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Tuesday, January 31, 2006

Another attempt at a super-fast battlecruiser

I thought it might be interesting to see what could be achieved with a very fast (my "super fast") light battlecruiser. The design is "light" in the sense that the armament has only four large caliber guns. Given my expertise with Springsharp, a 38 knot ship is very achievable, with the favored armament of 4-17in BLR and 16-QF guns. I have a very 1923-ish AA armament with 4-4.7in AA and 24-2pdr AA guns. The armor basis is 8in. The result is quite reasonable, if you accept that this is an acceptable thing to do:
GB/CB/1923, Great Britain Battlecruiser laid down 1923 (Engine 1945)

Displacement:
 37,977 t light; 39,287 t standard; 41,500 t normal; 43,271 t full load

Dimensions: Length overall / water x beam x draught
 873.06 ft / 867.00 ft x 95.00 ft x 33.00 ft (normal load)
 266.11 m / 264.26 m x 28.96 m  x 10.06 m

Armament:
      4 - 17.00" / 432 mm guns (2x2 guns), 2,456.50lbs / 1,114.25kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1923 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, 4 raised mounts - superfiring
      4 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
      24 - 1.57" / 40.0 mm guns (6x4 guns), 2.00lbs / 0.91kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships
 Weight of broadside 10,594 lbs / 4,805 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 760.00 ft / 231.65 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 135 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 760.00 ft / 231.65 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 6.00" / 152 mm  8.00" / 203 mm
 2nd: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

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

Machinery:
 Oil fired boilers, reciprocating cruising steam engines plus steam turbines, 
 Geared drive, 8 shafts, 308,750 ihp / 230,327 Kw = 38.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,984 tons

Complement:
 1,453 - 1,889

Cost:
 £12.310 million / $49.241 million

Distribution of weights at normal displacement:
 Armament: 1,324 tons, 3.2 %
 Armour: 7,563 tons, 18.2 %
    - Belts: 2,919 tons, 7.0 %
    - Torpedo bulkhead: 900 tons, 2.2 %
    - Armament: 1,356 tons, 3.3 %
    - Armour Deck: 2,181 tons, 5.3 %
    - Conning Tower: 207 tons, 0.5 %
 Machinery: 12,787 tons, 30.8 %
 Hull, fittings & equipment: 16,302 tons, 39.3 %
 Fuel, ammunition & stores: 3,523 tons, 8.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   33,396 lbs / 15,148 Kg = 13.6 x 17.0 " / 432 mm shells or 3.4 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 6.8 ft / 2.1 m
 Roll period: 15.3 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.56
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.534
 Length to Beam Ratio: 9.13 : 1
 'Natural speed' for length: 33.71 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 30.00 ft / 9.14 m
    - Mid (50 %):  30.00 ft / 9.14 m
    - Quarterdeck (15 %): 30.00 ft / 9.14 m
    - Stern:  30.00 ft / 9.14 m
    - Average freeboard: 30.40 ft / 9.27 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 156.3 %
  - Above water (accommodation/working, high = better): 231.9 %
 Waterplane Area: 58,956 Square feet or 5,477 Square metres
 Displacement factor (Displacement / loading): 95 %
 Structure weight / hull surface area: 179 lbs/sq ft or 873 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.48
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Monday, January 30, 2006

The US/CA/1941 design seems like a "Super Ship"

The US/CA/1941 design seems to be extremely capable, to the point of being a "super ship". This version increased the number of 5in DP guns to 16 and modernized the LAA armament with 40mm and 20mm guns. The number of 21in TT was increased to 10. This is the Springsharp report:
US/CA/1941, United States Heavy Cruiser laid down 1941 (Engine 1945)

Displacement:
 17,372 t light; 18,060 t standard; 19,700 t normal; 21,012 t full load

Dimensions: Length overall / water x beam x draught
 699.71 ft / 695.00 ft x 67.00 ft x 25.00 ft (normal load)
 213.27 m / 211.84 m x 20.42 m  x 7.62 m

Armament:
      12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      16 - 5.00" / 127 mm guns (8x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      40 - 1.57" / 40.0 mm guns (10x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 8 raised mounts - superfiring
      28 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on centreline, all amidships, 20 raised mounts - superfiring
 Weight of broadside 4,157 lbs / 1,886 kg
 Shells per gun, main battery: 120
 10 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 660.00 ft / 201.17 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 146 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 660.00 ft / 201.17 m 24.00 ft / 7.32 m

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

   - Armour deck: 3.50" / 89 mm, Conning tower: 5.00" / 127 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 156,416 shp / 116,687 Kw = 35.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,952 tons

Complement:
 830 - 1,080

Cost:
 £9.875 million / $39.501 million

Distribution of weights at normal displacement:
 Armament: 520 tons, 2.6 %
 Armour: 5,445 tons, 27.6 %
    - Belts: 1,660 tons, 8.4 %
    - Torpedo bulkhead: 586 tons, 3.0 %
    - Armament: 838 tons, 4.3 %
    - Armour Deck: 2,281 tons, 11.6 %
    - Conning Tower: 79 tons, 0.4 %
 Machinery: 3,950 tons, 20.1 %
 Hull, fittings & equipment: 7,458 tons, 37.9 %
 Fuel, ammunition & stores: 2,328 tons, 11.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   27,408 lbs / 12,432 Kg = 107.1 x 8.0 " / 203 mm shells or 3.3 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 15.6 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.592
 Length to Beam Ratio: 10.37 : 1
 'Natural speed' for length: 29.72 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 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
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.48 ft / 7.77 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 122.1 %
  - Above water (accommodation/working, high = better): 172.2 %
 Waterplane Area: 35,234 Square feet or 3,273 Square metres
 Displacement factor (Displacement / loading): 113 %
 Structure weight / hull surface area: 126 lbs/sq ft or 614 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.63
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, January 29, 2006

The US/CA/1937 design

The US/CA/1937 design retains the 8-21in torpedo tubes. The armour deck is increased to 3.5in and the 8in turrets now have 5in on the faces and barbettes. The secondary armament has been modernized to 12-5in twin DP guns with 24-1.1in quadruple AA guns. The ship is flush-decked with a transom stern. They are superior to anything that the Japanese actually built, although they might well have at least matched in not bettered them. This is the Springsharp report:
US/CA/1937, United States Heavy Cruiser laid down 1937 (Engine 1941)

Displacement:
 16,930 t light; 17,582 t standard; 19,250 t normal; 20,585 t full load

Dimensions: Length overall / water x beam x draught
 688.62 ft / 684.00 ft x 66.00 ft x 25.00 ft (normal load)
 209.89 m / 208.48 m x 20.12 m  x 7.62 m

Armament:
      12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      24 - 1.10" / 27.9 mm guns (6x4 guns), 0.67lbs / 0.30kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 3,838 lbs / 1,741 kg
 Shells per gun, main battery: 120
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 146 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 650.00 ft / 198.12 m 24.00 ft / 7.32 m

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 155,483 shp / 115,990 Kw = 35.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 3,003 tons

Complement:
 816 - 1,062

Cost:
 £8.568 million / $34.272 million

Distribution of weights at normal displacement:
 Armament: 480 tons, 2.5 %
 Armour: 5,276 tons, 27.4 %
    - Belts: 1,635 tons, 8.5 %
    - Torpedo bulkhead: 577 tons, 3.0 %
    - Armament: 779 tons, 4.0 %
    - Armour Deck: 2,222 tons, 11.5 %
    - Conning Tower: 62 tons, 0.3 %
 Machinery: 4,109 tons, 21.3 %
 Hull, fittings & equipment: 7,065 tons, 36.7 %
 Fuel, ammunition & stores: 2,320 tons, 12.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   25,470 lbs / 11,553 Kg = 99.5 x 8.0 " / 203 mm shells or 3.1 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 15.3 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.74
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.597
 Length to Beam Ratio: 10.36 : 1
 'Natural speed' for length: 29.47 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  30.00 ft / 9.14 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.48 ft / 7.46 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 127.3 %
  - Above water (accommodation/working, high = better): 168.8 %
 Waterplane Area: 34,312 Square feet or 3,188 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 124 lbs/sq ft or 606 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Saturday, January 28, 2006

The US/CA/1933 design

I hope that it goes without saying that the design series that I have been presenting are based on the premise of no Washington Naval Treaty, or any other limitation. The US/CA/1933 design now has ballooned to 18,800 tons normal, in order to reach 35 knots and still have adequate strength and seakeeping. It still seems that the US did not have an adequate light AA armament in this period. The first attempt at a better answer was the 1.1in MG gun, which is generally comparable to the Japanese 25mm gun. That was not really a mature weapon, and anyway, was too light. Oddly, the ultimate answer was to adopt the 20mm Oerlikon and the 40mm Bofors guns. This is the Springsharp report:
US/CA/1933, United States Heavy Cruiser laid down 1933 (Engine 1939)

Displacement:
16,435 t light; 17,056 t standard; 18,800 t normal; 20,195 t full load

Dimensions: Length overall / water x beam x draught
669.71 ft / 665.00 ft x 65.00 ft x 24.00 ft (normal load)
204.13 m / 202.69 m x 19.81 m  x 7.32 m

Armament:
     12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1933 Model
  Breech loading guns in turrets (on barbettes)
  on centreline ends, evenly spread, 4 raised guns - superfiring
     8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1933 Model
  Anti-aircraft guns in deck mounts with hoists
  on side, all amidships
     16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1933 Model
  Machine guns in deck mounts
  on side, all amidships, all raised mounts - superfiring
Weight of broadside 3,573 lbs / 1,621 kg
Shells per gun, main battery: 120
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
  - Belts:  Width (max) Length (avg)  Height (avg)
Main: 4.00" / 102 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
Ends: Unarmoured
  Main Belt covers 150 % of normal length

  - Torpedo Bulkhead:
 1.00" / 25 mm 650.00 ft / 198.12 m 23.00 ft / 7.01 m

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

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

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 181,511 shp / 135,407 Kw = 35.00 kts
Range 10,000nm at 15.00 kts
Bunker at max displacement = 3,138 tons

Complement:
802 - 1,043

Cost:
£7.743 million / $30.972 million

Distribution of weights at normal displacement:
Armament: 447 tons, 2.4 %
Armour: 4,400 tons, 23.4 %
   - Belts: 1,625 tons, 8.6 %
   - Torpedo bulkhead: 553 tons, 2.9 %
   - Armament: 349 tons, 1.9 %
   - Armour Deck: 1,811 tons, 9.6 %
   - Conning Tower: 61 tons, 0.3 %
Machinery: 4,911 tons, 26.1 %
Hull, fittings & equipment: 6,678 tons, 35.5 %
Fuel, ammunition & stores: 2,365 tons, 12.6 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
  21,573 lbs / 9,786 Kg = 84.3 x 8.0 " / 203 mm shells or 2.4 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 3.6 ft / 1.1 m
Roll period: 14.3 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
  - Recoil effect (Restricted arc if above 1.00): 0.71
Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.634
Length to Beam Ratio: 10.23 : 1
'Natural speed' for length: 25.79 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 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): 148.9 %
 - Above water (accommodation/working, high = better): 167.6 %
Waterplane Area: 32,637 Square feet or 3,032 Square metres
Displacement factor (Displacement / loading): 106 %
Structure weight / hull surface area: 120 lbs/sq ft or 586 Kg/sq metre
Hull strength (Relative):
 - Cross-sectional: 0.95
 - Longitudinal: 1.61
 - Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent

Friday, January 27, 2006

Chuck Hawks has a page on Heavy Cruisers

Chuck Hawks has a 2-page section about heavy cruisers in the World War II period. The first page has a nice, but small photo of the Exeter. I always think that the Exeter's funnels have a slight rake, but when I check it with a vertically aligned window edge, they are exactly vertical, instead. Chuck compares specifications for heavy cruisers from the different navies.

Thursday, January 26, 2006

The navy takes losses and damage off Crete

On 22 May 1941, while headed for Kithera Channel, Admiral King's force took damage. The Naiad had two turrets lost two turrets and had speed reduced. The "Carlisle was hit and her Captain killed". Admiral Rawlings, in the Warspite, turned to join Admiral King, and when nearing, the Warspite was hit, and lost half of her AA armament and had her speed reduced. The entire force withdrew to the southwest. The Greyhound, a destroyer, was bombed and sunk after sinking a caique. Admiral King had sent Fiji and Gloucester, along with the destroyers Kandahar and Kingston to pick up survivors. The cruisers were running out of AA ammunition and were overwhelmed and sank. The destroyers were forced to withdraw, returning after dark to pick up 523 survivors. This is based on the account in Vol.II of the Official History.

The US/CA/1927 design

The improvements incorporated in the US/CA/1927 design are a 34 knot speed and 3in deck armour. The hull is rather blocky, as to maximize strength, the dimensions have been kept compact for the 17,000 ton normal displacement. The draft did not change, but it is rather deep at 24 knots. The advantage is Springsharp is that a deeper draft increases hull strength and seakeeping. This is the Springsharp report:
US/CA/1927, United States Heavy Cruiser laid down 1927 (Engine 1939)

Displacement:
 14,782 t light; 15,367 t standard; 17,000 t normal; 18,307 t full load

Dimensions: Length overall / water x beam x draught
 659.54 ft / 655.00 ft x 64.00 ft x 24.00 ft (normal load)
 201.03 m / 199.64 m x 19.51 m  x 7.32 m

Armament:
      12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1927 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
   Machine guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 3,573 lbs / 1,621 kg
 Shells per gun, main battery: 120
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 610.00 ft / 185.93 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 143 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 610.00 ft / 185.93 m 21.00 ft / 6.40 m

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 149,277 shp / 111,360 Kw = 34.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,940 tons

Complement:
 743 - 967

Cost:
 £5.302 million / $21.207 million

Distribution of weights at normal displacement:
 Armament: 447 tons, 2.6 %
 Armour: 4,102 tons, 24.1 %
    - Belts: 1,542 tons, 9.1 %
    - Torpedo bulkhead: 474 tons, 2.8 %
    - Armament: 341 tons, 2.0 %
    - Armour Deck: 1,688 tons, 9.9 %
    - Conning Tower: 57 tons, 0.3 %
 Machinery: 4,039 tons, 23.8 %
 Hull, fittings & equipment: 6,194 tons, 36.4 %
 Fuel, ammunition & stores: 2,218 tons, 13.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,944 lbs / 9,500 Kg = 81.8 x 8.0 " / 203 mm shells or 2.5 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.4 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.591
 Length to Beam Ratio: 10.23 : 1
 'Natural speed' for length: 25.59 kts
 Power going to wave formation at top speed: 60 %
 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 %): 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 space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 141.6 %
  - Above water (accommodation/working, high = better): 161.1 %
 Waterplane Area: 30,414 Square feet or 2,826 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 119 lbs/sq ft or 583 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.57
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Wednesday, January 25, 2006

The US/CA/1923 design

The US/CA/1923 design is mainly distinguished by having 12-8in guns, as was planned at one point, post 1918, in the US. The speed is still 33 knots and the range 10,000nm. The power plant is about 35 SHP/ton of machinery, which is still pretty conservative. This is the Springsharp report:
US/CA/1923, United States Heavy Cruiser laid down 1923 (Engine 1935)

Displacement:
 12,985 t light; 13,532 t standard; 15,100 t normal; 16,355 t full load

Dimensions: Length overall / water x beam x draught
 638.47 ft / 635.00 ft x 64.00 ft x 24.00 ft (normal load)
 194.60 m / 193.55 m x 19.51 m  x 7.32 m

Armament:
      12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1923 Model
   Machine guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 3,573 lbs / 1,621 kg
 Shells per gun, main battery: 120
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 600.00 ft / 182.88 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 145 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 600.00 ft / 182.88 m 21.00 ft / 6.40 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 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, 122,207 shp / 91,167 Kw = 33.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,823 tons

Complement:
 680 - 885

Cost:
 £3.827 million / $15.310 million

Distribution of weights at normal displacement:
 Armament: 447 tons, 3.0 %
 Armour: 3,398 tons, 22.5 %
    - Belts: 1,509 tons, 10.0 %
    - Torpedo bulkhead: 466 tons, 3.1 %
    - Armament: 329 tons, 2.2 %
    - Armour Deck: 1,041 tons, 6.9 %
    - Conning Tower: 53 tons, 0.3 %
 Machinery: 3,472 tons, 23.0 %
 Hull, fittings & equipment: 5,668 tons, 37.5 %
 Fuel, ammunition & stores: 2,115 tons, 14.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   18,376 lbs / 8,335 Kg = 71.8 x 8.0 " / 203 mm shells or 2.4 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.3 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.542
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 25.20 kts
 Power going to wave formation at top speed: 58 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 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: 22.01 ft / 6.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 141.6 %
  - Above water (accommodation/working, high = better): 150.3 %
 Waterplane Area: 28,147 Square feet or 2,615 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 121 lbs/sq ft or 591 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.47
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Tuesday, January 24, 2006

The US/CA/1921 is not very imaginative

The US/CA/1921 is a not very imaginative improvement over the 1918 design. This has the 10-8in guns like the Pensacola, but with the twin turrets in the superfiring position. The hull also has the usual long, raised forecastle. The torpedo armament is increased to 8-21in TT and the speed is raised to 33 knots. This is the Springsharp report:
US/CA/1921, United States Heavy Cruiser laid down 1921 (Engine 1933)

Displacement:
 12,439 t light; 12,940 t standard; 14,500 t normal; 15,748 t full load

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

Armament:
      10 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1921 Model
   Machine guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 3,061 lbs / 1,388 kg
 Shells per gun, main battery: 120
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 560.00 ft / 170.69 m 15.00 ft / 4.57 m
 Ends: Unarmoured
   Main Belt covers 138 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 560.00 ft / 170.69 m 21.00 ft / 6.40 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 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, 121,075 shp / 90,322 Kw = 33.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,807 tons

Complement:
 659 - 858

Cost:
 £3.184 million / $12.734 million

Distribution of weights at normal displacement:
 Armament: 383 tons, 2.6 %
 Armour: 3,181 tons, 21.9 %
    - Belts: 1,336 tons, 9.2 %
    - Torpedo bulkhead: 435 tons, 3.0 %
    - Armament: 332 tons, 2.3 %
    - Armour Deck: 1,027 tons, 7.1 %
    - Conning Tower: 51 tons, 0.4 %
 Machinery: 3,528 tons, 24.3 %
 Hull, fittings & equipment: 5,348 tons, 36.9 %
 Fuel, ammunition & stores: 2,061 tons, 14.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,595 lbs / 7,981 Kg = 68.7 x 8.0 " / 203 mm shells or 2.2 torpedoes
 Stability (Unstable if below 1.00): 1.20
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.1 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.65
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.560
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 25.00 kts
 Power going to wave formation at top speed: 59 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 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: 22.01 ft / 6.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 145.5 %
  - Above water (accommodation/working, high = better): 152.2 %
 Waterplane Area: 27,748 Square feet or 2,578 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 116 lbs/sq ft or 567 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

Monday, January 23, 2006

This may be premature: US/CA/1918

Perhaps this is too early, but I went with 9-8in guns and 32 knots for ships laid down in 1918. I am not being ambitious enough, as the US was considering fast ships with 12-8in guns at that point. This is the Springsharp report:
US/CA/1918, United States Heavy Cruiser laid down 1918 (Engine 1931)

Displacement:
 11,513 t light; 11,977 t standard; 13,500 t normal; 14,718 t full load

Dimensions: Length overall / water x beam x draught
 618.47 ft / 615.00 ft x 62.00 ft x 22.00 ft (normal load)
 188.51 m / 187.45 m x 18.90 m  x 6.71 m

Armament:
      9 - 8.00" / 203 mm guns (3x3 guns), 256.00lbs / 116.12kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1918 Model
   Machine guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 2,805 lbs / 1,272 kg
 Shells per gun, main battery: 120
 6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 540.00 ft / 164.59 m 15.00 ft / 4.57 m
 Ends: Unarmoured
   Main Belt covers 135 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 540.00 ft / 164.59 m 21.00 ft / 6.40 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 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, 103,041 shp / 76,869 Kw = 32.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,741 tons

Complement:
 626 - 814

Cost:
 £2.258 million / $9.031 million

Distribution of weights at normal displacement:
 Armament: 351 tons, 2.6 %
 Armour: 3,012 tons, 22.3 %
    - Belts: 1,293 tons, 9.6 %
    - Torpedo bulkhead: 420 tons, 3.1 %
    - Armament: 254 tons, 1.9 %
    - Armour Deck: 997 tons, 7.4 %
    - Conning Tower: 49 tons, 0.4 %
 Machinery: 3,081 tons, 22.8 %
 Hull, fittings & equipment: 5,069 tons, 37.5 %
 Fuel, ammunition & stores: 1,987 tons, 14.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,771 lbs / 8,061 Kg = 69.4 x 8.0 " / 203 mm shells or 2.4 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.0 seconds
 Steadiness - As gun platform (Average = 50 %): 58 %
   - Recoil effect (Restricted arc if above 1.00): 0.65
 Seaboat quality  (Average = 1.00): 1.16

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.563
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 24.80 kts
 Power going to wave formation at top speed: 57 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 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: 22.01 ft / 6.71 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 139.0 %
  - Above water (accommodation/working, high = better): 161.3 %
 Waterplane Area: 26,944 Square feet or 2,503 Square metres
 Displacement factor (Displacement / loading): 113 %
 Structure weight / hull surface area: 113 lbs/sq ft or 553 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, January 22, 2006

The US/CA/1916 design

To obtain a reasonable design for the US/CA/1916, lightweight, high-power machinery was required. In some ways, the design is still not satisfactory, as the speed is just 31 knots. For the time, 31 knots was not unreasonable, but at least 32 knots would be better. This design is probably better protected than the real ships built at this date, and later. If I had been willing to accept less protection, I might have been able to reach 32 or 33 knots. The armament is now 8-8in in twin turrets. This is the Springsharp report:
US/CA/1916, United States Heavy Cruiser laid down 1916 (Engine 1927)

Displacement:
 10,505 t light; 10,900 t standard; 12,400 t normal; 13,600 t full load

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

Armament:
      8 - 8.00" / 203 mm guns (4x2 guns), 256.00lbs / 116.12kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      12 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
   Machine guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 2,177 lbs / 987 kg
 Shells per gun, main battery: 120
 6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 570.00 ft / 173.74 m 15.00 ft / 4.57 m
 Ends: Unarmoured
   Main Belt covers 147 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 570.00 ft / 173.74 m 21.00 ft / 6.40 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 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, 86,692 shp / 64,673 Kw = 31.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,699 tons

Complement:
 586 - 763

Cost:
 £1.603 million / $6.410 million

Distribution of weights at normal displacement:
 Armament: 272 tons, 2.2 %
 Armour: 3,015 tons, 24.3 %
    - Belts: 1,340 tons, 10.8 %
    - Torpedo bulkhead: 443 tons, 3.6 %
    - Armament: 262 tons, 2.1 %
    - Armour Deck: 924 tons, 7.5 %
    - Conning Tower: 46 tons, 0.4 %
 Machinery: 2,737 tons, 22.1 %
 Hull, fittings & equipment: 4,481 tons, 36.1 %
 Fuel, ammunition & stores: 1,895 tons, 15.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   16,942 lbs / 7,685 Kg = 66.2 x 8.0 " / 203 mm shells or 2.4 torpedoes
 Stability (Unstable if below 1.00): 1.20
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 13.9 seconds
 Steadiness - As gun platform (Average = 50 %): 59 %
   - Recoil effect (Restricted arc if above 1.00): 0.59
 Seaboat quality  (Average = 1.00): 1.19

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.553
 Length to Beam Ratio: 9.92 : 1
 'Natural speed' for length: 24.39 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = 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 (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: 21.09 ft / 6.43 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 133.1 %
  - Above water (accommodation/working, high = better): 151.2 %
 Waterplane Area: 24,975 Square feet or 2,320 Square metres
 Displacement factor (Displacement / loading): 116 %
 Structure weight / hull surface area: 107 lbs/sq ft or 525 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.48
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Saturday, January 21, 2006

My American heavy cruiser for 1914

This is my attempt at a heavy cruiser design for 1914 for the US (US/CA/1914). This is prior to the existence of such a type, although the British were already doing design studies that would produce such a ship. This design works reasonably well, although the broadside has only 5-8in guns, as there are four broadside guns and five on the centerline, with two forward and three aft. This is the Springsharp report:
US/CA/1914, United States Heavy Cruiser laid down 1914

Displacement:
 9,070 t light; 9,456 t standard; 10,950 t normal; 12,146 t full load

Dimensions: Length overall / water x beam x draught
 568.47 ft / 565.00 ft x 57.00 ft x 21.00 ft (normal load)
 173.27 m / 172.21 m x 17.37 m  x 6.40 m

Armament:
      5 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, majority aft, 2 raised mounts - superfiring
      4 - 8.00" / 203 mm guns in single mounts, 256.00lbs / 116.12kg shells, 1914 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts with hoists
   on centreline, all amidships
      8 - 0.40" / 10.2 mm guns in single mounts, 0.03lbs / 0.01kg shells, 1914 Model
   Machine guns in deck mounts 
   on centreline, all amidships, all raised mounts - superfiring
 Weight of broadside 2,358 lbs / 1,070 kg
 Shells per gun, main battery: 120
 4 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 530.00 ft / 161.54 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 144 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 530.00 ft / 161.54 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 4.00" / 102 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, 63,038 shp / 47,026 Kw = 29.00 kts
 Range 8,000nm at 15.00 kts
 Bunker at max displacement = 2,690 tons

Complement:
 534 - 695

Cost:
 £1.152 million / $4.607 million

Distribution of weights at normal displacement:
 Armament: 295 tons, 2.7 %
 Armour: 2,329 tons, 21.3 %
    - Belts: 878 tons, 8.0 %
    - Torpedo bulkhead: 392 tons, 3.6 %
    - Armament: 172 tons, 1.6 %
    - Armour Deck: 845 tons, 7.7 %
    - Conning Tower: 42 tons, 0.4 %
 Machinery: 2,428 tons, 22.2 %
 Hull, fittings & equipment: 4,017 tons, 36.7 %
 Fuel, ammunition & stores: 1,880 tons, 17.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,641 lbs / 6,641 Kg = 57.2 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 3.1 ft / 0.9 m
 Roll period: 13.7 seconds
 Steadiness - As gun platform (Average = 50 %): 71 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.42

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.567
 Length to Beam Ratio: 9.91 : 1
 'Natural speed' for length: 23.77 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 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: 21.09 ft / 6.43 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 143.0 %
  - Above water (accommodation/working, high = better): 156.8 %
 Waterplane Area: 22,830 Square feet or 2,121 Square metres
 Displacement factor (Displacement / loading): 115 %
 Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.69
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Friday, January 20, 2006

The US/CL/1943 is just an incremental improvement

The main feature of the US/CL/1943 is that the armour basis is now 4.5in, instead of 4in. Otherwise, the only other changes are increased length, displacement, and freeboard. The freeboard was needed improve seakeeping without narrowing the beam further or imcreasing the draft. This is the Springsharp report:
US/CL/1943, United States Light Cruiser laid down 1943 (Engine 1950)

Displacement:
 17,647 t light; 18,267 t standard; 19,850 t normal; 21,116 t full load

Dimensions: Length overall / water x beam x draught
 698.89 ft / 694.00 ft x 65.00 ft x 26.00 ft (normal load)
 213.02 m / 211.53 m x 19.81 m  x 7.92 m

Armament:
      15 - 6.00" / 152 mm guns (5x3 guns), 108.00lbs / 48.99kg shells, 1943 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, 1943 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      48 - 1.57" / 40.0 mm guns (12x4 guns), 1.95lbs / 0.89kg shells, 1943 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
      24 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1943 Model
   Breech loading guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 2,470 lbs / 1,120 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.50" / 114 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 144 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 650.00 ft / 198.12 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.50" / 114 mm 2.50" / 64 mm  4.50" / 114 mm
 2nd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 4.50" / 114 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 196,144 shp / 146,323 Kw = 37.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,849 tons

Complement:
 836 - 1,087

Cost:
 £10.040 million / $40.160 million

Distribution of weights at normal displacement:
 Armament: 309 tons, 1.6 %
 Armour: 5,737 tons, 28.9 %
    - Belts: 1,844 tons, 9.3 %
    - Torpedo bulkhead: 601 tons, 3.0 %
    - Armament: 695 tons, 3.5 %
    - Armour Deck: 2,526 tons, 12.7 %
    - Conning Tower: 71 tons, 0.4 %
 Machinery: 4,692 tons, 23.6 %
 Hull, fittings & equipment: 6,909 tons, 34.8 %
 Fuel, ammunition & stores: 2,203 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   26,209 lbs / 11,888 Kg = 242.7 x 6.0 " / 152 mm shells or 3.1 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 15.1 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.52
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.592
 Length to Beam Ratio: 10.68 : 1
 'Natural speed' for length: 29.64 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 %): 25.00 ft / 7.62 m
    - Mid (67 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.64 ft / 7.82 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 129.1 %
  - Above water (accommodation/working, high = better): 158.8 %
 Waterplane Area: 34,135 Square feet or 3,171 Square metres
 Displacement factor (Displacement / loading): 113 %
 Structure weight / hull surface area: 116 lbs/sq ft or 565 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.69
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Thursday, January 19, 2006

The US/CL/1941 design

The main improvement in the US/CL/1941 design is a 4in armoured deck. The other improvement is a modern LAA armament, with 12-5in DP, 48-40mm AA, and 24-2omm AA guns. A distortion, because of Springsharp, is that the beam is reduced. Springsharp rewards that with increased strength and seakeeping capability. This is the Springsharp report:
US/CL/1941, United States Light Cruiser laid down 1941 (Engine 1950)

Displacement:
 16,624 t light; 17,222 t standard; 18,750 t normal; 19,972 t full load

Dimensions: Length overall / water x beam x draught
 688.80 ft / 684.00 ft x 63.00 ft x 26.00 ft (normal load)
 209.95 m / 208.48 m x 19.20 m  x 7.92 m

Armament:
      15 - 6.00" / 152 mm guns (5x3 guns), 108.00lbs / 48.99kg 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 turrets (on barbettes)
   on side, all amidships
      48 - 1.57" / 40.0 mm guns (12x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
      24 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1941 Model
   Breech loading guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 2,470 lbs / 1,120 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 146 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 650.00 ft / 198.12 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  4.00" / 102 mm
 2nd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 189,631 shp / 141,465 Kw = 37.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,750 tons

Complement:
 800 - 1,041

Cost:
 £9.126 million / $36.504 million

Distribution of weights at normal displacement:
 Armament: 309 tons, 1.6 %
 Armour: 5,296 tons, 28.2 %
    - Belts: 1,632 tons, 8.7 %
    - Torpedo bulkhead: 601 tons, 3.2 %
    - Armament: 604 tons, 3.2 %
    - Armour Deck: 2,398 tons, 12.8 %
    - Conning Tower: 61 tons, 0.3 %
 Machinery: 4,537 tons, 24.2 %
 Hull, fittings & equipment: 6,483 tons, 34.6 %
 Fuel, ammunition & stores: 2,126 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,699 lbs / 10,750 Kg = 219.4 x 6.0 " / 152 mm shells or 2.8 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 3.1 ft / 1.0 m
 Roll period: 14.9 seconds
 Steadiness - As gun platform (Average = 50 %): 50 %
   - Recoil effect (Restricted arc if above 1.00): 0.54
 Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.586
 Length to Beam Ratio: 10.86 : 1
 'Natural speed' for length: 29.41 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.64 ft / 7.51 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 134.5 %
  - Above water (accommodation/working, high = better): 149.6 %
 Waterplane Area: 32,402 Square feet or 3,010 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 114 lbs/sq ft or 556 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.64
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Photo of a US/CL/1937 class light cruiser

This is a photo of the 37-knot light cruiser with 15-6in QF, 8-5in AA, 40-1.1in AA, and 12-21in TT. The armour basis is 4in. The ship is 16,231 tons Standard Displacement.

Wednesday, January 18, 2006

I will be posting a photo of a US/CL/1937 design ship

I was not able to finish the photo of the US/CL/1937 design ship last night, but it is very close to completion. The main armament layout is similar to the Mogami class, rather than the Brooklyn class. There are twin funnels and aircraft on the quarterdeck on catapults (not accounted for in Springsharp), with a centerline crane at the stern.

Tuesday, January 17, 2006

The US/CL/1937 design

The next logical step seemed to be to move to a light cruiser with 15-6in QF guns. The possibility was also there to raise the speed to 37 knots. One distortion is that the draft is too large, but by having a deep draft, Springsharp rewards us with greater strength and seakeeping ability. We use that artifice to achieve what we want. This is the Springsharp report:
US/CL/1937, United States Light Cruiser laid down 1937 (Engine 1950)

Displacement:
 15,688 t light; 16,231 t standard; 17,700 t normal; 18,875 t full load

Dimensions: Length overall / water x beam x draught
 681.80 ft / 677.00 ft x 66.00 ft x 26.00 ft (normal load)
 207.81 m / 206.35 m x 20.12 m  x 7.92 m

Armament:
      15 - 6.00" / 152 mm guns (5x3 guns), 108.00lbs / 48.99kg shells, 1937 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1937 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      40 - 1.10" / 27.9 mm guns (10x4 guns), 0.67lbs / 0.30kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 2,147 lbs / 974 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 630.00 ft / 192.02 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 143 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 630.00 ft / 192.02 m 24.00 ft / 7.32 m

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 179,384 shp / 133,821 Kw = 37.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,644 tons

Complement:
 766 - 997

Cost:
 £7.502 million / $30.006 million

Distribution of weights at normal displacement:
 Armament: 268 tons, 1.5 %
 Armour: 4,775 tons, 27.0 %
    - Belts: 1,588 tons, 9.0 %
    - Torpedo bulkhead: 559 tons, 3.2 %
    - Armament: 500 tons, 2.8 %
    - Armour Deck: 2,069 tons, 11.7 %
    - Conning Tower: 59 tons, 0.3 %
 Machinery: 4,291 tons, 24.2 %
 Hull, fittings & equipment: 6,354 tons, 35.9 %
 Fuel, ammunition & stores: 2,012 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,439 lbs / 10,632 Kg = 217.0 x 6.0 " / 152 mm shells or 2.9 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 3.5 ft / 1.1 m
 Roll period: 14.7 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.42
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.533
 Length to Beam Ratio: 10.26 : 1
 'Natural speed' for length: 29.53 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.64 ft / 7.51 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 130.5 %
  - Above water (accommodation/working, high = better): 155.4 %
 Waterplane Area: 31,948 Square feet or 2,968 Square metres
 Displacement factor (Displacement / loading): 114 %
 Structure weight / hull surface area: 116 lbs/sq ft or 565 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.68
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Sunday, January 15, 2006

The US/CL/1933 design

The US/CL/1933 design has two improvements: 1.1in AA guns and 3.5 inch deck armour. To satisfy Springsharp, the belt is abnormally long. The armament is now 12-6in QF, 8-5in AA, and 36-1.1in AA guns. To improve performance, the hull now has a transom stern. The size has ballooned to 16,100 tons normal displacement. This is the Springsharp report:
US/CL/1933, United States Light Cruiser laid down 1933 (Engine 1950)

Displacement:
 14,228 t light; 14,712 t standard; 16,100 t normal; 17,210 t full load

Dimensions: Length overall / water x beam x draught
 669.71 ft / 665.00 ft x 63.00 ft x 24.00 ft (normal load)
 204.13 m / 202.69 m x 19.20 m  x 7.32 m

Armament:
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1933 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1933 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 1.10" / 27.9 mm guns (9x4 guns), 0.67lbs / 0.30kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 6 raised mounts
 Weight of broadside 1,820 lbs / 826 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 620.00 ft / 188.98 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 143 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 620.00 ft / 188.98 m 24.00 ft / 7.32 m

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 154,625 shp / 115,350 Kw = 36.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,498 tons

Complement:
 714 - 929

Cost:
 £5.706 million / $22.823 million

Distribution of weights at normal displacement:
 Armament: 227 tons, 1.4 %
 Armour: 4,548 tons, 28.2 %
    - Belts: 1,563 tons, 9.7 %
    - Torpedo bulkhead: 551 tons, 3.4 %
    - Armament: 389 tons, 2.4 %
    - Armour Deck: 1,991 tons, 12.4 %
    - Conning Tower: 55 tons, 0.3 %
 Machinery: 3,699 tons, 23.0 %
 Hull, fittings & equipment: 5,754 tons, 35.7 %
 Fuel, ammunition & stores: 1,872 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,274 lbs / 10,557 Kg = 215.5 x 6.0 " / 152 mm shells or 2.9 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 14.5 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.42
 Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.560
 Length to Beam Ratio: 10.56 : 1
 'Natural speed' for length: 29.12 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.56 ft / 7.49 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 126.2 %
  - Above water (accommodation/working, high = better): 158.0 %
 Waterplane Area: 30,746 Square feet or 2,856 Square metres
 Displacement factor (Displacement / loading): 117 %
 Structure weight / hull surface area: 108 lbs/sq ft or 526 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.72
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Saturday, January 14, 2006

The US/CL/1927 design

The new features in the US/CL/1927 design are a flush deck, a 16-ft high 4in belt, 12-6in QF guns, a range of 10,000nm at 15 knots, so that the design is well-suited for Pacific warfare, and finally, a 1in torpedo bulkhead. Previous designs in this series had too low a range and lacked an armoured torpedo bulkhead. This design is more survivable than its predecessors in the series. This is the Springsharp report:]
US/CL/1927, United States Light Cruiser laid down 1927 (Engine 1950)

Displacement:
 12,700 t light; 13,149 t standard; 14,500 t normal; 15,581 t full load

Dimensions: Length overall / water x beam x draught
 619.71 ft / 615.00 ft x 59.00 ft x 23.00 ft (normal load)
 188.89 m / 187.45 m x 17.98 m  x 7.01 m

Armament:
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1927 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 24 raised mounts
 Weight of broadside 1,798 lbs / 816 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 460.00 ft / 140.21 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 115 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 460.00 ft / 140.21 m 22.00 ft / 6.71 m

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 177,749 shp / 132,601 Kw = 36.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,432 tons

Complement:
 659 - 858

Cost:
 £4.468 million / $17.871 million

Distribution of weights at normal displacement:
 Armament: 225 tons, 1.6 %
 Armour: 3,005 tons, 20.7 %
    - Belts: 1,202 tons, 8.3 %
    - Torpedo bulkhead: 374 tons, 2.6 %
    - Armament: 389 tons, 2.7 %
    - Armour Deck: 989 tons, 6.8 %
    - Conning Tower: 51 tons, 0.4 %
 Machinery: 4,252 tons, 29.3 %
 Hull, fittings & equipment: 5,218 tons, 36.0 %
 Fuel, ammunition & stores: 1,800 tons, 12.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   15,384 lbs / 6,978 Kg = 142.4 x 6.0 " / 152 mm shells or 1.9 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 3.0 ft / 0.9 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.50
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.608
 Length to Beam Ratio: 10.42 : 1
 'Natural speed' for length: 24.80 kts
 Power going to wave formation at top speed: 64 %
 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 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.56 ft / 7.49 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 162.5 %
  - Above water (accommodation/working, high = better): 143.2 %
 Waterplane Area: 26,740 Square feet or 2,484 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 106 lbs/sq ft or 516 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 2.02
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Friday, January 13, 2006

The US/CL/1923 design

The US/CL/1923 design is able to make 36 knots and has a 4in armour basis. The armament remains the same as the 1921 version. The draft is too deep at 23ft. The length and beam are also greater at 595ft (WL) x 58ft x 23ft. The normal displacement is 11,600 tons. This is the Springsharp report:
US/CL/1923, United States Light Cruiser laid down 1923 (Engine 1947)

Displacement:
 10,434 t light; 10,797 t standard; 11,600 t normal; 12,242 t full load

Dimensions: Length overall / water x beam x draught
 599.54 ft / 595.00 ft x 58.00 ft x 23.00 ft (normal load)
 182.74 m / 181.36 m x 17.68 m  x 7.01 m

Armament:
      9 - 6.00" / 152 mm guns (3x3 guns), 108.00lbs / 48.99kg shells, 1923 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 24 raised mounts
 Weight of broadside 1,474 lbs / 669 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 460.00 ft / 140.21 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 119 % of normal length

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 150,180 shp / 112,034 Kw = 36.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 1,445 tons

Complement:
 558 - 726

Cost:
 £3.024 million / $12.095 million

Distribution of weights at normal displacement:
 Armament: 184 tons, 1.6 %
 Armour: 2,080 tons, 17.9 %
    - Belts: 895 tons, 7.7 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 281 tons, 2.4 %
    - Armour Deck: 860 tons, 7.4 %
    - Conning Tower: 44 tons, 0.4 %
 Machinery: 3,710 tons, 32.0 %
 Hull, fittings & equipment: 4,460 tons, 38.4 %
 Fuel, ammunition & stores: 1,166 tons, 10.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   10,683 lbs / 4,846 Kg = 98.9 x 6.0 " / 152 mm shells or 1.3 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 2.9 ft / 0.9 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.45
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.512
 Length to Beam Ratio: 10.26 : 1
 'Natural speed' for length: 24.39 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:  29.00 ft / 8.84 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (67 %):  25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break)
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 22.68 ft / 6.91 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.2 %
  - Above water (accommodation/working, high = better): 137.4 %
 Waterplane Area: 23,237 Square feet or 2,159 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 104 lbs/sq ft or 509 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.92
  - Longitudinal: 2.05
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Thursday, January 12, 2006

The US/CL/1921 design

The US/CL/1921 design has an increased speed to 35 knots, increased range to 6,500nm at 15 knots, and 9-6in QF, 8-5in AA, 36-0.5in MG for AA, and 12-21in TT. The result is rather like a French light cruiser. This seems to be a better bargain than an Omaha, which had the odd casemate guns (odd for the period), and too small a size, so that they proved pretty much useless in WWII. This is the Springsharp report:
US/CL/1921, United States Light Cruiser laid down 1921 (Engine 1945)

Displacement:
 8,971 t light; 9,304 t standard; 10,050 t normal; 10,647 t full load

Dimensions: Length overall / water x beam x draught
 578.96 ft / 575.00 ft x 55.00 ft x 21.00 ft (normal load)
 176.47 m / 175.26 m x 16.76 m  x 6.40 m

Armament:
      9 - 6.00" / 152 mm guns (3x3 guns), 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1921 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1921 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 24 raised mounts
 Weight of broadside 1,474 lbs / 669 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 440.00 ft / 134.11 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 118 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 3.00" / 76 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 124,907 shp / 93,181 Kw = 35.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 1,343 tons

Complement:
 501 - 652

Cost:
 £2.317 million / $9.269 million

Distribution of weights at normal displacement:
 Armament: 184 tons, 1.8 %
 Armour: 1,690 tons, 16.8 %
    - Belts: 642 tons, 6.4 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 216 tons, 2.1 %
    - Armour Deck: 801 tons, 8.0 %
    - Conning Tower: 30 tons, 0.3 %
 Machinery: 3,154 tons, 31.4 %
 Hull, fittings & equipment: 3,943 tons, 39.2 %
 Fuel, ammunition & stores: 1,079 tons, 10.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   9,440 lbs / 4,282 Kg = 87.4 x 6.0 " / 152 mm shells or 1.2 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 2.7 ft / 0.8 m
 Roll period: 13.9 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.53
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.530
 Length to Beam Ratio: 10.45 : 1
 'Natural speed' for length: 23.98 kts
 Power going to wave formation at top speed: 62 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  28.00 ft / 8.53 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.68 ft / 6.61 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.2 %
  - Above water (accommodation/working, high = better): 132.5 %
 Waterplane Area: 21,655 Square feet or 2,012 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 100 lbs/sq ft or 488 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.98
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Wednesday, January 11, 2006

The US/CL/1918 design

My US/CL/1918 design is an attempt to modernize the light cruiser with turrets, while otherwise retaining the characteristics that it has acquired so far. the armament is now 8-6in QF, 4-4in AA, 16-0.5in MG (AA), and 12-21in TT. The armour basis is 3in with a maximum speed, without pressing, of 34 knots. The range is now 5,600nm at 15 knots. The design is still dependent on very lightweight machinery. This is the Springsharp report:
US/CL/1918, United States Light Cruiser laid down 1918 (Engine 1941)

Displacement:
 7,891 t light; 8,134 t standard; 8,750 t normal; 9,242 t full load

Dimensions: Length overall / water x beam x draught
 558.89 ft / 555.00 ft x 54.00 ft x 20.00 ft (normal load)
 170.35 m / 169.16 m x 16.46 m  x 6.10 m

Armament:
      8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1918 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      16 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1918 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 993 lbs / 450 kg
 Shells per gun, main battery: 120
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 420.00 ft / 128.02 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 116 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 3.00" / 76 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 102,606 shp / 76,544 Kw = 34.00 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 1,108 tons

Complement:
 452 - 588

Cost:
 £1.520 million / $6.081 million

Distribution of weights at normal displacement:
 Armament: 124 tons, 1.4 %
 Armour: 1,608 tons, 18.4 %
    - Belts: 614 tons, 7.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 220 tons, 2.5 %
    - Armour Deck: 746 tons, 8.5 %
    - Conning Tower: 27 tons, 0.3 %
 Machinery: 2,712 tons, 31.0 %
 Hull, fittings & equipment: 3,447 tons, 39.4 %
 Fuel, ammunition & stores: 859 tons, 9.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   9,018 lbs / 4,090 Kg = 83.5 x 6.0 " / 152 mm shells or 1.2 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 2.7 ft / 0.8 m
 Roll period: 13.9 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.40
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.511
 Length to Beam Ratio: 10.28 : 1
 'Natural speed' for length: 23.56 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 20.68 ft / 6.30 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 111.5 %
  - Above water (accommodation/working, high = better): 127.9 %
 Waterplane Area: 20,169 Square feet or 1,874 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 96 lbs/sq ft or 467 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.87
  - Overall: 1.01
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Tuesday, January 10, 2006

The US/CL/1916 design

To make the US/CL/1916 design work, lighter machinery was required than was allowed by Springsharp for this date. This ship is basically the US/CL/1914 with the forecastle lengthened, the 5in guns replaced with 6in guns, the armour basis reduced to 3in, and the speed increased to a competitive 33 knots. That meant lengthening the ship to 535ft on the waterline and increasing the displacement to achieve adequate strength. This is the resulting Springsharp report:
US/CL/1916, United States Light Cruiser laid down 1916 (Engine 1937)

Displacement:
 7,570 t light; 7,844 t standard; 8,450 t normal; 8,935 t full load

Dimensions: Length overall / water x beam x draught
 538.82 ft / 535.00 ft x 53.00 ft x 18.00 ft (normal load)
 164.23 m / 163.07 m x 16.15 m  x 5.49 m

Armament:
      6 - 6.00" / 152 mm guns (5 mounts), 108.00lbs / 48.99kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward, 2 raised mounts - superfiring
      6 - 6.00" / 152 mm guns (4 mounts), 108.00lbs / 48.99kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      4 - 4.00" / 102 mm guns (2x2 guns), 32.00lbs / 14.51kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 1,424 lbs / 646 kg
 Shells per gun, main battery: 120
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 410.00 ft / 124.97 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 118 % of normal length

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 3.00" / 76 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 93,827 shp / 69,995 Kw = 33.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 1,091 tons

Complement:
 439 - 572

Cost:
 £1.274 million / $5.096 million

Distribution of weights at normal displacement:
 Armament: 178 tons, 2.1 %
 Armour: 1,528 tons, 18.1 %
    - Belts: 601 tons, 7.1 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 147 tons, 1.7 %
    - Armour Deck: 753 tons, 8.9 %
    - Conning Tower: 27 tons, 0.3 %
 Machinery: 2,601 tons, 30.8 %
 Hull, fittings & equipment: 3,264 tons, 38.6 %
 Fuel, ammunition & stores: 880 tons, 10.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   8,376 lbs / 3,799 Kg = 77.6 x 6.0 " / 152 mm shells or 1.1 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 2.8 ft / 0.8 m
 Roll period: 13.4 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.53
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.579
 Length to Beam Ratio: 10.09 : 1
 'Natural speed' for length: 23.13 kts
 Power going to wave formation at top speed: 62 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 20.60 ft / 6.28 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 116.0 %
  - Above water (accommodation/working, high = better): 130.0 %
 Waterplane Area: 20,343 Square feet or 1,890 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 93 lbs/sq ft or 453 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.85
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Monday, January 09, 2006

A new series starting with the US/CL/1914

In a lost series of drawings from 1976, I had this concept for an American light cruiser for 1914 or thereabouts. The design is rather like the British Town class, except with 5in guns. I had thought that the 5in/51 QF gun had a good range and rate of fire, probably with a 60 lb. shot/shell, so that the piece was still fairly hard-hitting. This is the Springsharp report:
US/CL/1914, United States Light Cruiser laid down 1914

Displacement:
 5,645 t light; 5,842 t standard; 6,600 t normal; 7,206 t full load

Dimensions: Length overall / water x beam x draught
 478.75 ft / 475.00 ft x 49.00 ft x 17.00 ft (normal load)
 145.92 m / 144.78 m x 14.94 m  x 5.18 m

Armament:
      5 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, majority forward, 2 raised mounts - superfiring
      4 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1914 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1914 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread
 Weight of broadside 590 lbs / 267 kg
 Shells per gun, main battery: 180
 4 - 21.0" / 533.4 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: Unarmoured
   Main Belt covers 130 % of normal length

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

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

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 50,206 shp / 37,454 Kw = 29.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 1,364 tons

Complement:
 365 - 475

Cost:
 £0.675 million / $2.699 million

Distribution of weights at normal displacement:
 Armament: 74 tons, 1.1 %
 Armour: 1,523 tons, 23.1 %
    - Belts: 773 tons, 11.7 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 99 tons, 1.5 %
    - Armour Deck: 620 tons, 9.4 %
    - Conning Tower: 30 tons, 0.5 %
 Machinery: 1,934 tons, 29.3 %
 Hull, fittings & equipment: 2,115 tons, 32.0 %
 Fuel, ammunition & stores: 955 tons, 14.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   7,519 lbs / 3,410 Kg = 120.3 x 5.0 " / 127 mm shells or 1.2 torpedoes
 Stability (Unstable if below 1.00): 1.31
 Metacentric height 2.8 ft / 0.8 m
 Roll period: 12.3 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.22
 Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.584
 Length to Beam Ratio: 9.69 : 1
 'Natural speed' for length: 21.79 kts
 Power going to wave formation at top speed: 59 %
 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:  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): 104.3 %
  - Above water (accommodation/working, high = better): 124.1 %
 Waterplane Area: 16,767 Square feet or 1,558 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 77 lbs/sq ft or 377 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

Sunday, January 08, 2006

The US/BB/1937 design seems too good to be true

To my jaundiced eyes, the US/BB/1937 design seems to be too good to be true. The ship has a higher speed than the Yamato and carries a good (for 1937) AA armament. Admittedly, the armour basis is "only" 17 inches. The main improvements over the previous design are thicker armour deck and anti-torpedo bulkhead. There is a modest increase of the light AA armament. This is the Springsharp report:
US/BB/1937, United States Battleship laid down 1937

Displacement:
 61,913 t light; 64,708 t standard; 69,500 t normal; 73,333 t full load

Dimensions: Length overall / water x beam x draught
 860.80 ft / 855.00 ft x 112.00 ft x 35.00 ft (normal load)
 262.37 m / 260.60 m x 34.14 m  x 10.67 m

Armament:
      9 - 18.00" / 457 mm guns (3x3 guns), 2,916.00lbs / 1,322.68kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships, 4 raised mounts - superfiring
      42 - 1.10" / 27.9 mm guns (9 mounts), 0.67lbs / 0.30kg shells, 1937 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, 7 raised mounts - superfiring
      40 - 0.50" / 12.7 mm guns (32 mounts), 0.06lbs / 0.03kg shells, 1937 Model
   Machine guns in deck mounts 
   on side, evenly spread, 32 raised mounts
 Weight of broadside 27,774 lbs / 12,598 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 17.0" / 432 mm 600.00 ft / 182.88 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 108 % of normal length

   - Torpedo Bulkhead:
  6.00" / 152 mm 600.00 ft / 182.88 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 17.0" / 432 mm 12.0" / 305 mm  17.0" / 432 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 17.00" / 432 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 185,957 shp / 138,724 Kw = 29.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 8,625 tons

