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1

Friday, August 18th 2017, 3:46pm

Peruvian Future Projects

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

2

Friday, August 18th 2017, 9:31pm

Looks nice. A bit surprised it is bigger than the corvettes.

3

Friday, August 18th 2017, 10:51pm

Looks nice. A bit surprised it is bigger than the corvettes.


It is a larger design; a bit more heavily armed, far longer legged. Think oceanic versus coastal. Haven't quite figured out what A/S outfit might be necessary (hence the 'not specified' in the miscellaneous weight). They are not much faster than the Maranons but I think more capable.

4

Saturday, August 19th 2017, 1:37pm

Looks a sound design overall.
I guess the ASW armament isn't going to amount to much more than depth-charges and perhaps a Mousetrap-like rocket system unless Peru has access to more expensive and sophisticated weapon systems and then you would still need to trade off whether they are worth fitting on a reasonably small ship like this.

5

Saturday, August 19th 2017, 1:44pm

Depends on the weights you use for the ASW armament. A couple of DC rails (1t/rail) and DC throwers (1t/thrower) and 100 or so DCs (1t/3 DCs) would get you to about 40 tons. I found a value of 30 tons for a Squid launcher + ammunition somewhere so that would eat up quite a bit of the 30 tons and only give you 1 launcher if that were to be used. Not sure what the Mousetrap system Hood mentioned would be, but I would agree that DCs is probably going to be the option for this design.

6

Tuesday, August 22nd 2017, 2:57pm

Thank you all for your feedback. I've given more thought to the design and opted to beef it up a bit more. It's fast enough now to warrant calling it a corvette, and I've specified the details of the ASW gear - pretty much doubling that of the recent Maranon-class. My current thinking is four ships over the period 1948-49. Your comments are welcome.

Huancabamba, Peruvian Corvette laid down 1948

Displacement: 860 t light; 908 t standard; 1,062 t normal; 1,185 t full load

Dimensions: Length overall / water x beam x draught

270.50 ft / 262.47 ft x 33.14 ft x 8.20 ft (normal load) [82.45 m / 80.00 m x 10.10 m x 2.50 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, 11,695 shp / 8,725 Kw = 25.00 kts
Range 5,000nm at 15.00 kts
Bunker at max displacement = 277 tons

Complement: 92 - 120

Cost: £0.593 million / $2.374 million

Distribution of weights at normal displacement:

Armament: 11 tons, 1.1 %
Armor: 11 tons, 1.0 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 9 tons, 0.8 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.2 %
Machinery: 286 tons, 26.9 %
Hull, fittings & equipment: 452 tons, 42.6 %
Fuel, ammunition & stores: 202 tons, 19.0 %
Miscellaneous weights: 100 tons, 9.4 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 1,361 lbs / 617 Kg = 65.4 x 3.5 " / 88 mm shells or 0.6 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 %): 76 %
- Recoil effect (Restricted arc if above 1.00): 0.25
Seaboat quality (Average = 1.00): 1.43

Hull form characteristics:

Hull has a flush deck
Block coefficient: 0.521
Length to Beam Ratio: 7.92: 1
'Natural speed' for length: 16.20 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 53
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): 108.0 %
- Above water (accommodation/working, high = better): 190.6 %
Waterplane Area: 5,908 Square feet or 549 Square meters
Displacement factor (Displacement / loading): 137 %
Structure weight / hull surface area: 38 lbs/sq ft or 188 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 0.67
- Longitudinal: 5.03
- Overall: 0.82
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
Breakdown of Miscellaneous Weight

Provision for radar and other electronics - 15 tons
Provision for tropicalization - 15 tons
Antisubmarine detection equipment (ASDIC/Sonar) - 10 tons
Two depth charge racks for 100 kg depth charges - 20 tons
Four depth charge projectors for 100 kg depth charges - 5 tons each - 20 tons
Two hundred depth charges - 20 tons

7

Tuesday, August 22nd 2017, 7:09pm

Peruvian Small Transport

The observant would be correct in suspecting this design is cloned from Yugoslavia's Lubin class; the bow doors have been dispensed with and these ships would be normal cargo and emergency troop carriers; Peru still suffers from a lack of roads and rails linking the north with the center and south.

TBD, Peruvian Small Transport laid down 1948

Displacement: 685 t light; 709 t standard; 1,085 t normal; 1,386 t full load

Dimensions: Length overall / water x beam x draught

196.32 ft / 190.94 ft x 36.09 ft x 9.19 ft (normal load) [59.84 m / 58.20 m x 11.00 m x 2.80 m]

Armament:

2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1948 Model Anti-aircraft guns in deck mount on centerline forward
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1948 Model Anti-aircraft guns in deck mounts on side, all amidships, all raised mounts - superfiring
Weight of broadside 4 lbs / 2 kg
Shells per gun, main battery: 600

Armor:

Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.39" / 10 mm 0.39" / 10 mm -

Conning tower: 0.98" / 25 mm

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 2,399 shp / 1,790 Kw = 16.00 kts
Range 20,000nm at 12.00 kts
Bunker at max displacement = 678 tons

Complement: 93 - 122

Cost: £0.243 million / $0.973 million

Distribution of weights at normal displacement:

Armament: 1 tons, 0.0 %
Armor: 3 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.1 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.2 %
Machinery: 59 tons, 5.4 %
Hull, fittings & equipment: 373 tons, 34.4 %
Fuel, ammunition & stores: 400 tons, 36.9 %
Miscellaneous weights: 250 tons, 23.0 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 3,143 lbs / 1,426 Kg = 2,033.6 x 1.5 " / 37 mm shells or 1.7 torpedoes
Stability (Unstable if below 1.00): 1.17
Metacentric height 1.5 ft / 0.4 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 74 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.32

Hull form characteristics:

Hull has a flush deck
Block coefficient: 0.600
Length to Beam Ratio: 5.29: 1
'Natural speed' for length: 13.82 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 56
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.76 ft / 4.50 m
- Forecastle (30 %): 12.30 ft / 3.75 m
- Mid (45 %): 9.84 ft / 3.00 m
- Quarterdeck (35 %): 9.84 ft / 3.00 m
- Stern: 9.84 ft / 3.00 m
- Average freeboard: 11.06 ft / 3.37 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 44.4 %
- Above water (accommodation/working, high = better): 107.0 %
Waterplane Area: 5,040 Square feet or 468 Square meters
Displacement factor (Displacement / loading): 290 %
Structure weight / hull surface area: 51 lbs/sq ft or 249 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 1.12
- Longitudinal: 3.29
- Overall: 1.25
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Low-stowed cargo simmed as additional bunkers - true radius 9,000 nm on bunkers of 172 tons (BAM 310)

Breakdown of miscellaneous weight:

Provision for cargo handling gear (cranes): 50 tons
Provision for up to 100 troops over short distances: 200 tons

Low stowed cargo - 390 tons

8

Sunday, November 12th 2017, 12:28am

At present the Peruvian Navy lacks service craft. So I have drawn up plans for a small tender for destroyers and small flotilla craft.

********

Carrasco, Peruvian Destroyer Tender laid down 1948

Displacement: 2,321 t light; 2,409 t standard; 3,253 t normal; 3,929 t full load

Dimensions: Length overall / water x beam x draught

333.02 ft / 327.43 ft x 44.46 ft x 15.19 ft (normal load) [101.51 m / 99.80 m x 13.55 m x 4.63 m]

Armament:

2 - 4.13" / 105 mm guns (1x2 guns), 35.32lbs / 16.02kg shells, 1948 Model Dual purpose guns in deck mount on centerline forward
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1948 Model Anti-aircraft guns in deck mounts on side, all amidships
2 - 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 77 lbs / 35 kg
Shells per gun, main battery: 500

Armor:

Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm 0.59" / 15 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -

Conning tower: 0.98" / 25 mm

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 5,648 shp / 4,214 Kw = 18.00 kts
Range 15,000nm at 15.00 kts
Bunker at max displacement = 1,520 tons

Complement: 215 - 280

Cost: £0.810 million / $3.241 million

Distribution of weights at normal displacement:

Armament: 10 tons, 0.3 %
Armor: 9 tons, 0.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.1 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 5 tons, 0.1 %
Machinery: 138 tons, 4.2 %
Hull, fittings & equipment: 1,064 tons, 32.7 %
Fuel, ammunition & stores: 932 tons, 28.7 %
Miscellaneous weights: 1,100 tons, 33.8 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 7,995 lbs / 3,627 Kg = 226.4 x 4.1 " / 105 mm shells or 2.1 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.8 ft / 0.5 m
Roll period: 14.0 seconds
Steadiness - As gun platform (Average = 50 %): 56 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:

Hull has rise forward of midbreak
Block coefficient: 0.515
Length to Beam Ratio: 7.37: 1
'Natural speed' for length: 18.09 kts
Power going to wave formation at top speed: 45 %
Trim (Max stability = 0, Max steadiness = 100): 28
Bow angle (Positive = bow angles forward): 11.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.34 ft / 6.20 m
- Forecastle (15 %): 19.69 ft / 6.00 m
- Mid (50 %): 19.69 ft / 6.00 m (14.76 ft / 4.50 m aft of break)
- Quarterdeck (30 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 17.26 ft / 5.26 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 54.4 %
- Above water (accommodation/working, high = better): 155.9 %
Waterplane Area: 9,833 Square feet or 913 Square meters
Displacement factor (Displacement / loading): 222 %
Structure weight / hull surface area: 61 lbs/sq ft or 299 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 3.23
- Overall: 1.05
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

Low-stowed cargo simmed as additional fuel. Actual range is 5,000 nm with bunkers of 292 tons. (BAM 526). 550 tons of fuel available for transfer

Breakdown of miscellaneous weight:

Provision for navigational radar: 20 tons
Accommodation for additional crew and recreational spaces: 400 tons
Provision for workshop space: 300
Provision for spares storage space: 300 tons
Handling gear for cargo and repairs: 80 tons