Destoryer - Light coastal patrol/defense

[asavery]

Greeting,
I am just starting out and am trying to build my new-start Navy.  I have never used Spring Sharp (successfully) and want to test out a few ideas designs.  I can use all the help I can get.  I will have a number of designs and welcome critique.  The first is an early model destroyer (not really, but based on that design criteria) for coastal patrol/swarm defense.

A

Ancash-class , Peru, coastal patrol boat/destroyer, laid down 1895 (Engine 1900)

Displacement:
   400 t light; 411 t standard; 458 t normal; 496 t full load

Dimensions: Length overall / water x beam x draught
   220.00 ft / 220.00 ft x 27.00 ft x 5.00 ft (normal load)
   67.06 m / 67.06 m x 8.23 m  x 1.52 m

Armament:
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1895 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1895 Model
     Machine guns in deck mounts
     on side, all amidships
   Weight of broadside 32 lbs / 15 kg
   Shells per gun, main battery: 150
   2 - 18.0" / 457.2 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm   0.25" / 6 mm            -
   2nd:   0.25" / 6 mm         -               -

   - Conning tower: 0.50" / 13 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 4,519 ihp / 3,371 Kw = 22.00 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 84 tons (100% coal)
     Caution: Delicate, lightweight machinery

Complement:
   49 - 64

Cost:
   £0.053 million / $0.213 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0.9 %
   Armour: 2 tons, 0.4 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 1 tons, 0.1 %
   Machinery: 256 tons, 55.9 %
   Hull, fittings & equipment: 134 tons, 29.2 %
   Fuel, ammunition & stores: 59 tons, 12.8 %
   Miscellaneous weights: 4 tons, 0.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     146 lbs / 66 Kg = 4.6 x 4.0 " / 102 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 10.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.08
   Seaboat quality  (Average = 1.00): 1.17

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.540
   Length to Beam Ratio: 8.15 : 1
   'Natural speed' for length: 14.83 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 85
   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:      16.32 ft / 4.97 m
      - Forecastle (20 %):   10.38 ft / 3.16 m
      - Mid (50 %):      10.38 ft / 3.16 m
      - Quarterdeck (15 %):   10.38 ft / 3.16 m
      - Stern:      10.38 ft / 3.16 m
      - Average freeboard:   10.86 ft / 3.31 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 188.1 %
      - Above water (accommodation/working, high = better): 133.1 %
   Waterplane Area: 3,976 Square feet or 369 Square metres
   Displacement factor (Displacement / loading): 32 %
   Structure weight / hull surface area: 20 lbs/sq ft or 99 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.59
      - Overall: 0.56
   Caution: Hull subject to strain in open-sea
   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

[Ithekro]

If yoou don't intend to engage cruisers with you single 4" gun than I'd recommended switching it out for a smaller quickfire weapon lik a 12 pounder or a 9 pounder.  Or a single type with a few 6 pounders.  They should be enough to engage torpedo boats, destroyers, and small pirates.  The torpedoes and speed would be what one would use against cruisers and above (in numbers as you say).

[asavery]

Well, they certainly wouldn't go toe-to-toe with cruisers with guns...

Here are two followup classes as engine tech improves, please comment.

A


Ica-class, Peru Coastal Patrol laid down 1902 (Engine 1905)

Displacement:
   381 t light; 391 t standard; 450 t normal; 497 t full load

Dimensions: Length overall / water x beam x draught
   250.00 ft / 250.00 ft x 28.00 ft x 5.00 ft (normal load)
   76.20 m / 76.20 m x 8.53 m  x 1.52 m

Armament:
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1902 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1902 Model
     Machine guns in deck mounts
     on side, all amidships
   Weight of broadside 14 lbs / 6 kg
   Shells per gun, main battery: 150
   2 - 18.0" / 457.2 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm   0.25" / 6 mm            -
   2nd:   0.25" / 6 mm         -               -

   - Conning tower: 0.50" / 13 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 1 shaft, 3,946 shp / 2,943 Kw = 22.00 kts
   Range 1,500nm at 12.00 kts
   Bunker at max displacement = 106 tons (100% coal)

Complement:
   48 - 63

Cost:
   £0.047 million / $0.188 million

Distribution of weights at normal displacement:
   Armament: 2 tons, 0.4 %
   Armour: 1 tons, 0.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 1 tons, 0.1 %
   Machinery: 230 tons, 51.0 %
   Hull, fittings & equipment: 144 tons, 32.1 %
   Fuel, ammunition & stores: 69 tons, 15.3 %
   Miscellaneous weights: 4 tons, 0.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     188 lbs / 85 Kg = 13.9 x 3.0 " / 76 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.15
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 12.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 1.61

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.450
   Length to Beam Ratio: 8.93 : 1
   'Natural speed' for length: 15.81 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 90
   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:      17.39 ft / 5.30 m
      - Forecastle (20 %):   11.07 ft / 3.37 m
      - Mid (50 %):      11.07 ft / 3.37 m
      - Quarterdeck (15 %):   11.07 ft / 3.37 m
      - Stern:      11.07 ft / 3.37 m
      - Average freeboard:   11.58 ft / 3.53 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 168.8 %
      - Above water (accommodation/working, high = better): 159.8 %
   Waterplane Area: 4,254 Square feet or 395 Square metres
   Displacement factor (Displacement / loading): 67 %
   Structure weight / hull surface area: 19 lbs/sq ft or 94 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.63
      - Overall: 0.56
   Caution: Hull subject to strain in open-sea
   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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

---

Puno-class, Peru Coastal Patrol laid down 1905 (Engine 1909)

Displacement:
   400 t light; 410 t standard; 458 t normal; 495 t full load

Dimensions: Length overall / water x beam x draught
   260.00 ft / 260.00 ft x 28.00 ft x 5.00 ft (normal load)
   79.25 m / 79.25 m x 8.53 m  x 1.52 m

Armament:
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1905 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1905 Model
     Machine guns in deck mounts
     on side, all amidships
   Weight of broadside 14 lbs / 6 kg
   Shells per gun, main battery: 150
   2 - 18.0" / 457.2 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm   0.25" / 6 mm            -
   2nd:   0.25" / 6 mm         -               -

   - Conning tower: 0.50" / 13 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 1 shaft, 6,510 shp / 4,856 Kw = 25.00 kts
   Range 1,500nm at 12.00 kts
   Bunker at max displacement = 85 tons (100% coal)

Complement:
   49 - 64

Cost:
   £0.048 million / $0.192 million

Distribution of weights at normal displacement:
   Armament: 2 tons, 0.4 %
   Armour: 1 tons, 0.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 1 tons, 0.1 %
   Machinery: 233 tons, 50.9 %
   Hull, fittings & equipment: 160 tons, 35.0 %
   Fuel, ammunition & stores: 58 tons, 12.6 %
   Miscellaneous weights: 4 tons, 0.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     204 lbs / 93 Kg = 15.1 x 3.0 " / 76 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.21
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 11.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 1.28

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.440
   Length to Beam Ratio: 9.29 : 1
   'Natural speed' for length: 16.12 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 78
   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:      17.74 ft / 5.41 m
      - Forecastle (20 %):   11.29 ft / 3.44 m
      - Mid (50 %):      11.29 ft / 3.44 m
      - Quarterdeck (15 %):   11.29 ft / 3.44 m
      - Stern:      11.29 ft / 3.44 m
      - Average freeboard:   11.81 ft / 3.60 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 168.2 %
      - Above water (accommodation/working, high = better): 165.6 %
   Waterplane Area: 4,382 Square feet or 407 Square metres
   Displacement factor (Displacement / loading): 68 %
   Structure weight / hull surface area: 20 lbs/sq ft or 100 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.75
      - Overall: 0.56
   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

[Desertfox]

I would add a second 3" gun. Other than that, they are pretty decent destroyers.

[Borys]

Ahoj!
Nice.
IMO it would be nice to have them built at the rate of three a year, and to maintain two or three flotillas.
With a "shelf live" of 12 years, three a year equals three flotillas (36 vessels). Or two a year for two flotillas.
Borys