Isca Class

[snip]

Five Ships
--IRS Isca
--IRS Lauri
--IRS Caletum
--IRS Cularo
--IRS Irminio

GPC-17, Imperial Roman Republic Cruiser laid down 1917

Displacement:
   8,000 t light; 8,287 t standard; 9,332 t normal; 10,168 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (554.46 ft / 541.34 ft) x 57.41 ft x (19.69 / 21.05 ft)
   (169.00 m / 165.00 m) x 17.50 m  x (6.00 / 6.42 m)

Armament:
      6 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     3 x 2-gun mounts on centreline ends, majority forward
      1 raised mount - superfiring
      2 - 3.94" / 100 mm 45.0 cal guns - 30.78lbs / 13.96kg shells, 175 per gun
     Anti-air guns in deck mounts, 1917 Model
     2 x Single mounts on sides, aft deck centre
      2 raised mounts
      6 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 10,000 per gun
     Machine guns in deck mounts, 1911 Model
     6 x Single mounts on sides, evenly spread
      6 raised mounts
      Weight of broadside 1,186 lbs / 538 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.15" / 80 mm   396.69 ft / 120.91 m   16.40 ft / 5.00 m
   Ends:   Unarmoured
     Main Belt covers 113 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.36" / 60 mm   1.18" / 30 mm      2.36" / 60 mm
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.18" / 30 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 3.94" / 100 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,000 shp / 58,188 Kw = 31.23 kts
   Range 8,050nm at 14.00 kts
   Bunker at max displacement = 1,881 tons

Complement:
   474 - 617

Cost:
   £1.457 million / $5.829 million

Distribution of weights at normal displacement:
   Armament: 366 tons, 3.9 %
      - Guns: 366 tons, 3.9 %
   Armour: 1,469 tons, 15.7 %
      - Belts: 831 tons, 8.9 %
      - Armament: 161 tons, 1.7 %
      - Armour Deck: 439 tons, 4.7 %
      - Conning Tower: 38 tons, 0.4 %
   Machinery: 2,859 tons, 30.6 %
   Hull, fittings & equipment: 3,101 tons, 33.2 %
   Fuel, ammunition & stores: 1,332 tons, 14.3 %
   Miscellaneous weights: 205 tons, 2.2 %
      - Hull below water: 70 tons
      - Hull above water: 30 tons
      - On freeboard deck: 85 tons
      - Above deck: 20 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9,186 lbs / 4,167 Kg = 51.6 x 7.1 " / 180 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.26
   Metacentric height 3.3 ft / 1.0 m
   Roll period: 13.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.534 / 0.544
   Length to Beam Ratio: 9.43 : 1
   'Natural speed' for length: 23.27 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 3.87 ft / 1.18 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   16.72 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Forward deck:   20.00 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Aft deck:   53.28 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   10.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      19.72 ft / 6.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.7 %
      - Above water (accommodation/working, high = better): 162.0 %
   Waterplane Area: 21,366 Square feet or 1,985 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 95 lbs/sq ft or 466 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.52
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Misc Distribution
--Below Water (70t)
----30t Additional Pumps
----30t Improved Damage Control
----10t Additional Stores
--Above Water (30t)
----5t Improved Officer Accommodations
----25t Long Range Wireless
--On Deck (85t)
----37t 1912 Fire Control
----36t 12x530mm Torpedoes [One triple tube mount per side]
----10t Short Range Wireless
----2t Construction Reserve
--Above Deck (20t)
----15t Night Fighting Equipment
----5t Improved Signaling Equipment

[snip]

By the end of 1923H1, all ships had been updated to 1918 Fire Control.