), 1,230.19lbs / 558.00kg shells, 1909 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - superfiring
16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1909 Model
Quick firing guns in casemate mounts
on side, evenly spread, 6 raised mounts
Weight of broadside 10,354 lbs / 4,696 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.0" / 279 mm 450.00 ft / 137.16 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 8.00" / 203 mm 450.00 ft / 137.16 m 8.00 ft / 2.44 m
Main Belt covers 103 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 450.00 ft / 137.16 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: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 86,024 shp / 64,174 Kw = 27.00 kts
Range 5,400nm at 18.00 kts
Bunker at max displacement = 6,406 tons
Complement:
1,113 - 1,448
Cost:
£2.492 million / $9.967 million
Distribution of weights at normal displacement:
Armament: 1,294 tons, 4.4 %
Armour: 8,832 tons, 30.3 %
- Belts: 2,919 tons, 10.0 %
- Torpedo bulkhead: 899 tons, 3.1 %
- Armament: 2,370 tons, 8.1 %
- Armour Deck: 2,420 tons, 8.3 %
- Conning Tower: 224 tons, 0.8 %
Machinery: 3,910 tons, 13.4 %
Hull, fittings & equipment: 10,457 tons, 35.9 %
Fuel, ammunition & stores: 4,607 tons, 15.8 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
38,281 lbs / 17,364 Kg = 31.1 x 13.5 " / 343 mm shells or 5.4 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 5.0 ft / 1.5 m
Roll period: 16.4 seconds
Steadiness - As gun platform (Average = 50 %): 63 %
- Recoil effect (Restricted arc if above 1.00): 0.75
Seaboat quality (Average = 1.00): 1.26
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.624
Length to Beam Ratio: 7.70 : 1
'Natural speed' for length: 25.88 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: 29.00 ft / 8.84 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: 22.68 ft / 6.91 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 102.9 %
- Above water (accommodation/working, high = better): 170.0 %
Waterplane Area: 43,597 Square feet or 4,050 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 165 lbs/sq ft or 804 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.36
- 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
A 1908 British battlecruiser with better protection
When you look at just how bad the Indefatigable design was, especially compared to the Jane's Fighting Ships entry, you wonder why they couldn't have done better. I tried my hand at such a better design. I wanted the 9in belt and a 3in deck, in this case, along with a decent speed. My design relies on one turret being superfiring aft, and on oil-fired boilers, a big stretch. This is the Springsharp report:
GB/CB/1908, Great Britain Battlecruiser laid down 1908
Displacement:
19,068 t light; 19,835 t standard; 21,550 t normal; 22,922 t full load
Dimensions: Length overall / water x beam x draught
600.00 ft / 600.00 ft x 80.00 ft x 27.00 ft (normal load)
182.88 m / 182.88 m x 24.38 m x 8.23 m
Armament:
8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1908 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - superfiring
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: 80
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 9.00" / 229 mm 490.00 ft / 149.35 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 6.00" / 152 mm 490.00 ft / 149.35 m 8.00 ft / 2.44 m
Main Belt covers 126 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 490.00 ft / 149.35 m 26.00 ft / 7.92 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: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 9.00" / 229 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 73,360 shp / 54,727 Kw = 27.00 kts
Range 4,500nm at 15.00 kts
Bunker at max displacement = 3,087 tons
Complement:
889 - 1,156
Cost:
£1.966 million / $7.862 million
Distribution of weights at normal displacement:
Armament: 928 tons, 4.3 %
Armour: 6,790 tons, 31.5 %
- Belts: 2,416 tons, 11.2 %
- Torpedo bulkhead: 707 tons, 3.3 %
- Armament: 1,601 tons, 7.4 %
- Armour Deck: 1,916 tons, 8.9 %
- Conning Tower: 150 tons, 0.7 %
Machinery: 3,705 tons, 17.2 %
Hull, fittings & equipment: 7,645 tons, 35.5 %
Fuel, ammunition & stores: 2,482 tons, 11.5 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
24,423 lbs / 11,078 Kg = 28.3 x 12.0 " / 305 mm shells or 3.5 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 4.4 ft / 1.3 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 57 %
- Recoil effect (Restricted arc if above 1.00): 0.66
Seaboat quality (Average = 1.00): 1.14
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.582
Length to Beam Ratio: 7.50 : 1
'Natural speed' for length: 24.49 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: 27.00 ft / 8.23 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 20.68 ft / 6.30 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.9 %
- Above water (accommodation/working, high = better): 153.7 %
Waterplane Area: 34,519 Square feet or 3,207 Square metres
Displacement factor (Displacement / loading): 100 %
Structure weight / hull surface area: 149 lbs/sq ft or 728 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.46
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Sunday, November 27, 2005
Now, let us try well-protected battlecruisers
Now, let us see what might be done for a well-protected British battlecruiser for 1906, as an alternative to the Invincibles, but still a cruiser, not a fast battleship. This version is rather strange, as the dimensions are reduced to achieve adequate strength without ballooning the displacement unnecessarily. Part of the strangeness is that this version embraces the 25.5 knot speed, rather than 25 knots. The 25.5 knot speed was a feature of some design studies during the 1906-1908 period, and we are using that for this design. "Better protection" means a 9in belt. This design abandons the 16ft high thick belt for a thicker lower belt and a thinner upper belt, again to keep the displacement from undue increases. One of the two 12in gun turrets aft is superfiring. All turrets are on the centerline, with one amidships, although you would not necessarily know it from the Springsharp report:
GB/CB/1906, Great Britain Battlecruiser laid down 1906
Displacement:
17,560 t light; 18,299 t standard; 20,150 t normal; 21,631 t full load
Dimensions: Length overall / water x beam x draught
545.00 ft / 545.00 ft x 77.00 ft x 27.00 ft (normal load)
166.12 m / 166.12 m x 23.47 m x 8.23 m
Armament:
8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - superfiring
16 - 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, 8 raised mounts
Weight of broadside 7,424 lbs / 3,367 kg
Shells per gun, main battery: 80
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 9.00" / 229 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
Ends: Unarmoured
Upper: 6.00" / 152 mm 460.00 ft / 140.21 m 8.00 ft / 2.44 m
Main Belt covers 130 % of normal length
Main belt does not fully cover magazines and engineering spaces
- Torpedo Bulkhead:
1.50" / 38 mm 460.00 ft / 140.21 m 26.00 ft / 7.92 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: 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:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 59,493 shp / 44,382 Kw = 25.50 kts
Range 4,500nm at 15.00 kts
Bunker at max displacement = 3,332 tons
Complement:
845 - 1,099
Cost:
£1.935 million / $7.740 million
Distribution of weights at normal displacement:
Armament: 928 tons, 4.6 %
Armour: 5,834 tons, 29.0 %
- Belts: 2,266 tons, 11.2 %
- Torpedo bulkhead: 664 tons, 3.3 %
- Armament: 1,601 tons, 7.9 %
- Armour Deck: 1,160 tons, 5.8 %
- Conning Tower: 144 tons, 0.7 %
Machinery: 3,863 tons, 19.2 %
Hull, fittings & equipment: 6,935 tons, 34.4 %
Fuel, ammunition & stores: 2,590 tons, 12.9 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
20,343 lbs / 9,227 Kg = 23.5 x 12.0 " / 305 mm shells or 2.8 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 4.0 ft / 1.2 m
Roll period: 16.1 seconds
Steadiness - As gun platform (Average = 50 %): 55 %
- Recoil effect (Restricted arc if above 1.00): 0.76
Seaboat quality (Average = 1.00): 1.11
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.622
Length to Beam Ratio: 7.08 : 1
'Natural speed' for length: 23.35 kts
Power going to wave formation at top speed: 55 %
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 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 20.68 ft / 6.30 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 134.9 %
- Above water (accommodation/working, high = better): 146.8 %
Waterplane Area: 31,340 Square feet or 2,912 Square metres
Displacement factor (Displacement / loading): 96 %
Structure weight / hull surface area: 148 lbs/sq ft or 722 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.65
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Saturday, November 26, 2005
The next step: a 1923 British fast battleship with 18in guns
Last night, I designed the ultimate ship in the series of British fast battleships from 1905 to 1923. This ship is very compact in dimensions but has a full form, to achieve adequate strength. The speed is a modest 28 knots (faster than the Yamatos) and the armament is 9-18in, 16-6in, 6-4.7in AA, and 36-2pdr AA guns. The armour basis is 15in. The deck is a thick 8in. The ship seems to be small for the capabilities, so I wonder if there is some flaw that I am not seeing. This is the Springsharp report:
GB/BB/1923, Great Britain Battleship laid down 1923
Displacement:
58,640 t light; 61,238 t standard; 66,000 t normal; 69,810 t full load
Dimensions: Length overall / water x beam x draught
827.24 ft / 825.00 ft x 112.00 ft x 35.00 ft (normal load)
252.14 m / 251.46 m x 34.14 m x 10.67 m
Armament:
9 - 18.00" / 457 mm guns (3x3 guns), 2,916.00lbs / 1,322.68kg shells, 1923 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority aft, 1 raised mount aft - superfiring
16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1923 Model
Quick firing guns in turrets (on barbettes)
on side, evenly spread, 4 raised mounts
6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
Anti-aircraft guns in deck mounts with hoists
on side ends, evenly spread
36 - 1.57" / 40.0 mm guns (9x4 guns), 1.95lbs / 0.89kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 28,354 lbs / 12,861 kg
Shells per gun, main battery: 80
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 15.0" / 381 mm 540.00 ft / 164.59 m 16.00 ft / 4.88 m
Ends: Unarmoured
Main Belt covers 101 % of normal length
- Torpedo Bulkhead:
5.00" / 127 mm 540.00 ft / 164.59 m 31.00 ft / 9.45 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 15.0" / 381 mm 11.0" / 279 mm 15.0" / 381 mm
2nd: 6.00" / 152 mm 6.00" / 152 mm 6.00" / 152 mm
- Armour deck: 8.00" / 203 mm, Conning tower: 15.00" / 381 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 159,663 shp / 119,108 Kw = 29.00 kts
Range 7,500nm at 18.00 kts
Bunker at max displacement = 8,572 tons
Complement:
2,058 - 2,676
Cost:
£16.805 million / $67.219 million
Distribution of weights at normal displacement:
Armament: 3,544 tons, 5.4 %
Armour: 26,397 tons, 40.0 %
- Belts: 5,608 tons, 8.5 %
- Torpedo bulkhead: 3,097 tons, 4.7 %
- Armament: 5,569 tons, 8.4 %
- Armour Deck: 11,596 tons, 17.6 %
- Conning Tower: 528 tons, 0.8 %
Machinery: 5,336 tons, 8.1 %
Hull, fittings & equipment: 23,362 tons, 35.4 %
Fuel, ammunition & stores: 7,360 tons, 11.2 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
93,522 lbs / 42,421 Kg = 32.1 x 18.0 " / 457 mm shells or 16.1 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 7.0 ft / 2.1 m
Roll period: 17.8 seconds
Steadiness - As gun platform (Average = 50 %): 54 %
- Recoil effect (Restricted arc if above 1.00): 0.79
Seaboat quality (Average = 1.00): 1.09
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.714
Length to Beam Ratio: 7.37 : 1
'Natural speed' for length: 32.88 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 4.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.00 ft / 9.75 m
- Forecastle (20 %): 24.00 ft / 7.32 m
- Mid (67 %): 24.00 ft / 7.32 m
- Quarterdeck (15 %): 24.00 ft / 7.32 m
- Stern: 24.00 ft / 7.32 m
- Average freeboard: 24.64 ft / 7.51 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 81.0 %
- Above water (accommodation/working, high = better): 174.0 %
Waterplane Area: 78,348 Square feet or 7,279 Square metres
Displacement factor (Displacement / loading): 101 %
Structure weight / hull surface area: 224 lbs/sq ft or 1,091 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.24
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Friday, November 25, 2005
My current version of a 1919 British fast battleship
Continuing the current British fast battleship series is the 1919 version. The British considered 16.5in guns and I have adopted them. 16in guns were too small for that date, considering that larger guns were being actively developed. I had wanted 29 knots for this ship, but the size increase was greater than I wanted to have. I settled for a 28-knot ship with 9-16.5in BLR, 16-6in QF, 6-4.7in AA, and 36-2pdr AA guns. The armour basis is 14in. The deck is a respectable 6in. The torpedo bulkhead is a robust 4in. The hull is flush-decked and has a transom stern. This is the Springsharp report:
GB/BB/1919, Great Britain Battleship laid down 1919
Displacement:
47,618 t light; 49,778 t standard; 54,250 t normal; 57,828 t full load
Dimensions: Length overall / water x beam x draught
814.03 ft / 812.00 ft x 104.00 ft x 33.00 ft (normal load)
248.12 m / 247.50 m x 31.70 m x 10.06 m
Armament:
9 - 16.50" / 419 mm guns (3x3 guns), 2,425.00lbs / 1,099.96kg shells, 1919 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority aft, 1 raised mount aft - superfiring
16 - 6.00" / 152 mm guns (8x2 guns), 100.00lbs / 45.36kg shells, 1919 Model
Quick firing guns in turrets (on barbettes)
on side, evenly spread, 4 raised mounts
6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1919 Model
Anti-aircraft guns in deck mounts with hoists
on side ends, evenly spread
36 - 1.57" / 40.0 mm guns (9x4 guns), 2.00lbs / 0.91kg shells, 1919 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 23,808 lbs / 10,799 kg
Shells per gun, main battery: 80
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 14.0" / 356 mm 540.00 ft / 164.59 m 16.00 ft / 4.88 m
Ends: Unarmoured
Main Belt covers 102 % of normal length
- Torpedo Bulkhead:
4.00" / 102 mm 540.00 ft / 164.59 m 31.00 ft / 9.45 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 14.0" / 356 mm 10.0" / 254 mm 14.0" / 356 mm
2nd: 6.00" / 152 mm 6.00" / 152 mm 6.00" / 152 mm
- Armour deck: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 122,724 shp / 91,552 Kw = 28.00 kts
Range 7,500nm at 18.00 kts
Bunker at max displacement = 8,050 tons
Complement:
1,776 - 2,310
Cost:
£10.082 million / $40.327 million
Distribution of weights at normal displacement:
Armament: 2,791 tons, 5.1 %
Armour: 20,507 tons, 37.8 %
- Belts: 5,177 tons, 9.5 %
- Torpedo bulkhead: 2,478 tons, 4.6 %
- Armament: 4,707 tons, 8.7 %
- Armour Deck: 7,713 tons, 14.2 %
- Conning Tower: 432 tons, 0.8 %
Machinery: 4,358 tons, 8.0 %
Hull, fittings & equipment: 19,962 tons, 36.8 %
Fuel, ammunition & stores: 6,632 tons, 12.2 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
79,895 lbs / 36,240 Kg = 35.6 x 16.5 " / 419 mm shells or 13.4 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 6.2 ft / 1.9 m
Roll period: 17.6 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.88
Seaboat quality (Average = 1.00): 1.19
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.681
Length to Beam Ratio: 7.81 : 1
'Natural speed' for length: 32.56 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 4.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 29.00 ft / 8.84 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m
- Quarterdeck (15 %): 23.00 ft / 7.01 m
- Stern: 23.00 ft / 7.01 m
- Average freeboard: 23.48 ft / 7.16 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 80.3 %
- Above water (accommodation/working, high = better): 171.4 %
Waterplane Area: 69,486 Square feet or 6,455 Square metres
Displacement factor (Displacement / loading): 105 %
Structure weight / hull surface area: 212 lbs/sq ft or 1,036 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.19
