I am also considering a refit of the Poro class antiaircraft cruisers, but in a far less ambitious scheme a Level I refit to add radar; Ive looked at the possibility of refitting these vessels further and have not come up with a better idea, but I would welcome any suggestions for consideration.
The as-built Springsharp is as follows:
Poro, Philippine Light Cruiser laid down 1937
Displacement: 4,161 t light; 4,377 t standard; 4,862 t normal; 5,249 t full load
Dimensions: Length overall / water x beam x draught
446.19 ft / 446.19 ft x 44.95 ft x 19.69 ft (normal load) [136.00 m / 136.00 m x 13.70 m x 6.00 m]
Armament:
12 - 4.53" / 115 mm guns (6x2 guns), 46.40lbs / 21.05kg shells, 1937 Model Dual purpose guns in deck mounts with hoists on centreline ends, evenly spread, 3 raised mounts - superfiring
24 - 1.38" / 35.0 mm guns (6x4 guns), 1.31lbs / 0.59kg shells, 1937 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring
Weight of broadside 588 lbs / 267 kg
Shells per gun, main battery: 350
6 - 24.0" / 610 mm above water torpedoes
Armour:
Belts: Width (max) Length (avg) Height (avg)
Main: 2.76" / 70 mm 354.33 ft / 108.00 m 7.97 ft / 2.43 m
Ends: Unarmoured
Main Belt covers 122 % of normal length
Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.36" / 60 mm 2.36" / 60 mm -
2nd: 0.79" / 20 mm - -
Armour deck: 0.79" / 20 mm, Conning tower: 3.15" / 80 mm
Machinery:
Oil fired boilers, steam turbines, Geared drive, 2 shafts, 57,097 shp / 42,594 Kw = 33.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 872 tons
Complement: 290 - 378
Cost: £2.340 million / $9.359 million
Distribution of weights at normal displacement:
Armament: 74 tons, 1.5 %
Armour: 613 tons, 12.6 %
- Belts: 313 tons, 6.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 90 tons, 1.8 %
- Armour Deck: 191 tons, 3.9 %
- Conning Tower: 19 tons, 0.4 %
Machinery: 1,583 tons, 32.6 %
Hull, fittings & equipment: 1,812 tons, 37.3 %
Fuel, ammunition & stores: 701 tons, 14.4 %
Miscellaneous weights: 80 tons, 1.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 3,721 lbs / 1,688 Kg = 80.2 x 4.5 " / 115 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.07
Metacentric height 1.7 ft / 0.5 m
Roll period: 14.4 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.54
Seaboat quality (Average = 1.00): 1.21
Hull form characteristics:
Hull has rise forward of midbreak and transom stern
Block coefficient: 0.431
Length to Beam Ratio: 9.93: 1
'Natural speed' for length: 24.33 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 59
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: 29.53 ft / 9.00 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (50 %): 22.97 ft / 7.00 m (13.88 ft / 4.23 m aft of break)
- Quarterdeck (15 %): 13.88 ft / 4.23 m
- Stern: 13.88 ft / 4.23 m
- Average freeboard: 18.95 ft / 5.78 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.7 %
- Above water (accommodation/working, high = better): 113.5 %
Waterplane Area: 13,087 Square feet or 1,216 Square metres
Displacement factor (Displacement / loading): 109 %
Structure weight / hull surface area: 70 lbs/sq ft or 341 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.80
- Longitudinal: 2.75
- Overall: 0.90
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
The refit proposal is as follows:
Poro, Philippine Light Cruiser laid down 1937
Displacement: 4,156 t light; 4,372 t standard; 4,856 t normal; 5,243 t full load
Dimensions: Length overall / water x beam x draught
446.19 ft / 446.19 ft x 44.95 ft x 19.69 ft (normal load)
136.00 m / 136.00 m x 13.70 m x 6.00 m
Armament:
12 - 4.53" / 115 mm guns (6x2 guns), 46.40lbs / 21.05kg shells, 1937 Model Dual purpose guns in deck mounts with hoists on centreline ends, evenly spread, 3 raised mounts - superfiring
24 - 1.38" / 35.0 mm guns (6x4 guns), 1.31lbs / 0.59kg shells, 1937 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring
Weight of broadside 588 lbs / 267 kg
Shells per gun, main battery: 350
6 - 24.0" / 610 mm above water torpedoes
Armour:
Belts: Width (max) Length (avg) Height (avg)
Main: 2.76" / 70 mm 354.33 ft / 108.00 m 7.97 ft / 2.43 m
Ends: Unarmoured
Main Belt covers 122 % of normal length
Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.36" / 60 mm 2.36" / 60 mm -
2nd: 0.79" / 20 mm - -
Armour deck: 0.79" / 20 mm, Conning tower: 3.15" / 80 mm
Machinery:
Oil fired boilers, steam turbines, Geared drive, 2 shafts, 57,097 shp / 42,594 Kw = 33.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 872 tons
Complement: 290 - 378
Cost: £2.338 million / $9.351 million
Distribution of weights at normal displacement:
Armament: 74 tons, 1.5 %
Armour: 613 tons, 12.6 %
- Belts: 313 tons, 6.5 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 90 tons, 1.8 %
- Armour Deck: 191 tons, 3.9 %
- Conning Tower: 19 tons, 0.4 %
Machinery: 1,581 tons, 32.6 %
Hull, fittings & equipment: 1,808 tons, 37.2 %
Fuel, ammunition & stores: 700 tons, 14.4 %
Miscellaneous weights: 80 tons, 1.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 3,708 lbs / 1,682 Kg = 79.9 x 4.5 " / 115 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.07
Metacentric height 1.7 ft / 0.5 m
Roll period: 14.4 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.54
Seaboat quality (Average = 1.00): 1.21
Hull form characteristics:
Hull has rise forward of midbreak and transom stern
Block coefficient: 0.431
Length to Beam Ratio: 9.93: 1
'Natural speed' for length: 24.34 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 59
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: 29.53 ft / 9.00 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (50 %): 22.97 ft / 7.00 m (13.88 ft / 4.23 m aft of break)
- Quarterdeck (15 %): 13.88 ft / 4.23 m
- Stern: 13.88 ft / 4.23 m
- Average freeboard: 18.95 ft / 5.78 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.7 %
- Above water (accommodation/working, high = better): 113.4 %
Waterplane Area: 13,082 Square feet or 1,215 Square metres
Displacement factor (Displacement / loading): 109 %
Structure weight / hull surface area: 70 lbs/sq ft or 341 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.79
- Longitudinal: 2.75
- Overall: 0.90
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
Breakdown of Miscellaneous Weight:
Radar - 50 tons - added during Refit
Reserved for future growth - 30 tons
Level 1 Refit: 5%
Radar added.
Refit cost: 208 tons
Refit time: 20 days