Taking Swamphen's comment about the Orcas' role as auxiliary seaplane tenders, I tried my hand at a rough-and-ready Springsharp for such an exercise. The result is appended. They look impressive but I am in no way convinced that they would be good money for value to the Philippine Navy.
Thoughts? Comments? Offers?
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Orca, Philippine Auxiliary Seaplane Tender laid down 1929, Refitted 1944
Displacement: 20,557 t light; 21,050 t standard; 22,346 t normal; 23,383 t full load
Dimensions: Length overall / water x beam x draught
535.01 ft / 535.01 ft x 75.00 ft x 29.99 ft (normal load) [163.07 m / 163.07 m x 22.86 m x 9.14 m]
Armament:
4 - 4.53" / 115 mm guns (2x2 guns), 46.40lbs / 21.05kg shells, 1944 Model Dual purpose guns in deck mounts on centreline ends, evenly spread
8 - 1.38" / 35.0 mm guns (4x2 guns), 1.31lbs / 0.59kg shells, 1944 Model Anti-aircraft guns in deck mounts on side, all amidships
Weight of broadside 196 lbs / 89 kg
Shells per gun, main battery: 400
Armour:
Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.98" / 25 mm -
2nd: 0.59" / 15 mm 0.59" / 15 mm -
Conning tower: 3.15" / 80 mm
Machinery:
Oil fired boilers, steam turbines, Geared drive, 2 shafts, 26,890 shp / 20,060 Kw = 20.43 kts
Range 15,000nm at 10.00 kts
Bunker at max displacement = 2,333 tons
Complement: 913 - 1,187
Cost: £3.423 million / $13.691 million
Distribution of weights at normal displacement:
Armament: 25 tons, 0.1 %
Armour: 69 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 16 tons, 0.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 54 tons, 0.2 %
Machinery: 826 tons, 3.7 %
Hull, fittings & equipment: 13,938 tons, 62.4 %
Fuel, ammunition & stores: 1,789 tons, 8.0 %
Miscellaneous weights: 5,700 tons, 25.5 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 47,609 lbs / 21,595 Kg = 1,026.0 x 4.5 " / 115 mm shells or 5.6 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 3.9 ft / 1.2 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 41 %
- Recoil effect (Restricted arc if above 1.00): 0.01
Seaboat quality (Average = 1.00): 1.48
Hull form characteristics:
Hull has raised forecastle, raised quarterdeck
Block coefficient: 0.650
Length to Beam Ratio: 7.13: 1
'Natural speed' for length: 23.13 kts
Power going to wave formation at top speed: 45 %
Trim (Max stability = 0, Max steadiness = 100): 23
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: 31.99 ft / 9.75 m
- Forecastle (20 %): 25.98 ft / 7.92 m (18.01 ft / 5.49 m aft of break)
- Mid (50 %): 18.01 ft / 5.49 m
- Quarterdeck (15 %): 25.98 ft / 7.92 m (18.01 ft / 5.49 m before break)
- Stern: 25.98 ft / 7.92 m
- Average freeboard: 21.28 ft / 6.49 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 42.0 %
- Above water (accommodation/working, high = better): 115.5 %
Waterplane Area: 30,738 Square feet or 2,856 Square metres
Displacement factor (Displacement / loading): 293 %
Structure weight / hull surface area: 292 lbs/sq ft or 1,426 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 2.87
- Longitudinal: 4.87
- Overall: 3.03
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily
Breakdown of Miscellaneous Weight
Two 56-foot catapults aft, port and starboard - 400 tons
Aircraft handling cranes - aft - 200 tons
Twelve float reconnaissance aircraft @25 per - 300 tons
Provision for hangarage above deck - 300 tons
Provision for aviation workshops below deck - 500 tons
Provision for accommodation for flight and maintenance personnel - 500 @2 per - 1,000 tons
Provision for munitions and dry store stowage - 1,000 tons
Provision for aviation fuel storage - 2,000 tons
Cost of conversion - 5,140 tons
Time to convert - 218 days