Vilnius Union Ships, 1930+: The Good, The Bad, and the Unseaworthy

[Kaiser Kirk]

I'm going with the 17%, so 90/.17 = 529mm, not 90/.2 = 450.
I've also been wondering if the slope of the decapping plate should be considered. It adds~5% to thickness, so 90 becomes 94.5 = 555

[The Rock Doctor]

I thought we'd established the rule was 20%?

No idea about the slope.

[The Rock Doctor]

Don't think I've posted the G-class sloops, but if I have, I'm sure it's worth another look.

They have the same role as the Quackenbruck class, which is to protect Union auxiliaries doing their thing on the high seas.  This means a highish speed and a heavy armament, including torpedoes.




Enter ship name, Enter country Enter ship type laid down 1937

Displacement:
   1,647 t light; 1,792 t standard; 2,198 t normal; 2,522 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (374.77 ft / 360.89 ft) x 36.09 ft x (13.12 / 14.46 ft)
   (114.23 m / 110.00 m) x 11.00 m  x (4.00 / 4.41 m)

Armament:
      4 - 5.12" / 130 mm 45.0 cal guns - 67.62lbs / 30.67kg shells, 400 per gun
     Dual purpose guns in deck and hoist mounts, 1937 Model
     2 x 2-gun mounts on centreline, evenly spread
      1 - 5.91" / 150 mm 25.0 cal gun - 93.52lbs / 42.42kg shells, 150 per gun
     Breech loading gun in deck mount, 1937 Model
     1 x Single mount on centreline, forward deck centre
      1 raised mount
      6 - 1.97" / 50.0 mm 60.0 cal guns - 4.19lbs / 1.90kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1937 Model
     2 x Twin mounts on sides, forward deck aft
     1 x Twin mount on centreline, aft deck centre
      1 raised mount
      8 - 0.98" / 25.0 mm 70.0 cal guns - 0.53lbs / 0.24kg shells, 5,000 per gun
     Machine guns in deck mounts, 1937 Model
     4 x Twin mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 393 lbs / 178 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   1.18" / 30 mm      1.97" / 50 mm
   2nd:   0.59" / 15 mm   0.12" / 3 mm            -
   3rd:   0.59" / 15 mm         -               -
   4th:   0.59" / 15 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Electric cruising motors plus geared drives, 2 shafts, 17,426 shp / 13,000 Kw = 26.65 kts
   Range 8,000nm at 15.00 kts
   Bunker at max displacement = 731 tons

Complement:
   159 - 208

Cost:
   £0.851 million / $3.403 million

Distribution of weights at normal displacement:
   Armament: 93 tons, 4.2 %
      - Guns: 93 tons, 4.2 %
   Armour: 27 tons, 1.2 %
      - Armament: 27 tons, 1.2 %
   Machinery: 483 tons, 22.0 %
   Hull, fittings & equipment: 709 tons, 32.2 %
   Fuel, ammunition & stores: 551 tons, 25.1 %
   Miscellaneous weights: 336 tons, 15.3 %
      - Hull below water: 146 tons
      - On freeboard deck: 80 tons
      - Above deck: 110 tons

Fittings: 
-25 t:  Enhanced hydrophones and sonar (BW)
-121 t:  Electric drive (BW)
-16 t:  1x4 heavyweight 530mm torpeod carriage, no reloads (FD)
-20 t:  ASW ordnance TBD (FD)
-10 t:  Fire control (AD)
-10 t:  Nightfighting doodads (AD)
-25 t:  L/R wireless (AD)
-25 t:  Huelsmeyer device (AD)
-44 t + 40 t:  Weight reserve (FD/AD)

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,461 lbs / 1,116 Kg = 36.7 x 5.1 " / 130 mm shells or 0.8 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 13.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 80 %
         - Recoil effect (Restricted arc if above 1.00): 0.66
   Seaboat quality  (Average = 1.00): 1.77

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and small transom stern
   Block coefficient (normal/deep): 0.450 / 0.469
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 20.45 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 4.92 ft / 1.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  24.61 ft / 7.50 m,  19.69 ft / 6.00 m
      - Forward deck:   30.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Aft deck:   35.00 %,  11.81 ft / 3.60 m,  11.81 ft / 3.60 m
      - Quarter deck:   15.00 %,  11.81 ft / 3.60 m,  11.81 ft / 3.60 m
      - Average freeboard:      16.14 ft / 4.92 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 95.5 %
      - Above water (accommodation/working, high = better): 157.3 %
   Waterplane Area: 8,501 Square feet or 790 Square metres
   Displacement factor (Displacement / loading): 136 %
   Structure weight / hull surface area: 45 lbs/sq ft or 220 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.65
      - Longitudinal: 2.62
      - Overall: 0.75
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather