(Historical data)
Design work on sloops has been underway for the better part of two years, as Peru grapples with the need to police its rich fisheries and patrol its lengthy shoreline without diverting its relatively small quantity of destroyers and torpedo-boats to such roles.
The Rio class sloops were to undertake this role for the Marina, and are instead expected to do so as the core of a new Coast Guard. The class is sufficiently armed to function as an escort along the coast, but also has boats and extra accommodation to allow for prolonged fisheries inspection duties.
Rio Ucayali, laid down 1942 - Scrapped 1949
Rio Putumayo, laid down 1942
Rio Urubamba, laid down 1943
Rio Huallaga, laid down 1943
Rio Yavari, laid down 1944
Rio, Peruvian sloop, laid down 1942
Displacement: 1,000 t light; 1,053 t standard; 1,228 t normal; 1,367 t full load
Dimensions: Length overall / water x beam x draught
254.30 ft / 250.66 ft x 29.86 ft x 11.48 ft (normal load) [77.51 m / 76.40 m x 9.10 m x 3.50 m]
Armament:
2 - 4.13" / 105 mm guns (1x2 guns), 35.32lbs / 16.02kg shells, 1942 Model Dual purpose guns in a deck mount with hoist on centerline forward
2 - 4.13" / 105 mm guns (1x2 guns), 35.32lbs / 16.02kg shells, 1942 Model Dual purpose guns in a deck mount with hoist on centerline aft, all raised guns - superfiring
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1942 Model Anti-aircraft guns in deck mounts on side, evenly spread
6 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1942 Model Anti-aircraft guns in deck mounts on side, evenly spread
4 - 0.51" / 13.0 mm guns in single mounts, 0.07lbs / 0.03kg shells, 1942 Model Machine guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 149 lbs / 68 kg
Shells per gun, main battery: 300
Armor:
Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
2nd: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
3rd: 0.79" / 20 mm - -
4th: 0.39" / 10 mm - -
Machinery:
Oil fired boilers, steam turbines, Geared drive, 2 shafts, 12,236 shp / 9,128 Kw = 24.76 kts
Range 5,000nm at 15.00 kts (Bunkerage = 314 tons)
Complement: 103 - 134
Cost: £0.607 million / $2.429 million
Distribution of weights at normal displacement:
Armament: 19 tons, 1.5 %
Armor: 15 tons, 1.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 15 tons, 1.2 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 320 tons, 26.0 %
Hull, fittings & equipment: 536 tons, 43.7 %
Fuel, ammunition & stores: 228 tons, 18.5 %
Miscellaneous weights: 110 tons, 9.0 %
-20 t: Accommodation for 10 fisheries officers or marines
-20 t: Two additional 5 t boats plus davits
-20 t: Boom for minesweeping/trawling/salvage
-16 t: 48 DC + rails and throwers
-14 t: Weight reserve
-10 t: ASDIC
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 1,432 lbs / 650 Kg = 40.5 x 4.1 " / 105 mm shells or 0.6 torpedoes
Stability (Unstable if below 1.00): 1.11
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.44
Seaboat quality (Average = 1.00): 1.24
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.500
Length to Beam Ratio: 8.40: 1
'Natural speed' for length: 15.83 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 40
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.67 ft / 6.30 m
- Forecastle (20 %): 17.72 ft / 5.40 m
- Mid (50 %): 17.72 ft / 5.40 m (9.84 ft / 3.00 m aft of break)
- Quarterdeck (15 %): 9.84 ft / 3.00 m
- Stern: 9.84 ft / 3.00 m
- Average freeboard: 14.02 ft / 4.27 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 107.6 %
- Above water (accommodation/working, high = better): 124.3 %
Waterplane Area: 4,986 Square feet or 463 Square meters
Displacement factor (Displacement / loading): 134 %
Structure weight / hull surface area: 51 lbs/sq ft or 249 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 0.85
- Longitudinal: 5.48
- Overall: 1.02
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily