USS Langley, United States Seaplane Tender laid down 1911
Displacement:
11,256 t light; 11,527 t standard; 12,530 t normal; 13,333 t full load
Dimensions: Length overall / water x beam x draught
533.46 ft / 520.21 ft x 65.25 ft x 20.00 ft (normal load)
162.60 m / 158.56 m x 19.89 m x 6.10 m
Armament:
4 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1911 Model
Breech loading guns in deck mounts
on side ends, evenly spread
Weight of broadside 250 lbs / 113 kg
Shells per gun, main battery: 150
Machinery:
Oil fired boilers, complex reciprocating steam engines,
Electric motors, 2 shafts, 7,070 ihp / 5,274 Kw = 15.50 kts
Range 10,000nm at 10.00 kts
Bunker at max displacement = 1,806 tons
Complement:
591 - 769
Cost:
£0.480 million / $1.920 million
Distribution of weights at normal displacement:
Armament: 31 tons, 0.2 %
Machinery: 427 tons, 3.4 %
Hull, fittings & equipment: 3,822 tons, 30.5 %
Fuel, ammunition & stores: 1,275 tons, 10.2 %
Miscellaneous weights: 6,975 tons, 55.7 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
21,551 lbs / 9,776 Kg = 344.8 x 5.0 " / 127 mm shells or 2.5 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 2.7 ft / 0.8 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 40 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.60
Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.646
Length to Beam Ratio: 7.97 : 1
'Natural speed' for length: 22.81 kts
Power going to wave formation at top speed: 29 %
Trim (Max stability = 0, Max steadiness = 100): 20
Bow angle (Positive = bow angles forward): 4.00 degrees
Stern overhang: 10.50 ft / 3.20 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 39.37 ft / 12.00 m
- Forecastle (16 %): 35.87 ft / 10.93 m (29.75 ft / 9.07 m aft of break)
- Mid (50 %): 24.50 ft / 7.47 m
- Quarterdeck (38 %): 28.00 ft / 8.53 m (23.62 ft / 7.20 m before break)
- Stern: 28.87 ft / 8.80 m
- Average freeboard: 28.88 ft / 8.80 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 74.1 %
- Above water (accommodation/working, high = better): 219.8 %
Waterplane Area: 25,908 Square feet or 2,407 Square metres
Displacement factor (Displacement / loading): 155 %
Structure weight / hull surface area: 81 lbs/sq ft or 397 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.87
- Longitudinal: 3.26
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Can carry up to 9 Flying Boats, PM type.