Minesweeper

[ledeper]

Whale-class, Baltic-Confederation Minesweeper laid down 1911

Displacement:
   610 t light; 630 t standard; 718 t normal; 787 t full load

Dimensions: Length overall / water x beam x draught
   231,12 ft / 229,66 ft x 32,81 ft x 6,56 ft (normal load)
   70,44 m / 70,00 m x 10,00 m  x 2,00 m

Armament:
      2 - 4,00" / 102 mm guns in single mounts, 32,00lbs / 14,51kg shells, 1911 Model
     Quick firing guns in deck mounts
     on centreline, all forward, 1 raised mount
      2 - 0,79" / 20,0 mm guns (1x2 guns), 0,24lbs / 0,11kg shells, 1911 Model
     Machine guns in deck mount
     on side amidships
   Weight of broadside 64 lbs / 29 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,50" / 13 mm         -               -

   - Conning tower: 2,00" / 51 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 3.039 ihp / 2.267 Kw = 18,75 kts
   Range 3.500nm at 10,00 kts
   Bunker at max displacement = 157 tons (100% coal)

Complement:
   69 - 90

Cost:
   £0,056 million / $0,226 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 1,1 %
   Armour: 6 tons, 0,8 %
      - Belts: 0 tons, 0,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 2 tons, 0,3 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 3 tons, 0,5 %
   Machinery: 202 tons, 28,1 %
   Hull, fittings & equipment: 295 tons, 41,1 %
   Fuel, ammunition & stores: 107 tons, 14,9 %
   Miscellaneous weights: 100 tons, 13,9 %
                             - 50 tons(50 Mines)
                              -15 tons(Crane and Sweeping Gear)
                              -25 tons Wireless


Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     939 lbs / 426 Kg = 29,4 x 4,0 " / 102 mm shells or 0,5 torpedoes
   Stability (Unstable if below 1.00): 1,29
   Metacentric height 1,5 ft / 0,5 m
   Roll period: 11,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 65 %
         - Recoil effect (Restricted arc if above 1.00): 0,07
   Seaboat quality  (Average = 1.00): 1,30

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,508
   Length to Beam Ratio: 7,00 : 1
   'Natural speed' for length: 15,15 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 5,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16,67 ft / 5,08 m
      - Forecastle (20 %):   10,60 ft / 3,23 m
      - Mid (50 %):      10,60 ft / 3,23 m
      - Quarterdeck (15 %):   10,60 ft / 3,23 m
      - Stern:      10,60 ft / 3,23 m
      - Average freeboard:   11,08 ft / 3,38 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 115,2 %
      - Above water (accommodation/working, high = better): 142,4 %
   Waterplane Area: 4.868 Square feet or 452 Square metres
   Displacement factor (Displacement / loading): 125 %
   Structure weight / hull surface area: 40 lbs/sq ft or 196 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,93
      - Longitudinal: 2,07
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Good seaboat, rides out heavy weather easily