Praeventores class Battleship

[snip]

While still under construction in 1910, the Praeventores class are the most powerful battleships yet constructed for the Imperial Navy. Building off of the Invicta class, they mount four more 340mm guns and have a stronger TDS.

Ships in Class: Two
--IRS Praeventores
--IRS Termine

Praeventores, Imperial Roman Republic Battleship laid down 1909

Displacement:
   25,500 t light; 27,090 t standard; 28,132 t normal; 28,966 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (633.20 ft / 623.36 ft) x 88.58 ft x (26.25 / 26.92 ft)
   (193.00 m / 190.00 m) x 27.00 m  x (8.00 / 8.20 m)

Armament:
      12 - 13.39" / 340 mm 45.0 cal guns - 1,212.54lbs / 550.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     4 x 3-gun mounts on centreline, evenly spread
      16 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in casemate mounts, 1909 Model
     16 x Single mounts on sides, evenly spread
      16 hull mounts in casemates- Limited use in heavy seas
      4 - 2.95" / 75.0 mm 50.0 cal guns - 13.23lbs / 6.00kg shells, 150 per gun
     Quick firing guns in casemate mounts, 1902 Model
     4 x Single mounts on side ends, evenly spread
      4 hull mounts in casemates- Limited use in heavy seas
      Weight of broadside 15,979 lbs / 7,248 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.6" / 320 mm   405.18 ft / 123.50 m   18.04 ft / 5.50 m
   Ends:   3.94" / 100 mm   218.14 ft / 66.49 m   9.84 ft / 3.00 m
   Upper:   3.94" / 100 mm   405.18 ft / 123.50 m   9.02 ft / 2.75 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   405.18 ft / 123.50 m   26.25 ft / 8.00 m
   Beam between torpedo bulkheads 78.74 ft / 24.00 m

   - Hull void:
      0.39" / 10 mm   405.18 ft / 123.50 m   18.04 ft / 5.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.4" / 340 mm   7.09" / 180 mm      11.0" / 280 mm
   2nd:   3.94" / 100 mm   0.98" / 25 mm      1.97" / 50 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 3.94" / 100 mm
   Forecastle: 0.98" / 25 mm  Quarter deck: 0.98" / 25 mm

   - Conning towers: Forward 9.84" / 250 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 36,000 shp / 26,856 Kw = 21.35 kts
   Range 5,500nm at 10.00 kts
   Bunker at max displacement = 1,876 tons

Complement:
   1,085 - 1,411

Cost:
   £2.562 million / $10.249 million

Distribution of weights at normal displacement:
   Armament: 3,379 tons, 12.0 %
      - Guns: 3,379 tons, 12.0 %
   Armour: 11,021 tons, 39.2 %
      - Belts: 4,942 tons, 17.6 %
      - Torpedo bulkhead: 620 tons, 2.2 %
      - Void: 107 tons, 0.4 %
      - Armament: 2,417 tons, 8.6 %
      - Armour Deck: 2,739 tons, 9.7 %
      - Conning Tower: 196 tons, 0.7 %
   Machinery: 1,636 tons, 5.8 %
   Hull, fittings & equipment: 8,448 tons, 30.0 %
   Fuel, ammunition & stores: 2,632 tons, 9.4 %
   Miscellaneous weights: 1,015 tons, 3.6 %
      - Hull below water: 437 tons
      - Hull above water: 100 tons
      - On freeboard deck: 438 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     40,836 lbs / 18,523 Kg = 34.1 x 13.4 " / 340 mm shells or 6.3 torpedoes
   Stability (Unstable if below 1.00): 1.17
   Metacentric height 5.6 ft / 1.7 m
   Roll period: 15.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.83
   Seaboat quality  (Average = 1.00): 1.34

Hull form characteristics:
   Hull has low quarterdeck ,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.679 / 0.682
   Length to Beam Ratio: 7.04 : 1
   'Natural speed' for length: 24.97 kts
   Power going to wave formation at top speed: 43 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 10.00 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 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Forward deck:   30.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Aft deck:   35.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Quarter deck:   15.00 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Average freeboard:      17.51 ft / 5.34 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 76.6 %
      - Above water (accommodation/working, high = better): 143.9 %
   Waterplane Area: 43,447 Square feet or 4,036 Square metres
   Displacement factor (Displacement / loading): 97 %
   Structure weight / hull surface area: 173 lbs/sq ft or 847 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.21
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc Distribution
--Below Water (522t)
----410t Electric Drives
----18t 12x450mm Torpedo (45 Pattern C)
----2t Additional Torpedo handling equipment
----5t Additional Pumps
--Above Water (100t)
----30t Flag Facilities
----30t Improved Officer Accommodations
----30t Improved Crew Accommodations
----10t Short-Range Wireless
--On Deck (438t)
----338t 1908 Fire Control
----40t Flag Facilities
----20t Admiralty Accommodations
----25t Long-Range Wireless
----15t Construction Reserve
--Above Deck (40t)
----20t Improved Aquisition Structures
----10t Additional Searchlights
----10t Improved Signaling Equipment

[snip]

In 1913 both Praeventores and Termine were refit with 1912 Fire Control.

Praeventores, Imperial Roman Republic Battleship laid down 1909

Displacement:
   25,500 t light; 27,090 t standard; 28,132 t normal; 28,966 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (633.20 ft / 623.36 ft) x 88.58 ft x (26.25 / 26.92 ft)
   (193.00 m / 190.00 m) x 27.00 m  x (8.00 / 8.20 m)

Armament:
      12 - 13.39" / 340 mm 45.0 cal guns - 1,212.54lbs / 550.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     4 x 3-gun mounts on centreline, evenly spread
      16 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in casemate mounts, 1909 Model
     16 x Single mounts on sides, evenly spread
      16 hull mounts in casemates- Limited use in heavy seas
      4 - 2.95" / 75.0 mm 50.0 cal guns - 13.23lbs / 6.00kg shells, 150 per gun
     Quick firing guns in casemate mounts, 1902 Model
     4 x Single mounts on side ends, evenly spread
      4 hull mounts in casemates- Limited use in heavy seas
      Weight of broadside 15,979 lbs / 7,248 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.6" / 320 mm   405.18 ft / 123.50 m   18.04 ft / 5.50 m
   Ends:   3.94" / 100 mm   218.14 ft / 66.49 m   9.84 ft / 3.00 m
   Upper:   3.94" / 100 mm   405.18 ft / 123.50 m   9.02 ft / 2.75 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   405.18 ft / 123.50 m   26.25 ft / 8.00 m
   Beam between torpedo bulkheads 78.74 ft / 24.00 m

   - Hull void:
      0.39" / 10 mm   405.18 ft / 123.50 m   18.04 ft / 5.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.4" / 340 mm   7.09" / 180 mm      11.0" / 280 mm
   2nd:   3.94" / 100 mm   0.98" / 25 mm      1.97" / 50 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 3.94" / 100 mm
   Forecastle: 0.98" / 25 mm  Quarter deck: 0.98" / 25 mm

   - Conning towers: Forward 9.84" / 250 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 36,000 shp / 26,856 Kw = 21.35 kts
   Range 5,500nm at 10.00 kts
   Bunker at max displacement = 1,876 tons

Complement:
   1,085 - 1,411

Cost:
   £2.562 million / $10.249 million

Distribution of weights at normal displacement:
   Armament: 3,379 tons, 12.0 %
      - Guns: 3,379 tons, 12.0 %
   Armour: 11,021 tons, 39.2 %
      - Belts: 4,942 tons, 17.6 %
      - Torpedo bulkhead: 620 tons, 2.2 %
      - Void: 107 tons, 0.4 %
      - Armament: 2,417 tons, 8.6 %
      - Armour Deck: 2,739 tons, 9.7 %
      - Conning Tower: 196 tons, 0.7 %
   Machinery: 1,636 tons, 5.8 %
   Hull, fittings & equipment: 8,448 tons, 30.0 %
   Fuel, ammunition & stores: 2,632 tons, 9.4 %
   Miscellaneous weights: 1,015 tons, 3.6 %
      - Hull below water: 437 tons
      - Hull above water: 100 tons
      - On freeboard deck: 438 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     40,836 lbs / 18,523 Kg = 34.1 x 13.4 " / 340 mm shells or 6.3 torpedoes
   Stability (Unstable if below 1.00): 1.17
   Metacentric height 5.6 ft / 1.7 m
   Roll period: 15.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.83
   Seaboat quality  (Average = 1.00): 1.34

Hull form characteristics:
   Hull has low quarterdeck ,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.679 / 0.682
   Length to Beam Ratio: 7.04 : 1
   'Natural speed' for length: 24.97 kts
   Power going to wave formation at top speed: 43 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 10.00 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 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Forward deck:   30.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Aft deck:   35.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Quarter deck:   15.00 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Average freeboard:      17.51 ft / 5.34 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 76.6 %
      - Above water (accommodation/working, high = better): 143.9 %
   Waterplane Area: 43,447 Square feet or 4,036 Square metres
   Displacement factor (Displacement / loading): 97 %
   Structure weight / hull surface area: 173 lbs/sq ft or 847 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.21
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc Distribution
--Below Water (522t)
----410t Electric Drives
----18t 12x450mm Torpedo (45 Pattern C)
----2t Additional Torpedo handling equipment
----5t Additional Pumps
--Above Water (100t)
----30t Flag Facilities
----30t Improved Officer Accommodations
----30t Improved Crew Accommodations
----10t Short-Range Wireless
--On Deck (438t)
----338t 1912 Fire Control
----40t Flag Facilities
----20t Admiralty Accommodations
----25t Long-Range Wireless
----15t Construction Reserve
--Above Deck (40t)
----20t Improved Aquisition Structures
----10t Additional Searchlights
----10t Improved Signaling Equipment

[snip]

In 1921H2, both ships of this class were updated to 1918 Fire Control.