GTB-W Class

[TacCovert4]

TB-X, Aztec Torpedo Boat laid down 1917

Displacement:
   500 t light; 515 t standard; 567 t normal; 609 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (290.00 ft / 286.75 ft) x 22.97 ft x (7.35 / 7.71 ft)
   (88.39 m / 87.40 m) x 7.00 m  x (2.24 / 2.35 m)

Armament:
      3 - 2.76" / 70.0 mm 50.0 cal guns - 11.09lbs / 5.03kg shells, 200 per gun
     Quick firing guns in deck mounts, 1917 Model
     3 x Single mounts on centreline ends, majority forward
      1 raised mount - superfiring
      8 - 0.31" / 8.0 mm 70.0 cal guns - 0.02lbs / 0.01kg shells, 2,000 per gun
     Machine guns in deck mounts, 1917 Model
     4 x Twin mounts on sides, evenly spread
      Weight of broadside 33 lbs / 15 kg

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18,928 shp / 14,121 Kw = 32.25 kts
   Range 2,950nm at 12.00 kts
   Bunker at max displacement = 94 tons

Complement:
   57 - 75

Cost:
   £0.114 million / $0.456 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 1.3 %
      - Guns: 7 tons, 1.3 %
   Machinery: 308 tons, 54.4 %
   Hull, fittings & equipment: 167 tons, 29.4 %
   Fuel, ammunition & stores: 67 tons, 11.9 %
   Miscellaneous weights: 17 tons, 3.0 %
      - On freeboard deck: 16 tons
      - Above deck: 1 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     148 lbs / 67 Kg = 14.1 x 2.8 " / 70 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 11.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 61 %
         - Recoil effect (Restricted arc if above 1.00): 0.12
   Seaboat quality  (Average = 1.00): 0.80

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.410 / 0.420
   Length to Beam Ratio: 12.49 : 1
   'Natural speed' for length: 16.93 kts
   Power going to wave formation at top speed: 67 %
   Trim (Max stability = 0, Max steadiness = 100): 76
   Bow angle (Positive = bow angles forward): 15.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  12.14 ft / 3.70 m,  11.32 ft / 3.45 m
      - Forward deck:   30.00 %,  11.32 ft / 3.45 m,  9.02 ft / 2.75 m
      - Aft deck:   35.00 %,  9.02 ft / 2.75 m,  8.37 ft / 2.55 m
      - Quarter deck:   15.00 %,  8.37 ft / 2.55 m,  8.37 ft / 2.55 m
      - Average freeboard:      9.68 ft / 2.95 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 179.4 %
      - Above water (accommodation/working, high = better): 127.8 %
   Waterplane Area: 4,078 Square feet or 379 Square metres
   Displacement factor (Displacement / loading): 40 %
   Structure weight / hull surface area: 22 lbs/sq ft or 108 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.20
      - Overall: 0.54
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather


9t 1 x 3 x 533mm TT Centerline behind bridge
6t 2 x 1 x 533mm TT Forward (fixed mount)

1t - 10xASW Harpoon

1t - 1908 Fire Control

Trial Speed -34.74kts