Okręt hydrograficzny typu Bałtyk

Okręt hydrograficzny typu Bałtyk 1920 (1 szt.)

Rozważania pt. „co od Niemców brać?” jeszcze chwilę mogą potrwać. W tzw. „międzyczasie” pojawił się w naszej flocie nieduży, ale pożyteczny okręt. Jest to jednostka hydrograficzna przeznaczona do prac pomiarowych i kartograficznych, wytyczania i oznakowywania torów wodnych oraz ewentualnie trałowania przeszkód podwodnych. Wielkość okrętu predestynuje go do działań głównie na Bałtyku, większa jednostka (lub jednostki) do prac w koloniach planowana jest na najbliższe lata. Mimo swojej, raczej pokojowej funkcji okręt jest uzbrojony, w czasie wojny istnieje możliwość montażu zrzutni bomb głębinowych lub wykorzystanie jednostki w charakterze pomocniczego trałowca.

Bałtyk, Poland Survey ship laid down 1920

Displacement:

            554 t light; 567 t standard; 597 t normal; 621 t full load

Dimensions: Length overall / water x beam x draught

            185,14 ft / 183,73 ft x 26,25 ft x 7,87 ft (normal load)

            56,43 m / 56,00 m x 8,00 m  x 2,40 m

Armament:

      1 - 2,95" / 75,0 mm guns in single mounts, 14,11lbs / 6,40kg shells, 1910 Model

              Quick firing gun in deck mount on centreline forward

      1 - 0,98" / 25,0 mm guns in single mounts, 0,55lbs / 0,25kg shells, 1919 Model

              Anti-aircraft gun in deck mount on centreline amidships, 1 raised gun

            Weight of broadside 15 lbs / 7 kg

            Shells per gun, main battery: 150

Machinery:

            Diesel Internal combustion motors,

            Geared drive, 2 shafts, 927 shp / 691 Kw = 14,00 kts

            Range 4 500nm at 8,00 kts

            Bunker at max displacement = 54 tons

Complement:

            59 - 78

Cost:

            £0,060 million / $0,239 million

Distribution of weights at normal displacement:

            Armament: 2 tons, 0,3%

            Machinery: 32 tons, 5,4%

            Hull, fittings & equipment: 514 tons, 86,1%

            Fuel, ammunition & stores: 43 tons, 7,2%

            Miscellaneous weights: 6 tons, 1,0%

Overall survivability and seakeeping ability:

            Survivability (Non-critical penetrating hits needed to sink ship):

              3 155 lbs / 1 431 Kg = 245,1 x 3,0 " / 75 mm shells or 3,1 torpedoes

            Stability (Unstable if below 1.00): 1,12

            Metacentric height 0,8 ft / 0,3 m

            Roll period: 12,1 seconds

            Steadiness      - As gun platform (Average = 50 %): 70 %

                                   - Recoil effect (Restricted arc if above 1.00): 0,02

            Seaboat quality  (Average = 1.00): 1,56

Hull form characteristics:

            Hull has rise forward of midbreak, raised quarterdeck

            Block coefficient: 0,550

            Length to Beam Ratio: 7,00 : 1

            'Natural speed' for length: 13,55 kts

            Power going to wave formation at top speed: 48 %

            Trim (Max stability = 0, Max steadiness = 100): 45

            Bow angle (Positive = bow angles forward): 6,00 degrees

            Stern overhang: 0,00 ft / 0,00 m

            Freeboard (% = measuring location as a percentage of overall length):

               - Stem:                    13,45 ft / 4,10 m

               - Forecastle (13%): 12,47 ft / 3,80 m

               - Mid (60%):            12,47 ft / 3,80 m (4,92 ft / 1,50 m aft of break)

               - Quarterdeck (0%):            4,92 ft / 1,50 m (0,00 ft / 0,00 m before break)

               - Stern:                    4,92 ft / 1,50 m

               - Average freeboard:          8,52 ft / 2,60 m

            Ship tends to be wet forward

Ship space, strength and comments:

            Space - Hull below water (magazines/engines, low = better): 22,7%

                        - Above water (accommodation/working, high = better): 85,5%

            Waterplane Area: 3 365 Square feet or 313 Square metres

            Displacement factor (Displacement / loading): 709%

            Structure weight / hull surface area: 99 lbs/sq ft or 484 Kg/sq metre

            Hull strength (Relative):

                        - Cross-sectional: 2,85

                        - Longitudinal: 5,82

                        - Overall: 3,06

            Hull space for machinery, storage, compartmentation is excellent

            Room for accommodation and workspaces is cramped

            Ship has slow, easy roll, a good, steady gun platform

            Excellent seaboat, comfortable, can fire her guns in the heaviest weather