WesWorld

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

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

Quoted from "Doorcf"

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.

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.

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.

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

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

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

To be constructed under the small craft rules. Intended for service on the upper Amazon. The main armament is, in fact, a 120mm howitzer.

*****
Chachapoyas, Peruvian River Monitor laid down 1949

Displacement: 179 t light; 192 t standard; 200 t normal; 207 t full load

Dimensions: Length overall / water x beam x draught

157.14 ft / 155.84 ft x 21.33 ft x 4.92 ft (normal load) [47.90 m / 47.50 m x 6.50 m x 1.50 m]

Armament:

1 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1949 Model Quick firing gun in deck mount on centerline forward
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1949 Model Anti-aircraft guns in deck mount on centerline amidships
4 - 0.79" / 20.0 mm guns (1x4 guns), 0.24lbs / 0.11kg shells, 1949 Model Anti-aircraft guns in deck mount on centerline aft
Weight of broadside 57 lbs / 26 kg
Shells per gun, main battery: 250

Armor:

Belts: Width (max) Length (avg) Height (avg)
Main: 0.79" / 20 mm 82.02 ft / 25.00 m 3.28 ft / 1.00 m
Ends: Unarmored
Main Belt covers 81 % of normal length

Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.59" / 15 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 534 shp / 399 Kw = 15.00 kts
Range 2,000nm at 10.00 kts
Bunker at max displacement = 15 tons

Complement: 26 - 34

Cost: £0.107 million / $0.429 million

Distribution of weights at normal displacement:

Armament: 7 tons, 3.5 %
Armor: 12 tons, 6.1 %
- Belts: 9 tons, 4.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 1.4 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 13 tons, 6.5 %
Hull, fittings & equipment: 117 tons, 58.5 %
Fuel, ammunition & stores: 21 tons, 10.4 %
Miscellaneous weights: 30 tons, 15.0 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 563 lbs / 255 Kg = 10.7 x 4.7 " / 120 mm shells or 0.6 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 0.6 ft / 0.2 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 65 %
- Recoil effect (Restricted arc if above 1.00): 0.25
Seaboat quality (Average = 1.00): 1.81

Hull form characteristics:

Hull has a flush deck and transom stern
Block coefficient: 0.428
Length to Beam Ratio: 7.31: 1
'Natural speed' for length: 14.79 kts
Power going to wave formation at top speed: 49 %
Trim (Max stability = 0, Max steadiness = 100): 36
Bow angle (Positive = bow angles forward): 9.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 8.20 ft / 2.50 m
- Forecastle (20 %): 8.20 ft / 2.50 m
- Mid (50 %): 8.20 ft / 2.50 m
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 8.20 ft / 2.50 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 67.3 %
- Above water (accommodation/working, high = better): 130.0 %
Waterplane Area: 2,164 Square feet or 201 Square meters
Displacement factor (Displacement / loading): 160 %
Structure weight / hull surface area: 33 lbs/sq ft or 163 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 1.02
- Longitudinal: 4.24
- Overall: 1.18
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

Nice replacement for the older Riverine Gunboats although smaller

Also a small question, is the 120mm a new design or the old howitzers used by the army?

Quoted from "Doorcf"

Nice replacement for the older Riverine Gunboats although smaller

Also a small question, is the 120mm a new design or the old howitzers used by the army?

Given the relatively small numbers projected, it would be a modern design of foreign origin and manufacture, as the 120mm round is not presently in the Peruvian Army's inventory.

Looks a nice little river gunboat design.

Hi. What are 30ts of misc for on such a small design? Seems excessive, but probably I have missed something...

Quoted from "HoOmAn"

Hi. What are 30ts of misc for on such a small design? Seems excessive, but probably I have missed something...

Hey, long time no see Hoo. Hope things are well with you.

The miscellaneous weight is there in case (a) they have to carry troops over short distances (they'll be operating on the upper Amazon) or (b) carry equipment or cargo.

