Pierwsze trałowce

W ramach rozbudowy sił minowych postanowiłem zbudować dla naszej floty pierwszą serię trałowców. Na razie są to niewielkie jednostki przeznaczone do trałowania min w bezpośrednim sąsiedztwie portów. Mają więc mały zasięg, niewielkie rozmiary i generalnie dość ograniczone możliwości. Niemniej jednak, są to okręty pionierskie w skali światowej – nikt inny nic specjalnie lepszego w tym czasie (1908 r.) nie posiadał. A na większe okręty tej klasy przyjdzie jeszcze czas:)

Czajka, polish minesweeper laid down 1908

Displacement:
    93 t light; 96 t standard; 100 t normal; 104 t full load

Dimensions: Length overall / water x beam x draught
    81,56 ft / 76,08 ft x 15,52 ft x 5,41 ft (normal load)
    24,86 m / 23,19 m x 4,73 m  x 1,65 m

Armament:
      1 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1908 Model
      Quick firing gun in deck mount
      on centreline forward
    Weight of broadside 2 lbs / 1 kg
    Shells per gun, main battery: 1 200

Armour:
   - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    0,59" / 15 mm          -                  -

Machinery:
    Coal fired boilers, simple reciprocating steam engines,
    Direct drive, 1 shaft, 356 ihp / 266 Kw = 13,00 kts
    Range 800nm at 8,00 kts
    Bunker at max displacement = 8 tons (100% coal)

Complement:
    15 - 20

Cost:
    £0,010 million / $0,040 million

Distribution of weights at normal displacement:
    Armament: 0 tons, 0,2%
    Armour: 0 tons, 0,4%
       - Belts: 0 tons, 0,0%
       - Torpedo bulkhead: 0 tons, 0,0%
       - Armament: 0 tons, 0,4%
       - Armour Deck: 0 tons, 0,0%
       - Conning Tower: 0 tons, 0,0%
    Machinery: 47 tons, 47,1%
    Hull, fittings & equipment: 36 tons, 35,9%
    Fuel, ammunition & stores: 8 tons, 7,5%
    Miscellaneous weights: 9 tons, 9,0%

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      49 lbs / 22 Kg = 31,6 x 1,5 " / 37 mm shells or 0,1 torpedoes
    Stability (Unstable if below 1.00): 1,23
    Metacentric height 0,4 ft / 0,1 m
    Roll period: 9,8 seconds
    Steadiness    - As gun platform (Average = 50 %): 50 %
            - Recoil effect (Restricted arc if above 1.00): 0,01
    Seaboat quality  (Average = 1.00): 0,98

Hull form characteristics:
    Hull has a flush deck
    Block coefficient: 0,550
    Length to Beam Ratio: 4,90 : 1
    'Natural speed' for length: 8,72 kts
    Power going to wave formation at top speed: 71 %
    Trim (Max stability = 0, Max steadiness = 100): 50
    Bow angle (Positive = bow angles forward): 0,00 degrees
    Stern overhang: 5,48 ft / 1,67 m
    Freeboard (% = measuring location as a percentage of overall length):
       - Stem:        8,46 ft / 2,58 m
       - Forecastle (12%):    7,48 ft / 2,28 m
       - Mid (50%):        5,48 ft / 1,67 m
       - Quarterdeck (21%):    5,48 ft / 1,67 m
       - Stern:        6,04 ft / 1,84 m
       - Average freeboard:    6,20 ft / 1,89 m
    Ship tends to be wet forward

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 164,5%
        - Above water (accommodation/working, high = better): 61,4%
    Waterplane Area: 799 Square feet or 74 Square metres
    Displacement factor (Displacement / loading): 78%
    Structure weight / hull surface area: 25 lbs/sq ft or 120 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 1,06
        - Longitudinal: 8,68
        - Overall: 1,31
    Hull space for machinery, storage, compartmentation is cramped
    Room for accommodation and workspaces is cramped
    Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

12 mines

Czajka (1908)
Szpak (1908)
Dzięcioł (1908)
Derkacz (1908)