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The World of Navalism => Imperial Navy => Imperial Roman Republic => Player Nations => Retired => Topic started by: snip on August 14, 2017, 08:24:56 AM

Title: A-Class Destroyer
Post by: snip on August 14, 2017, 08:24:56 AM
The first example of the Torpedo Boat Destroyer (later shortened to Destroyer) type in the Imperial Navy. While a decent ship in her day, by 1910 the class is hopelessly obsolete and maintained to supplement the coastal defense responsibilities of the Navy.

Ten Ships:
--Pennant Number 1 to Number 10

QuoteA-Class, Roman Imperial Republic Destroyer laid down 1892

Displacement:
   400 t light; 410 t standard; 455 t normal; 492 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (200.13 ft / 196.85 ft) x 19.69 ft x (9.84 / 10.37 ft)
   (61.00 m / 60.00 m) x 6.00 m  x (3.00 / 3.16 m)

Armament:
      1 - 2.95" / 75.0 mm 45.0 cal gun - 13.23lbs / 6.00kg shells, 90 per gun
     Breech loading gun in deck mount, 1885 Model
     1 x Single mount on centreline, aft deck aft
      4 - 1.77" / 45.0 mm 40.0 cal guns - 2.76lbs / 1.25kg shells, 150 per gun
     Breech loading guns in deck mounts, 1885 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 24 lbs / 11 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.39" / 10 mm         -               -
   2nd:   0.39" / 10 mm         -               -

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 6,500 ihp / 4,849 Kw = 24.38 kts
   Range 1,750nm at 10.00 kts
   Bunker at max displacement = 81 tons (100% coal)
     Caution: Delicate, lightweight machinery

Complement:
   49 - 64

Cost:
   £0.054 million / $0.215 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0.9 %
      - Guns: 4 tons, 0.9 %
   Armour: 5 tons, 1.0 %
      - Armament: 5 tons, 1.0 %
   Machinery: 276 tons, 60.6 %
   Hull, fittings & equipment: 99 tons, 21.8 %
   Fuel, ammunition & stores: 56 tons, 12.3 %
   Miscellaneous weights: 16 tons, 3.5 %
      - On freeboard deck: 16 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     89 lbs / 41 Kg = 6.9 x 3.0 " / 75 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.46
   Metacentric height 0.8 ft / 0.3 m
   Roll period: 9.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.07
   Seaboat quality  (Average = 1.00): 0.95

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.418 / 0.428
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 14.03 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 53
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Forward deck:   30.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Aft deck:   35.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Quarter deck:   15.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Average freeboard:      8.20 ft / 2.50 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 197.9 %
      - Above water (accommodation/working, high = better): 76.9 %
   Waterplane Area: 2,412 Square feet or 224 Square metres
   Displacement factor (Displacement / loading): 18 %
   Structure weight / hull surface area: 20 lbs/sq ft or 98 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.78
      - Overall: 0.57
   Cramped machinery, storage, compartmentation space
   Cramped accommodation and workspace room
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Misc Distribution
--On Deck (16t)
----6t 4x350mm Torpedos [Two single tube mounts per side]
----5t Improved spray protections for Torpedo tubes
----5t Construction Reserve.