Playing with SS for the first time in a while.
KMS Tärnö, Other Minewarfare laid down 1945
Displacement:
326 t light; 335 t standard; 424 t normal; 495 t full load
Dimensions: Length overall / water x beam x draught
137,80 ft / 137,80 ft x 22,97 ft x 8,53 ft (normal load)
42,00 m / 42,00 m x 7,00 m x 2,60 m
Armament:
4 - 1,57" / 40,0 mm guns (2x2 guns), 1,95lbs / 0,89kg shells, 1945 Model
Automatic rapid fire guns in turrets (on barbettes)
on centreline ends, evenly spread
4 - 0,52" / 13,2 mm guns (2x2 guns), 0,07lbs / 0,03kg shells, 1945 Model
Machine guns in deck mounts
on side, all amidships
Weight of broadside 8 lbs / 4 kg
Shells per gun, main battery: 150
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1,57" / 40 mm 0,79" / 20 mm 0,79" / 20 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 3 905 shp / 2 913 Kw = 20,00 kts
Range 1 500nm at 20,00 kts
Bunker at max displacement = 160 tons
Complement:
46 - 60
Cost:
£0,181 million / $0,725 million
Distribution of weights at normal displacement:
Armament: 1 tons, 0,3 %
Armour: 6 tons, 1,4 %
- Belts: 0 tons, 0,0 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 6 tons, 1,4 %
- Armour Deck: 0 tons, 0,0 %
- Conning Tower: 0 tons, 0,0 %
Machinery: 99 tons, 23,2 %
Hull, fittings & equipment: 171 tons, 40,2 %
Fuel, ammunition & stores: 98 tons, 23,1 %
Miscellaneous weights: 50 tons, 11,8 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
702 lbs / 318 Kg = 359,4 x 1,6 " / 40 mm shells or 0,5 torpedoes
Stability (Unstable if below 1.00): 1,04
Metacentric height 0,6 ft / 0,2 m
Roll period: 12,5 seconds
Steadiness - As gun platform (Average = 50 %): 56 %
- Recoil effect (Restricted arc if above 1.00): 0,07
Seaboat quality (Average = 1.00): 1,27
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0,550
Length to Beam Ratio: 6,00 : 1
'Natural speed' for length: 11,74 kts
Power going to wave formation at top speed: 75 %
Trim (Max stability = 0, Max steadiness = 100): 44
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: 13,12 ft / 4,00 m
- Forecastle (20 %): 13,12 ft / 4,00 m
- Mid (50 %): 13,12 ft / 4,00 m
- Quarterdeck (15 %): 13,12 ft / 4,00 m
- Stern: 13,12 ft / 4,00 m
- Average freeboard: 13,12 ft / 4,00 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 91,0 %
- Above water (accommodation/working, high = better): 120,0 %
Waterplane Area: 2 209 Square feet or 205 Square metres
Displacement factor (Displacement / loading): 162 %
Structure weight / hull surface area: 31 lbs/sq ft or 154 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,75
- Longitudinal: 16,84
- Overall: 1,02
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily