Minewarfare Vessels

[Sachmle]

M-200 Class, NUS Minesweeper laid down 1912 (Engine 1909)

Image based on parts by Wes Wilson, modified by me.

Displacement:
   480 t light; 499 t standard; 676 t normal; 818 t full load

Dimensions: Length overall / water x beam x draught
   207.00 ft / 200.00 ft x 30.00 ft x 8.00 ft (normal load)
   63.09 m / 60.96 m x 9.14 m  x 2.44 m

Armament:
      1 - 4.00" / 102 mm guns in single mounts, 30.00lbs / 13.61kg shells, 1906 Model
     Quick firing gun in deck mount
     on centreline forward
      6 - 1.00" / 25.4 mm guns in single mounts, 0.50lbs / 0.23kg shells, 1906 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 33 lbs / 15 kg
   Shells per gun, main battery: 300

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm   1.00" / 25 mm            -

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,254 ihp / 935 Kw = 15.00 kts
   Range 7,500nm at 10.00 kts
   Bunker at max displacement = 318 tons (100% coal)

Complement:
   66 - 86

Cost:
   £0.034 million / $0.136 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0.6 %
   Armour: 3 tons, 0.5 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.5 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 96 tons, 14.3 %
   Hull, fittings & equipment: 256 tons, 37.9 %
   Fuel, ammunition & stores: 196 tons, 29.0 %
   Miscellaneous weights: 120 tons, 17.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,565 lbs / 710 Kg = 48.9 x 4.0 " / 102 mm shells or 0.8 torpedoes
   Stability (Unstable if below 1.00): 1.26
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 11.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.05
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has raised forecastle, rise forward of midbreak
   Block coefficient: 0.493
   Length to Beam Ratio: 6.67 : 1
   'Natural speed' for length: 14.14 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): 14.04 degrees
   Stern overhang: 2.00 ft / 0.61 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      20.00 ft / 6.10 m
      - Forecastle (20 %):   18.00 ft / 5.49 m (16.00 ft / 4.88 m aft of break)
      - Mid (50 %):      16.00 ft / 4.88 m (8.00 ft / 2.44 m aft of break)
      - Quarterdeck (15 %):   8.00 ft / 2.44 m
      - Stern:      8.00 ft / 2.44 m
      - Average freeboard:   12.56 ft / 3.83 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 71.9 %
      - Above water (accommodation/working, high = better): 134.0 %
   Waterplane Area: 3,972 Square feet or 369 Square metres
   Displacement factor (Displacement / loading): 193 %
   Structure weight / hull surface area: 36 lbs/sq ft or 175 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.85
      - Longitudinal: 4.52
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

10t W/T
100t Mines
20t Sweeping gear