Baltic Minesweeper

[ledeper]

Upper version in SS3! Downer in SS2


Whale-class, Baltic-Confederation   Minesweeper  laid down 1911(SS3)

Displacement:
   627 t light; 650 t standard; 713 t normal; 764 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (232,83 ft / 229,66 ft) x 32,81 ft x (6,56 / 6,93 ft)
   (70,97 m / 70,00 m) x 10,00 m  x (2,00 / 2,11 m)

Armament:
      2 - 4,00" / 102 mm 45,0 cal guns - 32,27lbs / 14,64kg shells, 250 per gun
     Quick firing guns in deck mounts, 1911 Model
     2 x Single mounts on centreline, forward evenly spread
      1 raised mount
      2 - 0,79" / 20,0 mm 45,0 cal guns - 0,25lbs / 0,11kg shells, 250 per gun
     Machine guns in deck mounts, 1911 Model
     2 x Single mounts on sides amidships
      Weight of broadside 65 lbs / 30 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1,00" / 25 mm         -               -

   - Conning towers: Forward 2,00" / 51 mm,  Aft 0,00" / 0 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 2.569 ihp / 1.917 Kw = 18,00 kts
   Range 2.500nm at 10,00 kts
   Bunker at max displacement = 114 tons (100% coal)

Complement:
   68 - 89

Cost:
   £0,049 million / $0,196 million

Distribution of weights at normal displacement:
   Armament: 12 tons, 1,6 %
   Armour: 8 tons, 1,1 %
      - Armament: 5 tons, 0,7 %
      - Conning Tower: 3 tons, 0,5 %
   Machinery: 171 tons, 23,9 %
   Hull, fittings & equipment: 286 tons, 40,2 %
   Fuel, ammunition & stores: 86 tons, 12,1 %
   Miscellaneous weights: 150 tons, 21,0 %
      - Hull above water: 50 tons (50 Mines)
      - On freeboard deck: 75 tons(Crane and Sweeping Gear)
      - Above deck: 25 tons(Wireless)


Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1.354 lbs / 614 Kg = 42,3 x 4,0 " / 102 mm shells or 0,7 torpedoes
   Stability (Unstable if below 1.00): 1,28
   Metacentric height 1,5 ft / 0,4 m
   Roll period: 11,4 seconds
   Steadiness   - As gun platform (Average = 50 %): 73 %
         - Recoil effect (Restricted arc if above 1.00): 0,09
   Seaboat quality  (Average = 1.00): 1,46

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0,505 / 0,512
   Length to Beam Ratio: 7,00 : 1
   'Natural speed' for length: 15,15 kts
   Power going to wave formation at top speed: 52 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 10,00 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 %,  17,98 ft / 5,48 m,  10,60 ft / 3,23 m
      - Forward deck:   30,00 %,  10,60 ft / 3,23 m,  10,60 ft / 3,23 m
      - Aft deck:   35,00 %,  10,60 ft / 3,23 m,  10,60 ft / 3,23 m
      - Quarter deck:   15,00 %,  10,60 ft / 3,23 m,  10,60 ft / 3,23 m
      - Average freeboard:      11,19 ft / 3,41 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90,9 %
      - Above water (accommodation/working, high = better): 144,0 %
   Waterplane Area: 4.852 Square feet or 451 Square metres
   Displacement factor (Displacement / loading): 135 %
   Structure weight / hull surface area: 40 lbs/sq ft or 195 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,13
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Whale-class, Baltic-Confederation Minesweeper laid down 1911  (SS2)

Displacement:
   632 t light; 652 t standard; 715 t normal; 766 t full load

Dimensions: Length overall / water x beam x draught
   231,23 ft / 229,66 ft x 32,81 ft x 6,56 ft (normal load)
   70,48 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
   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:   1,00" / 25 mm   1,00" / 25 mm            -

   - Conning tower: 2,00" / 51 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 2.574 ihp / 1.920 Kw = 18,00 kts
   Range 2.500nm at 10,00 kts
   Bunker at max displacement = 114 tons (100% coal)

Complement:
   68 - 89

Cost:
   £0,053 million / $0,211 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 1,1 %
   Armour: 10 tons, 1,3 %
      - Belts: 0 tons, 0,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 6 tons, 0,9 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 3 tons, 0,5 %
   Machinery: 171 tons, 23,9 %
   Hull, fittings & equipment: 293 tons, 41,0 %
   Fuel, ammunition & stores: 83 tons, 11,6 %
   Miscellaneous weights: 150 tons, 21,0 %
                              - 50 tons(50 Mines)
                          -75 tons(Crane and Sweeping Gear)
                              -25 tons Wireless

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1.007 lbs / 457 Kg = 31,5 x 4,0 " / 102 mm shells or 0,5 torpedoes
   Stability (Unstable if below 1.00): 1,21
   Metacentric height 1,3 ft / 0,4 m
   Roll period: 12,0 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0,08
   Seaboat quality  (Average = 1.00): 1,44

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,506
   Length to Beam Ratio: 7,00 : 1
   'Natural speed' for length: 15,15 kts
   Power going to wave formation at top speed: 52 %
   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:      17,98 ft / 5,48 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:   11,19 ft / 3,41 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 109,2 %
      - Above water (accommodation/working, high = better): 144,2 %
   Waterplane Area: 4.858 Square feet or 451 Square metres
   Displacement factor (Displacement / loading): 126 %
   Structure weight / hull surface area: 40 lbs/sq ft or 195 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,10
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Korpen]

75ton for sweeping gera is hugly exessive; 5 to 10 ton at most seems more resonable.

http://web.telia.com/~u31829269/minesweeper/index.html

I generally think they are to large and expensive, sweepers is something one want lots of.

[Ithekro]

Why does your minesweeper carry mines?

[Korpen]

Why does your minesweeper carry mines?

The obvious answer would be; "to be able to lay mines". ;)
It is very common for minesweepers to be able to function as auxiliary minelayers (together with tramp freighter, ferries, fishing boats, liners and everything else that floats), primarily for defensive fields.

[Sachmle]

Why does your minesweeper carry mines?

Don't feel to bad Ithekro, I asked the same thing when I posted a minesweeper. Everyone said, "Where's the room for the mines?" and I said exactly what you just said.

[ledeper]

 Dual pourpose role, to lay mines inshallow waters