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
A 1916 fast British battleship
Jumping back to my series of British fast battleships, I designed a 16in-gunned version for 1916. This is attempting to fit into that series, and uses a secondary armament of 5.5in QF guns with a main battery of 16in BLR. The armour basis is 13in. The result is almost a battlecruiser or a fast battleship reminiscent of the late 1930's. The layout is conservative, with four twin turrets for the 16in guns. The 5.5in guns would be in shields and mounted high (upper deck and superstructure). As usual, I have retained a 16ft high belt of the maximum thickness, unlike the usual practice of having a thick lower belt and a thinner upper belt. There is no "upper deck side" armour, either. The deck is 4in thick, and hopefully that would suffice. The torpedo bulkhead is 3in thick, which is substantial for the period. The speed is 27.5 knots with a 6,200nm range at a cruising speed of 17 knots. This is the Springsharp report:
GB/BB/1916, Great Britain Battleship laid down 1916
Displacement:
35,019 t light; 36,614 t standard; 39,800 t normal; 42,349 t full load
Dimensions: Length overall / water x beam x draught
710.00 ft / 710.00 ft x 95.00 ft x 32.00 ft (normal load)
216.41 m / 216.41 m x 28.96 m x 9.75 m
Armament:
8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1916 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
14 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1916 Model
Quick firing guns in deck mounts with hoists
on side, evenly spread, 4 raised mounts
4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1916 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread
16 - 1.57" / 40.0 mm guns (1x16 guns), 2.00lbs / 0.91kg shells, 1916 Model
Quick firing guns in deck mount
on side
Weight of broadside 17,709 lbs / 8,032 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 13.0" / 330 mm 470.00 ft / 143.26 m 16.00 ft / 4.88 m
Ends: 5.00" / 127 mm 240.00 ft / 73.15 m 16.00 ft / 4.88 m
Main Belt covers 102 % of normal length
- Torpedo Bulkhead:
3.00" / 76 mm 470.00 ft / 143.26 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: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
- Armour deck: 4.00" / 102 mm, Conning tower: 13.00" / 330 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 110,883 shp / 82,719 Kw = 27.50 kts
Range 6,200nm at 17.00 kts
Bunker at max displacement = 5,735 tons
Complement:
1,408 - 1,831
Cost:
£5.995 million / $23.978 million
Distribution of weights at normal displacement:
Armament: 2,213 tons, 5.6 %
Armour: 14,164 tons, 35.6 %
- Belts: 4,911 tons, 12.3 %
- Torpedo bulkhead: 1,565 tons, 3.9 %
- Armament: 3,553 tons, 8.9 %
- Armour Deck: 3,807 tons, 9.6 %
- Conning Tower: 326 tons, 0.8 %
Machinery: 4,131 tons, 10.4 %
Hull, fittings & equipment: 14,511 tons, 36.5 %
Fuel, ammunition & stores: 4,781 tons, 12.0 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
47,417 lbs / 21,508 Kg = 23.2 x 16.0 " / 406 mm shells or 7.1 torpedoes
Stability (Unstable if below 1.00): 1.04
Metacentric height 5.0 ft / 1.5 m
Roll period: 17.9 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.92
Seaboat quality (Average = 1.00): 1.02
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.645
Length to Beam Ratio: 7.47 : 1
'Natural speed' for length: 26.65 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: 29.00 ft / 8.84 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: 21.76 ft / 6.63 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 97.8 %
- Above water (accommodation/working, high = better): 151.6 %
Waterplane Area: 51,452 Square feet or 4,780 Square metres
Displacement factor (Displacement / loading): 99 %
Structure weight / hull surface area: 198 lbs/sq ft or 965 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.25
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
The D design from 22 November 1906 (real world)
The D design from 22 November 1906 was nominally a battlecruiser. The specifications were as follows:
Length between perpendiculars: 565ft
Estimated length overall: 607ft
Beam: 81ft
Mean draft: 27ft
Speed: 24 knots
estimated power: 45,000 SHP
Armour: Lower belt: 10in
Upper belt: 8in
Normal displacement: 20,700 tons
This ship would have been a good opponent for the German battlecruisers, as its protection was adequate against 11in guns.
The X4 Design from 2 December 1905 (real world)
In the real world, fast battleships were under real consideration after the Dreadnought. The X4 Design from 2 December 1905 had the following specifications:
Length between perpendiculars: 580ft
Length overall: 623ft
Beam: 83ft
Mean draft: 27ft-6in
Armament: 10-12in/45 BLR
8-4in QF
18-12pdr QF
3-18in torpedo tubes
Armour basis: 11in
Speed: 25 knots
Power: 45,000 SHP
Machinery Wt: 12.67 SHP/ton
Coal-fired boilers
Load displacement: 22,500 tons
Thursday, November 24, 2005
OK, so now how about the 15in-gunned fast battleship
We seem to be on a roll, so let us try the 15in-gunned fast battleship to be laid down in 1913. By accepting slightly lower protection than we might otherwise have, we have a 27-knot ship with a 17 knot cruising speed and a 5,600nm range. The armour basis is 12in, which should do quite well for a WWI-style ship. I actually reduced length and beam to achieve adequate composite strength. I also have lowered the freeboard for that same end. Does this seem reasonable and useful? This is the Springsharp report:
GB/BB/1913, Great Britain Battleship laid down 1913
Displacement:
30,154 t light; 31,523 t standard; 34,500 t normal; 36,882 t full load
Dimensions: Length overall / water x beam x draught
675.00 ft / 675.00 ft x 90.00 ft x 31.00 ft (normal load)
205.74 m / 205.74 m x 27.43 m x 9.45 m
Armament:
8 - 15.00" / 381 mm guns (4x2 guns), 1,687.50lbs / 765.44kg shells, 1913 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
14 - 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, 4 raised mounts
Weight of broadside 15,012 lbs / 6,809 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
Ends: 5.00" / 127 mm 225.00 ft / 68.58 m 16.00 ft / 4.88 m
Main Belt covers 103 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 450.00 ft / 137.16 m 30.00 ft / 9.14 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12.0" / 305 mm 9.00" / 229 mm 12.0" / 305 mm
2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
- Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 95,921 shp / 71,557 Kw = 27.00 kts
Range 5,600nm at 17.00 kts
Bunker at max displacement = 5,359 tons
Complement:
1,265 - 1,645
Cost:
£3.445 million / $13.780 million
Distribution of weights at normal displacement:
Armament: 1,877 tons, 5.4 %
Armour: 12,127 tons, 35.1 %
- Belts: 4,372 tons, 12.7 %
- Torpedo bulkhead: 999 tons, 2.9 %
- Armament: 3,066 tons, 8.9 %
- Armour Deck: 3,416 tons, 9.9 %
- Conning Tower: 274 tons, 0.8 %
Machinery: 3,759 tons, 10.9 %
Hull, fittings & equipment: 12,393 tons, 35.9 %
Fuel, ammunition & stores: 4,346 tons, 12.6 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
41,367 lbs / 18,764 Kg = 24.5 x 15.0 " / 381 mm shells or 5.8 torpedoes
Stability (Unstable if below 1.00): 1.05
Metacentric height 4.7 ft / 1.4 m
Roll period: 17.5 seconds
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0.92
Seaboat quality (Average = 1.00): 1.06
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.641
Length to Beam Ratio: 7.50 : 1
'Natural speed' for length: 25.98 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: 29.00 ft / 8.84 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: 21.76 ft / 6.63 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 100.5 %
- Above water (accommodation/working, high = better): 151.4 %
Waterplane Area: 46,162 Square feet or 4,289 Square metres
Displacement factor (Displacement / loading): 100 %
Structure weight / hull surface area: 185 lbs/sq ft or 903 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.33
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Almost indistinguishable from a battlecruiser
I tried a 13.5in-gunned fast battleship in the alternate design series tradition (fewer guns) and I was pleased with the result. Except for having much better protection, the design is very battlecruiser-like. The speed in at least acceptable at 26.5 knots. The cruising speed is higher at 15 knots for a longer range of 5,200 nm. The armour basis is 11in. The machinery is only helped by using all-oil fired boilers but otherwise is not lightweight. This is the Springsharp report:
GB/BB/1910, Great Britain Battleship laid down 1910
Displacement:
23,764 t light; 24,766 t standard; 26,800 t normal; 28,427 t full load
Dimensions: Length overall / water x beam x draught
645.00 ft / 645.00 ft x 86.00 ft x 29.00 ft (normal load)
196.60 m / 196.60 m x 26.21 m x 8.84 m
Armament:
8 - 13.50" / 343 mm guns (4x2 guns), 1,230.19lbs / 558.00kg shells, 1910 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - superfiring
16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1910 Model
Quick firing guns in casemate mounts
on side, evenly spread, 8 raised mounts
Weight of broadside 10,354 lbs / 4,696 kg
Shells per gun, main battery: 80
4 - 21.0" / 533.4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.0" / 279 mm 430.00 ft / 131.06 m 16.00 ft / 4.88 m
Ends: 5.00" / 127 mm 215.00 ft / 65.53 m 16.00 ft / 4.88 m
Main Belt covers 103 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 430.00 ft / 131.06 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: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
- Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 75,872 shp / 56,600 Kw = 26.50 kts
Range 5,200nm at 15.00 kts
Bunker at max displacement = 3,662 tons
Complement:
1,046 - 1,361
Cost:
£2.358 million / $9.431 million
Distribution of weights at normal displacement:
Armament: 1,294 tons, 4.8 %
Armour: 9,500 tons, 35.4 %
- Belts: 3,872 tons, 14.4 %
- Torpedo bulkhead: 859 tons, 3.2 %
- Armament: 2,340 tons, 8.7 %
- Armour Deck: 2,216 tons, 8.3 %
- Conning Tower: 212 tons, 0.8 %
Machinery: 3,135 tons, 11.7 %
Hull, fittings & equipment: 9,835 tons, 36.7 %
Fuel, ammunition & stores: 3,036 tons, 11.3 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
35,072 lbs / 15,908 Kg = 28.5 x 13.5 " / 343 mm shells or 5.2 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 4.6 ft / 1.4 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.77
Seaboat quality (Average = 1.00): 1.19
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.583
Length to Beam Ratio: 7.50 : 1
'Natural speed' for length: 25.40 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 %): 24.00 ft / 7.32 m
- Mid (67 %): 24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
- Quarterdeck (15 %): 16.00 ft / 4.88 m
- Stern: 16.00 ft / 4.88 m
- Average freeboard: 21.68 ft / 6.61 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 99.7 %
- Above water (accommodation/working, high = better): 158.4 %
Waterplane Area: 39,933 Square feet or 3,710 Square metres
Displacement factor (Displacement / loading): 103 %
Structure weight / hull surface area: 167 lbs/sq ft or 815 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.41
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
A battleship-cruiser in the spirit of my alternate series
This design is somewhat reminiscent of actual plans for a fast battleship shortly after the dreadnought was built. I wanted 25.5 knots and 8-12in guns. The belt is 10in, which is better than most battlecruisers built by the British. The design is much more potent than the sad little Invincibles with a 6in belt. The deck armour is light, but that does not seem to have had too much affect on the survivability in Springsharp. This is the Springsharp report:
GB/BB/1906, Great Britain Battleship laid down 1906
Displacement:
19,732 t light; 20,502 t standard; 21,700 t normal; 22,658 t full load
Dimensions: Length overall / water x beam x draught
575.00 ft / 575.00 ft x 80.00 ft x 27.00 ft (normal load)
175.26 m / 175.26 m x 24.38 m x 8.23 m
Armament:
8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1906 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - superfiring
16 - 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, 8 raised mounts
Weight of broadside 7,424 lbs / 3,367 kg
Shells per gun, main battery: 80
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 10.0" / 254 mm 490.00 ft / 149.35 m 16.00 ft / 4.88 m
Ends: 5.00" / 127 mm 85.00 ft / 25.91 m 16.00 ft / 4.88 m
Main Belt covers 131 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 490.00 ft / 149.35 m 26.00 ft / 7.92 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 10.0" / 254 mm 7.00" / 178 mm 10.0" / 254 mm
2nd: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 2.00" / 51 mm, Conning tower: 10.00" / 254 mm
Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 60,658 shp / 45,251 Kw = 25.50 kts
Range 4,500nm at 12.00 kts
Bunker at max displacement = 2,156 tons
Complement:
893 - 1,162
Cost:
£2.022 million / $8.086 million
Distribution of weights at normal displacement:
Armament: 928 tons, 4.3 %
Armour: 7,372 tons, 34.0 %
- Belts: 3,459 tons, 15.9 %
- Torpedo bulkhead: 707 tons, 3.3 %
- Armament: 1,780 tons, 8.2 %
- Armour Deck: 1,258 tons, 5.8 %
- Conning Tower: 168 tons, 0.8 %
Machinery: 3,939 tons, 18.2 %
Hull, fittings & equipment: 7,493 tons, 34.5 %
Fuel, ammunition & stores: 1,968 tons, 9.1 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
23,588 lbs / 10,699 Kg = 27.3 x 12.0 " / 305 mm shells or 3.3 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 4.4 ft / 1.3 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 58 %
- Recoil effect (Restricted arc if above 1.00): 0.67
Seaboat quality (Average = 1.00): 1.15
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.612
Length to Beam Ratio: 7.19 : 1
'Natural speed' for length: 23.98 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: 27.00 ft / 8.23 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 20.68 ft / 6.30 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 125.0 %
- Above water (accommodation/working, high = better): 150.8 %
Waterplane Area: 34,007 Square feet or 3,159 Square metres
Displacement factor (Displacement / loading): 96 %
Structure weight / hull surface area: 149 lbs/sq ft or 730 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.47
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Wednesday, November 23, 2005
A battleship in the design philosophy of my "lost series"
I believe that my battleship design in the series that is lost, perhaps permanently, included a feature where the guns, even in 1905, were on the centerline, but there were only four turrets, not five. I tried this approach for a 1905 British battleship. There is nothing special here, except that the belt is 16ft high and there are the four turrets, with one superfiring over the other at the stern. If the boilers were oil-fired, the ship could be rather fast. I tried this, in fact, and with no other changes, 22.5 knots could be reached with oil-fired boilers. This is the Springsharp report:
GB/BB/1905, Great Britain Battleship laid down 1905
Displacement:
16,560 t light; 17,272 t standard; 18,850 t normal; 20,112 t full load
Dimensions: Length overall / water x beam x draught
540.00 ft / 540.00 ft x 80.00 ft x 27.00 ft (normal load)
164.59 m / 164.59 m x 24.38 m x 8.23 m
Armament:
8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount aft - 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: 80
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 10.0" / 254 mm 365.00 ft / 111.25 m 16.00 ft / 4.88 m
Ends: 5.00" / 127 mm 175.00 ft / 53.34 m 16.00 ft / 4.88 m
Main Belt covers 104 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 365.00 ft / 111.25 m 26.00 ft / 7.92 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 10.0" / 254 mm 7.00" / 178 mm 10.0" / 254 mm
2nd: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
- Armour deck: 2.00" / 51 mm, Conning tower: 10.00" / 254 mm
Machinery:
Coal fired boilers, steam turbines,
Direct drive, 4 shafts, 26,418 shp / 19,708 Kw = 21.00 kts
Range 4,500nm at 12.00 kts
Bunker at max displacement = 2,840 tons (100% coal)
Complement:
803 - 1,045
Cost:
£1.667 million / $6.669 million
Distribution of weights at normal displacement:
Armament: 928 tons, 4.9 %
Armour: 6,569 tons, 34.9 %
- Belts: 3,031 tons, 16.1 %
- Torpedo bulkhead: 527 tons, 2.8 %
- Armament: 1,727 tons, 9.2 %
- Armour Deck: 1,132 tons, 6.0 %
- Conning Tower: 153 tons, 0.8 %
Machinery: 2,202 tons, 11.7 %
Hull, fittings & equipment: 6,861 tons, 36.4 %
Fuel, ammunition & stores: 2,290 tons, 12.1 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
24,306 lbs / 11,025 Kg = 28.1 x 12.0 " / 305 mm shells or 3.9 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 4.2 ft / 1.3 m
Roll period: 16.4 seconds
Steadiness - As gun platform (Average = 50 %): 78 %
- Recoil effect (Restricted arc if above 1.00): 0.80
Seaboat quality (Average = 1.00): 1.56
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.566
Length to Beam Ratio: 6.75 : 1
'Natural speed' for length: 23.24 kts
Power going to wave formation at top speed: 44 %
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 %): 22.00 ft / 6.71 m
- Mid (67 %): 22.00 ft / 6.71 m (14.00 ft / 4.27 m aft of break)
- Quarterdeck (15 %): 14.00 ft / 4.27 m
- Stern: 14.00 ft / 4.27 m
- Average freeboard: 19.68 ft / 6.00 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 103.2 %
- Above water (accommodation/working, high = better): 143.6 %
Waterplane Area: 30,594 Square feet or 2,842 Square metres
Displacement factor (Displacement / loading): 102 %
Structure weight / hull surface area: 152 lbs/sq ft or 742 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.66
- 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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Tuesday, November 22, 2005
Wringing the last bit of performance out of the design
By reducing the gratuitous extra length from the armour belt and thinning it to 8in, I was able to get 37 knots from my "cruiser killer" design (GB/CB/1923). Of course, the design is only possible because of using the lightest weight machinery (41.8 SHP/ton). So you have a fast ship with 9-14in BLR, 16-5.5in QF, 6-4.7in AA, and 36-2pdr AA. This is the revised Springsharp report:
GB/CB/1923, Great Britain Battlecruiser laid down 1923 (Engine 1950)
Displacement:
40,502 t light; 42,012 t standard; 43,500 t normal; 44,690 t full load
Dimensions: Length overall / water x beam x draught
867.97 ft / 865.00 ft x 112.00 ft x 34.00 ft (normal load)
264.56 m / 263.65 m x 34.14 m x 10.36 m
Armament:
9 - 14.00" / 356 mm guns (3x3 guns), 1,372.00lbs / 622.33kg shells, 1923 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
16 - 5.50" / 140 mm guns (8x2 guns), 83.19lbs / 37.73kg shells, 1923 Model
Quick firing guns in turrets (on barbettes)
on side, all amidships, 4 raised mounts - superfiring
6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side ends, majority forward, all raised mounts - superfiring
36 - 1.57" / 40.0 mm guns (3x12 guns), 1.95lbs / 0.89kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 2 raised mounts
Weight of broadside 14,061 lbs / 6,378 kg
Shells per gun, main battery: 80
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 8.00" / 203 mm 620.00 ft / 188.98 m 16.00 ft / 4.88 m
Ends: Unarmoured
Main Belt covers 110 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 620.00 ft / 188.98 m 33.00 ft / 10.06 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: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
3rd: 1.00" / 25 mm - -
- Armour deck: 4.00" / 102 mm, Conning tower: 10.00" / 254 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 276,990 shp / 206,635 Kw = 37.00 kts
Range 5,400nm at 15.00 kts
Bunker at max displacement = 2,678 tons
Complement:
1,505 - 1,957
Cost:
£11.118 million / $44.470 million
Distribution of weights at normal displacement:
Armament: 1,758 tons, 4.0 %
Armour: 12,918 tons, 29.7 %
- Belts: 3,309 tons, 7.6 %
- Torpedo bulkhead: 1,514 tons, 3.5 %
- Armament: 3,028 tons, 7.0 %
- Armour Deck: 4,800 tons, 11.0 %
- Conning Tower: 266 tons, 0.6 %
Machinery: 6,627 tons, 15.2 %
Hull, fittings & equipment: 19,200 tons, 44.1 %
Fuel, ammunition & stores: 2,998 tons, 6.9 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
62,369 lbs / 28,290 Kg = 45.5 x 14.0 " / 356 mm shells or 9.0 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 7.5 ft / 2.3 m
Roll period: 17.2 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.01
Hull form characteristics:
Hull has low forecastle
and transom stern
Block coefficient: 0.462
Length to Beam Ratio: 7.72 : 1
'Natural speed' for length: 34.47 kts
Power going to wave formation at top speed: 57 %
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: 34.00 ft / 10.36 m
- Forecastle (20 %): 26.00 ft / 7.92 m (27.00 ft / 8.23 m aft of break)
- 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: 27.44 ft / 8.36 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 97.2 %
- Above water (accommodation/working, high = better): 221.7 %
Waterplane Area: 64,867 Square feet or 6,026 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 208 lbs/sq ft or 1,014 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
Monday, November 21, 2005
This is my latest attempt at an "edgy" very fast cruiser killer
Frank Fox calls this sort of ship a "cruiser killer". That is how he describes the Alaska class, which is one of his favorite ship designs. I tried my hand again at a very fast armoured cruiser, and given that the design has 14in guns, we would be destined to call the design a battlecruiser. I wanted at least 36 knots, and I was able to achieve 36.5 knots. the armour belt is 9in, which should be sufficient to protect against the lesser cruisers. Those who have been following my string of designs may recognize this as being reminiscent of a design I did in the summer of 2001. This is the Springsharp report:
GB/CB/1923, Great Britain Battlecruiser laid down 1923 (Engine 1950)
Displacement:
41,508 t light; 43,039 t standard; 44,550 t normal; 45,758 t full load
Dimensions: Length overall / water x beam x draught
867.97 ft / 865.00 ft x 112.00 ft x 34.00 ft (normal load)
264.56 m / 263.65 m x 34.14 m x 10.36 m
Armament:
9 - 14.00" / 356 mm guns (3x3 guns), 1,372.00lbs / 622.33kg shells, 1923 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
16 - 5.50" / 140 mm guns (8x2 guns), 83.19lbs / 37.73kg shells, 1923 Model
Quick firing guns in turrets (on barbettes)
on side, all amidships, 4 raised mounts - superfiring
6 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side ends, majority forward, all raised mounts - superfiring
36 - 1.57" / 40.0 mm guns (3x12 guns), 1.95lbs / 0.89kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 2 raised mounts
Weight of broadside 14,061 lbs / 6,378 kg
Shells per gun, main battery: 80
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 9.00" / 229 mm 700.00 ft / 213.36 m 16.00 ft / 4.88 m
Ends: Unarmoured
Main Belt covers 124 % of normal length
- Torpedo Bulkhead:
2.00" / 51 mm 700.00 ft / 213.36 m 33.00 ft / 10.06 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 11.0" / 279 mm 6.00" / 152 mm 11.0" / 279 mm
2nd: 4.00" / 102 mm 4.00" / 102 mm 4.00" / 102 mm
3rd: 1.00" / 25 mm - -
- Armour deck: 4.00" / 102 mm, Conning tower: 11.00" / 279 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 268,276 shp / 200,134 Kw = 36.50 kts
Range 5,400nm at 15.00 kts
Bunker at max displacement = 2,719 tons
Complement:
1,533 - 1,993
Cost:
£11.135 million / $44.540 million
Distribution of weights at normal displacement:
Armament: 1,758 tons, 3.9 %
Armour: 14,184 tons, 31.8 %
- Belts: 4,109 tons, 9.2 %
- Torpedo bulkhead: 1,709 tons, 3.8 %
- Armament: 3,220 tons, 7.2 %
- Armour Deck: 4,848 tons, 10.9 %
- Conning Tower: 298 tons, 0.7 %
Machinery: 6,418 tons, 14.4 %
Hull, fittings & equipment: 19,148 tons, 43.0 %
Fuel, ammunition & stores: 3,042 tons, 6.8 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
65,787 lbs / 29,840 Kg = 47.9 x 14.0 " / 356 mm shells or 9.9 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 7.4 ft / 2.3 m
Roll period: 17.2 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.03
Hull form characteristics:
Hull has low forecastle
and transom stern
Block coefficient: 0.473
Length to Beam Ratio: 7.72 : 1
'Natural speed' for length: 34.41 kts
Power going to wave formation at top speed: 57 %
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: 34.00 ft / 10.36 m
- Forecastle (20 %): 26.00 ft / 7.92 m (27.00 ft / 8.23 m aft of break)
- 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: 27.44 ft / 8.36 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 93.1 %
- Above water (accommodation/working, high = better): 219.8 %
Waterplane Area: 65,509 Square feet or 6,086 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 205 lbs/sq ft or 1,003 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.47
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
A British 1905 armoured cruiser
I found out quickly that to achieve a reasonable 1905 British armoured cruiser, we needed to use lighter machinery than 12 SHP/ton of machinery. In the real world, the Invincibles had somewhat lighter machinery than that (although only 12.44 SHP/ton). The problem is partly that my armour weight is 4,672 tons while the Invincibles had just 3,460 tons of armour. This is the Springsharp report:
GB/CA/1905, Great Britain Armoured Cruiser laid down 1905 (Engine 1907)
Displacement:
13,369 t light; 13,900 t standard; 16,300 t normal; 18,220 t full load
Dimensions: Length overall / water x beam x draught
555.00 ft / 555.00 ft x 76.00 ft x 26.00 ft (normal load)
169.16 m / 169.16 m x 23.16 m x 7.92 m
Armament:
8 - 9.20" / 234 mm guns (4x2 guns), 380.00lbs / 172.37kg shells, 1905 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread
16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
Quick firing guns in casemate mounts
on side, all amidships
12 guns in hull casemates - Limited use in heavy seas
Weight of broadside 3,552 lbs / 1,611 kg
Shells per gun, main battery: 100
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 6.00" / 152 mm 400.00 ft / 121.92 m 16.00 ft / 4.88 m
Ends: 4.00" / 102 mm 155.00 ft / 47.24 m 16.00 ft / 4.88 m
Main Belt covers 111 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 400.00 ft / 121.92 m 25.00 ft / 7.62 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: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
- Armour deck: 2.00" / 51 mm, Conning tower: 7.00" / 178 mm
Machinery:
Coal fired boilers, steam turbines,
Direct drive, 4 shafts, 45,828 shp / 34,187 Kw = 25.00 kts
Range 5,200nm at 15.00 kts
Bunker at max displacement = 4,321 tons (100% coal)
Complement:
720 - 937
Cost:
£1.250 million / $4.999 million
Distribution of weights at normal displacement:
Armament: 453 tons, 2.8 %
Armour: 4,672 tons, 28.7 %
- Belts: 1,981 tons, 12.2 %
- Torpedo bulkhead: 555 tons, 3.4 %
- Armament: 980 tons, 6.0 %
- Armour Deck: 1,059 tons, 6.5 %
- Conning Tower: 97 tons, 0.6 %
Machinery: 2,864 tons, 17.6 %
Hull, fittings & equipment: 5,379 tons, 33.0 %
Fuel, ammunition & stores: 2,931 tons, 18.0 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
23,223 lbs / 10,534 Kg = 59.6 x 9.2 " / 234 mm shells or 3.6 torpedoes
Stability (Unstable if below 1.00): 1.28
Metacentric height 5.2 ft / 1.6 m
Roll period: 14.0 seconds
Steadiness - As gun platform (Average = 50 %): 74 %
- Recoil effect (Restricted arc if above 1.00): 0.35
Seaboat quality (Average = 1.00): 1.47
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.520
Length to Beam Ratio: 7.30 : 1
'Natural speed' for length: 23.56 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: 26.00 ft / 7.92 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 20.60 ft / 6.28 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 110.3 %
- Above water (accommodation/working, high = better): 157.4 %
Waterplane Area: 28,630 Square feet or 2,660 Square metres
Displacement factor (Displacement / loading): 116 %
Structure weight / hull surface area: 123 lbs/sq ft or 601 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.62
- 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
Sunday, November 20, 2005
A Japanese armoured cruiser laid down in 1905
I thought that I would try a design in Springsharp that would be similar to what my alternate history series. I did a design for a Japanese armoured cruiser with a 25 knot speed, 6in belt, and 8-8in guns. The ship underperforms, possibly from the armouring scheme. The fact that coal-fired boilers are used is probably a large factor. The main armament would be in echelon. This is the Springsharp report:
Jap/CA/1905, Japan Armoured Cruiser laid down 1905
Displacement:
14,026 t light; 14,529 t standard; 16,950 t normal; 18,887 t full load
Dimensions: Length overall / water x beam x draught
550.00 ft / 550.00 ft x 75.00 ft x 26.00 ft (normal load)
167.64 m / 167.64 m x 22.86 m x 7.92 m
Armament:
8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1905 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread
16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
Quick firing guns in casemate mounts
on side, all amidships
12 guns in hull casemates - Limited use in heavy seas
Weight of broadside 2,560 lbs / 1,161 kg
Shells per gun, main battery: 110
4 - 18.0" / 457.2 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 6.00" / 152 mm 465.00 ft / 141.73 m 16.00 ft / 4.88 m
Ends: 4.00" / 102 mm 85.00 ft / 25.91 m 16.00 ft / 4.88 m
Main Belt covers 130 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 465.00 ft / 141.73 m 24.00 ft / 7.32 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: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
- Armour deck: 2.00" / 51 mm, Conning tower: 7.00" / 178 mm
Machinery:
Coal fired boilers, steam turbines,
Direct drive, 4 shafts, 47,680 shp / 35,569 Kw = 25.00 kts
Range 4,500nm at 15.00 kts
Bunker at max displacement = 4,358 tons (100% coal)
Complement:
742 - 965
Cost:
£1.316 million / $5.264 million
Distribution of weights at normal displacement:
Armament: 320 tons, 1.9 %
Armour: 4,665 tons, 27.5 %
- Belts: 2,021 tons, 11.9 %
- Torpedo bulkhead: 619 tons, 3.7 %
- Armament: 857 tons, 5.1 %
- Armour Deck: 1,068 tons, 6.3 %
- Conning Tower: 100 tons, 0.6 %
Machinery: 3,973 tons, 23.4 %
Hull, fittings & equipment: 5,067 tons, 29.9 %
Fuel, ammunition & stores: 2,924 tons, 17.3 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
21,168 lbs / 9,602 Kg = 82.7 x 8.0 " / 203 mm shells or 3.0 torpedoes
Stability (Unstable if below 1.00): 1.37
Metacentric height 5.6 ft / 1.7 m
Roll period: 13.3 seconds
Steadiness - As gun platform (Average = 50 %): 74 %
- Recoil effect (Restricted arc if above 1.00): 0.24
Seaboat quality (Average = 1.00): 1.48
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.553
Length to Beam Ratio: 7.33 : 1
'Natural speed' for length: 23.45 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: 26.00 ft / 7.92 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (67 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 20.60 ft / 6.28 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 128.3 %
- Above water (accommodation/working, high = better): 154.1 %
Waterplane Area: 28,873 Square feet or 2,682 Square metres
Displacement factor (Displacement / loading): 112 %
Structure weight / hull surface area: 115 lbs/sq ft or 562 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.56
- 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
My 1976-era alternate history
Starting in early 1976, I did a series of drawings, with specifications, for an alternate history naval building race and the start of a war. I have not been able to find the drawings, but I am holding out hope that it might still exist in storage. The scenario started from 1905 and continued up through 1914. I actually continued filling in gaps and continuing the timeline into the latter 1970's. The focus was on a competition between Great Britain and Japan. They both were building fleets with dreadnought battleships, medium caliber-armed armoured cruisers, light cruisers, destroyers, submarines, and eventually, aviation (I believe). I also had fleets for the neutral nations, which included the United States and Germany. The United States had one particularly nice light cruiser design from somewhere in the 1912-1914 timeframe, armed with 5in QF guns and torpedo tubes. On the outbreak of war, the action took place in the seas around Indonesia and the Philippines.
Saturday, November 19, 2005
By going larger, a better fast light cruiser is possible
Keeping in the Italian design mode (except for the British), I went to a larger design (something like the Duca d'Aosta). My design is underperforming because of the limitations of Springsharp. I cannot obtain light enough machinery to be equal the real world performance. My ship has 8-6in QF, 4-4in AA, and 16-40mm AA guns with 6-21in TT and a speed of 36 knots. My ship only has a belt of 2in and a deck of 1in. This is the Springsharp report:
GB/CL/1929, Great Britain Light Cruiser laid down 1929 (Engine 1950)
Displacement:
8,057 t light; 8,325 t standard; 8,950 t normal; 9,450 t full load
Dimensions: Length overall / water x beam x draught
613.45 ft / 608.00 ft x 56.00 ft x 21.00 ft (normal load)
186.98 m / 185.32 m x 17.07 m x 6.40 m
Armament:
8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1929 Model
Quick firing guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1929 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships
16 - 1.57" / 40.0 mm guns (8x2 guns), 1.95lbs / 0.89kg shells, 1929 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 6 raised mounts
Weight of broadside 1,023 lbs / 464 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.00" / 51 mm 470.00 ft / 143.26 m 12.00 ft / 3.66 m
Ends: Unarmoured
Main Belt covers 119 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 1.00" / 25 mm 2.00" / 51 mm
- Armour deck: 1.00" / 25 mm, Conning tower: 4.00" / 102 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 120,587 shp / 89,958 Kw = 36.00 kts
Range 6,000nm at 15.00 kts
Bunker at max displacement = 1,125 tons
Complement:
459 - 598
Cost:
£3.173 million / $12.693 million
Distribution of weights at normal displacement:
Armament: 128 tons, 1.4 %
Armour: 1,037 tons, 11.6 %
- Belts: 454 tons, 5.1 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 148 tons, 1.7 %
- Armour Deck: 398 tons, 4.4 %
- Conning Tower: 37 tons, 0.4 %
Machinery: 2,885 tons, 32.2 %
Hull, fittings & equipment: 4,007 tons, 44.8 %
Fuel, ammunition & stores: 893 tons, 10.0 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
9,182 lbs / 4,165 Kg = 85.0 x 6.0 " / 152 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 2.8 ft / 0.8 m
Roll period: 14.2 seconds
Steadiness - As gun platform (Average = 50 %): 67 %
- Recoil effect (Restricted arc if above 1.00): 0.44
Seaboat quality (Average = 1.00): 1.33
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.438
Length to Beam Ratio: 10.86 : 1
'Natural speed' for length: 24.66 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: 3.00 ft / 0.91 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 space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 115.8 %
- Above water (accommodation/working, high = better): 178.7 %
Waterplane Area: 21,513 Square feet or 1,999 Square metres
Displacement factor (Displacement / loading): 114 %
Structure weight / hull surface area: 98 lbs/sq ft or 479 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 2.21
- 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, November 18, 2005
A better protected GB/CL/1927
I failed at achieving 36.5 knots, but I was able to add more protection, partly by reducing some, so that I could have a 1in belt that covers a good bit of side. The range is less, but this seemed to be an improvement. Adding the belt improved seakeeping! This is the Springsharp report:
GB/CL/1925, Great Britain Light Cruiser laid down 1927 (Engine 1950)
Displacement:
6,102 t light; 6,318 t standard; 6,720 t normal; 7,042 t full load
Dimensions: Length overall / water x beam x draught
555.36 ft / 550.00 ft x 52.00 ft x 21.00 ft (normal load)
169.27 m / 167.64 m x 15.85 m x 6.40 m
Armament:
8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1927 Model
Dual purpose guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
16 - 1.57" / 40.0 mm guns (8x2 guns), 1.95lbs / 0.89kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 6 raised mounts
Weight of broadside 940 lbs / 427 kg
Shells per gun, main battery: 150
4 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.00" / 25 mm 530.00 ft / 161.54 m 10.00 ft / 3.05 m
Ends: Unarmoured
Main Belt covers 148 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm 0.75" / 19 mm 0.75" / 19 mm
- Armour deck: 0.75" / 19 mm, Conning tower: 1.00" / 25 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 103,563 shp / 77,258 Kw = 36.00 kts
Range 4,500nm at 15.00 kts
Bunker at max displacement = 724 tons
Complement:
370 - 482
Cost:
£2.397 million / $9.588 million
Distribution of weights at normal displacement:
Armament: 118 tons, 1.7 %
Armour: 521 tons, 7.8 %
- Belts: 205 tons, 3.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 65 tons, 1.0 %
- Armour Deck: 243 tons, 3.6 %
- Conning Tower: 8 tons, 0.1 %
Machinery: 2,478 tons, 36.9 %
Hull, fittings & equipment: 2,986 tons, 44.4 %
Fuel, ammunition & stores: 618 tons, 9.2 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,931 lbs / 2,237 Kg = 45.7 x 6.0 " / 152 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 2.7 ft / 0.8 m
Roll period: 13.2 seconds
Steadiness - As gun platform (Average = 50 %): 55 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.10
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.392
Length to Beam Ratio: 10.58 : 1
'Natural speed' for length: 23.45 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.00 ft / 0.91 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 space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 133.0 %
- Above water (accommodation/working, high = better): 147.5 %
Waterplane Area: 17,527 Square feet or 1,628 Square metres
Displacement factor (Displacement / loading): 105 %
Structure weight / hull surface area: 93 lbs/sq ft or 455 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.92
- Longitudinal: 2.04
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
This page has some nice photos of the Bartolemo Colleoni
I found a page that describes the action off Cape Spada when the Bartolomeo Colleoni was sunk by the Sydney. In particular, it has some photos that are both good and new to me.
The next step is a high-speed light cruiser
I thought that a Barbiano-style light cruiser. The problem with my first attempt is that there is no belt, only turret, barbette, deck, and conning tower. My first attempt was to reach 36 knots with 8-6in guns. That goal proved achievable. I wanted a 555ft length and as low a displacement as possible. I assumed that a relatively high freeboard would be required. I also assumed that the design would use the lightest machinery that Springsharp would allow. I expect that I will do several iterations to achieve better performance. This is the Springsharp report:
GB/CL/1925, Great Britain Light Cruiser laid down 1927 (Engine 1950)
Displacement:
5,962 t light; 6,177 t standard; 6,650 t normal; 7,029 t full load
Dimensions: Length overall / water x beam x draught
555.36 ft / 550.00 ft x 51.00 ft x 21.00 ft (normal load)
169.27 m / 167.64 m x 15.54 m x 6.40 m
Armament:
8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1927 Model
Dual purpose guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
16 - 1.57" / 40.0 mm guns (8x2 guns), 1.95lbs / 0.89kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 6 raised mounts
Weight of broadside 940 lbs / 427 kg
Shells per gun, main battery: 150
4 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm 1.00" / 25 mm 1.00" / 25 mm
- Armour deck: 1.00" / 25 mm, Conning tower: 1.00" / 25 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 102,857 shp / 76,731 Kw = 36.00 kts
Range 5,400nm at 15.00 kts
Bunker at max displacement = 852 tons
Complement:
367 - 478
Cost:
£2.371 million / $9.482 million
Distribution of weights at normal displacement:
Armament: 118 tons, 1.8 %
Armour: 410 tons, 6.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 84 tons, 1.3 %
- Armour Deck: 319 tons, 4.8 %
- Conning Tower: 8 tons, 0.1 %
Machinery: 2,461 tons, 37.0 %
Hull, fittings & equipment: 2,974 tons, 44.7 %
Fuel, ammunition & stores: 688 tons, 10.3 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,804 lbs / 2,179 Kg = 44.5 x 6.0 " / 152 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 2.6 ft / 0.8 m
Roll period: 13.3 seconds
Steadiness - As gun platform (Average = 50 %): 56 %
- Recoil effect (Restricted arc if above 1.00): 0.42
Seaboat quality (Average = 1.00): 1.11
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.395
Length to Beam Ratio: 10.78 : 1
'Natural speed' for length: 23.45 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.00 ft / 0.91 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 space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 133.6 %
- Above water (accommodation/working, high = better): 145.8 %
Waterplane Area: 17,220 Square feet or 1,600 Square metres
Displacement factor (Displacement / loading): 106 %
Structure weight / hull surface area: 93 lbs/sq ft or 453 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.92
- Longitudinal: 2.07
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Thursday, November 17, 2005
4,000 tons must be a magic number
To get the benefit of destroyer-like composite strength assessment, I seemed to need to keep a scout cruiser below 4,000 tons normal displacement. I tried varying displacement and draft to see if I could squeeze out just a little more. I reduced freeboard, as I seemed to have adequate seakeeping capability. I was able to get a range of 4,200 nm and a maximum speed of 39 knots. That is with 6-5.5in, 8-57mm, 12-40mm, and 8-21in TT. It is only a marginal gain, but it still is nice. This is yet another Springsharp report:
GB/CL/1931, Great Britain Scout Cruiser laid down 1927 (Engine 1950)
Displacement:
3,605 t light; 3,735 t standard; 3,995 t normal; 4,203 t full load
Dimensions: Length overall / water x beam x draught
460.36 ft / 455.00 ft x 42.00 ft x 18.00 ft (normal load)
140.32 m / 138.68 m x 12.80 m x 5.49 m
Armament:
6 - 5.50" / 140 mm guns (3x2 guns), 83.19lbs / 37.73kg shells, 1927 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