Pascamayo, Peruvian Logistics Support Vessel; laid down 1949

Displacement: 1,760 t light; 1,820 t standard; 1,910 t normal; 1,982 t full load

Dimensions: Length overall / water x beam x draught

332.98 ft / 328.08 ft x 49.21 ft x 6.56 ft (normal load) [101.49 m / 100.00 m x 15.00 m x 2.00 m]

Armament:

8 - 1.46" / 37.0 mm guns (2x4 guns), 1.55lbs / 0.70kg shells, 1949 Model Anti-aircraft guns in deck mounts on centerline ends, evenly spread
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1949 Model Anti-aircraft guns in deck mounts on side, all aft
Weight of broadside 14 lbs / 6 kg
Shells per gun, main battery: 2,400

Machinery:


Diesel Internal combustion motors, Geared drive, 2 shafts, 2,425 shp / 1,809 Kw = 15.00 kts
Range 3,000nm at 12.00 kts
Bunker at max displacement = 161 tons

Complement: 143 - 187

Cost: £0.544 million / $2.178 million

Distribution of weights at normal displacement:

Armament: 2 tons, 0.1 %
Machinery: 59 tons, 3.1 %
Hull, fittings & equipment: 799 tons, 41.9 %
Fuel, ammunition & stores: 150 tons, 7.9 %
Miscellaneous weights: 900 tons, 47.1 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 4,375 lbs / 1,985 Kg = 2,831.0 x 1.5 " / 37 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 2.1 ft / 0.6 m
Roll period: 14.3 seconds
Steadiness - As gun platform (Average = 50 %): 73 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.09

Hull form characteristics:

Hull has raised quarterdeck
Block coefficient: 0.631
Length to Beam Ratio: 6.67: 1
'Natural speed' for length: 18.11 kts
Power going to wave formation at top speed: 34 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 8.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 11.48 ft / 3.50 m
- Forecastle (20 %): 9.84 ft / 3.00 m
- Mid (50 %): 9.84 ft / 3.00 m
- Quarterdeck (30 %): 11.48 ft / 3.50 m (9.84 ft / 3.00 m before break)
- Stern: 11.48 ft / 3.50 m
- Average freeboard: 10.47 ft / 3.19 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 63.9 %
- Above water (accommodation/working, high = better): 159.3 %
Waterplane Area: 12,154 Square feet or 1,129 Square meters
Displacement factor (Displacement / loading): 185 %
Structure weight / hull surface area: 54 lbs/sq ft or 266 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 1.13
- Longitudinal: 0.96
- Overall: 1.00
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

Breakdown of Miscellaneous Weight

Provision for bow doors and ramp - 20 tons
Provision for electronics - 20 tons
Cargo - 860 tons, including vehicles

Constructed under LST rules - Cost = 1760 tons - (Misc weight/2) 450 tons = 1310 tons

Bolognesi, Peruvian Destroyer laid down 1949

Displacement: 2,110 t light; 2,332 t standard; 2,598 t normal; 2,810 t full load

Dimensions: Length overall / water x beam x draught

409.37 ft / 393.70 ft x 39.37 ft x 13.12 ft (normal load) [124.78 m / 120.00 m x 12.00 m x 4.00 m]

Armament:

4 - 5.12" / 130 mm guns (2x2 guns), 67.03lbs / 30.41kg shells, 1949 Model Automatic rapid fire guns in deck mounts with hoists on centreline ends, evenly spread
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1949 Model Anti-aircraft guns in deck mounts on side, evenly spread
4 - 1.18" / 30.0 mm guns in single mounts, 0.82lbs / 0.37kg shells, 1949 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 317 lbs / 144 kg
Shells per gun, main battery: 900
6 - 17.7" / 450 mm above water torpedoes

Armor:

Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 0.59" / 15 mm 0.59" / 15 mm -
3rd: 0.59" / 15 mm - -

