Ariminum Class Cruiser

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The Ariminum Class Cruisers represent the earliest version of the "Hexagon" Cruisers referred to for their armament layout. The most numerous single example of the type, the Ariminum's are also the oldest and are slowing being removed from frontline duties.

Four Ships [Originally eight, four scrapped 1913H1]

Ariminum, Imperial Roman Republic Cruiser laid down 1890

Displacement:
   3,500 t light; 3,628 t standard; 4,009 t normal; 4,314 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (311.68 ft / 308.40 ft) x 42.65 ft x (20.51 / 21.70 ft)
   (95.00 m / 94.00 m) x 13.00 m  x (6.25 / 6.61 m)

Armament:
      6 - 5.51" / 140 mm 45.0 cal guns - 79.37lbs / 36.00kg shells, 125 per gun
     Breech loading guns in deck mounts, 1890 Model
     2 x Single mounts on centreline ends, evenly spread
     4 x Single mounts on side ends, evenly spread
      8 - 2.95" / 75.0 mm 45.0 cal guns - 13.23lbs / 6.00kg shells, 250 per gun
     Breech loading guns in deck mounts, 1890 Model
     6 x Single mounts on sides, evenly spread
     2 x Single mounts on sides, aft deck aft
      2 hull mounts in casemates- Limited use in all but light seas
      Weight of broadside 582 lbs / 264 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0.79" / 20 mm   295.51 ft / 90.07 m   7.84 ft / 2.39 m
   Ends:   0.39" / 10 mm     12.86 ft / 3.92 m   7.84 ft / 2.39 m
     Main Belt covers 147 % of normal length
     Main belt does not fully cover magazines and engineering spaces

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm         -               -
   2nd:   0.59" / 15 mm         -               -

   - Protected deck - single deck:
   For and Aft decks: 1.57" / 40 mm
   Forecastle: 1.18" / 30 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 5.91" / 150 mm, Aft 3.94" / 100 mm

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   No drive to shaft, 2 shafts, 9,000 ihp / 6,714 Kw = 19.51 kts
   Range 4,000nm at 10.00 kts
   Bunker at max displacement = 686 tons (100% coal)

Complement:
   251 - 327

Cost:
   £0.392 million / $1.569 million

Distribution of weights at normal displacement:
   Armament: 94 tons, 2.3 %
      - Guns: 94 tons, 2.3 %
   Armour: 430 tons, 10.7 %
      - Belts: 72 tons, 1.8 %
      - Armament: 42 tons, 1.0 %
      - Armour Deck: 262 tons, 6.5 %
      - Conning Towers: 54 tons, 1.3 %
   Machinery: 1,718 tons, 42.9 %
   Hull, fittings & equipment: 1,098 tons, 27.4 %
   Fuel, ammunition & stores: 509 tons, 12.7 %
   Miscellaneous weights: 160 tons, 4.0 %
      - Hull below water: 20 tons
      - Hull above water: 70 tons
      - On freeboard deck: 60 tons
      - Above deck: 10 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,242 lbs / 1,017 Kg = 26.8 x 5.5 " / 140 mm shells or 0.6 torpedoes
   Stability (Unstable if below 1.00): 1.54
   Metacentric height 2.9 ft / 0.9 m
   Roll period: 10.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.17
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.520 / 0.529
   Length to Beam Ratio: 7.23 : 1
   'Natural speed' for length: 17.56 kts
   Power going to wave formation at top speed: 52 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): -30.00 degrees
   Stern overhang: -8.20 ft / -2.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   2.09 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Forward deck:   30.00 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Aft deck:   65.82 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Quarter deck:   2.09 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Average freeboard:      15.58 ft / 4.75 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 148.5 %
      - Above water (accommodation/working, high = better): 105.6 %
   Waterplane Area: 8,928 Square feet or 829 Square metres
   Displacement factor (Displacement / loading): 92 %
   Structure weight / hull surface area: 70 lbs/sq ft or 341 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 3.28
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Adequate 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

Misc Distribution
--Below Water (20t)
----18t 12x350mm Torpedos (35 Pattern A)
----2t Additional Torpedo Handing Equipment
--Above Water (70t)
----10t Improved Officer Accommodations
----10t Improved Crew Accommodations
----20t Additional Troop Compliment
----5t Construction Reserve
--On Deck (60t)
----30t Additional Troop Compliment
----10t Flag Facilities
----5t Admiralty Accommodations
----15t Construction Reserve
--Above Deck (10t)
----5t Improved Aquisition Structures
----5t Additional Searchlights