A Class Torpedo Boat

[snip]

The first dedicated Torpedo Boat, the A-Class was a resounding disappointment.

Six Ships:
--Pennant Number 1 to Number 21

Torpedo Boat A, Imperial Roman Navy Torpedo Boat laid down 1890

Displacement:
   250 t light; 256 t standard; 274 t normal; 288 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (137.80 ft / 131.23 ft) x 18.04 ft x (9.84 / 10.18 ft)
   (42.00 m / 40.00 m) x 5.50 m  x (3.00 / 3.10 m)

Armament:
      2 - 1.77" / 45.0 mm 40.0 cal guns - 2.76lbs / 1.25kg shells, 60 per gun
     Breech loading guns in deck mounts, 1885 Model
     2 x Single mounts on centreline, forward evenly spread
      Weight of broadside 6 lbs / 3 kg

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 6,000 ihp / 4,476 Kw = 23.98 kts
   Range 850nm at 10.00 kts
   Bunker at max displacement = 32 tons (100% coal)
     Caution: Delicate, lightweight machinery

Complement:
   33 - 43

Cost:
   £0.034 million / $0.135 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.3 %
      - Guns: 1 tons, 0.3 %
   Machinery: 177 tons, 64.5 %
   Hull, fittings & equipment: 69 tons, 25.1 %
   Fuel, ammunition & stores: 24 tons, 8.6 %
   Miscellaneous weights: 4 tons, 1.5 %
      - On freeboard deck: 4 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     50 lbs / 23 Kg = 17.9 x 1.8 " / 45 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 10.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 0.64

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.411 / 0.418
   Length to Beam Ratio: 7.27 : 1
   'Natural speed' for length: 11.46 kts
   Power going to wave formation at top speed: 77 %
   Trim (Max stability = 0, Max steadiness = 100): 79
   Bow angle (Positive = bow angles forward): -30.00 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 %,  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): 208.8 %
      - Above water (accommodation/working, high = better): 69.5 %
   Waterplane Area: 1,468 Square feet or 136 Square metres
   Displacement factor (Displacement / loading): 12 %
   Structure weight / hull surface area: 21 lbs/sq ft or 100 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 4.97
      - Overall: 0.63
   Caution: Hull subject to strain in open-sea
   Extremely poor machinery, storage, compartmentation space
   Cramped accommodation and workspace room
   Caution: Lacks seaworthiness - very limited seakeeping ability
Misc Distribution
--On Deck (4t)
----3t 2x350mm Torpedos [Two single mounts on centerline]
----1t Improved spray protection for torpedos

[snip]

All examples of this design were scrapped in 1912H1.