Pocket Minesweeper

[Desertfox]

A simple inexpensive minesweeper to replace the current ad hoc converted fishing boats. Its made with non strategic material (wood)  and the basic hull design can be used as a gunboat (with 3" gun).


C-1, New Switzerland  Coastal Minesweeper laid down 1908

Displacement:
   50 t light; 51 t standard; 61 t normal; 68 t full load

Dimensions: Length overall / water x beam x draught
   110.00 ft / 110.00 ft x 15.00 ft x 3.00 ft (normal load)
   33.53 m / 33.53 m x 4.57 m  x 0.91 m

Armament:
      1 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1908 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 0.50" / 12.7 mm guns (1x2 guns), 0.06lbs / 0.03kg shells, 1908 Model
     Machine guns in deck mount
     on centreline aft
   Weight of broadside 2 lbs / 1 kg
   Shells per gun, main battery: 500

Machinery:
   Petrol Internal combustion motors,
   Direct drive, 1 shaft, 261 shp / 194 Kw = 14.00 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 17 tons

Complement:
   10 - 14

Cost:
   £0.004 million / $0.015 million

Distribution of weights at normal displacement:
   Armament: 0 tons, 0.4 %
   Machinery: 13 tons, 21.6 %
   Hull, fittings & equipment: 29 tons, 47.8 %
   Fuel, ammunition & stores: 11 tons, 18.6 %
   Miscellaneous weights: 7 tons, 11.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     146 lbs / 66 Kg = 74.6 x 1.6 " / 40 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.32
   Metacentric height 0.5 ft / 0.1 m
   Roll period: 9.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.02
   Seaboat quality  (Average = 1.00): 1.30

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.430
   Length to Beam Ratio: 7.33 : 1
   'Natural speed' for length: 10.49 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 38
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      10.00 ft / 3.05 m
      - Forecastle (20 %):   7.00 ft / 2.13 m
      - Mid (40 %):      7.00 ft / 2.13 m
      - Quarterdeck (25 %):   3.00 ft / 0.91 m
      - Stern:      3.00 ft / 0.91 m
      - Average freeboard:   5.54 ft / 1.69 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 87.5 %
      - Above water (accommodation/working, high = better): 107.3 %
   Waterplane Area: 984 Square feet or 91 Square metres
   Displacement factor (Displacement / loading): 172 %
   Structure weight / hull surface area: 18 lbs/sq ft or 88 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.89
      - Longitudinal: 2.80
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Good seaboat, rides out heavy weather easily

[Borys]

Displacement:
   50 t light; 51 t standard; 61 t normal; 68 t full load
Bunker at max displacement = 17 tons

ZIPPO!

[Ithekro]

So it is a coastal lighter than?

[Borys]

LOL!

[Korpen]

Hehe, I was also toying with the idea of a petrol engine in my wooden sweepers, but decided against it for a ronson.

[Phoenix]

Chinese fisherman to his mate: "Pass me that fire-rocket will you ?"

[maddox]

17 tons of fuel.

That is about 20 000 liters.
Somewere in that unarmored bathtub there is a HUGE petrol tank of 20m³

Or are it several flat tanks spread all over the boaty?  

I can see it in front of me, a ship loaded with a 1000 5 gallon jerrycans

[Borys]

Do I see a spark of an idea in your eye?
Borys

[Desertfox]

Well just look at the name of the ship...

Better?

C-1, New Switzerland  Minesweeper laid down 1908

Displacement:
   42 t light; 44 t standard; 48 t normal; 51 t full load

Dimensions: Length overall / water x beam x draught
   100.00 ft / 100.00 ft x 14.00 ft x 3.00 ft (normal load)
   30.48 m / 30.48 m x 4.27 m  x 0.91 m

Armament:
      1 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1908 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 0.50" / 12.7 mm guns (1x2 guns), 0.06lbs / 0.03kg shells, 1908 Model
     Machine guns in deck mount
     on centreline aft
   Weight of broadside 2 lbs / 1 kg
   Shells per gun, main battery: 500

Machinery:
   Diesel Internal combustion motors,
   Direct drive, 1 shaft, 229 shp / 171 Kw = 14.00 kts
   Range 1,000nm at 10.00 kts
   Bunker at max displacement = 8 tons

Complement:
   8 - 11

Cost:
   £0.003 million / $0.013 million

Distribution of weights at normal displacement:
   Armament: 0 tons, 0.5 %
   Machinery: 12 tons, 24.1 %
   Hull, fittings & equipment: 23 tons, 48.6 %
   Fuel, ammunition & stores: 6 tons, 12.1 %
   Miscellaneous weights: 7 tons, 14.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     99 lbs / 45 Kg = 50.7 x 1.6 " / 40 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 0.4 ft / 0.1 m
   Roll period: 9.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.400
   Length to Beam Ratio: 7.14 : 1
   'Natural speed' for length: 10.00 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 40
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      9.00 ft / 2.74 m
      - Forecastle (20 %):   7.00 ft / 2.13 m
      - Mid (40 %):      7.00 ft / 2.13 m
      - Quarterdeck (25 %):   2.50 ft / 0.76 m
      - Stern:      2.50 ft / 0.76 m
      - Average freeboard:   5.25 ft / 1.60 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.8 %
      - Above water (accommodation/working, high = better): 108.0 %
   Waterplane Area: 815 Square feet or 76 Square metres
   Displacement factor (Displacement / loading): 149 %
   Structure weight / hull surface area: 17 lbs/sq ft or 83 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 3.26
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Good seaboat, rides out heavy weather easily

[Borys]

Well just look at the name of the ship...

Better?

Much, much better.
Totally ahistorical, but much better than the coastal lighter.
Borys