Conning tower: 1.57" / 40 mm

Machinery:

Oil fired boilers, steam turbines, Geared drive, 2 shafts, 36,238 shp / 27,034 Kw = 32.00 kts
Range 5,000nm at 16.00 kts
Bunker at max displacement = 478 tons

Complement: 181 - 236

Cost: £1.798 million / $7.191 million

Distribution of weights at normal displacement:

Armament: 46 tons, 1.8 %
Armor: 26 tons, 1.0 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 19 tons, 0.7 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 6 tons, 0.2 %
Machinery: 876 tons, 33.7 %
Hull, fittings & equipment: 1,062 tons, 40.9 %
Fuel, ammunition & stores: 487 tons, 18.8 %
Miscellaneous weights: 100 tons, 3.8 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 1,897 lbs / 861 Kg = 28.3 x 5.1 " / 130 mm shells or 0.6 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 1.6 ft / 0.5 m
Roll period: 13.0 seconds
Steadiness - As gun platform (Average = 50 %): 76 %
- Recoil effect (Restricted arc if above 1.00): 0.41
Seaboat quality (Average = 1.00): 1.40

Hull form characteristics:

Hull has rise forward of midbreak and transom stern
Block coefficient: 0.447
Length to Beam Ratio: 10.00: 1
'Natural speed' for length: 22.79 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 54
Bow angle (Positive = bow angles forward): 28.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 23.29 ft / 7.10 m
- Forecastle (20 %): 22.64 ft / 6.90 m
- Mid (50 %): 21.98 ft / 6.70 m (14.44 ft / 4.40 m aft of break)
- Quarterdeck (15 %): 14.44 ft / 4.40 m
- Stern: 14.44 ft / 4.40 m
- Average freeboard: 18.49 ft / 5.64 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 132.9 %
- Above water (accommodation/working, high = better): 157.8 %
Waterplane Area: 10,245 Square feet or 952 Square meters
Displacement factor (Displacement / loading): 116 %
Structure weight / hull surface area: 51 lbs/sq ft or 250 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 0.68
- Longitudinal: 3.26
- Overall: 0.79
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Reserved for air warning radar - 15 tons
Reserved for surface search radar - 15 tons
Reserved for fire control radar - 15 tons
Reserved for AS detection equipment - 20 tons
Reserved for Ahead-Thrown AS Weapon - 15 tons
Reserved for AS outfit including DC and K-guns - 20 tons

Ahead-thrown AS weapon is mounted in B position before the bridge, and is trainable.
Torpedo tubes are for short range A/S weapons mounted three on each beam

You're switching gun sizes?

Quoted from "Brockpaine"

You're switching gun sizes?

That is the plan - seeking to catch up with the rest of the world.

This class of small cargo ship was designed to be able to navigate the waters of the Peruvian Amazon and support economic development there. They would be operated by Naviera Amazónica Peruana S. A.

Loreto, Peruvian Riverine Cargo Ship laid down 1949

Displacement: 630 t light; 656 t standard; 1,270 t normal; 1,761 t full load

Dimensions: Length overall / water x beam x draught

185.57 ft / 180.45 ft x 31.99 ft x 10.66 ft (normal load) [56.56 m / 55.00 m x 9.75 m x 3.25 m]

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 880 shp / 656 Kw = 12.00 kts
Range 48,000nm at 10.00 kts
Bunker at max displacement = 1,105 tons

Complement: 11 - 14

Cost: £0.191 million / $0.765 million

Distribution of weights at normal displacement:

Armament: 0 tons, 0.0 %
Machinery: 21 tons, 1.7 %
Hull, fittings & equipment: 409 tons, 32.2 %
Fuel, ammunition & stores: 639 tons, 50.4 %
Miscellaneous weights: 200 tons, 15.8 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 705 lbs / 320 Kg = 6.5 x 6 " / 152 mm shells or .4 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 1.2 ft / 0.4 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:

Hull has a flush deck
Block coefficient: 0.722
Length to Beam Ratio: 5.64 : 1
'Natural speed' for length: 13.43 kts
Power going to wave formation at top speed: 48 %
Trim (Max stability = 0, Max steadiness = 100): 51
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 16.40 ft / 5.00 m
- Forecastle (20 %): 15.58 ft / 4.75 m
- Mid (50 %): 13.94 ft / 4.25 m
- Quarterdeck (10 %): 13.94 ft / 4.25 m
- Stern: 13.94 ft / 4.25 m
- Average freeboard: 14.58 ft / 4.45 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 24.2 %
- Above water (accommodation/working, high = better): 121.2 %
Waterplane Area: 4,718 Square feet or 438 Square metres
Displacement factor (Displacement / loading): 523 %
Structure weight / hull surface area: 47 lbs/sq ft or 231 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 7.88
- Overall: 1.23
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, rides out heavy weather easily

Low-stowed cargo simmed as additional bunkers. Actual radius 8,000 nm on bunkers of 106 tons. Remaining bunkers represent cargo ~ 500 tons

Breakdown of miscellaneous weight:

Provision for working deck gear - 10 tons per hatch for two hatches - 20 tons
High stowed and deck cargo - 180 tons

Crew complement and survivability reduced for commercial service

Morales, Peruvian Salvage Tug laid down 1949

Displacement: 1,075 t light; 1,113 t standard; 1,840 t normal; 2,421 t full load

Dimensions: Length overall / water x beam x draught

218.73 ft / 213.25 ft x 39.37 ft x 13.94 ft (normal load) [66.67 m / 65.00 m x 12.00 m x 4.25 m]

Armament:

2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1949 Model Anti-aircraft guns in deck mount on centerline forward
2 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1949 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 4 lbs / 2 kg
Shells per gun, main battery: 500

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 7,732 shp / 5,768 Kw = 20.00 kts
Range 16,000nm at 15.00 kts
Bunker at max displacement = 1,309 tons

Complement: 139 - 182

Cost: £0.490 million / $1.960 million

Distribution of weights at normal displacement:

Armament: 0 tons, 0.0 %
Machinery: 187 tons, 10.2 %
Hull, fittings & equipment: 667 tons, 36.3 %
Fuel, ammunition & stores: 765 tons, 41.6 %
Miscellaneous weights: 220 tons, 12.0 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 5,327 lbs / 2,416 Kg = 3,446.9 x 1.5 " / 37 mm shells or 1.9 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 1.6 ft / 0.5 m
Roll period: 13.1 seconds
Steadiness - As gun platform (Average = 50 %): 68 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.09

Hull form characteristics: Hull has rise forward of midbreak
Block coefficient: 0.550
Length to Beam Ratio: 5.42: 1
'Natural speed' for length: 14.60 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 62
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 18.04 ft / 5.50 m
- Forecastle (20 %): 17.22 ft / 5.25 m
- Mid (50 %): 17.22 ft / 5.25 m (10.66 ft / 3.25 m aft of break)
- Quarterdeck (50 %): 10.66 ft / 3.25 m
- Stern: 10.66 ft / 3.25 m
- Average freeboard: 14.01 ft / 4.27 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 47.5 %
- Above water (accommodation/working, high = better): 138.3 %
Waterplane Area: 5,859 Square feet or 544 Square meters
Displacement factor (Displacement / loading): 308 %
Structure weight / hull surface area: 68 lbs/sq ft or 333 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 1.12
- Longitudinal: 5.66
- Overall: 1.32
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent

Breakdown of Miscellaneous Weight

Subsidiary low-speed towing diesel - 40 tons
Towing equipment - 80 tons
Salvage crane - 30 tons
High-capacity pumps - 40 tons
Submarine rescue apparatus/chamber - 30 tons