UNK Design Studies

[Carthaginian]

Ok, to simplify things, I'm just going to try and keep all 'studies' posted here in this thread. From here on out, any unaccepted designs will go here till I think they have garnered all useful input.

First up is a cruiser designed for scout work and other general fleet duties. It's an outgrowth of the Cleveland class, and is also slated to be built on the American side of the Atlantic. As such, it is named after an American city. Built on an identical hullform, the Rochester class of protected cruiser gives up the 6" guns in single mounts for the lighter 5.5" gun, but mounts eight of the weapons in four twin turrets. They also sacrifice seakeeping for speed, being the first cruisers of the Royal Navy to break 30 knots.

Rochester, United Norman Kingdom Scout Cruiser laid down 1916

Displacement:
   5,000 t light; 5,194 t standard; 5,624 t normal; 5,968 t full load

Dimensions: Length overall / water x beam x draught
   420.00 ft / 410.00 ft x 45.00 ft x 22.00 ft (normal load)
   128.02 m / 124.97 m x 13.72 m  x 6.71 m

Armament:
      8 - 5.50" / 140 mm guns (4x2 guns), 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on centreline, evenly spread, 2 raised mounts
     Aft Main mounts separated by engine room
      8 - 3.00" / 76.2 mm guns in single mounts, 12.00lbs / 5.44kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 1.00" / 25.4 mm guns in single mounts, 0.50lbs / 0.23kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread
   Weight of broadside 698 lbs / 317 kg
   Shells per gun, main battery: 200
   4 - 20.0" / 508 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.50" / 64 mm   364.00 ft / 110.95 m   14.00 ft / 4.27 m
   Ends:   Unarmoured
     Main Belt covers 137 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   1.00" / 25 mm         -               -
   3rd:   0.25" / 6 mm         -               -

   - Armour deck: 1.00" / 25 mm, Conning tower: 2.50" / 64 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 56,000 shp / 41,776 Kw = 30.24 kts
   Range 6,000nm at 12.00 kts
   Bunker at max displacement = 774 tons

Complement:
   324 - 422

Cost:
   £0.898 million / $3.590 million

Distribution of weights at normal displacement:
   Armament: 97 tons, 1.7 %
   Armour: 802 tons, 14.3 %
      - Belts: 507 tons, 9.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 54 tons, 1.0 %
      - Armour Deck: 224 tons, 4.0 %
      - Conning Tower: 17 tons, 0.3 %
   Machinery: 2,086 tons, 37.1 %
   Hull, fittings & equipment: 1,894 tons, 33.7 %
   Fuel, ammunition & stores: 624 tons, 11.1 %
   Miscellaneous weights: 120 tons, 2.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,278 lbs / 1,487 Kg = 39.4 x 5.5 " / 140 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.07
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 14.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.54
   Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.485
   Length to Beam Ratio: 9.11 : 1
   'Natural speed' for length: 20.25 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 63
   Bow angle (Positive = bow angles forward): 22.62 degrees
   Stern overhang: -5.00 ft / -1.52 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24.00 ft / 7.32 m
      - Forecastle (20 %):   22.00 ft / 6.71 m
      - Mid (50 %):      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:   18.16 ft / 5.54 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 136.1 %
      - Above water (accommodation/working, high = better): 109.0 %
   Waterplane Area: 12,127 Square feet or 1,127 Square metres
   Displacement factor (Displacement / loading): 96 %
   Structure weight / hull surface area: 78 lbs/sq ft or 381 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.06
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform

[Jefgte]

5000t-128m with 8x140
...30kts...
Seaboat quality: 1.12

IMO, the hull is too short


;)