Almirante Gastão Motta, Brazilian Underway Replenishment Ship laid down 1943
Displacement:
6,120 t light; 6,492 t standard; 17,915 t normal; 27,052 t full load
Dimensions: Length overall / water x beam x draught
536.01 ft / 524.93 ft x 63.65 ft x 28.87 ft (normal load)
163.38 m / 160.00 m x 19.40 m x 8.80 m
Armament:
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1943 Model
Machine guns in deck mounts
on side, all amidships
Weight of broadside 7 lbs / 3 kg
Shells per gun, main battery: 3,000
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 7,654 shp / 5,710 Kw = 15.00 kts
Range 124,500nm at 12.00 kts
Bunker at max displacement = 20,560 tons
Complement:
773 - 1,006
Cost:
£1.588 million / $6.352 million
Distribution of weights at normal displacement:
Armament: 1 tons, 0.0 %
Machinery: 198 tons, 1.1 %
Hull, fittings & equipment: 3,421 tons, 19.1 %
Fuel, ammunition & stores: 11,795 tons, 65.8 %
Miscellaneous weights: 2,500 tons, 14.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
79,598 lbs / 36,105 Kg = 51,502.6 x 1.5 " / 37 mm shells or 11.8 torpedoes
Stability (Unstable if below 1.00): 1.44
Metacentric height 4.8 ft / 1.5 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.79
Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.650
Length to Beam Ratio: 8.25 : 1
'Natural speed' for length: 22.91 kts
Power going to wave formation at top speed: 28 %
Trim (Max stability = 0, Max steadiness = 100): 42
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.59 ft / 7.80 m
- Forecastle (15 %): 24.93 ft / 7.60 m (13.12 ft / 4.00 m aft of break)
- Mid (50 %): 13.12 ft / 4.00 m
- Quarterdeck (25 %): 22.31 ft / 6.80 m (13.12 ft / 4.00 m before break)
- Stern: 22.97 ft / 7.00 m
- Average freeboard: 17.31 ft / 5.28 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 20.6 %
- Above water (accommodation/working, high = better): 81.6 %
Waterplane Area: 25,236 Square feet or 2,345 Square metres
Displacement factor (Displacement / loading): 617 %
Structure weight / hull surface area: 84 lbs/sq ft or 412 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.26
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Ships in Class:
- MIBN Almirante Gastão Motta
- MIBN Almirante Guilhem