Complement:
 2,139 - 2,782

Cost:
 £31.663 million / $126.651 million

Distribution of weights at normal displacement:
 Armament: 3,472 tons, 5.0 %
 Armour: 29,472 tons, 42.4 %
    - Belts: 7,378 tons, 10.6 %
    - Torpedo bulkhead: 4,262 tons, 6.1 %
    - Armament: 5,590 tons, 8.0 %
    - Armour Deck: 11,622 tons, 16.7 %
    - Conning Tower: 619 tons, 0.9 %
 Machinery: 5,154 tons, 7.4 %
 Hull, fittings & equipment: 23,815 tons, 34.3 %
 Fuel, ammunition & stores: 7,587 tons, 10.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   107,231 lbs / 48,639 Kg = 36.8 x 18.0 " / 457 mm shells or 20.4 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 7.3 ft / 2.2 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has low forecastle
 Block coefficient: 0.726
 Length to Beam Ratio: 7.63 : 1
 'Natural speed' for length: 29.24 kts
 Power going to wave formation at top speed: 52 %
 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 %): 1.00 ft / 0.30 m (25.00 ft / 7.62 m aft of break)
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 22.68 ft / 6.91 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 75.4 %
  - Above water (accommodation/working, high = better): 174.8 %
 Waterplane Area: 78,525 Square feet or 7,295 Square metres
 Displacement factor (Displacement / loading): 103 %
 Structure weight / hull surface area: 224 lbs/sq ft or 1,096 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.07
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

Saturday, January 07, 2006

A better Ger/CL/1920 fleet cruiser photo

I had always been unhappy with my original drawing of the Ger/CL/1920 fleet cruiser. Looking at the original photo, I realized what the issue was for me. The stacks were too high and wide. This class of ships were to have 6-6in QF guns with a 37 knot speed. This is the revised photo:

Ger/CL/1921 fleet cruiser photo

The US/BB/1933 is suitable for Pacific warfare

I increased the displacement of the US/BB/1933 so as to have slightly better protection but especially to have a 12,000nm range at 15 knots. The armament is more modern, with 24-5in DP, 36-1.1in AA, as well as the 9-18in BLR, and 36-0.5in MG. What I don't understand is why this is achievable on such a relatively small displacement compared with the Yamato class. Part of the answer may be that the Japanese ship carried more protection. This is the Springsharp report:
US/BB/1933, United States Battleship laid down 1933

Displacement:
 55,163 t light; 57,817 t standard; 62,500 t normal; 66,246 t full load

Dimensions: Length overall / water x beam x draught
 790.54 ft / 785.00 ft x 112.00 ft x 33.00 ft (normal load)
 240.96 m / 239.27 m x 34.14 m  x 10.06 m

Armament:
      9 - 18.00" / 457 mm guns (3x3 guns), 2,916.00lbs / 1,322.68kg shells, 1933 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1933 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships, 4 raised mounts - superfiring
      36 - 1.10" / 27.9 mm guns (9x4 guns), 0.67lbs / 0.30kg shells, 1933 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, 7 raised mounts - superfiring
      32 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1933 Model
   Machine guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 27,770 lbs / 12,596 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 17.0" / 432 mm 530.00 ft / 161.54 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 104 % of normal length

   - Torpedo Bulkhead:
  5.00" / 127 mm 530.00 ft / 161.54 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 17.0" / 432 mm 12.0" / 305 mm  17.0" / 432 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 17.00" / 432 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 138,819 shp / 103,559 Kw = 27.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 8,429 tons

Complement:
 1,976 - 2,569

Cost:
 £25.588 million / $102.351 million

Distribution of weights at normal displacement:
 Armament: 3,471 tons, 5.6 %
 Armour: 25,508 tons, 40.8 %
    - Belts: 6,635 tons, 10.6 %
    - Torpedo bulkhead: 3,138 tons, 5.0 %
    - Armament: 5,590 tons, 8.9 %
    - Armour Deck: 9,568 tons, 15.3 %
    - Conning Tower: 577 tons, 0.9 %
 Machinery: 4,045 tons, 6.5 %
 Hull, fittings & equipment: 22,138 tons, 35.4 %
 Fuel, ammunition & stores: 7,337 tons, 11.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   96,463 lbs / 43,755 Kg = 33.1 x 18.0 " / 457 mm shells or 17.7 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 7.3 ft / 2.2 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.80
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has low forecastle
 Block coefficient: 0.754
 Length to Beam Ratio: 7.01 : 1
 'Natural speed' for length: 28.02 kts
 Power going to wave formation at top speed: 51 %
 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:  29.00 ft / 8.84 m
    - Forecastle (20 %): 1.00 ft / 0.30 m (25.00 ft / 7.62 m aft of break)
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 22.44 ft / 6.84 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 76.7 %
  - Above water (accommodation/working, high = better): 178.1 %
 Waterplane Area: 73,887 Square feet or 6,864 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 226 lbs/sq ft or 1,103 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.19
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

Friday, January 06, 2006

The US/BB/1927 design

This is a transitional design, in that the speed merits the ship's designation as a fast battleship. To achieve everything, the dimensions and displacement had to increase considerably. The deck armour was increased to 6in so as to better resist bombing and falling shot at long range. The main armament is now in triple turrets. The only reason that I can see that this is viable at the size it is, is that the range is quite modest. The short range (6,500nm at 15 knots) makes it less useful for Pacific operations. To achieve a 12,000nm range, I would expect that the size would need to increase dramatically. This is the Springsharp report:
US/BB/1927, United States Battleship laid down 1927

Displacement:
 50,159 t light; 52,708 t standard; 55,300 t normal; 57,373 t full load

Dimensions: Length overall / water x beam x draught
 750.54 ft / 745.00 ft x 110.00 ft x 33.00 ft (normal load)
 228.76 m / 227.08 m x 33.53 m  x 10.06 m

Armament:
      9 - 18.00" / 457 mm guns (3x3 guns), 2,916.00lbs / 1,322.68kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships, 4 raised mounts - superfiring
      8 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1927 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      36 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
   Machine guns in deck mounts 
   on side, evenly spread, all raised mounts
 Weight of broadside 28,474 lbs / 12,916 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 16.0" / 406 mm 460.00 ft / 140.21 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 95 % of normal length

   - Torpedo Bulkhead:
  5.00" / 127 mm 460.00 ft / 140.21 m 32.00 ft / 9.75 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: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 16.00" / 406 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 129,718 shp / 96,770 Kw = 27.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,665 tons

Complement:
 1,802 - 2,343

Cost:
 £19.340 million / $77.362 million

Distribution of weights at normal displacement:
 Armament: 3,559 tons, 6.4 %
 Armour: 21,436 tons, 38.8 %
    - Belts: 5,537 tons, 10.0 %
    - Torpedo bulkhead: 2,723 tons, 4.9 %
    - Armament: 5,281 tons, 9.6 %
    - Armour Deck: 7,393 tons, 13.4 %
    - Conning Tower: 500 tons, 0.9 %
 Machinery: 4,095 tons, 7.4 %
 Hull, fittings & equipment: 21,069 tons, 38.1 %
 Fuel, ammunition & stores: 5,141 tons, 9.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   73,720 lbs / 33,439 Kg = 25.3 x 18.0 " / 457 mm shells or 12.3 torpedoes
 Stability (Unstable if below 1.00): 1.08
 Metacentric height 6.6 ft / 2.0 m
 Roll period: 17.9 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.92
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has low forecastle
 Block coefficient: 0.716
 Length to Beam Ratio: 6.77 : 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): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  29.00 ft / 8.84 m
    - Forecastle (20 %): 1.00 ft / 0.30 m (25.00 ft / 7.62 m aft of break)
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 22.44 ft / 6.84 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 88.4 %
  - Above water (accommodation/working, high = better): 176.0 %
 Waterplane Area: 66,607 Square feet or 6,188 Square metres
 Displacement factor (Displacement / loading): 95 %
 Structure weight / hull surface area: 235 lbs/sq ft or 1,149 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.34
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

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