Hello again.
I decided to try my hand at designing a light commerce raider. the sustained speed requirement is less than my usual, as I do not see this ship acting with the fleet. she has 400 tons miscellaneous 50 for electronics and a depth charge rack. that can be used for extra fuel or plunder. (I'm only thinking very expensive items here as 350 tons is not enough to ship bulk cargo.
T-100, Empire of Brazil Comerce Raider laid down 1944
Displacement:
1,908 t light; 2,011 t standard; 2,300 t normal; 2,532 t full load
Dimensions: Length overall / water x beam x draught
450.00 ft / 450.00 ft x 42.00 ft x 9.00 ft (normal load)
137.16 m / 137.16 m x 12.80 m x 2.74 m
Armament:
3 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1944 Model
Dual purpose guns in deck mounts
on centreline ends, majority forward
16 - 1.46" / 37.0 mm guns (4x4 guns), 1.55lbs / 0.70kg shells, 1944 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
8 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1944 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 185 lbs / 84 kg
Shells per gun, main battery: 500
8 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.00" / 25 mm 80.00 ft / 24.38 m 5.00 ft / 1.52 m
Ends: Unarmoured
Main Belt covers 27 % of normal length
Main belt does not fully cover magazines and engineering spaces
- Conning tower: 3.00" / 76 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 32,737 shp / 24,422 Kw = 32.00 kts
Range 6,300nm at 15.00 kts
Bunker at max displacement = 521 tons
Complement:
165 - 215
Cost:
£1.367 million / $5.468 million
Distribution of weights at normal displacement:
Armament: 23 tons, 1.0 %
Armour: 34 tons, 1.5 %
- Belts: 22 tons, 1.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 0 tons, 0.0 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 11 tons, 0.5 %
Machinery: 836 tons, 36.3 %
Hull, fittings & equipment: 615 tons, 26.7 %
Fuel, ammunition & stores: 392 tons, 17.1 %
Miscellaneous weights: 400 tons, 17.4 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,011 lbs / 459 Kg = 19.2 x 4.7 " / 120 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.32
Metacentric height 2.2 ft / 0.7 m
Roll period: 11.8 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 1.14
Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
and transom stern
Block coefficient: 0.473
Length to Beam Ratio: 10.71 : 1
'Natural speed' for length: 24.16 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 53
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: 22.00 ft / 6.71 m
- Forecastle (20 %): 22.00 ft / 6.71 m (13.00 ft / 3.96 m aft of break)
- Mid (50 %): 13.00 ft / 3.96 m
- Quarterdeck (20 %): 20.00 ft / 6.10 m (13.00 ft / 3.96 m before break)
- Stern: 20.00 ft / 6.10 m
- Average freeboard: 16.20 ft / 4.94 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 146.1 %
- Above water (accommodation/working, high = better): 135.8 %
Waterplane Area: 12,779 Square feet or 1,187 Square metres
Displacement factor (Displacement / loading): 100 %
Structure weight / hull surface area: 30 lbs/sq ft or 148 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 0.86
- Overall: 0.53
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
the reason for the 37 and 20 mm armament is for AA as I see that as being the primary threat to a commerce raider from the perspective of economics. hate to see a 10,000 dollar plane sink a 2 million dollar raider. rather a 10 million dollar cruiser did it. the raised quarterdeck is to provide for an elevated bridge and gun platform. she is designed more like a cargo vessel with guns than a destroyer.