I am toying with answers to the question "What does the Peruvian Navy need for the rest of the decade?"
The following design is the first one I've come up with. The designation 'offshore patrol vessel' is rather anachronistic, but those are the roles it would fulfill - monitoring the offshore fisheries, anti-smuggling patrols, search and rescue at sea, etc. If built, they would supplement, and eventually replace (post 1950s) the current force of sloops. Any thoughts?
TBD, Peruvian Offshore Patrol Vessel laid down 1948
Displacement: 766 t light; 813 t standard; 1,000 t normal; 1,149 t full load
Dimensions: Length overall / water x beam x draught:
254.10 ft / 246.06 ft x 33.14 ft x 9.84 ft (normal load) [77.45 m / 75.00 m x 10.10 m x 3.00 m]
Armament:
4 - 3.46" / 88.0 mm guns (2x2 guns), 20.79lbs / 9.43kg shells, 1948 Model Anti-aircraft guns in deck mounts with hoists on centerline ends, evenly spread
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1948 Model Anti-aircraft guns in deck mounts on centerline ends, evenly spread, all raised mounts
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1948 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 90 lbs / 41 kg
Shells per gun, main battery: 500
Armor:
Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.59" / 15 mm 0.98" / 25 mm
2nd: 0.59" / 15 mm 0.59" / 15 mm -
3rd: 0.39" / 10 mm - -
Conning tower: 0.98" / 25 mm
Machinery:
Diesel Internal combustion motors, Geared drive, 2 shafts, 4,411 shp / 3,291 Kw = 20.00 kts
Range 6,500nm at 15.00 kts
Bunker at max displacement = 337 tons
Complement: 88 - 115
Cost: £0.383 million / $1.532 million
Distribution of weights at normal displacement:
Armament: 11 tons, 1.1 %
Armor: 11 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 9 tons, 0.9 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.2 %
Machinery: 108 tons, 10.8 %
Hull, fittings & equipment: 556 tons, 55.6 %
Fuel, ammunition & stores: 234 tons, 23.4 %
Miscellaneous weights: 80 tons, 8.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 3,105 lbs / 1,408 Kg = 149.3 x 3.5 " / 88mm shells or 1.4 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.1 ft / 0.3 m
Roll period: 13.0 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.24
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.436
Length to Beam Ratio: 7.43: 1
'Natural speed' for length: 15.69 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20 %): 18.04 ft / 5.50 m
- Mid (50 %): 14.76 ft / 4.50 m
- Quarterdeck (20 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 16.04 ft / 4.89 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 55.6 %
- Above water (accommodation/working, high = better): 173.5 %
Waterplane Area: 5,143 Square feet or 478 Square meters
Displacement factor (Displacement / loading): 252 %
Structure weight / hull surface area: 51 lbs/sq ft or 250 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 8.41
- Overall: 1.13
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Provision for radar and other electronics - 25 tons
Provision for tropicalization - 15 tons
To be specified - 40 tons