To use up some excess material I've planned this ship earlier than intended. She is broadly like the British Manxman Class. The machinery, guns and rangefinders are identical to the Mendoza Class. No belt or deck armour is fitted to reduce weight and improve speed, and if a shell hits those mines the ship is doomed anyway. She has three roles, minelaying at night, a peacetime training ship with 50-80 cadets and as a secondary cruiser if things get tough or as a destroyer flottila leader. Is 300tons misc weight enough for 100-150 mines?
General San Martin, Argentina Minelayer/Cruiser laid down 1931
Displacement:
2,582 t light; 2,726 t standard; 3,077 t normal; 3,358 t full load
Dimensions: Length overall / water x beam x draught
450.16 ft / 442.91 ft x 43.31 ft x 11.48 ft (normal load)
137.21 m / 135.00 m x 13.20 m x 3.50 m
Armament:
6 - 5.12" / 130 mm guns (3x2 guns), 67.03lbs / 30.40kg shells, 1931 Model
Breech loading guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
32 - 1.46" / 37.0 mm guns (8x4 guns), 1.55lbs / 0.70kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
16 - 0.79" / 20.0 mm guns (4x4 guns), 0.24lbs / 0.11kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread
Weight of broadside 456 lbs / 207 kg
Shells per gun, main battery: 300
6 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 0.79" / 20 mm
- Conning tower: 2.76" / 70 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 40,800 shp / 30,436 Kw = 32.26 kts
Range 5,800nm at 15.00 kts
Bunker at max displacement = 632 tons
Complement:
206 - 268
Cost:
£1.334 million / $5.338 million
Distribution of weights at normal displacement:
Armament: 57 tons, 1.9 %
Armour: 38 tons, 1.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 25 tons, 0.8 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 13 tons, 0.4 %
Machinery: 1,197 tons, 38.9 %
Hull, fittings & equipment: 991 tons, 32.2 %
Fuel, ammunition & stores: 495 tons, 16.1 %
Miscellaneous weights: 300 tons, 9.7 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,467 lbs / 666 Kg = 21.9 x 5.1 " / 130 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.32
Metacentric height 2.3 ft / 0.7 m
Roll period: 11.9 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.33
Seaboat quality (Average = 1.00): 1.12
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.489
Length to Beam Ratio: 10.23 : 1
'Natural speed' for length: 24.01 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 44
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.31 ft / 6.80 m
- Forecastle (20 %): 17.06 ft / 5.20 m
- Mid (50 %): 17.06 ft / 5.20 m
- Quarterdeck (15 %): 17.06 ft / 5.20 m
- Stern: 17.06 ft / 5.20 m
- Average freeboard: 17.48 ft / 5.33 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 152.1 %
- Above water (accommodation/working, high = better): 162.8 %
Waterplane Area: 13,155 Square feet or 1,222 Square metres
Displacement factor (Displacement / loading): 95 %
Structure weight / hull surface area: 44 lbs/sq ft or 217 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.57
- Longitudinal: 1.37
- Overall: 0.62
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent