Eskortowiec

Jeden z okrętów z prezentowanego niedawno typu Minóg postanowiono ukończyć eksperymentalnie jako pierwszy w naszej flocie eskortowiec rodzimej konstrukcji. Na niezmienionym kadłubie trałowca posadowiono armatę kal. 102 mm starego modelu, wzór 1895 (L/40, prędkość wylotowa 700 m/s, zasięg 9,5 km, szybkostrzelność 15 strz./min.). Ustawione na przedłużonej w stronę rufy nadbudówce działko kal. 37 mm McLeana przystosowano do strzelania przeciwlotniczego. Z rufy usunięto miny oraz trały, a w ich miejsce zamontowano na grawitacyjne zrzutnie bomb głębinowych, które w ostatnim czasie opracowaliśmy z wykorzystaniem planów tego typu broni otrzymanych z Wielkiej Brytanii. 

Tarpon, polish anti-submarine gunboat laid down 1916

Displacement:
    355 t light; 366 t standard; 410 t normal; 445 t full load

Dimensions: Length overall / water x beam x draught
    144,73 ft / 136,22 ft x 22,15 ft x 9,71 ft (normal load)
    44,11 m / 41,52 m x 6,75 m  x 2,96 m

Armament:
      1 - 4,02" / 102 mm guns in single mounts, 32,38lbs / 14,69kg shells, 1895 Model
      Quick firing gun in deck mount
      on centreline forward
      1 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1916 Model
      Anti-aircraft gun in deck mount
      on centreline aft, 1 raised gun
      1 - 0,30" / 7,6 mm guns in single mounts, 0,01lbs / 0,00kg shells, 1913 Model
      Machine gun in deck mount
      on centreline forward, 1 raised gun
    Weight of broadside 34 lbs / 15 kg
    Shells per gun, main battery: 150

Machinery:
    Coal fired boilers, simple reciprocating steam engines,
    Direct drive, 1 shaft, 1 229 ihp / 917 Kw = 15,50 kts
    Range 3 400nm at 9,00 kts
    Bunker at max displacement = 79 tons (100% coal)

Complement:
    45 - 59

Cost:
    £0,068 million / $0,274 million

Distribution of weights at normal displacement:
    Armament: 4 tons, 1,0%
    Machinery: 184 tons, 45,0%
    Hull, fittings & equipment: 156 tons, 38,1%
    Fuel, ammunition & stores: 55 tons, 13,4%
    Miscellaneous weights: 10 tons, 2,4%

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      240 lbs / 109 Kg = 7,4 x 4,0 " / 102 mm shells or 0,2 torpedoes
    Stability (Unstable if below 1.00): 1,19
    Metacentric height 0,7 ft / 0,2 m
    Roll period: 11,0 seconds
    Steadiness    - As gun platform (Average = 50 %): 100 %
            - Recoil effect (Restricted arc if above 1.00): 0,21
    Seaboat quality  (Average = 1.00): 2,00

Hull form characteristics:
    Hull has a flush deck
    Block coefficient: 0,489
    Length to Beam Ratio: 6,15 : 1
    'Natural speed' for length: 11,67 kts
    Power going to wave formation at top speed: 62 %
    Trim (Max stability = 0, Max steadiness = 100): 50
    Bow angle (Positive = bow angles forward): 6,00 degrees
    Stern overhang: 6,99 ft / 2,13 m
    Freeboard (% = measuring location as a percentage of overall length):
       - Stem:        14,47 ft / 4,41 m
       - Forecastle (20%):    12,96 ft / 3,95 m
       - Mid (50%):        11,98 ft / 3,65 m
       - Quarterdeck (15%):    11,98 ft / 3,65 m
       - Stern:        12,47 ft / 3,80 m
       - Average freeboard:    12,48 ft / 3,80 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 156,3%
        - Above water (accommodation/working, high = better): 98,6%
    Waterplane Area: 1 910 Square feet or 177 Square metres
    Displacement factor (Displacement / loading): 96%
    Structure weight / hull surface area: 31 lbs/sq ft or 150 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0,78
        - Longitudinal: 16,33
        - Overall: 1,06
    Hull space for machinery, storage, compartmentation is cramped
    Room for accommodation and workspaces is adequate
    Ship has slow, easy roll, a good, steady gun platform
    Excellent seaboat, comfortable, can fire her guns in the heaviest weather

1 depth charge rack