Born of the Peru Fleet

[Jefgte]

Rio Serena class , Peru Patrol boat laid down 1893

1893
Rio Serena
Rio Moropa
Rio Pastaza
1894
Rio Tigre
Rio Putumayo
Rio Napo

Displacement:
   150 t light; 154 t standard; 157 t normal; 159 t full load

Dimensions: Length overall / water x beam x draught
   131.23 ft / 131.23 ft x 17.72 ft x 5.91 ft (normal load)
   40.00 m / 40.00 m x 5.40 m  x 1.80 m

Armament:
      2 - 2.00" / 50.8 mm guns in single mounts, 4.00lbs / 1.81kg shells, 1893 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, 1893 Model
     Quick firing guns in deck mounts
     on side, evenly spread
   Weight of broadside 8 lbs / 4 kg
   Shells per gun, main battery: 200

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0.79" / 20 mm   124.67 ft / 38.00 m   6.17 ft / 1.88 m
   Ends:   Unarmoured
     Main Belt covers 146 % of normal length

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

   - Armour deck: 0.50" / 13 mm

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 260 ihp / 194 Kw = 12.31 kts
   Range 900nm at 5.00 kts
   Bunker at max displacement = 6 tons (100% coal)

Complement:
   21 - 28

Cost:
   £0.013 million / $0.052 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.6 %
   Armour: 39 tons, 24.6 %
      - Belts: 24 tons, 15.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 1.1 %
      - Armour Deck: 13 tons, 8.4 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 49 tons, 31.2 %
   Hull, fittings & equipment: 56 tons, 35.7 %
   Fuel, ammunition & stores: 7 tons, 4.6 %
   Miscellaneous weights: 5 tons, 3.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     180 lbs / 82 Kg = 45.1 x 2.0 " / 51 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.40
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 9.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 1.88

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.400
   Length to Beam Ratio: 7.41 : 1
   'Natural speed' for length: 11.46 kts
   Power going to wave formation at top speed: 43 %
   Trim (Max stability = 0, Max steadiness = 100): 38
   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:      8.86 ft / 2.70 m
      - Forecastle (18 %):   8.86 ft / 2.70 m
      - Mid (30 %):      4.92 ft / 1.50 m
      - Quarterdeck (10 %):   4.92 ft / 1.50 m
      - Stern:      4.92 ft / 1.50 m
      - Average freeboard:   5.87 ft / 1.79 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 110.3 %
      - Above water (accommodation/working, high = better): 68.1 %
   Waterplane Area: 1 431 Square feet or 133 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 24 lbs/sq ft or 117 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.27
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[The Rock Doctor]

They look like handy little short-range patrol boats.

[Sachmle]

Belt and deck armor on a 150t ship? Why? She's so expendable it's not worth it. I'd put the weight saved into more range or speed. Other than that she is a handy little ship.

[Borys]

Ahoj!

Belt and deck armor on a 150t ship?

Wait until you see more of Jefgte's designs.
He's quite an excentric :)
Borys

[Sachmle]

I've seen some on the other discussion boards I frequent.  He also does out-f*ckin'-standing scratch built models.

[Ithekro]

So we are in for a ride then?  ???

[Jefgte]

Belt & armour are just 20mm

I install them for the stability.
The machinery is 49T for 12.3kts on a 150T ship - 33% of the deplacement.
When I remove the belt armour the ship nearly caspize.


Jef

[Carthaginian]

So we are in for a ride then?  ???

http://www.phpbbplanet.com/warshipprojects/viewtopic.php?t=1623&mforum=warshipprojects

Jef's scratch-built family of WWII Panzerschiffs.
As you can see, had the Kriegsmarine had this man working for them, they'd have probably won the naval war. ;)

[Jefgte]

A better Serana Coastal Gun Boat

more guns & range increase


Serena, Peru Coastal Gun Boat laid down 1893

Displacement:
   150 t light; 156 t standard; 173 t normal; 187 t full load

Dimensions: Length overall / water x beam x draught
   124.67 ft / 124.67 ft x 17.81 ft x 6.59 ft (normal load)
   38.00 m / 38.00 m x 5.43 m  x 2.01 m

Armament:
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1893 Model
     Breech loading gun in deck mount
     on centreline
      4 - 2.00" / 50.8 mm guns in single mounts, 4.00lbs / 1.81kg shells, 1893 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, 1893 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 30 lbs / 13 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         -               -

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 250 ihp / 186 Kw = 12.38 kts
   Range 3 000nm at 7.00 kts
   Bunker at max displacement = 31 tons (100% coal)

Complement:
   23 - 31

Cost:
   £0.015 million / $0.060 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 2.1 %
   Armour: 4 tons, 2.4 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 4 tons, 2.4 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 47 tons, 27.2 %
   Hull, fittings & equipment: 85 tons, 49.1 %
   Fuel, ammunition & stores: 23 tons, 13.4 %
   Miscellaneous weights: 10 tons, 5.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     235 lbs / 106 Kg = 17.4 x 3.0 " / 76 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 0.5 ft / 0.1 m
   Roll period: 10.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
     and transom stern
   Block coefficient: 0.414
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 13.31 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 36
   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:      13.12 ft / 4.00 m
      - Forecastle (15 %):   12.30 ft / 3.75 m
      - Mid (40 %):      8.37 ft / 2.55 m
      - Quarterdeck (8 %):   8.37 ft / 2.55 m
      - Stern:      8.37 ft / 2.55 m
      - Average freeboard:   9.50 ft / 2.90 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 111.1 %
      - Above water (accommodation/working, high = better): 106.8 %
   Waterplane Area: 1 431 Square feet or 133 Square metres
   Displacement factor (Displacement / loading): 126 %
   Structure weight / hull surface area: 25 lbs/sq ft or 123 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.76
      - Longitudinal: 11.86
      - 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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather