Peru 1912 gun boat

[Jefgte]

125T, Peru GB laid down 1912

Displacement:
   125 t light; 129 t standard; 135 t normal; 139 t full load

Dimensions: Length overall / water x beam x draught
   161.94 ft / 160.76 ft x 22.97 ft x 3.17 ft (normal load)
   49.36 m / 49.00 m x 7.00 m  x 0.97 m

Armament:
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1912 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread
      2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1912 Model
     Breech loading guns in deck mounts
     on centreline, all amidships
   Weight of broadside 27 lbs / 12 kg
   Shells per gun, main battery: 120
   2 - 18.0" / 457.2 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         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 1 580 shp / 1 178 Kw = 20.04 kts
   Range 1 800nm at 7.00 kts
   Bunker at max displacement = 10 tons

Complement:
   19 - 25

Cost:
   £0.015 million / $0.059 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 2.5 %
   Armour: 3 tons, 1.9 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 1.9 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 54 tons, 39.8 %
   Hull, fittings & equipment: 59 tons, 43.9 %
   Fuel, ammunition & stores: 10 tons, 7.4 %
   Miscellaneous weights: 6 tons, 4.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     96 lbs / 43 Kg = 7.1 x 3.0 " / 76 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 10.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.12
   Seaboat quality  (Average = 1.00): 1.17

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.404
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 12.68 kts
   Power going to wave formation at top speed: 61 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      13.45 ft / 4.10 m
      - Forecastle (15 %):   12.47 ft / 3.80 m
      - Mid (30 %):      8.53 ft / 2.60 m
      - Quarterdeck (15 %):   8.53 ft / 2.60 m
      - Stern:      8.53 ft / 2.60 m
      - Average freeboard:   9.48 ft / 2.89 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 152.5 %
      - Above water (accommodation/working, high = better): 148.4 %
   Waterplane Area: 2 278 Square feet or 212 Square metres
   Displacement factor (Displacement / loading): 83 %
   Structure weight / hull surface area: 16 lbs/sq ft or 77 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.46
      - Longitudinal: 3.20
      - 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

[The Rock Doctor]

As a "slow" ship, I'd prefer to see the hull strength at 1.00.  Regardless of whether you agree with that opinion, the cross-sectional hull strength of this design still needs to be 0.50 or better.

A shorter, deeper hull might be a better fit here - you're not trying to jam in an excessive amount of weapons, so reduced deck space is okay, and increased draught would improve the hull strength.

The type in general will be quite useful, so it's good that you're working on it.  I'd build more patrol vessels for Gran Colombia except that I'm bottle-necked on capital ships and fixated on adding auxiliaries.

[Jefgte]

cross sectional hull; 0.46...

a mistake... >:(

[The Rock Doctor]

That's okay:  just re-assign the responsible engineer to mapping bird-poop deposits in the Atacama desert.

[Jefgte]

re SS

125T, Peru GB laid down 1912

Displacement:
   125 t light; 131 t standard; 137 t normal; 142 t full load

Dimensions: Length overall / water x beam x draught
   138.89 ft / 137.80 ft x 19.69 ft x 4.17 ft (normal load)
   42.33 m / 42.00 m x 6.00 m  x 1.27 m

Armament:
      2 - 3.54" / 90.0 mm guns in single mounts, 22.24lbs / 10.09kg shells, 1912 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread
      2 - 2.00" / 50.8 mm guns in single mounts, 4.00lbs / 1.81kg shells, 1912 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, 1912 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 53 lbs / 24 kg
   Shells per gun, main battery: 120

Armour:
   - 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         -               -

Machinery:
   Petrol Internal combustion motors,
   Geared drive, 2 shafts, 600 shp / 448 Kw = 15.56 kts
   Range 2 000nm at 7.00 kts
   Bunker at max displacement = 10 tons

Complement:
   19 - 26

Cost:
   £0.013 million / $0.053 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 4.8 %
   Armour: 4 tons, 3.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 4 tons, 3.3 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 24 tons, 17.5 %
   Hull, fittings & equipment: 84 tons, 61.1 %
   Fuel, ammunition & stores: 12 tons, 9.0 %
   Miscellaneous weights: 6 tons, 4.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     295 lbs / 134 Kg = 13.3 x 3.5 " / 90 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 11.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 77 %
         - Recoil effect (Restricted arc if above 1.00): 0.38
   Seaboat quality  (Average = 1.00): 1.93

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.424
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 11.74 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 40
   Bow angle (Positive = bow angles forward): 5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.47 ft / 3.80 m
      - Forecastle (15 %):   11.48 ft / 3.50 m
      - Mid (30 %):      11.48 ft / 3.50 m (7.55 ft / 2.30 m aft of break)
      - Quarterdeck (15 %):   7.55 ft / 2.30 m
      - Stern:      7.55 ft / 2.30 m
      - Average freeboard:   8.79 ft / 2.68 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.2 %
      - Above water (accommodation/working, high = better): 142.6 %
   Waterplane Area: 1 696 Square feet or 158 Square metres
   Displacement factor (Displacement / loading): 123 %
   Structure weight / hull surface area: 27 lbs/sq ft or 129 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.81
      - Longitudinal: 6.94
      - Overall: 1.00
   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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather