F/CA/1921, France Cruiser laid down 1921 (Engine 1925) Displacement: 13,119 t light; 13,650 t standard; 14,600 t normal; 15,360 t full load Dimensions: Length overall / water x beam x draught 634.71 ft / 630.00 ft x 64.00 ft x 22.00 ft (normal load) 193.46 m / 192.02 m x 19.51 m x 6.71 m Armament: 8 - 9.45" / 240 mm guns (4x2 guns), 421.80lbs / 191.32kg shells, 1921 Model Breech loading guns in turrets (on barbettes) on centreline, evenly spread, 2 raised mounts Aft Main mounts separated by engine room 8 - 5.12" / 130 mm guns in single mounts, 67.03lbs / 30.41kg shells, 1921 Model Quick firing guns in deck mounts with hoists on side, all amidships 6 - 3.54" / 90.0 mm guns (4 mounts), 22.24lbs / 10.09kg shells, 1921 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring 24 - 1.85" / 47.0 mm guns (16 mounts), 3.17lbs / 1.44kg shells, 1921 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 4,120 lbs / 1,869 kg Shells per gun, main battery: 100 6 - 21.7" / 549.9999 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 4.00" / 102 mm 430.00 ft / 131.06 m 12.00 ft / 3.66 m Ends: 3.00" / 76 mm 175.00 ft / 53.34 m 10.00 ft / 3.05 m 25.00 ft / 7.62 m Unarmoured ends Main Belt covers 105 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 430.00 ft / 131.06 m 18.00 ft / 5.49 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 4.00" / 102 mm 3.00" / 76 mm 4.00" / 102 mm 2nd: 2.00" / 51 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 107,854 shp / 80,459 Kw = 32.00 kts Range 5,400nm at 15.00 kts Bunker at max displacement = 1,711 tons Complement: 663 - 863 Cost: £3.518 million / $14.071 million Distribution of weights at normal displacement: Armament: 515 tons, 3.5 % Armour: 3,109 tons, 21.3 % - Belts: 1,051 tons, 7.2 % - Torpedo bulkhead: 286 tons, 2.0 % - Armament: 653 tons, 4.5 % - Armour Deck: 1,067 tons, 7.3 % - Conning Tower: 51 tons, 0.4 % Machinery: 3,502 tons, 24.0 % Hull, fittings & equipment: 5,993 tons, 41.0 % Fuel, ammunition & stores: 1,481 tons, 10.1 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 16,059 lbs / 7,284 Kg = 38.1 x 9.4 " / 240 mm shells or 2.0 torpedoes Stability (Unstable if below 1.00): 1.10 Metacentric height 3.1 ft / 0.9 m Roll period: 15.3 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.96 Seaboat quality (Average = 1.00): 1.07 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.576 Length to Beam Ratio: 9.84 : 1 'Natural speed' for length: 25.10 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: 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): 151.9 % - Above water (accommodation/working, high = better): 168.2 % Waterplane Area: 28,836 Square feet or 2,679 Square metres Displacement factor (Displacement / loading): 103 % Structure weight / hull surface area: 126 lbs/sq ft or 616 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.96 - Longitudinal: 1.45 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Friday, March 31, 2006

### The F/CA/1921 design

The F/CA/1921 design was an attempt to have harder-hitting guns that what had been carried previously. The design now has 8-9.4in (24cm) guns for the main armament. The AA armament was increased, as well. The heavy AA armament now has 6-90mm guns. This is the Springsharp report:

## Thursday, March 30, 2006

### The F/CA/1918 is a much more modern design

The F/CA/1918, with four twin 7.6in (19.5cm) gun turrets is a much more modern design than its predecessor. The secondary armament is reduced in caliber to 5.1in guns (13cm). The ship has a torpedo armament, as well. The speed is increased to 32 knots, a modern minimum. This is the Springsharp report:

F/CA/1918, France Cruiser laid down 1918 (Engine 1922) Displacement: 11,584 t light; 11,989 t standard; 12,900 t normal; 13,629 t full load Dimensions: Length overall / water x beam x draught 619.10 ft / 615.00 ft x 62.00 ft x 20.00 ft (normal load) 188.70 m / 187.45 m x 18.90 m x 6.10 m Armament: 8 - 7.68" / 195 mm guns (4x2 guns), 226.24lbs / 102.62kg shells, 1918 Model Breech loading guns in turrets (on barbettes) on centreline, evenly spread, 2 raised mounts Aft Main mounts separated by engine room 8 - 5.12" / 130 mm guns in single mounts, 67.03lbs / 30.41kg shells, 1918 Model Quick firing guns in deck mounts with hoists on side, all amidships 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1918 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1918 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 2,486 lbs / 1,128 kg Shells per gun, main battery: 100 4 - 21.7" / 549.9999 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 4.00" / 102 mm 400.00 ft / 121.92 m 12.00 ft / 3.66 m Ends: 3.00" / 76 mm 175.00 ft / 53.34 m 10.00 ft / 3.05 m 40.00 ft / 12.19 m Unarmoured ends Main Belt covers 100 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 400.00 ft / 121.92 m 18.00 ft / 5.49 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 4.00" / 102 mm 3.00" / 76 mm 4.00" / 102 mm 2nd: 2.00" / 51 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 101,743 shp / 75,901 Kw = 32.00 kts Range 5,400nm at 15.00 kts Bunker at max displacement = 1,640 tons Complement: 604 - 786 Cost: £2.299 million / $9.197 million Distribution of weights at normal displacement: Armament: 311 tons, 2.4 % Armour: 2,846 tons, 22.1 % - Belts: 997 tons, 7.7 % - Torpedo bulkhead: 266 tons, 2.1 % - Armament: 511 tons, 4.0 % - Armour Deck: 1,024 tons, 7.9 % - Conning Tower: 47 tons, 0.4 % Machinery: 3,451 tons, 26.8 % Hull, fittings & equipment: 4,976 tons, 38.6 % Fuel, ammunition & stores: 1,316 tons, 10.2 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 14,776 lbs / 6,702 Kg = 65.3 x 7.7 " / 195 mm shells or 1.9 torpedoes Stability (Unstable if below 1.00): 1.18 Metacentric height 3.3 ft / 1.0 m Roll period: 14.3 seconds Steadiness - As gun platform (Average = 50 %): 52 % - Recoil effect (Restricted arc if above 1.00): 0.59 Seaboat quality (Average = 1.00): 1.04 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.592 Length to Beam Ratio: 9.92 : 1 'Natural speed' for length: 24.80 kts Power going to wave formation at top speed: 58 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 4.00 degrees Stern overhang: 2.00 ft / 0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 30.00 ft / 9.14 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: 21.84 ft / 6.66 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 155.2 % - Above water (accommodation/working, high = better): 175.6 % Waterplane Area: 27,681 Square feet or 2,572 Square metres Displacement factor (Displacement / loading): 105 % Structure weight / hull surface area: 112 lbs/sq ft or 547 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.97 - Longitudinal: 1.27 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Tuesday, March 28, 2006

### The F/CA/1916 design actually has a mixed armament

The F/CA/1916 design has somewhat of a pre-Dreadnought flavor, in that the armament is mixed, although it resembles a more conventional, uniform armament. If the design did not have a secondary armament of 5.5in guns, it would be quite conventional. With the secondary armament, we see shades of the late 19th or early 20th Century (much earlier than 1916). The AA armament has been increased, due to year and the size of the ship. The speed was raised to 31 knots, but the range kept at the rather short 5,400nm at 15 knots. The ships probably would be used on the Atlantic coast and the Mediterranean Sea, so long range is less of an issue. This is the Springsharp report:

F/CA/1916, France Cruiser laid down 1916 (Engine 1920) Displacement: 10,328 t light; 10,728 t standard; 11,600 t normal; 12,297 t full load Dimensions: Length overall / water x beam x draught 618.96 ft / 615.00 ft x 60.00 ft x 19.00 ft (normal load) 188.66 m / 187.45 m x 18.29 m x 5.79 m Armament: 9 - 7.68" / 195 mm guns in single mounts, 226.24lbs / 102.62kg shells, 1916 Model Breech loading guns in deck mounts with hoists on centreline, evenly spread, 2 raised mounts 8 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1916 Model Quick firing guns in deck mounts with hoists on side, all amidships 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1916 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1916 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 2,846 lbs / 1,291 kg Shells per gun, main battery: 100 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 4.00" / 102 mm 400.00 ft / 121.92 m 12.00 ft / 3.66 m Ends: 3.00" / 76 mm 175.00 ft / 53.34 m 10.00 ft / 3.05 m 40.00 ft / 12.19 m Unarmoured ends Main Belt covers 100 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 400.00 ft / 121.92 m 18.00 ft / 5.49 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 4.00" / 102 mm 3.00" / 76 mm 4.00" / 102 mm 2nd: 2.00" / 51 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 82,941 shp / 61,874 Kw = 31.00 kts Range 5,400nm at 15.00 kts Bunker at max displacement = 1,569 tons Complement: 558 - 726 Cost: £1.745 million / $6.979 million Distribution of weights at normal displacement: Armament: 356 tons, 3.1 % Armour: 2,573 tons, 22.2 % - Belts: 994 tons, 8.6 % - Torpedo bulkhead: 266 tons, 2.3 % - Armament: 289 tons, 2.5 % - Armour Deck: 979 tons, 8.4 % - Conning Tower: 44 tons, 0.4 % Machinery: 2,900 tons, 25.0 % Hull, fittings & equipment: 4,500 tons, 38.8 % Fuel, ammunition & stores: 1,272 tons, 11.0 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 13,850 lbs / 6,282 Kg = 61.2 x 7.7 " / 195 mm shells or 1.9 torpedoes Stability (Unstable if below 1.00): 1.22 Metacentric height 3.3 ft / 1.0 m Roll period: 13.8 seconds Steadiness - As gun platform (Average = 50 %): 56 % - Recoil effect (Restricted arc if above 1.00): 0.68 Seaboat quality (Average = 1.00): 1.12 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.579 Length to Beam Ratio: 10.25 : 1 'Natural speed' for length: 24.80 kts Power going to wave formation at top speed: 55 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 4.00 degrees Stern overhang: 2.00 ft / 0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 28.00 ft / 8.53 m - Forecastle (20 %): 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: 20.76 ft / 6.33 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 156.5 % - Above water (accommodation/working, high = better): 187.8 % Waterplane Area: 26,465 Square feet or 2,459 Square metres Displacement factor (Displacement / loading): 103 % Structure weight / hull surface area: 107 lbs/sq ft or 522 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.99 - Longitudinal: 1.16 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Monday, March 27, 2006

### The F/CA/1914 cruiser design

The F/CA/1914 design is trying to be pretty conservative, while having adequate performance. The result is pretty reasonable. The design does depend on lightweight machinery, but otherwise is not pushing the limits. The main armament is 9-7.6in guns while the secondary armament is 8-5.5in QF guns. There is a limited AA armament, suitable for the date. This is the Springsharp report:

F/CA/1914, France Cruiser laid down 1914 (Engine 1918) Displacement: 8,974 t light; 9,341 t standard; 10,200 t normal; 10,887 t full load Dimensions: Length overall / water x beam x draught 578.42 ft / 575.00 ft x 59.00 ft x 18.00 ft (normal load) 176.30 m / 175.26 m x 17.98 m x 5.49 m Armament: 9 - 7.68" / 195 mm guns in single mounts, 226.24lbs / 102.62kg shells, 1914 Model Breech loading guns in deck mounts with hoists on centreline, evenly spread, 2 raised mounts 8 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1914 Model Quick firing guns in deck mounts with hoists on side, all amidships 2 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1914 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring 8 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1914 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts Weight of broadside 2,776 lbs / 1,259 kg Shells per gun, main battery: 100 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 4.00" / 102 mm 400.00 ft / 121.92 m 12.00 ft / 3.66 m Ends: 3.00" / 76 mm 175.00 ft / 53.34 m 10.00 ft / 3.05 m Main Belt covers 107 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 400.00 ft / 121.92 m 17.00 ft / 5.18 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 4.00" / 102 mm 3.00" / 76 mm 4.00" / 102 mm 2nd: 2.00" / 51 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm Machinery: Oil fired boilers, steam turbines, Direct drive, 4 shafts, 60,831 shp / 45,380 Kw = 29.00 kts Range 5,400nm at 15.00 kts Bunker at max displacement = 1,547 tons Complement: 506 - 659 Cost: £1.162 million / $4.647 million Distribution of weights at normal displacement: Armament: 347 tons, 3.4 % Armour: 2,475 tons, 24.3 % - Belts: 990 tons, 9.7 % - Torpedo bulkhead: 252 tons, 2.5 % - Armament: 289 tons, 2.8 % - Armour Deck: 905 tons, 8.9 % - Conning Tower: 41 tons, 0.4 % Machinery: 2,194 tons, 21.5 % Hull, fittings & equipment: 3,957 tons, 38.8 % Fuel, ammunition & stores: 1,226 tons, 12.0 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 13,810 lbs / 6,264 Kg = 61.0 x 7.7 " / 195 mm shells or 2.0 torpedoes Stability (Unstable if below 1.00): 1.21 Metacentric height 3.2 ft / 1.0 m Roll period: 13.8 seconds Steadiness - As gun platform (Average = 50 %): 57 % - Recoil effect (Restricted arc if above 1.00): 0.70 Seaboat quality (Average = 1.00): 1.14 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.585 Length to Beam Ratio: 9.75 : 1 'Natural speed' for length: 23.98 kts Power going to wave formation at top speed: 54 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 2.00 ft / 0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 27.00 ft / 8.23 m - Forecastle (20 %): 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: 19.76 ft / 6.02 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 144.7 % - Above water (accommodation/working, high = better): 182.2 % Waterplane Area: 24,458 Square feet or 2,272 Square metres Displacement factor (Displacement / loading): 106 % Structure weight / hull surface area: 105 lbs/sq ft or 511 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.98 - Longitudinal: 1.14 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Sunday, March 26, 2006

### The F/BB/1941 battleship

The F/BB/1941 battleship now has a 32-knot speed and a 16in armour basis. The torpedo bulkhead is also increased to 5in in thickness. The French need is for a ship with good speed for operating on both the Atlantic coast and the Mediterranean Sea. This is the ultimate design in this series, although the armament is unchanged, as what we have been using seems to be sufficient. This is the Springsharp report:

F/BB/1941, France Battleship laid down 1941 Displacement: 66,183 t light; 68,781 t standard; 72,250 t normal; 75,025 t full load Dimensions: Length overall / water x beam x draught 910.89 ft / 905.00 ft x 120.00 ft x 35.00 ft (normal load) 277.64 m / 275.84 m x 36.58 m x 10.67 m Armament: 8 - 18.00" / 457 mm guns (2x4 guns), 2,916.00lbs / 1,322.68kg shells, 1941 Model Breech loading guns in turrets (on barbettes) on centreline, all forward, 1 raised mount - superfiring 18 - 5.51" / 140 mm guns (6x3 guns), 83.72lbs / 37.98kg shells, 1941 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 16 - 3.94" / 100 mm guns (8x2 guns), 30.51lbs / 13.84kg shells, 1941 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships, all raised mounts - superfiring 48 - 1.85" / 47.0 mm guns (24x2 guns), 3.17lbs / 1.44kg shells, 1941 Model Anti-aircraft guns in deck mounts on side, evenly spread, 18 raised mounts Weight of broadside 25,475 lbs / 11,555 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 16.0" / 406 mm 620.00 ft / 188.98 m 16.00 ft / 4.88 m Ends: Unarmoured Main Belt covers 105 % of normal length - Torpedo Bulkhead: 5.00" / 127 mm 620.00 ft / 188.98 m 34.00 ft / 10.36 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 16.0" / 406 mm 12.0" / 305 mm 16.0" / 406 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 8.00" / 203 mm, Conning tower: 16.00" / 406 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 270,882 shp / 202,078 Kw = 32.00 kts Range 8,500nm at 15.00 kts Bunker at max displacement = 6,244 tons Complement: 2,202 - 2,864 Cost: £37.051 million / $148.203 million Distribution of weights at normal displacement: Armament: 3,184 tons, 4.4 % Armour: 28,656 tons, 39.7 % - Belts: 6,775 tons, 9.4 % - Torpedo bulkhead: 3,900 tons, 5.4 % - Armament: 4,897 tons, 6.8 % - Armour Deck: 12,486 tons, 17.3 % - Conning Tower: 598 tons, 0.8 % Machinery: 7,159 tons, 9.9 % Hull, fittings & equipment: 27,184 tons, 37.6 % Fuel, ammunition & stores: 6,067 tons, 8.4 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 111,186 lbs / 50,433 Kg = 38.1 x 18.0 " / 457 mm shells or 20.5 torpedoes Stability (Unstable if below 1.00): 1.13 Metacentric height 8.3 ft / 2.5 m Roll period: 17.5 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.64 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.665 Length to Beam Ratio: 7.54 : 1 'Natural speed' for length: 30.08 kts Power going to wave formation at top speed: 54 % 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: 33.00 ft / 10.06 m - Forecastle (20 %): 29.00 ft / 8.84 m - Mid (67 %): 29.00 ft / 8.84 m (21.00 ft / 6.40 m aft of break) - Quarterdeck (15 %): 21.00 ft / 6.40 m - Stern: 21.00 ft / 6.40 m - Average freeboard: 26.68 ft / 8.13 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 78.5 % - Above water (accommodation/working, high = better): 195.5 % Waterplane Area: 84,364 Square feet or 7,838 Square metres Displacement factor (Displacement / loading): 106 % Structure weight / hull surface area: 235 lbs/sq ft or 1,149 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.98 - Longitudinal: 1.28 - Overall: 1.00 Hull space for machinery, storage, compartmentation is excellent Room for accommodation and workspaces is excellent

## Saturday, March 25, 2006

### The F/BB/1937 design HAD to have 18in guns

I felt like any ship laid down in 1937 that didn't need to follow restrictive treaties needed 18in guns. The F/BB/1937 has eight in two quadruple turrets mounted forward. The armour basis was increased to 15in, the deck to 8in, and the speed to 31 knots. The speed increase was costly, as achieving adequate seakeeping involved increasing freeboard and length. The need for hull strength ballooned the displacement, making achieving the minimum acceptable seakeeping that much more difficult. This is the Springsharp report:

F/BB/1937, France Battleship laid down 1937 Displacement: 60,805 t light; 63,293 t standard; 66,700 t normal; 69,426 t full load Dimensions: Length overall / water x beam x draught 862.80 ft / 857.00 ft x 118.00 ft x 34.00 ft (normal load) 262.98 m / 261.21 m x 35.97 m x 10.36 m Armament: 8 - 18.00" / 457 mm guns (2x4 guns), 2,916.00lbs / 1,322.68kg shells, 1937 Model Breech loading guns in turrets (on barbettes) on centreline, all forward, 1 raised mount - superfiring 18 - 5.51" / 140 mm guns (6x3 guns), 83.72lbs / 37.98kg shells, 1937 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 16 - 3.94" / 100 mm guns (8x2 guns), 30.51lbs / 13.84kg shells, 1937 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships, all raised mounts - superfiring 48 - 1.85" / 47.0 mm guns (24x2 guns), 3.17lbs / 1.44kg shells, 1937 Model Anti-aircraft guns in deck mounts on side, evenly spread, 18 raised mounts Weight of broadside 25,475 lbs / 11,555 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 15.0" / 381 mm 570.00 ft / 173.74 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 241.00 ft / 73.46 m 12.00 ft / 3.66 m 46.00 ft / 14.02 m Unarmoured ends Main Belt covers 102 % of normal length - Torpedo Bulkhead: 4.00" / 102 mm 570.00 ft / 173.74 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 15.0" / 381 mm 12.0" / 305 mm 15.0" / 381 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 8.00" / 203 mm, Conning tower: 15.00" / 381 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 234,595 shp / 175,008 Kw = 31.00 kts Range 8,500nm at 15.00 kts Bunker at max displacement = 6,133 tons Complement: 2,074 - 2,697 Cost: £31.164 million / $124.656 million Distribution of weights at normal displacement: Armament: 3,184 tons, 4.8 % Armour: 25,847 tons, 38.8 % - Belts: 6,436 tons, 9.6 % - Torpedo bulkhead: 2,531 tons, 3.8 % - Armament: 4,577 tons, 6.9 % - Armour Deck: 11,772 tons, 17.6 % - Conning Tower: 532 tons, 0.8 % Machinery: 6,502 tons, 9.7 % Hull, fittings & equipment: 25,272 tons, 37.9 % Fuel, ammunition & stores: 5,895 tons, 8.8 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 98,262 lbs / 44,571 Kg = 33.7 x 18.0 " / 457 mm shells or 16.5 torpedoes Stability (Unstable if below 1.00): 1.13 Metacentric height 8.0 ft / 2.4 m Roll period: 17.5 seconds Steadiness - As gun platform (Average = 50 %): 52 % - Recoil effect (Restricted arc if above 1.00): 0.65 Seaboat quality (Average = 1.00): 1.04 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.679 Length to Beam Ratio: 7.26 : 1 'Natural speed' for length: 29.27 kts Power going to wave formation at top speed: 55 % 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: 32.00 ft / 9.75 m - Forecastle (20 %): 28.00 ft / 8.53 m - Mid (67 %): 28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break) - Quarterdeck (15 %): 20.00 ft / 6.10 m - Stern: 20.00 ft / 6.10 m - Average freeboard: 25.68 ft / 7.83 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 81.4 % - Above water (accommodation/working, high = better): 188.4 % Waterplane Area: 79,538 Square feet or 7,389 Square metres Displacement factor (Displacement / loading): 104 % Structure weight / hull surface area: 234 lbs/sq ft or 1,143 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.97 - Longitudinal: 1.30 - Overall: 1.00 Hull space for machinery, storage, compartmentation is excellent Room for accommodation and workspaces is excellent

## Friday, March 24, 2006

### Not inspiring, but workmanlike: the F/BB/1933 battleship design

The F/BB/1933 design has nothing very exciting about it, but it is pretty compact and capable. The main improvements are a 30 knot speed and improved AA armament. The heavy AA guns are now 100mm, with 40-47mm AA guns. For a small increase and length and displacement, a higher speed was able to be achieved. The ship is only slightly faster than the optimal speed for the length. The only knock on the design is that it "tends to be wet forward". As an aside, Frank Fox says that most of the American fast battleships tended to be wet, and not have the best seakeeping characteristics. This is the Springsharp report:

F/BB/1933, France Battleship laid down 1933 Displacement: 50,954 t light; 53,056 t standard; 56,200 t normal; 58,715 t full load Dimensions: Length overall / water x beam x draught 819.71 ft / 815.00 ft x 112.00 ft x 33.00 ft (normal load) 249.85 m / 248.41 m x 34.14 m x 10.06 m Armament: 8 - 16.93" / 430 mm guns (2x4 guns), 2,425.91lbs / 1,100.37kg shells, 1933 Model Breech loading guns in turrets (on barbettes) on centreline, all forward, 1 raised mount - superfiring 18 - 5.51" / 140 mm guns (6x3 guns), 83.72lbs / 37.98kg shells, 1933 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 16 - 3.94" / 100 mm guns (8x2 guns), 30.51lbs / 13.84kg shells, 1933 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships, all raised mounts - superfiring 40 - 1.85" / 47.0 mm guns (20x2 guns), 3.17lbs / 1.44kg shells, 1933 Model Anti-aircraft guns in deck mounts on side, evenly spread, 16 raised mounts Weight of broadside 21,529 lbs / 9,765 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 14.0" / 356 mm 560.00 ft / 170.69 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 235.00 ft / 71.63 m 12.00 ft / 3.66 m 20.00 ft / 6.10 m Unarmoured ends Main Belt covers 106 % of normal length - Torpedo Bulkhead: 3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 14.0" / 356 mm 11.0" / 279 mm 14.0" / 356 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 7.00" / 178 mm, Conning tower: 15.00" / 381 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 186,456 shp / 139,096 Kw = 30.00 kts Range 8,500nm at 15.00 kts Bunker at max displacement = 5,660 tons Complement: 1,824 - 2,372 Cost: £22.712 million / $90.850 million Distribution of weights at normal displacement: Armament: 2,691 tons, 4.8 % Armour: 21,248 tons, 37.8 % - Belts: 5,890 tons, 10.5 % - Torpedo bulkhead: 1,832 tons, 3.3 % - Armament: 3,972 tons, 7.1 % - Armour Deck: 9,080 tons, 16.2 % - Conning Tower: 474 tons, 0.8 % Machinery: 5,433 tons, 9.7 % Hull, fittings & equipment: 21,582 tons, 38.4 % Fuel, ammunition & stores: 5,246 tons, 9.3 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 82,674 lbs / 37,500 Kg = 34.1 x 16.9 " / 430 mm shells or 13.3 torpedoes Stability (Unstable if below 1.00): 1.11 Metacentric height 7.2 ft / 2.2 m Roll period: 17.5 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.68 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.653 Length to Beam Ratio: 7.28 : 1 'Natural speed' for length: 28.55 kts Power going to wave formation at top speed: 54 % 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: 31.00 ft / 9.45 m - Forecastle (20 %): 27.00 ft / 8.23 m - Mid (67 %): 27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break) - Quarterdeck (15 %): 19.00 ft / 5.79 m - Stern: 19.00 ft / 5.79 m - Average freeboard: 24.68 ft / 7.52 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 82.1 % - Above water (accommodation/working, high = better): 181.5 % Waterplane Area: 70,118 Square feet or 6,514 Square metres Displacement factor (Displacement / loading): 105 % Structure weight / hull surface area: 224 lbs/sq ft or 1,094 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.97 - Longitudinal: 1.35 - Overall: 1.00 Hull space for machinery, storage, compartmentation is excellent Room for accommodation and workspaces is excellent

## Thursday, March 23, 2006

### The F/BB/1927 design

The F/BB/1927 design has 8-43cm guns (16.9in), 18-5.5in QF guns, 12-90mm AA guns, and 36-47mm AA guns. The armour basis is now 15 in with a 7in deck. The main armament is now in two quadruple turrets, grouped forward. In Springsharp, that is more costly than having one at either end. The maximum speed is still 29 knots, but the range is now 8,500nm at 15 knots. This is the Springsharp report:

F/BB/1927, France Battleship laid down 1927 Displacement: 49,475 t light; 51,536 t standard; 54,800 t normal; 57,412 t full load Dimensions: Length overall / water x beam x draught 799.71 ft / 795.00 ft x 112.00 ft x 33.00 ft (normal load) 243.75 m / 242.32 m x 34.14 m x 10.06 m Armament: 8 - 16.93" / 430 mm guns (2 mounts), 2,425.91lbs / 1,100.37kg shells, 1927 Model Breech loading guns in turrets (on barbettes) on centreline, all forward, 3 raised guns - superfiring 18 - 5.51" / 140 mm guns (6x3 guns), 83.72lbs / 37.98kg shells, 1927 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 12 - 3.54" / 90.0 mm guns (6x2 guns), 22.24lbs / 10.09kg shells, 1927 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships, all raised mounts - superfiring 36 - 1.85" / 47.0 mm guns (18x2 guns), 3.17lbs / 1.44kg shells, 1927 Model Anti-aircraft guns in deck mounts on side, evenly spread, 12 raised mounts Weight of broadside 21,295 lbs / 9,659 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 14.0" / 356 mm 560.00 ft / 170.69 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 235.00 ft / 71.63 m 12.00 ft / 3.66 m Main Belt covers 108 % of normal length - Torpedo Bulkhead: 3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 14.0" / 356 mm 11.0" / 279 mm 14.0" / 356 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 7.00" / 178 mm, Conning tower: 15.00" / 381 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 162,387 shp / 121,140 Kw = 29.00 kts Range 8,500nm at 15.00 kts Bunker at max displacement = 5,876 tons Complement: 1,790 - 2,328 Cost: £17.037 million / $68.149 million Distribution of weights at normal displacement: Armament: 2,662 tons, 4.9 % Armour: 20,931 tons, 38.2 % - Belts: 5,877 tons, 10.7 % - Torpedo bulkhead: 1,832 tons, 3.3 % - Armament: 3,902 tons, 7.1 % - Armour Deck: 8,855 tons, 16.2 % - Conning Tower: 466 tons, 0.9 % Machinery: 5,126 tons, 9.4 % Hull, fittings & equipment: 20,756 tons, 37.9 % Fuel, ammunition & stores: 5,325 tons, 9.7 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 81,413 lbs / 36,928 Kg = 33.6 x 16.9 " / 430 mm shells or 13.3 torpedoes Stability (Unstable if below 1.00): 1.12 Metacentric height 7.4 ft / 2.2 m Roll period: 17.3 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: 0.653 Length to Beam Ratio: 7.10 : 1 'Natural speed' for length: 28.20 kts Power going to wave formation at top speed: 53 % 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: 31.00 ft / 9.45 m - Forecastle (20 %): 27.00 ft / 8.23 m - Mid (67 %): 27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break) - Quarterdeck (15 %): 19.00 ft / 5.79 m - Stern: 19.00 ft / 5.79 m - Average freeboard: 24.68 ft / 7.52 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 81.5 % - Above water (accommodation/working, high = better): 180.3 % Waterplane Area: 68,382 Square feet or 6,353 Square metres Displacement factor (Displacement / loading): 104 % Structure weight / hull surface area: 221 lbs/sq ft or 1,079 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.96 - Longitudinal: 1.40 - Overall: 1.00 Hull space for machinery, storage, compartmentation is excellent Room for accommodation and workspaces is excellent

## Wednesday, March 22, 2006

### The F/BB/1923 design

The main improvements in the F/BB/1923 design are the 29 knot speed and the main armament now being 9-16.5in guns in triple turrets. The freeboard is a foot higher, and this ship is not wet forward. The protection against gunfire seems adequate, while the underwater protection is above-average (if it will take 11 torpedoes, that is how I would rate the design). The AA armament is sub-standard, but in 1923, it matters little. This is the Springsharp report:

F/BB/1923, France Battleship laid down 1923 Displacement: 47,998 t light; 50,041 t standard; 53,000 t normal; 55,367 t full load Dimensions: Length overall / water x beam x draught 789.71 ft / 785.00 ft x 108.00 ft x 33.00 ft (normal load) 240.70 m / 239.27 m x 32.92 m x 10.06 m Armament: 9 - 16.54" / 420 mm guns (3x3 guns), 2,260.56lbs / 1,025.37kg shells, 1923 Model Breech loading guns in turrets (on barbettes) on centreline ends, majority forward, 1 raised mount - superfiring 16 - 5.51" / 140 mm guns (8x2 guns), 83.72lbs / 37.98kg shells, 1923 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1923 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1923 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 21,824 lbs / 9,899 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 14.0" / 356 mm 550.00 ft / 167.64 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 195.00 ft / 59.44 m 12.00 ft / 3.66 m 40.00 ft / 12.19 m Unarmoured ends Main Belt covers 108 % of normal length - Torpedo Bulkhead: 3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 14.0" / 356 mm 11.0" / 279 mm 14.0" / 356 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 159,715 shp / 119,147 Kw = 29.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 5,327 tons Complement: 1,746 - 2,270 Cost: £13.727 million / $54.910 million Distribution of weights at normal displacement: Armament: 2,728 tons, 5.1 % Armour: 20,003 tons, 37.7 % - Belts: 5,688 tons, 10.7 % - Torpedo bulkhead: 1,832 tons, 3.5 % - Armament: 4,763 tons, 9.0 % - Armour Deck: 7,295 tons, 13.8 % - Conning Tower: 426 tons, 0.8 % Machinery: 5,338 tons, 10.1 % Hull, fittings & equipment: 19,928 tons, 37.6 % Fuel, ammunition & stores: 5,002 tons, 9.4 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 72,365 lbs / 32,824 Kg = 32.0 x 16.5 " / 420 mm shells or 11.2 torpedoes Stability (Unstable if below 1.00): 1.07 Metacentric height 6.4 ft / 2.0 m Roll period: 17.9 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.78 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.663 Length to Beam Ratio: 7.27 : 1 'Natural speed' for length: 28.02 kts Power going to wave formation at top speed: 53 % 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: 31.00 ft / 9.45 m - Forecastle (20 %): 27.00 ft / 8.23 m - Mid (67 %): 27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break) - Quarterdeck (15 %): 19.00 ft / 5.79 m - Stern: 19.00 ft / 5.79 m - Average freeboard: 24.68 ft / 7.52 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 87.5 % - Above water (accommodation/working, high = better): 177.7 % Waterplane Area: 65,725 Square feet or 6,106 Square metres Displacement factor (Displacement / loading): 101 % Structure weight / hull surface area: 218 lbs/sq ft or 1,065 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.97 - Longitudinal: 1.29 - Overall: 1.00 Hull space for machinery, storage, compartmentation is adequate Room for accommodation and workspaces is excellent

### The drawings at Alt Naval are quite good (Corrected)

Roger, who handles Greece at Wesworld (says Gavin), has some good drawings on his Alt Naval site for the Japanese navy alternate history portion of his site. They are really top quality, and I am impressed. i have tried my hand at this, and it is not easy, although if you work at a large enough scale, it is easier. The main challenge is how to follow scale measurements, and to know the correct size to make things. Gavin, who is the Red Admiral at Wesworld, corrected my misunderstanding.

## Tuesday, March 21, 2006

### The French battleship design F/BB/1921

Blogger was down last night, so I am posting this today, instead of yesterday. The next logical step seemed to be to move to a larger caliber gun for French battleships. We are designing ships as if the Washington Naval Treaty didn't exist, so we can go larger and have larger guns than was the case in "real life". This design has 8-16.5in guns in quadruple turrets, 16-5.5in QF guns in twin turrets, and the usual AA armament. The speed is now 28 knots with a range of 7.500nm at 15 knots. The armour basis is 14 inches with a 6 inch deck. This is the Springsharp report:

F/BB/1921, France Battleship laid down 1921 Displacement: 42,864 t light; 44,697 t standard; 47,500 t normal; 49,743 t full load Dimensions: Length overall / water x beam x draught 749.03 ft / 745.00 ft x 102.00 ft x 33.00 ft (normal load) 228.30 m / 227.08 m x 31.09 m x 10.06 m Armament: 8 - 16.54" / 420 mm guns (2x4 guns), 2,260.56lbs / 1,025.37kg shells, 1921 Model Breech loading guns in turrets (on barbettes) on centreline ends, evenly spread, 1 raised mount 16 - 5.51" / 140 mm guns (8x2 guns), 83.72lbs / 37.98kg shells, 1921 Model Quick firing guns in turrets (on barbettes) on side, all amidships, all raised mounts - superfiring 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1921 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1921 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 19,564 lbs / 8,874 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 14.0" / 356 mm 550.00 ft / 167.64 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 195.00 ft / 59.44 m 12.00 ft / 3.66 m Main Belt covers 114 % of normal length - Torpedo Bulkhead: 3.00" / 76 mm 550.00 ft / 167.64 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 14.0" / 356 mm 11.0" / 279 mm 14.0" / 356 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 131,943 shp / 98,430 Kw = 28.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 5,046 tons Complement: 1,608 - 2,091 Cost: £10.667 million / $42.667 million Distribution of weights at normal displacement: Armament: 2,445 tons, 5.1 % Armour: 17,927 tons, 37.7 % - Belts: 5,632 tons, 11.9 % - Torpedo bulkhead: 1,832 tons, 3.9 % - Armament: 3,529 tons, 7.4 % - Armour Deck: 6,539 tons, 13.8 % - Conning Tower: 396 tons, 0.8 % Machinery: 4,544 tons, 9.6 % Hull, fittings & equipment: 17,948 tons, 37.8 % Fuel, ammunition & stores: 4,636 tons, 9.8 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 64,308 lbs / 29,169 Kg = 28.4 x 16.5 " / 420 mm shells or 10.2 torpedoes Stability (Unstable if below 1.00): 1.06 Metacentric height 5.7 ft / 1.7 m Roll period: 17.9 seconds Steadiness - As gun platform (Average = 50 %): 55 % - Recoil effect (Restricted arc if above 1.00): 0.88 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.663 Length to Beam Ratio: 7.30 : 1 'Natural speed' for length: 27.29 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: 2.00 ft / 0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 29.00 ft / 8.84 m - Forecastle (20 %): 26.00 ft / 7.92 m - Mid (67 %): 26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break) - Quarterdeck (15 %): 18.00 ft / 5.49 m - Stern: 18.00 ft / 5.49 m - Average freeboard: 23.60 ft / 7.19 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 86.7 % - Above water (accommodation/working, high = better): 166.0 % Waterplane Area: 58,907 Square feet or 5,473 Square metres Displacement factor (Displacement / loading): 102 % Structure weight / hull surface area: 216 lbs/sq ft or 1,054 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.96 - Longitudinal: 1.40 - Overall: 1.00 Hull space for machinery, storage, compartmentation is adequate Room for accommodation and workspaces is excellent

## Monday, March 20, 2006

### Brasseys for 1919, 1920, and 1921

If you are interested in the ships planned but not built due to the Washington Naval Treaty, the 1919, 1920, and 1921 Brassey's Naval Annual volumes are a "must read". One of the features that I particularly was interested in was the lists of guns that were either planned or under develpment by the various nations. If nothing else, you can see the manifestation of what information made its way into the public eye, whether it was correct or not. Copies, when found, are often over $100 (US).

## Sunday, March 19, 2006

### The F/BB/1918 design is a much better ship

The F/BB/1918 design is vastly superior to its predecessor. The main armament now consists of 8-40cm guns (15.75in) in quadruple turrets, on forward and one aft. The armour basis was increased to 14in, with a 5in deck. The speed was increased to 27 knots and the range to 7,500nm at 15 knots. Also, the Springsharp entries are more complete, and more attention was paid to some important details (sadly, the last designs were not so complete). This is the Springsharp report:

F/BB/1918, France Battleship laid down 1918 Displacement: 35,708 t light; 37,281 t standard; 40,000 t normal; 42,175 t full load Dimensions: Length overall / water x beam x draught 685.00 ft / 685.00 ft x 98.00 ft x 31.00 ft (normal load) 208.79 m / 208.79 m x 29.87 m x 9.45 m Armament: 8 - 15.75" / 400 mm guns (2x4 guns), 1,952.76lbs / 885.76kg shells, 1918 Model Breech loading guns in turrets (on barbettes) on centreline ends, evenly spread, 1 raised mount 16 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1918 Model Quick firing guns in casemate mounts on side, all amidships, all raised mounts - superfiring 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1918 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1918 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 17,101 lbs / 7,757 kg Shells per gun, main battery: 80 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 14.0" / 356 mm 520.00 ft / 158.50 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 165.00 ft / 50.29 m 12.00 ft / 3.66 m Main Belt covers 117 % of normal length - Torpedo Bulkhead: 3.00" / 76 mm 520.00 ft / 158.50 m 30.00 ft / 9.14 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 14.0" / 356 mm 11.0" / 279 mm 14.0" / 356 mm 2nd: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm - Armour deck: 5.00" / 127 mm, Conning tower: 14.00" / 356 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 107,116 shp / 79,909 Kw = 27.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 4,894 tons Complement: 1,413 - 1,838 Cost: £7.173 million / $28.691 million Distribution of weights at normal displacement: Armament: 2,138 tons, 5.3 % Armour: 14,904 tons, 37.3 % - Belts: 5,276 tons, 13.2 % - Torpedo bulkhead: 1,732 tons, 4.3 % - Armament: 2,687 tons, 6.7 % - Armour Deck: 4,857 tons, 12.1 % - Conning Tower: 353 tons, 0.9 % Machinery: 3,864 tons, 9.7 % Hull, fittings & equipment: 14,802 tons, 37.0 % Fuel, ammunition & stores: 4,292 tons, 10.7 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 54,648 lbs / 24,788 Kg = 28.0 x 15.7 " / 400 mm shells or 8.7 torpedoes Stability (Unstable if below 1.00): 1.11 Metacentric height 5.9 ft / 1.8 m Roll period: 16.9 seconds Steadiness - As gun platform (Average = 50 %): 55 % - Recoil effect (Restricted arc if above 1.00): 0.78 Seaboat quality (Average = 1.00): 1.10 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.673 Length to Beam Ratio: 6.99 : 1 'Natural speed' for length: 26.17 kts Power going to wave formation at top speed: 54 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 0.00 degrees Stern overhang: -2.00 ft / -0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 28.00 ft / 8.53 m - Forecastle (20 %): 25.00 ft / 7.62 m - Mid (67 %): 25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break) - Quarterdeck (15 %): 17.00 ft / 5.18 m - Stern: 17.00 ft / 5.18 m - Average freeboard: 22.60 ft / 6.89 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 89.7 % - Above water (accommodation/working, high = better): 161.3 % Waterplane Area: 52,503 Square feet or 4,878 Square metres Displacement factor (Displacement / loading): 101 % Structure weight / hull surface area: 201 lbs/sq ft or 983 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.95 - Longitudinal: 1.49 - Overall: 1.00 Hull space for machinery, storage, compartmentation is adequate Room for accommodation and workspaces is excellent

## Saturday, March 18, 2006

### The French F/BB/1916 battleship design

Compared to some of the other designs that I have produced for this date, this seems to be an under-achiever, although it seems reasonable, given contemporary French ideas. I was able to raise the speed to 25 knots, and the armament to 16-13.4in guns (34cm). The design seems very suitable for Mediterranean naval warfare. Ships with this armament were actually planned. Perhaps the caliber should have been increased to 14.6in, but that will have to wait, if it happens at all. This is the Springsharp report:

F/BB/1916, France Battleship laid down 1916 Displacement: 30,831 t light; 31,507 t standard; 33,800 t normal; 35,635 t full load Dimensions: Length overall / water x beam x draught 635.00 ft / 635.00 ft x 95.00 ft x 30.00 ft (normal load) 193.55 m / 193.55 m x 28.96 m x 9.14 m Armament: 16 - 13.39" / 340 mm guns (4x4 guns), 1,199.24lbs / 543.97kg shells, 1916 Model Breech loading guns in turrets (on barbettes) on centreline, evenly spread, 1 raised mount Main guns limited to end-on fire Aft Main mounts separated by engine room 16 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1916 Model Quick firing guns in casemate mounts on side, all amidships, all raised mounts - superfiring 4 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1916 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships 16 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1916 Model Anti-aircraft guns in deck mounts on side, evenly spread, 8 raised mounts Weight of broadside 20,667 lbs / 9,374 kg Shells per gun, main battery: 0 Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 13.0" / 330 mm 480.00 ft / 146.30 m 16.00 ft / 4.88 m Ends: 5.00" / 127 mm 110.00 ft / 33.53 m 12.00 ft / 3.66 m 45.00 ft / 13.72 m Unarmoured ends Main Belt covers 116 % of normal length - Torpedo Bulkhead: 2.00" / 51 mm 480.00 ft / 146.30 m 27.00 ft / 8.23 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: 3.00" / 76 mm, Conning tower: 13.00" / 330 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 73,019 shp / 54,472 Kw = 25.00 kts Range 6,500nm at 15.00 kts Bunker at max displacement = 4,128 tons Complement: 1,246 - 1,620 Cost: £5.940 million / $23.760 million Distribution of weights at normal displacement: Armament: 2,583 tons, 7.6 % Armour: 12,077 tons, 35.7 % - Belts: 4,468 tons, 13.2 % - Torpedo bulkhead: 959 tons, 2.8 % - Armament: 3,784 tons, 11.2 % - Armour Deck: 2,573 tons, 7.6 % - Conning Tower: 293 tons, 0.9 % Machinery: 2,721 tons, 8.0 % Hull, fittings & equipment: 13,450 tons, 39.8 % Fuel, ammunition & stores: 2,969 tons, 8.8 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 39,754 lbs / 18,032 Kg = 33.1 x 13.4 " / 340 mm shells or 5.9 torpedoes Stability (Unstable if below 1.00): 1.03 Metacentric height 4.9 ft / 1.5 m Roll period: 18.1 seconds Steadiness - As gun platform (Average = 50 %): 57 % - Recoil effect (Restricted arc if above 1.00): 1.09 Seaboat quality (Average = 1.00): 1.14 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.654 Length to Beam Ratio: 6.68 : 1 'Natural speed' for length: 25.20 kts Power going to wave formation at top speed: 52 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 0.00 degrees Stern overhang: -2.00 ft / -0.61 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 27.00 ft / 8.23 m - Forecastle (20 %): 24.00 ft / 7.32 m - Mid (67 %): 24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break) - Quarterdeck (15 %): 16.00 ft / 4.88 m - Stern: 16.00 ft / 4.88 m - Average freeboard: 21.60 ft / 6.58 m Ship tends to be wet forward Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 101.1 % - Above water (accommodation/working, high = better): 154.4 % Waterplane Area: 46,369 Square feet or 4,308 Square metres Displacement factor (Displacement / loading): 89 % Structure weight / hull surface area: 207 lbs/sq ft or 1,010 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.95 - Longitudinal: 1.57 - Overall: 1.00 Hull space for machinery, storage, compartmentation is adequate Room for accommodation and workspaces is excellent

## Thursday, March 16, 2006

### The J/DD/1941 is disappointing

I had hoped that the J/DD/1941 could have a speed of 36 knots, but the cost is too great. Springsharp continues to be a problem because the power required is greater than it should be. I had to be content to raise the range to 7,200nm at 15 knots. This is the Springsharp report:

J/DD/1941, Japan Destroyer laid down 1941 (Engine 1950) Displacement: 1,980 t light; 2,061 t standard; 2,390 t normal; 2,653 t full load Dimensions: Length overall / water x beam x draught 377.36 ft / 375.00 ft x 36.00 ft x 13.00 ft (normal load) 115.02 m / 114.30 m x 10.97 m x 3.96 m Armament: 6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1941 Model Dual purpose guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1941 Model Anti-aircraft guns in deck mounts on side, all amidships, 4 raised mounts - superfiring Weight of broadside 465 lbs / 211 kg Shells per gun, main battery: 120 10 - 24.0" / 609.6 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Geared drive, 2 shafts, 62,044 shp / 46,285 Kw = 35.00 kts Range 7,200nm at 15.00 kts Bunker at max displacement = 592 tons Complement: 170 - 222 Cost: £1.794 million / $7.174 million Distribution of weights at normal displacement: Armament: 58 tons, 2.4 % Machinery: 1,228 tons, 51.4 % Hull, fittings & equipment: 693 tons, 29.0 % Fuel, ammunition & stores: 410 tons, 17.2 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 592 lbs / 269 Kg = 9.5 x 5.0 " / 127 mm shells or 0.3 torpedoes Stability (Unstable if below 1.00): 1.33 Metacentric height 1.8 ft / 0.5 m Roll period: 11.3 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.56 Seaboat quality (Average = 1.00): 1.08 Hull form characteristics: Hull has rise forward of midbreak, raised quarterdeck Block coefficient: 0.477 Length to Beam Ratio: 10.42 : 1 'Natural speed' for length: 19.36 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 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 (37 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break) - Quarterdeck (15 %): 15.00 ft / 4.57 m (14.00 ft / 4.27 m before break) - Stern: 15.00 ft / 4.57 m - Average freeboard: 17.96 ft / 5.47 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 184.2 % - Above water (accommodation/working, high = better): 55.0 % Waterplane Area: 8,809 Square feet or 818 Square metres Displacement factor (Displacement / loading): 70 % Structure weight / hull surface area: 36 lbs/sq ft or 173 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.44 - Longitudinal: 2.58 - Overall: 0.53 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is cramped

## Wednesday, March 15, 2006

### The J/DD/1937 design

The J/DD/1937 design is a more substantial ship than her predecessors. The normal displacement is now 2,300 tons. The range is extended to 6,000nm at 15 knots. The maximum speed and main armament are unchanged. 35 knots is about all that is feasible with Springsharp in its present state where it overstates the power needed for smaller ships. This is the Springsharp report:

J/DD/1937, Japan Destroyer laid down 1937 (Engine 1945) Displacement: 1,939 t light; 2,019 t standard; 2,300 t normal; 2,525 t full load Dimensions: Length overall / water x beam x draught 372.36 ft / 370.00 ft x 35.00 ft x 13.00 ft (normal load) 113.50 m / 112.78 m x 10.67 m x 3.96 m Armament: 6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1937 Model Dual purpose guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 16 - 2.24" / 57.0 mm guns (8x2 guns), 5.65lbs / 2.56kg shells, 1937 Model Anti-aircraft guns in deck mounts on side, all amidships, 4 raised mounts - superfiring Weight of broadside 465 lbs / 211 kg Shells per gun, main battery: 120 10 - 24.0" / 609.6 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Geared drive, 2 shafts, 60,930 shp / 45,454 Kw = 35.00 kts Range 6,000nm at 15.00 kts Bunker at max displacement = 506 tons Complement: 165 - 215 Cost: £1.567 million / $6.269 million Distribution of weights at normal displacement: Armament: 58 tons, 2.5 % Machinery: 1,219 tons, 53.0 % Hull, fittings & equipment: 663 tons, 28.8 % Fuel, ammunition & stores: 361 tons, 15.7 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 515 lbs / 234 Kg = 8.2 x 5.0 " / 127 mm shells or 0.3 torpedoes Stability (Unstable if below 1.00): 1.29 Metacentric height 1.6 ft / 0.5 m Roll period: 11.5 seconds Steadiness - As gun platform (Average = 50 %): 55 % - Recoil effect (Restricted arc if above 1.00): 0.64 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak, raised quarterdeck Block coefficient: 0.478 Length to Beam Ratio: 10.57 : 1 'Natural speed' for length: 19.24 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 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 (37 %): 23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break) - Quarterdeck (15 %): 15.00 ft / 4.57 m (14.00 ft / 4.27 m before break) - Stern: 15.00 ft / 4.57 m - Average freeboard: 17.96 ft / 5.47 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 190.0 % - Above water (accommodation/working, high = better): 49.8 % Waterplane Area: 8,461 Square feet or 786 Square metres Displacement factor (Displacement / loading): 65 % Structure weight / hull surface area: 34 lbs/sq ft or 167 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.43 - Longitudinal: 2.72 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is extremely poor

## Tuesday, March 14, 2006

### The J/DD/1933 design

The J/DD/1933 design is larger, has dual-purpose 5in guns and 10-24in TT. The range is increased to 5,400nm at 15 knots. Admittedly, this is not trying to much different than the real Japanese destroyers. This is the Springsharp report:

J/DD/1933, Japan Destroyer laid down 1933 (Engine 1940) Displacement: 1,825 t light; 1,868 t standard; 2,120 t normal; 2,322 t full load Dimensions: Length overall / water x beam x draught 367.31 ft / 365.00 ft x 34.00 ft x 13.00 ft (normal load) 111.96 m / 111.25 m x 10.36 m x 3.96 m Armament: 6 - 5.00" / 127 mm guns (3x2 guns), 62.50lbs / 28.35kg shells, 1933 Model Dual purpose guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 12 - 2.24" / 57.0 mm guns (6x2 guns), 5.65lbs / 2.56kg shells, 1933 Model Anti-aircraft guns in deck mounts on side, all amidships, 4 raised mounts - superfiring Weight of broadside 443 lbs / 201 kg Shells per gun, main battery: 0 10 - 24.0" / 609.6 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Geared drive, 2 shafts, 57,477 shp / 42,878 Kw = 35.00 kts Range 5,400nm at 15.00 kts Bunker at max displacement = 454 tons Complement: 156 - 203 Cost: £1.282 million / $5.127 million Distribution of weights at normal displacement: Armament: 55 tons, 2.6 % Machinery: 1,148 tons, 54.2 % Hull, fittings & equipment: 622 tons, 29.3 % Fuel, ammunition & stores: 295 tons, 13.9 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 450 lbs / 204 Kg = 7.2 x 5.0 " / 127 mm shells or 0.3 torpedoes Stability (Unstable if below 1.00): 1.24 Metacentric height 1.5 ft / 0.4 m Roll period: 11.8 seconds Steadiness - As gun platform (Average = 50 %): 53 % - Recoil effect (Restricted arc if above 1.00): 0.69 Seaboat quality (Average = 1.00): 1.07 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.460 Length to Beam Ratio: 10.74 : 1 'Natural speed' for length: 19.10 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 25.00 ft / 7.62 m - Forecastle (20 %): 22.00 ft / 6.71 m - Mid (37 %): 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: 17.20 ft / 5.24 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 192.8 % - Above water (accommodation/working, high = better): 43.1 % Waterplane Area: 7,982 Square feet or 742 Square metres Displacement factor (Displacement / loading): 60 % Structure weight / hull surface area: 34 lbs/sq ft or 167 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.43 - Longitudinal: 2.61 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is extremely poor

## Monday, March 13, 2006

### The J/DD/1927 design

The J/DD/1927 design is a great improvement over its smaller predecessors. The armament is now 6-4.7in QF guns, in twin mounts, and 9-24in TT. The speed and range are the same as the 1921 design, 35 knots maximum speed with a 4,500nm range at 15 knots. This ship suffers from the fact that the Springsharp power calculation overstates what a destroyer would need to make particular speed. This is the Springsharp report:

J/DD/1927, Japan Destroyer laid down 1927 (Engine 1937) Displacement: 1,741 t light; 1,780 t standard; 1,990 t normal; 2,158 t full load Dimensions: Length overall / water x beam x draught 357.31 ft / 355.00 ft x 33.00 ft x 13.00 ft (normal load) 108.91 m / 108.20 m x 10.06 m x 3.96 m Armament: 6 - 4.70" / 119 mm guns (3x2 guns), 51.91lbs / 23.55kg shells, 1927 Model Quick firing guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1927 Model Anti-aircraft gun in a deck mount with hoist on side amidships, 1 raised gun 8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1927 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring Weight of broadside 370 lbs / 168 kg Shells per gun, main battery: 0 9 - 24.0" / 609.6 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Direct drive, 2 shafts, 56,041 shp / 41,806 Kw = 35.00 kts Range 4,500nm at 15.00 kts Bunker at max displacement = 377 tons Complement: 148 - 193 Cost: £0.928 million / $3.712 million Distribution of weights at normal displacement: Armament: 46 tons, 2.3 % Machinery: 1,110 tons, 55.8 % Hull, fittings & equipment: 584 tons, 29.4 % Fuel, ammunition & stores: 249 tons, 12.5 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 408 lbs / 185 Kg = 7.9 x 4.7 " / 119 mm shells or 0.3 torpedoes Stability (Unstable if below 1.00): 1.25 Metacentric height 1.4 ft / 0.4 m Roll period: 11.7 seconds Steadiness - As gun platform (Average = 50 %): 54 % - Recoil effect (Restricted arc if above 1.00): 0.66 Seaboat quality (Average = 1.00): 1.09 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.457 Length to Beam Ratio: 10.76 : 1 'Natural speed' for length: 18.84 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 25.00 ft / 7.62 m - Forecastle (20 %): 22.00 ft / 6.71 m - Mid (37 %): 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: 17.20 ft / 5.24 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 196.0 % - Above water (accommodation/working, high = better): 48.0 % Waterplane Area: 7,518 Square feet or 698 Square metres Displacement factor (Displacement / loading): 57 % Structure weight / hull surface area: 33 lbs/sq ft or 160 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.43 - Longitudinal: 2.90 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is extremely poor

## Sunday, March 12, 2006

### The J/DD/1921 design

The J/DD/1921 design really indicates a problem with how Springsharp computes the speed and power for small ships. The real Japanese destroyers from 1918 to 1921 achieved much higher speeds with less power for similar dimensions and displacement. The J/DD/1921 is having to compensate for that by going to lighter weight machinery, because a power that is too high is required to reach only 35 knots. The J/DD/1921 design has a greater range than its predecessor, 4,500nm at 15 knots. Otherwise, the armament and overall design is the same. This is the Springsharp report:

J/DD/1921, Japan Destroyer laid down 1921 (Engine 1937) Displacement: 1,429 t light; 1,462 t standard; 1,650 t normal; 1,800 t full load Dimensions: Length overall / water x beam x draught 337.26 ft / 335.00 ft x 31.00 ft x 13.00 ft (normal load) 102.80 m / 102.11 m x 9.45 m x 3.96 m Armament: 4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1921 Model Quick firing guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1921 Model Anti-aircraft gun in a deck mount with hoist on side amidships, 1 raised gun 8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1921 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring Weight of broadside 266 lbs / 121 kg Shells per gun, main battery: 0 6 - 21.0" / 533.4 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Direct drive, 2 shafts, 50,513 shp / 37,683 Kw = 35.00 kts Range 4,500nm at 15.00 kts Bunker at max displacement = 338 tons Complement: 129 - 168 Cost: £0.528 million / $2.112 million Distribution of weights at normal displacement: Armament: 33 tons, 2.0 % Machinery: 924 tons, 56.0 % Hull, fittings & equipment: 472 tons, 28.6 % Fuel, ammunition & stores: 221 tons, 13.4 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 348 lbs / 158 Kg = 6.7 x 4.7 " / 119 mm shells or 0.2 torpedoes Stability (Unstable if below 1.00): 1.39 Metacentric height 1.5 ft / 0.5 m Roll period: 10.5 seconds Steadiness - As gun platform (Average = 50 %): 55 % - Recoil effect (Restricted arc if above 1.00): 0.50 Seaboat quality (Average = 1.00): 1.10 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.428 Length to Beam Ratio: 10.81 : 1 'Natural speed' for length: 18.30 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 24.00 ft / 7.32 m - Forecastle (20 %): 21.00 ft / 6.40 m - Mid (37 %): 21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break) - Quarterdeck (15 %): 13.00 ft / 3.96 m - Stern: 13.00 ft / 3.96 m - Average freeboard: 16.20 ft / 4.94 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 194.6 % - Above water (accommodation/working, high = better): 87.3 % Waterplane Area: 6,511 Square feet or 605 Square metres Displacement factor (Displacement / loading): 54 % Structure weight / hull surface area: 30 lbs/sq ft or 146 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.41 - Longitudinal: 2.97 - Overall: 0.50 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is cramped

## Saturday, March 11, 2006

### The J/DD/1918 design

The J/DD/1918 design doesn't seem to have a lot to commend it. The armament is unimproved over its predecessor, except that the light AA armament is now 8-57mm. The speed is now 34 knots, which was expensive, and the range is 3,750nm at 15 knots. For a 1918 ship, I was not willing to pay more in size to achieve a better design. This is the Springsharp report:

J/DD/1918, Japan Destroyer laid down 1918 (Engine 1927) Displacement: 1,416 t light; 1,449 t standard; 1,620 t normal; 1,757 t full load Dimensions: Length overall / water x beam x draught 327.26 ft / 325.00 ft x 32.00 ft x 13.00 ft (normal load) 99.75 m / 99.06 m x 9.75 m x 3.96 m Armament: 4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1918 Model Quick firing guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1918 Model Anti-aircraft gun in a deck mount with hoist on side amidships, 1 raised gun 8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1918 Model Anti-aircraft guns in deck mounts on side, all amidships, 2 raised mounts - superfiring Weight of broadside 266 lbs / 121 kg Shells per gun, main battery: 0 6 - 21.0" / 533.4 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Geared drive, 2 shafts, 45,088 shp / 33,636 Kw = 34.00 kts Range 3,750nm at 15.00 kts Bunker at max displacement = 308 tons Complement: 126 - 165 Cost: £0.411 million / $1.645 million Distribution of weights at normal displacement: Armament: 33 tons, 2.1 % Machinery: 915 tons, 56.5 % Hull, fittings & equipment: 468 tons, 28.9 % Fuel, ammunition & stores: 204 tons, 12.6 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 351 lbs / 159 Kg = 6.8 x 4.7 " / 119 mm shells or 0.2 torpedoes Stability (Unstable if below 1.00): 1.41 Metacentric height 1.6 ft / 0.5 m Roll period: 10.5 seconds Steadiness - As gun platform (Average = 50 %): 56 % - Recoil effect (Restricted arc if above 1.00): 0.46 Seaboat quality (Average = 1.00): 1.11 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.419 Length to Beam Ratio: 10.16 : 1 'Natural speed' for length: 18.03 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 24.00 ft / 7.32 m - Forecastle (20 %): 21.00 ft / 6.40 m - Mid (37 %): 21.00 ft / 6.40 m (13.00 ft / 3.96 m aft of break) - Quarterdeck (15 %): 13.00 ft / 3.96 m - Stern: 13.00 ft / 3.96 m - Average freeboard: 16.20 ft / 4.94 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 196.4 % - Above water (accommodation/working, high = better): 89.1 % Waterplane Area: 6,481 Square feet or 602 Square metres Displacement factor (Displacement / loading): 52 % Structure weight / hull surface area: 31 lbs/sq ft or 150 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.42 - Longitudinal: 3.05 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is cramped

## Friday, March 10, 2006

### The J/DD/1916 design

The J/DD/1916 design has a higher speed, although only 33 knots, and a faster cruising speed, so that the range is now 3,500nm at 15 knots. The armament was increased with two more torpedo tubes, so that the armament is 4-4.7in QF guns, 1-3in AA, and 2-57mm AA guns, and 6-21in TT. This is the Springsharp report:

J/DD/1916, Japan Destroyer laid down 1916 (Engine 1921) Displacement: 1,207 t light; 1,234 t standard; 1,390 t normal; 1,515 t full load Dimensions: Length overall / water x beam x draught 310.21 ft / 308.00 ft x 31.00 ft x 12.00 ft (normal load) 94.55 m / 93.88 m x 9.45 m x 3.66 m Armament: 4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1916 Model Quick firing guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model Anti-aircraft gun in a deck mount with hoist on side amidships, 1 raised gun 4 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1916 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring Weight of broadside 244 lbs / 111 kg Shells per gun, main battery: 0 6 - 21.0" / 533.4 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Geared drive, 2 shafts, 37,386 shp / 27,890 Kw = 33.00 kts Range 3,500nm at 15.00 kts Bunker at max displacement = 280 tons Complement: 113 - 147 Cost: £0.288 million / $1.152 million Distribution of weights at normal displacement: Armament: 30 tons, 2.2 % Machinery: 773 tons, 55.6 % Hull, fittings & equipment: 403 tons, 29.0 % Fuel, ammunition & stores: 183 tons, 13.2 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 310 lbs / 141 Kg = 6.0 x 4.7 " / 119 mm shells or 0.2 torpedoes Stability (Unstable if below 1.00): 1.40 Metacentric height 1.6 ft / 0.5 m Roll period: 10.4 seconds Steadiness - As gun platform (Average = 50 %): 52 % - Recoil effect (Restricted arc if above 1.00): 0.46 Seaboat quality (Average = 1.00): 1.04 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.425 Length to Beam Ratio: 9.94 : 1 'Natural speed' for length: 17.55 kts Power going to wave formation at top speed: 70 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 23.00 ft / 7.01 m - Forecastle (20 %): 20.00 ft / 6.10 m - Mid (37 %): 20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break) - Quarterdeck (15 %): 12.00 ft / 3.66 m - Stern: 12.00 ft / 3.66 m - Average freeboard: 15.20 ft / 4.63 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 194.5 % - Above water (accommodation/working, high = better): 80.4 % Waterplane Area: 5,972 Square feet or 555 Square metres Displacement factor (Displacement / loading): 49 % Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.43 - Longitudinal: 2.83 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is cramped

## Thursday, March 09, 2006

### The J/DD/1914 design

The J/DD/1914 design is very conservative for a large destroyer designed in 1914. The design worked immediately in Springsharp, although I tweaked the design so that I could add an AA armament. The design has a gun armament of 4-4.7in QF, 1-3in AA, and 4-57mm AA. The torpedo armament is 4-21in TT. The speed is a conservative 32 knots. This is the Springsharp report:

J/DD/1914, Japan Destroyer laid down 1914 Displacement: 1,050 t light; 1,074 t standard; 1,180 t normal; 1,265 t full load Dimensions: Length overall / water x beam x draught 299.15 ft / 297.00 ft x 30.00 ft x 10.00 ft (normal load) 91.18 m / 90.53 m x 9.14 m x 3.05 m Armament: 4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1914 Model Quick firing guns in deck mounts with hoists on centreline, evenly spread Aft Main mounts separated by engine room 1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model Anti-aircraft gun in a deck mount with hoist on side amidships, 1 raised gun 4 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1914 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring Weight of broadside 244 lbs / 111 kg Shells per gun, main battery: 0 4 - 21.0" / 533.4 mm above water torpedoes Machinery: Oil fired boilers, steam turbines, Direct drive, 2 shafts, 30,954 shp / 23,091 Kw = 32.00 kts Range 3,500nm at 12.00 kts Bunker at max displacement = 191 tons Complement: 99 - 130 Cost: £0.195 million / $0.778 million Distribution of weights at normal displacement: Armament: 30 tons, 2.6 % Machinery: 647 tons, 54.8 % Hull, fittings & equipment: 373 tons, 31.6 % Fuel, ammunition & stores: 130 tons, 11.0 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 288 lbs / 131 Kg = 5.5 x 4.7 " / 119 mm shells or 0.2 torpedoes Stability (Unstable if below 1.00): 1.35 Metacentric height 1.4 ft / 0.4 m Roll period: 10.7 seconds Steadiness - As gun platform (Average = 50 %): 53 % - Recoil effect (Restricted arc if above 1.00): 0.59 Seaboat quality (Average = 1.00): 1.05 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.464 Length to Beam Ratio: 9.90 : 1 'Natural speed' for length: 17.23 kts Power going to wave formation at top speed: 71 % Trim (Max stability = 0, Max steadiness = 100): 50 Bow angle (Positive = bow angles forward): 3.00 degrees Stern overhang: 1.00 ft / 0.30 m Freeboard (% = measuring location as a percentage of overall length): - Stem: 22.00 ft / 6.71 m - Forecastle (20 %): 19.00 ft / 5.79 m - Mid (50 %): 19.00 ft / 5.79 m (11.00 ft / 3.35 m aft of break) - Quarterdeck (15 %): 11.00 ft / 3.35 m - Stern: 11.00 ft / 3.35 m - Average freeboard: 15.24 ft / 4.65 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 194.6 % - Above water (accommodation/working, high = better): 112.2 % Waterplane Area: 5,748 Square feet or 534 Square metres Displacement factor (Displacement / loading): 45 % Structure weight / hull surface area: 29 lbs/sq ft or 142 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.43 - Longitudinal: 3.06 - Overall: 0.52 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is adequate

## Wednesday, March 08, 2006

### The (online) International Journal of Naval History

The International Journal of Naval History has been around long enough that the first issue was published in 2002. If I have seen the journal previously, I had forgotten, but it seems worth a read, as they lastest issue, from December 2005, has a good article about the American monitor Miantonomoh visiting Britain in the summer of 1866. Particularly interesting were the pictures in the PowerPoint presentation (best seen with a PowerPoint reader, not OpenOffice) (Photo
Gallery).

### The J/CL/1941 light cruiser design

The J/CL/1941 light cruiser design now has 15-6.1in QF guns, 12-5in DP, and 48-57mm AA guns in twin mounts. The torpedo armament has stayed at 8-24in TT. The speed is 37 knots, so the design is the embodiment of the original Mogami design, except that much more is required to achieve that then the original, too small displacement (to have been 8,500 tons standard). My main criticism of this design is that the armour basis is too light at 3in with a 2in deck. The roll period is now a very good 14.1 seconds and with the seakeeping ability, the result is a good, fast ship. The range might have been increased, but that would have required additional size. This is the Springsharp report:

J/CL/1941, Japan Light Cruiser laid down 1941 (Engine 1950) Displacement: 12,778 t light; 13,365 t standard; 14,400 t normal; 15,228 t full load Dimensions: Length overall / water x beam x draught 666.89 ft / 662.00 ft x 64.00 ft x 21.00 ft (normal load) 203.27 m / 201.78 m x 19.51 m x 6.40 m Armament: 15 - 6.10" / 155 mm guns (5x3 guns), 113.62lbs / 51.54kg shells, 1941 Model Quick firing guns in turrets (on barbettes) on centreline ends, majority forward, 2 raised mounts - superfiring 12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1941 Model Dual purpose guns in deck mounts with hoists on side, all amidships 48 - 2.24" / 57.0 mm guns (24x2 guns), 5.65lbs / 2.56kg shells, 1941 Model Anti-aircraft guns in deck mounts on side, all amidships, 12 raised mounts - superfiring Weight of broadside 2,726 lbs / 1,236 kg Shells per gun, main battery: 180 8 - 24.0" / 609.6 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m Ends: Unarmoured Main Belt covers 110 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 3.00" / 76 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 188,126 shp / 140,342 Kw = 37.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 1,862 tons Complement: 656 - 854 Cost: £8.429 million / $33.715 million Distribution of weights at normal displacement: Armament: 341 tons, 2.4 % Armour: 1,925 tons, 13.4 % - Belts: 701 tons, 4.9 % - Torpedo bulkhead: 334 tons, 2.3 % - Armament: 296 tons, 2.1 % - Armour Deck: 556 tons, 3.9 % - Conning Tower: 38 tons, 0.3 % Machinery: 4,501 tons, 31.3 % Hull, fittings & equipment: 6,011 tons, 41.7 % Fuel, ammunition & stores: 1,622 tons, 11.3 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 13,566 lbs / 6,154 Kg = 119.4 x 6.1 " / 155 mm shells or 1.7 torpedoes Stability (Unstable if below 1.00): 1.21 Metacentric height 3.6 ft / 1.1 m Roll period: 14.1 seconds Steadiness - As gun platform (Average = 50 %): 52 % - Recoil effect (Restricted arc if above 1.00): 0.60 Seaboat quality (Average = 1.00): 1.04 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.566 Length to Beam Ratio: 10.34 : 1 'Natural speed' for length: 25.73 kts Power going to wave formation at top speed: 62 % 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: 33.00 ft / 10.06 m - Forecastle (20 %): 27.00 ft / 8.23 m - Mid (67 %): 27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break) - Quarterdeck (15 %): 19.00 ft / 5.79 m - Stern: 19.00 ft / 5.79 m - Average freeboard: 24.84 ft / 7.57 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 174.8 % - Above water (accommodation/working, high = better): 179.4 % Waterplane Area: 30,029 Square feet or 2,790 Square metres Displacement factor (Displacement / loading): 105 % Structure weight / hull surface area: 116 lbs/sq ft or 567 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.94 - Longitudinal: 1.71 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Tuesday, March 07, 2006

### The J/CL/1937 design is a 37-knot ship

The only improvement in the J/CL/1937 design is that the maximum speed is now 37 knots. The other changes are more beam, a foot more draft, and a small increase in length, which improved seakeeping and lowered the power required for the extra knot. I considered increasing the main armament to 15-6.1in guns, but decided to defer that for the next interation. This is the Springsharp report:

J/CL/1937, Japan Light Cruiser laid down 1937 (Engine 1947) Displacement: 12,084 t light; 12,579 t standard; 13,600 t normal; 14,417 t full load Dimensions: Length overall / water x beam x draught 663.80 ft / 659.00 ft x 62.00 ft x 21.00 ft (normal load) 202.33 m / 200.86 m x 18.90 m x 6.40 m Armament: 12 - 6.10" / 155 mm guns (4x3 guns), 113.62lbs / 51.54kg shells, 1937 Model Quick firing guns in turrets (on barbettes) on centreline ends, evenly spread, 2 raised mounts - superfiring 8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1937 Model Dual purpose guns in deck mounts with hoists on side, all amidships 32 - 2.24" / 57.0 mm guns (16x2 guns), 5.65lbs / 2.56kg shells, 1937 Model Anti-aircraft guns in deck mounts on side, all amidships, 12 raised mounts - superfiring Weight of broadside 2,044 lbs / 927 kg Shells per gun, main battery: 180 8 - 24.0" / 609.6 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m Ends: Unarmoured Main Belt covers 111 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 3.00" / 76 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 179,924 shp / 134,223 Kw = 37.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 1,839 tons Complement: 629 - 818 Cost: £6.872 million / $27.488 million Distribution of weights at normal displacement: Armament: 256 tons, 1.9 % Armour: 1,839 tons, 13.5 % - Belts: 699 tons, 5.1 % - Torpedo bulkhead: 334 tons, 2.5 % - Armament: 239 tons, 1.8 % - Armour Deck: 530 tons, 3.9 % - Conning Tower: 37 tons, 0.3 % Machinery: 4,445 tons, 32.7 % Hull, fittings & equipment: 5,545 tons, 40.8 % Fuel, ammunition & stores: 1,516 tons, 11.1 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 12,534 lbs / 5,685 Kg = 110.3 x 6.1 " / 155 mm shells or 1.6 torpedoes Stability (Unstable if below 1.00): 1.23 Metacentric height 3.6 ft / 1.1 m Roll period: 13.8 seconds Steadiness - As gun platform (Average = 50 %): 51 % - Recoil effect (Restricted arc if above 1.00): 0.49 Seaboat quality (Average = 1.00): 1.03 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.555 Length to Beam Ratio: 10.63 : 1 'Natural speed' for length: 25.67 kts Power going to wave formation at top speed: 62 % 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: 32.00 ft / 9.75 m - Forecastle (20 %): 26.00 ft / 7.92 m - Mid (67 %): 26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break) - Quarterdeck (15 %): 18.00 ft / 5.49 m - Stern: 18.00 ft / 5.49 m - Average freeboard: 23.84 ft / 7.27 m Ship space, strength and comments: Space - Hull below water (magazines/engines, low = better): 178.6 % - Above water (accommodation/working, high = better): 169.9 % Waterplane Area: 28,642 Square feet or 2,661 Square metres Displacement factor (Displacement / loading): 106 % Structure weight / hull surface area: 112 lbs/sq ft or 546 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.95 - Longitudinal: 1.62 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

## Monday, March 06, 2006

### The J/CL/1933 is a great advancement

The J/CL/1937 design is much more capable than its immediate predecessor. The armament was greatly improved with four triple 6.1in turrets and 8-5in DP guns in twin mounts. The light AA armament was slightly increased, as well. The displacement was not much changed, as the normal displacement was 12,900 tons. The freeboard and beam were increased, and that improved the hull strength. That is sufficient for a 36-knot ships with a 7,500nm range at 15 knots. This is the Springsharp report:

J/CL/1933, Japan Light Cruiser laid down 1933 (Engine 1943) Displacement: 11,303 t light; 11,781 t standard; 12,800 t normal; 13,615 t full load Dimensions: Length overall / water x beam x draught 656.71 ft / 652.00 ft x 61.00 ft x 20.00 ft (normal load) 200.17 m / 198.73 m x 18.59 m x 6.10 m Armament: 12 - 6.10" / 155 mm guns (4x3 guns), 113.62lbs / 51.54kg shells, 1933 Model Quick firing guns in turrets (on barbettes) on centreline ends, evenly spread, 2 raised mounts - superfiring 8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1933 Model Dual purpose guns in deck mounts with hoists on side, all amidships 32 - 2.24" / 57.0 mm guns (16x2 guns), 5.65lbs / 2.56kg shells, 1933 Model Anti-aircraft guns in deck mounts on side, all amidships, 12 raised mounts - superfiring Weight of broadside 2,044 lbs / 927 kg Shells per gun, main battery: 180 8 - 24.0" / 609.6 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m Ends: Unarmoured Main Belt covers 112 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 3.00" / 76 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 156,021 shp / 116,391 Kw = 36.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 1,833 tons Complement: 601 - 782 Cost: £5.552 million / $22.206 million Distribution of weights at normal displacement: Armament: 256 tons, 2.0 % Armour: 1,820 tons, 14.2 % - Belts: 698 tons, 5.5 % - Torpedo bulkhead: 334 tons, 2.6 % - Armament: 233 tons, 1.8 % - Armour Deck: 520 tons, 4.1 % - Conning Tower: 35 tons, 0.3 % Machinery: 4,029 tons, 31.5 % Hull, fittings & equipment: 5,198 tons, 40.6 % Fuel, ammunition & stores: 1,497 tons, 11.7 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 12,433 lbs / 5,639 Kg = 109.4 x 6.1 " / 155 mm shells or 1.6 torpedoes Stability (Unstable if below 1.00): 1.24 Metacentric height 3.5 ft / 1.1 m Roll period: 13.6 seconds Steadiness - As gun platform (Average = 50 %): 51 % - Recoil effect (Restricted arc if above 1.00): 0.50 Seaboat quality (Average = 1.00): 1.03 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.563 Length to Beam Ratio: 10.69 : 1 'Natural speed' for length: 25.53 kts Power going to wave formation at top speed: 61 % 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: 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): 175.6 % - Above water (accommodation/working, high = better): 166.2 % Waterplane Area: 28,103 Square feet or 2,611 Square metres Displacement factor (Displacement / loading): 107 % Structure weight / hull surface area: 110 lbs/sq ft or 536 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, March 05, 2006

### There are two improvements in the J/CL/1927 design

The J/CL/1927 design is still too large for the armament, but the design does incorporate two improvements over the 1923 design: a 36 knot speed and twin 4.7in AA guns. The size growth was moderated by lighter weight machinery. I considered using triple 6.1in guns, but decided that was still inappropriate for 1927. The ships do have good strategic mobility and are well-suited to run with aircraft carriers. The US found in WWII that they really wanted faster cruisers and destroyers for that purposed. In the 1920's, prior to much experience with aircraft carriers, the US authorities decided that aviation eliminated the need for speed, and that slower ships were perfectly acceptable. The Japanese tended to want higher speed for cruisers, while the generally accepted 34 knot destroyers, because they wanted a powerful gun and torpedo armament. The original design for the Mogami class is a case in point, as they wanted a 37-knot speed. This is the Springsharp report for the J/CL/1927:

J/CL/1927, Japan Light Cruiser laid down 1927 (Engine 1937) Displacement: 10,754 t light; 11,159 t standard; 12,200 t normal; 13,033 t full load Dimensions: Length overall / water x beam x draught 651.54 ft / 647.00 ft x 57.00 ft x 20.00 ft (normal load) 198.59 m / 197.21 m x 17.37 m x 6.10 m Armament: 8 - 6.10" / 155 mm guns (4x2 guns), 113.62lbs / 51.54kg shells, 1927 Model Quick firing guns in turrets (on barbettes) on centreline ends, evenly spread, 2 raised mounts - superfiring 8 - 4.70" / 119 mm guns (4x2 guns), 51.91lbs / 23.55kg shells, 1927 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships 24 - 2.24" / 57.0 mm guns (12x2 guns), 5.65lbs / 2.56kg shells, 1927 Model Anti-aircraft guns in deck mounts on side, all amidships, 8 raised mounts - superfiring Weight of broadside 1,460 lbs / 662 kg Shells per gun, main battery: 180 8 - 24.0" / 609.6 mm above water torpedoes Armour: - Belts: Width (max) Length (avg) Height (avg) Main: 3.00" / 76 mm 475.00 ft / 144.78 m 12.00 ft / 3.66 m Ends: Unarmoured Main Belt covers 113 % of normal length Main belt does not fully cover magazines and engineering spaces - Torpedo Bulkhead: 1.00" / 25 mm 475.00 ft / 144.78 m 19.00 ft / 5.79 m - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max) Main: 3.00" / 76 mm 2.00" / 51 mm 2.00" / 51 mm - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm Machinery: Oil fired boilers, steam turbines, Geared drive, 4 shafts, 151,489 shp / 113,011 Kw = 36.00 kts Range 7,500nm at 15.00 kts Bunker at max displacement = 1,874 tons Complement: 579 - 754 Cost: £4.064 million / $16.255 million Distribution of weights at normal displacement: Armament: 182 tons, 1.5 % Armour: 1,734 tons, 14.2 % - Belts: 695 tons, 5.7 % - Torpedo bulkhead: 334 tons, 2.7 % - Armament: 181 tons, 1.5 % - Armour Deck: 489 tons, 4.0 % - Conning Tower: 34 tons, 0.3 % Machinery: 4,199 tons, 34.4 % Hull, fittings & equipment: 4,639 tons, 38.0 % Fuel, ammunition & stores: 1,446 tons, 11.9 % Miscellaneous weights: 0 tons, 0.0 % Overall survivability and seakeeping ability: Survivability (Non-critical penetrating hits needed to sink ship): 10,603 lbs / 4,810 Kg = 93.3 x 6.1 " / 155 mm shells or 1.4 torpedoes Stability (Unstable if below 1.00): 1.28 Metacentric height 3.3 ft / 1.0 m Roll period: 13.1 seconds Steadiness - As gun platform (Average = 50 %): 51 % - Recoil effect (Restricted arc if above 1.00): 0.41 Seaboat quality (Average = 1.00): 1.02 Hull form characteristics: Hull has rise forward of midbreak Block coefficient: 0.579 Length to Beam Ratio: 11.35 : 1 'Natural speed' for length: 25.44 kts Power going to wave formation at top speed: 61 % 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: 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): 190.3 % - Above water (accommodation/working, high = better): 152.5 % Waterplane Area: 26,445 Square feet or 2,457 Square metres Displacement factor (Displacement / loading): 105 % Structure weight / hull surface area: 102 lbs/sq ft or 497 Kg/sq metre Hull strength (Relative): - Cross-sectional: 0.97 - Longitudinal: 1.37 - Overall: 1.00 Hull space for machinery, storage, compartmentation is cramped Room for accommodation and workspaces is excellent

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