22kts Battleships Protection

[Jefgte]

Testing 2 x2 M2x6" Protector for the 22kts battleships line vs DDs attacks.

BB protector, NUS 3200t laid down 1922 (Engine 1920)

Displacement:
   3 200 t light; 3 372 t standard; 3 706 t normal; 3 973 t full load

Dimensions: Length overall / water x beam x draught
   393.08 ft / 390.42 ft x 43.64 ft x 15.23 ft (normal load)
   119.81 m / 119.00 m x 13.30 m  x 4.64 m

Armament:
     8 - 6.00" / 152 mm guns (4x2 guns), 108.00lbs / 48.99kg shells, 1922 Model
     Breech loading guns in deck mounts with hoists
     on centreline, evenly spread, 2 raised mounts
     Aft Main mounts separated by engine room
     4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.88kg shells, 1922 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread
     2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1922 Model
     Machine guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
   Weight of broadside 872 lbs / 395 kg
   Shells per gun, main battery: 200
   6 - 21.0" / 533 mm above water torpedoes

Armour:
  - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.36" / 60 mm   285.43 ft / 87.00 m   8.01 ft / 2.44 m
   Ends:   1.18" / 30 mm     65.62 ft / 20.00 m   8.01 ft / 2.44 m
     39.37 ft / 12.00 m Unarmoured ends
     Main Belt covers 112 % of normal length

  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.36" / 60 mm   0.79" / 20 mm      1.57" / 40 mm
   2nd:   0.79" / 20 mm         -               -
   3rd:   0.50" / 13 mm         -               -

  - Armour deck: 0.79" / 20 mm, Conning tower: 1.57" / 40 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 27 800 shp / 20 739 Kw = 27.01 kts
   Range 7 000nm at 12.00 kts
   Bunker at max displacement = 601 tons

Complement:
   236 - 308

Cost:
   £0.926 million / $3.705 million

Distribution of weights at normal displacement:
   Armament: 109 tons, 2.9 %
   Armour: 466 tons, 12.6 %
      - Belts: 245 tons, 6.6 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 47 tons, 1.3 %
      - Armour Deck: 165 tons, 4.5 %
      - Conning Tower: 8 tons, 0.2 %
   Machinery: 972 tons, 26.2 %
   Hull, fittings & equipment: 1 542 tons, 41.6 %
   Fuel, ammunition & stores: 505 tons, 13.6 %
   Miscellaneous weights: 112 tons, 3.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3 762 lbs / 1 707 Kg = 34.8 x 6.0 " / 152 mm shells or 0.9 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 1.8 ft / 0.6 m
   Roll period: 13.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 61 %
         - Recoil effect (Restricted arc if above 1.00): 0.73
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 8.95 : 1
   'Natural speed' for length: 19.76 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 7.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.65 ft / 6.60 m
      - Forecastle (20 %):   18.37 ft / 5.60 m
      - Mid (50 %):      15.09 ft / 4.60 m
      - Quarterdeck (18 %):   15.09 ft / 4.60 m
      - Stern:      15.09 ft / 4.60 m
      - Average freeboard:   16.50 ft / 5.03 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 111.9 %
      - Above water (accommodation/working, high = better): 110.3 %
   Waterplane Area: 11 351 Square feet or 1 055 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 77 lbs/sq ft or 378 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.38
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Good seaboat, rides out heavy weather easily

[Valles]

While different in many details, according to variation in practices between the navies, I still think that she's very clearly a product of much the same kind of design logic as produced the newer Maori cruiser designs - and, with her size and armament, I think she's a very credible take on same. The things that I'd do differently if I were building her are also, for the most part, things I'm weird about more than anything that could count as possibly problematic.

Overall? Well done, sir!

[Laertes]

I'm very impressed. While one could squabble about the tracking speed on those turrets, she looks like she'll basically be an area denial weapon to torpedo boats - "this circle, 6nm or so in radius around me, is one into which I will not permit access" - without there being a great deal you can do back to her.

I might be inclined to scale back her seakeeping. In a heavy sea, torpedo attacks might as well be spitballs, so her tactical niche would be limited.