12 - 1.57" / 40.0 mm guns (6x2 guns), 1.95lbs / 0.89kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 568 lbs / 258 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 112,997 shp / 84,296 Kw = 38.75 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 467 tons
Complement:
250 - 326
Cost:
£1.945 million / $7.780 million
Distribution of weights at normal displacement:
Armament: 71 tons, 1.8 %
Machinery: 2,493 tons, 62.4 %
Hull, fittings & equipment: 1,041 tons, 26.1 %
Fuel, ammunition & stores: 390 tons, 9.8 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
677 lbs / 307 Kg = 8.1 x 5.5 " / 140 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.54
Metacentric height 2.8 ft / 0.9 m
Roll period: 10.5 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.04
Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak
Block coefficient: 0.406
Length to Beam Ratio: 10.83 : 1
'Natural speed' for length: 21.33 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.00 ft / 0.91 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.00 ft / 8.23 m
- Forecastle (20 %): 23.00 ft / 7.01 m (21.00 ft / 6.40 m aft of break)
- Mid (50 %): 19.00 ft / 5.79 m (17.00 ft / 5.18 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 18.77 ft / 5.72 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 214.7 %
- Above water (accommodation/working, high = better): 114.2 %
Waterplane Area: 11,809 Square feet or 1,097 Square metres
Displacement factor (Displacement / loading): 67 %
Structure weight / hull surface area: 41 lbs/sq ft or 202 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.44
- Longitudinal: 1.83
- Overall: 0.50
Hull space for machinery, storage, compartmentation is extremely poor
Room for accommodation and workspaces is adequate
I wanted to see if I could squeeze a little more out of the scout cruiser
I took another try at the scout cruiser to see if I could get better performance than I had. I wanted to see if I could use 6-5.5in guns, with the same LAA armament: 8-57mm in twin mounts, and 12-40mm in twin mounts. The torpedo armament is still 8-21in TT. I was able to reach 38.75 knots, although I derated the range to 4,000 nm. This is the Springsharp report:
GB/CL/1931, Great Britain Scout Cruiser laid down 1927 (Engine 1950)
Displacement:
3,605 t light; 3,735 t standard; 3,995 t normal; 4,203 t full load
Dimensions: Length overall / water x beam x draught
460.36 ft / 455.00 ft x 42.00 ft x 18.00 ft (normal load)
140.32 m / 138.68 m x 12.80 m x 5.49 m
Armament:
6 - 5.50" / 140 mm guns (3x2 guns), 83.19lbs / 37.73kg shells, 1927 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
12 - 1.57" / 40.0 mm guns (6x2 guns), 1.95lbs / 0.89kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 568 lbs / 258 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 112,997 shp / 84,296 Kw = 38.75 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 467 tons
Complement:
250 - 326
Cost:
£1.945 million / $7.780 million
Distribution of weights at normal displacement:
Armament: 71 tons, 1.8 %
Machinery: 2,493 tons, 62.4 %
Hull, fittings & equipment: 1,041 tons, 26.1 %
Fuel, ammunition & stores: 390 tons, 9.8 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
677 lbs / 307 Kg = 8.1 x 5.5 " / 140 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.54
Metacentric height 2.8 ft / 0.9 m
Roll period: 10.5 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.04
Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak
Block coefficient: 0.406
Length to Beam Ratio: 10.83 : 1
'Natural speed' for length: 21.33 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.00 ft / 0.91 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.00 ft / 8.23 m
- Forecastle (20 %): 23.00 ft / 7.01 m (21.00 ft / 6.40 m aft of break)
- Mid (50 %): 19.00 ft / 5.79 m (17.00 ft / 5.18 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 18.77 ft / 5.72 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 214.7 %
- Above water (accommodation/working, high = better): 114.2 %
Waterplane Area: 11,809 Square feet or 1,097 Square metres
Displacement factor (Displacement / loading): 67 %
Structure weight / hull surface area: 41 lbs/sq ft or 202 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.44
- Longitudinal: 1.83
- Overall: 0.50
Hull space for machinery, storage, compartmentation is extremely poor
Room for accommodation and workspaces is adequate
A more satisfactory high-speed scout
Springsharp let me achieve a better high-speed scout by going to a smaller displacement. That way, I was able to get a 38 knot maximum speed with a 15 knot cruising speed. The armament is 6-13cm DP guns, 8-57mm AA, and 12-40mm AA guns with 8-21in TT. There is no protection. This allows a better ship to be designed on a normal displacement of 3,450 tons. This is more of a super destroyer, which was what was intended, anyway. This is the Springsharp report:
GB/CL/1927, Great Britain Scout Cruiser laid down 1927 (Engine 1950)
Displacement:
3,093 t light; 3,204 t standard; 3,450 t normal; 3,647 t full load
Dimensions: Length overall / water x beam x draught
440.36 ft / 435.00 ft x 41.00 ft x 16.00 ft (normal load)
134.22 m / 132.59 m x 12.50 m x 4.88 m
Armament:
6 - 5.10" / 130 mm guns (3x2 guns), 66.33lbs / 30.08kg shells, 1927 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
12 - 1.57" / 40.0 mm guns (6x2 guns), 1.95lbs / 0.89kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 467 lbs / 212 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 98,493 shp / 73,476 Kw = 38.00 kts
Range 4,200nm at 15.00 kts
Bunker at max displacement = 443 tons
Complement:
224 - 292
Cost:
£1.629 million / $6.518 million
Distribution of weights at normal displacement:
Armament: 58 tons, 1.7 %
Machinery: 2,077 tons, 60.2 %
Hull, fittings & equipment: 957 tons, 27.7 %
Fuel, ammunition & stores: 357 tons, 10.4 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
676 lbs / 307 Kg = 10.2 x 5.1 " / 130 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.50
Metacentric height 2.6 ft / 0.8 m
Roll period: 10.6 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.37
Seaboat quality (Average = 1.00): 1.04
Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak
Block coefficient: 0.423
Length to Beam Ratio: 10.61 : 1
'Natural speed' for length: 20.86 kts
Power going to wave formation at top speed: 68 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 3.00 ft / 0.91 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.00 ft / 8.23 m
- Forecastle (20 %): 23.00 ft / 7.01 m (21.00 ft / 6.40 m aft of break)
- Mid (50 %): 19.00 ft / 5.79 m (17.00 ft / 5.18 m aft of break)
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 18.77 ft / 5.72 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 207.1 %
- Above water (accommodation/working, high = better): 116.8 %
Waterplane Area: 11,144 Square feet or 1,035 Square metres
Displacement factor (Displacement / loading): 67 %
Structure weight / hull surface area: 40 lbs/sq ft or 198 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.45
- Longitudinal: 2.01
- Overall: 0.52
Hull space for machinery, storage, compartmentation is extremely poor
Room for accommodation and workspaces is adequate
Wednesday, November 16, 2005
A disappointing attempt to make a very fast scout
I tried designing a very fast scout for the British in 1921, but the result was very unsatisfactory and disappointing. The issue seems to be the usual. The machinery weight is too great compared to what could actually be achieved. The freeboard is very high, but I will not accept a low seakeeping ability, so this is what was required to achieve something acceptable. I wanted a lower displacement, but the design had inadequate strength, unless the displacement ballooned. This is the Springsharp report:
GB/CL/1927, Great Britain Scout Cruiser laid down 1927 (Engine 1950)
Displacement:
5,119 t light; 5,264 t standard; 5,600 t normal; 5,869 t full load
Dimensions: Length overall / water x beam x draught
469.62 ft / 465.00 ft x 42.00 ft x 16.00 ft (normal load)
143.14 m / 141.73 m x 12.80 m x 4.88 m
Armament:
6 - 5.10" / 130 mm guns (3x2 guns), 66.33lbs / 30.08kg shells, 1927 Model
Quick firing guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1927 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 459 lbs / 208 kg
Shells per gun, main battery: 120
8 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -
2nd: 1.00" / 25 mm - -
3rd: 1.00" / 25 mm - -
- Conning tower: 2.00" / 51 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 114,050 shp / 85,081 Kw = 36.00 kts
Range 4,200nm at 15.00 kts
Bunker at max displacement = 605 tons
Complement:
323 - 420
Cost:
£2.216 million / $8.863 million
Distribution of weights at normal displacement:
Armament: 57 tons, 1.0 %
Armour: 37 tons, 0.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 24 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 14 tons, 0.2 %
Machinery: 2,728 tons, 48.7 %
Hull, fittings & equipment: 2,296 tons, 41.0 %
Fuel, ammunition & stores: 481 tons, 8.6 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2,812 lbs / 1,275 Kg = 42.4 x 5.1 " / 130 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 1.9 ft / 0.6 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.01
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.627
Length to Beam Ratio: 11.07 : 1
'Natural speed' for length: 21.56 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 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 (37 %): 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: 21.28 ft / 6.49 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 165.2 %
- Above water (accommodation/working, high = better): 124.6 %
Waterplane Area: 14,651 Square feet or 1,361 Square metres
Displacement factor (Displacement / loading): 94 %
Structure weight / hull surface area: 74 lbs/sq ft or 361 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.86
- Longitudinal: 3.57
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
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