Peru 1915-1919 program

[Jefgte]

2100T , Peru Squadron Gunboat laid down 1916 (Engine 1912)

Putre LD 1916
Robore LD 1917

Displacement:
   2 100 t light; 2 184 t standard; 2 544 t normal; 2 832 t full load

Dimensions: Length overall / water x beam x draught
   392.49 ft / 390.42 ft x 43.37 ft x 11.58 ft (normal load)
   119.63 m / 119.00 m x 13.22 m  x 3.53 m

Armament:
      4 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on centreline, evenly spread
     Aft Main mounts separated by engine room
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
     Breech loading guns in deck mounts
     on centreline, all amidships
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 459 lbs / 208 kg
   Shells per gun, main battery: 125
   8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.15" / 80 mm   242.78 ft / 74.00 m   8.01 ft / 2.44 m
   Ends:   1.57" / 40 mm     78.74 ft / 24.00 m   6.89 ft / 2.10 m
     68.90 ft / 21.00 m Unarmoured ends
     Main Belt covers 96 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.79" / 20 mm         -               -
   3rd:   0.50" / 13 mm         -               -

   - Armour deck: 0.08" / 2 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 14 000 shp / 10 444 Kw = 24.24 kts
   Range 7 000nm at 12.00 kts
   Bunker at max displacement = 648 tons

Complement:
   178 - 232

Cost:
   £0.327 million / $1.308 million

Distribution of weights at normal displacement:
   Armament: 57 tons, 2.3 %
   Armour: 319 tons, 12.6 %
      - Belts: 290 tons, 11.4 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 14 tons, 0.5 %
      - Armour Deck: 16 tons, 0.6 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 558 tons, 21.9 %
   Hull, fittings & equipment: 1 045 tons, 41.1 %
   Fuel, ammunition & stores: 444 tons, 17.4 %
   Miscellaneous weights: 120 tons, 4.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3 712 lbs / 1 684 Kg = 34.4 x 6.0 " / 152 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.28
   Metacentric height 2.2 ft / 0.7 m
   Roll period: 12.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.26
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.454
   Length to Beam Ratio: 9.00 : 1
   'Natural speed' for length: 19.76 kts
   Power going to wave formation at top speed: 51 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 6.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      19.69 ft / 6.00 m
      - Forecastle (18 %):   14.44 ft / 4.40 m
      - Mid (40 %):      11.15 ft / 3.40 m
      - Quarterdeck (17 %):   11.15 ft / 3.40 m
      - Stern:      11.15 ft / 3.40 m
      - Average freeboard:   12.48 ft / 3.81 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 93.9 %
      - Above water (accommodation/working, high = better): 91.6 %
   Waterplane Area: 10 837 Square feet or 1 007 Square metres
   Displacement factor (Displacement / loading): 126 %
   Structure weight / hull surface area: 65 lbs/sq ft or 318 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.22
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   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 Rock Doctor]

A 2mm armor deck doesn't accomplish besides ensuring that I can't stomp a hole through it...

Otherwise, it's looking better.

[miketr]

In a number of ways looks like my Large Patrol boat found at the bottom of here.

http://www.navalism.org/index.php?topic=2573.msg27707#msg27707

Some ways better some ways worse.  Good over all.  I agree with Rock I would ditch an armor deck so thin.

Michael

[Jefgte]

2mm armor deck !  :D  :D  :D

That's a mistake
(originaly 20mm & after no number)
------------

Large Patrol Boat is also the job for Putre & Robore but they are made also to be in the battleline with a higher speed, FC & 8x21" TT.


;)

[Jefgte]

2x2100t squadron gunboats or 4x550t DE -  ???

IMO, 4x550t DE are better for the Peruvian 800 000t merchant Fleet

550T, Peru DE laid down 1916 (Engine 1912)

Displacement:
   550 t light; 575 t standard; 761 t normal; 910 t full load

Dimensions: Length overall / water x beam x draught
   228.17 ft / 226.38 ft x 26.25 ft x 10.83 ft (normal load)
   69.55 m / 69.00 m x 8.00 m  x 3.30 m

Armament:
      2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
     Quick firing gun in deck mount
     on centreline amidships
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 119 lbs / 54 kg
   Shells per gun, main battery: 150
   3 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.50" / 13 mm         -               -
   3rd:   0.50" / 13 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 8 600 shp / 6 416 Kw = 24.46 kts
   Range 7 500nm at 12.00 kts
   Bunker at max displacement = 334 tons

Complement:
   72 - 94

Cost:
   £0.123 million / $0.491 million

Distribution of weights at normal displacement:
   Armament: 15 tons, 2.0 %
   Armour: 5 tons, 0.7 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 5 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 309 tons, 40.6 %
   Hull, fittings & equipment: 171 tons, 22.4 %
   Fuel, ammunition & stores: 211 tons, 27.8 %
   Miscellaneous weights: 50 tons, 6.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     261 lbs / 118 Kg = 4.9 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.34
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 10.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0.20
   Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.414
   Length to Beam Ratio: 8.63 : 1
   'Natural speed' for length: 15.05 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 6.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      17.06 ft / 5.20 m
      - Forecastle (19 %):   13.12 ft / 4.00 m
      - Mid (50 %):      9.19 ft / 2.80 m
      - Quarterdeck (18 %):   9.19 ft / 2.80 m
      - Stern:      8.86 ft / 2.70 m
      - Average freeboard:   10.81 ft / 3.30 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 153.5 %
      - Above water (accommodation/working, high = better): 64.6 %
   Waterplane Area: 3 689 Square feet or 343 Square metres
   Displacement factor (Displacement / loading): 88 %
   Structure weight / hull surface area: 23 lbs/sq ft or 114 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.18
      - Overall: 0.58
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Jefgte]

550t DE with higher seaboat quality.
IMO, very important for a little DD. The crew is in better condition to do the job.

550T, Peru DE-Putre class laid down 1916

Displacement:
   550 t light; 582 t standard; 754 t normal; 892 t full load

Dimensions: Length overall / water x beam x draught
   226.38 ft / 226.38 ft x 26.64 ft x 10.68 ft (normal load)
   69.00 m / 69.00 m x 8.12 m  x 3.26 m

Armament:
      2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Breech loading guns in deck mounts
     on centreline, evenly spread
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
     Quick firing gun in deck mount
     on centreline amidships
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 119 lbs / 54 kg
   Shells per gun, main battery: 250
   3 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.50" / 13 mm         -               -
   3rd:   0.50" / 13 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 8 600 shp / 6 415 Kw = 24.50 kts
   Range 8 250nm at 12.00 kts
   Bunker at max displacement = 310 tons

Complement:
   71 - 93

Cost:
   £0.121 million / $0.484 million

Distribution of weights at normal displacement:
   Armament: 15 tons, 2.0 %
   Armour: 5 tons, 0.7 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 5 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 302 tons, 40.0 %
   Hull, fittings & equipment: 184 tons, 24.3 %
   Fuel, ammunition & stores: 204 tons, 27.1 %
   Miscellaneous weights: 45 tons, 6.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     290 lbs / 132 Kg = 5.5 x 4.7 " / 120 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.36
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 10.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 77 %
         - Recoil effect (Restricted arc if above 1.00): 0.22
   Seaboat quality  (Average = 1.00): 1.33

Hull form characteristics:
   Hull has low forecastle
   Block coefficient: 0.410
   Length to Beam Ratio: 8.50 : 1
   'Natural speed' for length: 15.05 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   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:      17.06 ft / 5.20 m
      - Forecastle (19 %):   13.12 ft / 4.00 m (13.78 ft / 4.20 m aft of break)
      - Mid (50 %):      10.50 ft / 3.20 m
      - Quarterdeck (18 %):   9.84 ft / 3.00 m
      - Stern:      9.19 ft / 2.80 m
      - Average freeboard:   11.52 ft / 3.51 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 152.0 %
      - Above water (accommodation/working, high = better): 73.4 %
   Waterplane Area: 3 735 Square feet or 347 Square metres
   Displacement factor (Displacement / loading): 93 %
   Structure weight / hull surface area: 24 lbs/sq ft or 117 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.65
      - Overall: 0.59
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Guinness]

What's the DDE's job?

[Sachmle]

4x550t DE are better for the Peruvian 800 000t merchant Fleet

My guess is MM protection.

[Guinness]

Hmmm. If the job of this ship is to convoy merchant men, let's consider likely opponents:

AMCs: the 120mm guns might be up to the task, or the three torpedoes, but it's going to depend on how many of these can get in close enough to use them. More speed is likely an asset there.

Real live cruisers: I suspect these little boats would be useless against a real protected cruiser, much less something bigger.

Submarines: No listed anti-submarine armament, though there certainly could be some in the miscellaneous weights. Against enemy submarines these boats could be effective. You'd need a lot of them to be really effective, of course, since sonar hasn't arrived to the Nverse yet.

Range is excellent.

The problem is, of course, that you'd have these boats, and they'd be ok for convoy duty, but not much else. I'd find it hard to resist dropping down to 100mm for the main armament and mounting at least 3, and using the weight saved for more speed. That would give you more utility in the long run, even if they had to lose maybe 15 or 20% bunkerage. Of course, that sort of ship would be a real destroyer, which you are obviously trying to avoid.

P3D would also say this design is an abuse of the DD rules, and though I don't agree with him as to just what proportion of weight should be engines in a DD, I think I'd agree with him that this ship is too underengined for a new-build DD rule ship. This is why I made the conscious decision to build my 300t 18 knot sloops to 1.00 overall strength.

[Jefgte]

Exellent analyse Mike.

I considere a DE like a half DD fleet.
Good for the antisubmarine job (not detailled in the SS)
Merchant fleet & BS protection.

[P3D]

There's no submarine threat for Peruvian MM that I am aware of.
Any decent AMC would have 6" guns and would not get knocked out from a few 120mm shells - especially as you have only two of them, a cruiser with FC would outgun the ships easily - and even an AMC without FC, as you could spot for 6+ guns in their case. Add longer-ranged main guns.

Minimum speed for a ~500t combatant under the destroyer rules should be around 28kts. IMHO.

[Jefgte]

There's no submarine threat for Peruvian MM that I am aware of.

http://www.navalism.org/index.php?topic=2958.0

4 x 750t subs are going to be laid down in 1916.

[Korpen]

There's no submarine threat for Peruvian MM that I am aware of.

http://www.navalism.org/index.php?topic=2958.0

4 x 750t subs are going to be laid down in 1916.

You expect your own submarines to go rouge and start attacking you own merchantmen?

[Jefgte]

oups...

Misunderstood  :D
--------------

There's no submarine threat for Peruvian MM that I am aware of.

Nobody knows  ???

[Jefgte]

An other fleet DD - 1000t study
I rework the hull of the Arica class & always good seaboat quality for the crew.
Putre-1916
Robore-1917


1000T, Peru DD laid down 1916 (Engine 1912)

Displacement:
   1 000 t light; 1 037 t standard; 1 201 t normal; 1 333 t full load

Dimensions: Length overall / water x beam x draught
   321.52 ft / 321.52 ft x 33.46 ft x 9.77 ft (normal load)
   98.00 m / 98.00 m x 10.20 m  x 2.98 m

Armament:
      3 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1916 Model
     Breech loading guns in deck mounts
     on centreline ends, majority aft, 1 raised mount aft
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread
   Weight of broadside 185 lbs / 84 kg
   Shells per gun, main battery: 120
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.79" / 20 mm         -               -
   3rd:   0.79" / 20 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 18 792 shp / 14 019 Kw = 28.94 kts
   Range 5 000nm at 12.00 kts
   Bunker at max displacement = 295 tons

Complement:
   101 - 132

Cost:
   £0.217 million / $0.869 million

Distribution of weights at normal displacement:
   Armament: 23 tons, 1.9 %
   Armour: 9 tons, 0.7 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 9 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 559 tons, 46.5 %
   Hull, fittings & equipment: 335 tons, 27.9 %
   Fuel, ammunition & stores: 201 tons, 16.7 %
   Miscellaneous weights: 75 tons, 6.2 %
                100 depth charges
                ...

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     400 lbs / 181 Kg = 7.6 x 4.7 " / 120 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.36
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 10.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 78 %
         - Recoil effect (Restricted arc if above 1.00): 0.18
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.400
   Length to Beam Ratio: 9.61 : 1
   'Natural speed' for length: 17.93 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 64
   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:      18.04 ft / 5.50 m
      - Forecastle (18 %):   14.76 ft / 4.50 m
      - Mid (50 %):      12.14 ft / 3.70 m
      - Quarterdeck (16 %):   11.81 ft / 3.60 m
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   13.13 ft / 4.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 171.5 %
      - Above water (accommodation/working, high = better): 97.6 %
   Waterplane Area: 6 623 Square feet or 615 Square metres
   Displacement factor (Displacement / loading): 68 %
   Structure weight / hull surface area: 29 lbs/sq ft or 140 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.45
      - Overall: 0.56
   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