MS-28 Class OPV (Offshore Patrol Vessel)

[TacCovert4]

MS-28, Aztec Offshore Patrol Vessel laid down 1928

Displacement:
   549 t light; 576 t standard; 624 t normal; 663 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (201.39 ft / 196.85 ft) x 24.61 ft x (8.20 / 8.63 ft)
   (61.38 m / 60.00 m) x 7.50 m  x (2.50 / 2.63 m)

Armament:
      2 - 3.94" / 100 mm 50.0 cal guns - 32.30lbs / 14.65kg shells, 150 per gun
     Quick firing guns in deck mount, 1928 Model
     1 x Single mount on centreline, forward deck centre
      1 - 2.76" / 70.0 mm 50.0 cal gun - 11.09lbs / 5.03kg shells, 200 per gun
     Anti-air gun in deck mount, 1928 Model
     1 x Single mount on centreline, aft deck centre
      8 - 1.18" / 30.0 mm 50.0 cal guns - 0.86lbs / 0.39kg shells, 2,000 per gun
     Anti-air guns in deck mounts, 1928 Model
     8 x Single mounts on sides, evenly spread
      Weight of broadside 83 lbs / 37 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.18" / 30 mm         -               -
   2nd:   0.79" / 20 mm         -               -

   - Box over magazines:
   0.79" / 20 mm

   - Conning towers: Forward 0.79" / 20 mm, Aft 0.00" / 0 mm

Machinery:
   Diesel Internal combustion motors,
   Geared drive, 2 shafts, 5,730 shp / 4,275 Kw = 22.00 kts
   Range 2,000nm at 14.00 kts
   Bunker at max displacement = 88 tons

Complement:
   62 - 81

Cost:
   £0.187 million / $0.747 million

Distribution of weights at normal displacement:
   Armament: 18 tons, 2.9 %
      - Guns: 18 tons, 2.9 %
   Armour: 12 tons, 1.9 %
      - Armament: 3 tons, 0.5 %
      - Armour Deck: 8 tons, 1.2 %
      - Conning Tower: 1 tons, 0.2 %
   Machinery: 178 tons, 28.6 %
   Hull, fittings & equipment: 153 tons, 24.6 %
   Fuel, ammunition & stores: 75 tons, 12.1 %
   Miscellaneous weights: 187 tons, 30.0 %
      - Hull below water: 68 tons
      - On freeboard deck: 67 tons
      - Above deck: 52 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     479 lbs / 217 Kg = 15.7 x 3.9 " / 100 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.06
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 12.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.21
   Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.550 / 0.555
   Length to Beam Ratio: 8.00 : 1
   'Natural speed' for length: 14.03 kts
   Power going to wave formation at top speed: 68 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 20.00 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 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Forward deck:   30.00 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Aft deck:   35.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Quarter deck:   15.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Average freeboard:      10.33 ft / 3.15 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 113.5 %
      - Above water (accommodation/working, high = better): 105.6 %
   Waterplane Area: 3,380 Square feet or 314 Square metres
   Displacement factor (Displacement / loading): 104 %
   Structure weight / hull surface area: 27 lbs/sq ft or 130 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.65
      - Longitudinal: 2.59
      - Overall: 0.75
   Caution: Hull subject to strain in open-sea
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room

54t - Diesel Engines
15t - Enhanced Hydrophones

35t - Minesweeping Equipment
2t - DC Throwers
18t - Depth Charges
12t - 1x3x21in HW TT


2t - 1918 FC
25t - LR Radio
25t - NF Devices

Range:  3500nm @ 14kts or 8500nm @ 10kts