Tian Yan - Class:
Minewarfare Mothership
Displacement:
4.558 t light; 4.988 t standard; 5.911 t normal; 6.650 t full load
Dimensions:
Length overall / water x beam x draught
457,30 ft / 446,19 ft x 58,40 ft x 14,44 ft (normal load)
139,38 m / 136,00 m x 17,80 m x 4,40 m
Armament:
6 - 4,13" / 105 mm guns (3x2 guns), 35,32lbs / 16,02kg shells, 1943 Model
Breech loading guns in deck mounts with hoists
on centreline ends, majority forward, 2 raised mounts - superfiring
8 - 1,46" / 37,0 mm guns (4x2 guns), 1,55lbs / 0,70kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side, all amidships, 2 raised mounts - superfiring
6 - 0,31" / 8,0 mm guns (3x2 guns), 0,02lbs / 0,01kg shells, 1943 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 224 lbs / 102 kg
Shells per gun, main battery: 2.400
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 11.431 shp / 8.528 Kw = 20,00 kts
Range 8.000nm at 17,00 kts
Bunker at max displacement = 1.662 tons
Complement:
336 - 438
Cost:
£1,469 million / $5,876 million
Distribution of weights at normal displacement:
Armament: 28 tons, 0,5%
Machinery: 295 tons, 5,0%
Hull, fittings & equipment: 2.485 tons, 42,0%
Fuel, ammunition & stores: 1.353 tons, 22,9%
Miscellaneous weights: 1.750 tons, 29,6%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
16.134 lbs / 7.318 Kg = 456,8 x 4,1 " / 105 mm shells or 2,7 torpedoes
Stability (Unstable if below 1.00): 1,00
Metacentric height 2,2 ft / 0,7 m
Roll period: 16,5 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0,17
Seaboat quality (Average = 1.00): 2,00
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0,550
Length to Beam Ratio: 7,64 : 1
'Natural speed' for length: 21,12 kts
Power going to wave formation at top speed: 42 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30,51 ft / 9,30 m
- Forecastle (20%): 28,54 ft / 8,70 m
- Mid (50%): 28,54 ft / 8,70 m (22,31 ft / 6,80 m aft of break)
- Quarterdeck (15%): 22,31 ft / 6,80 m
- Stern: 22,31 ft / 6,80 m
- Average freeboard: 25,58 ft / 7,80 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 58,4%
- Above water (accommodation/working, high = better): 259,7%
Waterplane Area: 18.185 Square feet or 1.689 Square metres
Displacement factor (Displacement / loading): 230%
Structure weight / hull surface area: 76 lbs/sq ft or 370 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,88
- Longitudinal: 4,12
- Overall: 1,03
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
Comments:
Bunker at max displacement = 1.662 tons
Operational Range: 3000nm (662 tons)
1000tons Diesel fuel for other use
Breakdown of Miscellaneous Weight:
- 25 tons for catapult
- 25 tons for aircraft (GY-196)
- 25 tons for electronic equipment
- 25 tons for degaussing system
- 150 tons for other use
Optional placement:
- 1500 tons for mines
or
- 12 boats with minesweeping gear
- 4 tug boats
- 4 buoy boats
- 1 leader boat
or
- 10 small minesweepers
- 6 Buoyboats
- 1 leader boat
small boats (onboard):
Tonnage: 15 tons
Length: 13,5m o.a. / 13m wl
Width: 3,48m
Draught: 0,9m
Freeboard: 2,35m
Engine: 2x 6cyl diesel 150 hp / 12 kn / 2 shafts
Range: 175 sm / 12 kn
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Ships in Class:
HICMS Tian Yan; laid down 1944
HICMS Lie Ying; laid down 1944