Gunboats
Project 611, Argentina Light Patrol Craft laid down 1933
MGB-1 to 12 and 14 to 31
Displacement:
177 t light; 181 t standard; 192 t normal; 200 t full load
Dimensions: Length overall / water x beam x draught
149.13 ft / 144.36 ft x 21.33 ft x 5.74 ft (normal load)
45.46 m / 44.00 m x 6.50 m x 1.75 m
Armament:
1 - 2.95" / 75.0 mm guns in single mounts, 13.66lbs / 6.20kg shells, 1932 Model
Quick firing gun in deck mount
on centreline forward
4 - 0.79" / 20.0 mm guns (1x4 guns), 0.24lbs / 0.11kg shells, 1933 Model
Anti-aircraft guns in deck mount
on centreline aft
4 - 0.30" / 7.62 mm guns (2x2 guns), 0.02lbs / 0.01kg shells, 1933 Model
Machine guns in deck mounts
on side, all forward
Weight of broadside 15 lbs / 7 kg
Shells per gun, main battery: 80
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm - -
- Conning tower: 0.98" / 25 mm
Machinery:
Diesel Internal combustion motors,
Direct drive, 2 shafts, 2,000 shp / 1,492 Kw = 21.18 kts
Range 1,500nm at 12.00 kts
Bunker at max displacement = 19 tons
Complement:
25 - 33
Cost:
£0.075 million / $0.299 million
Distribution of weights at normal displacement:
Armament: 2 tons, 0.9 %
Armour: 2 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.4 %
Machinery: 58 tons, 30.4 %
Hull, fittings & equipment: 104 tons, 54.3 %
Fuel, ammunition & stores: 15 tons, 7.8 %
Miscellaneous weights: 11 tons, 5.7 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
310 lbs / 141 Kg = 24.1 x 3.0 " / 75 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 0.6 ft / 0.2 m
Roll period: 11.4 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.14
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.380
Length to Beam Ratio: 6.77 : 1
'Natural speed' for length: 14.47 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 43
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: 13.12 ft / 4.00 m
- Forecastle (20 %): 10.50 ft / 3.20 m
- Mid (50 %): 9.35 ft / 2.85 m
- Quarterdeck (15 %): 9.35 ft / 2.85 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 9.88 ft / 3.01 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 111.7 %
- Above water (accommodation/working, high = better): 142.7 %
Waterplane Area: 1,947 Square feet or 181 Square metres
Displacement factor (Displacement / loading): 134 %
Structure weight / hull surface area: 27 lbs/sq ft or 134 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.79
- Longitudinal: 8.27
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent