Patrol boats

[swamphen]

A post-war plan for a small fleet of patrol sloops to monitor things around these islands that the ASBs dropped into my laps in 1905.  ;D

As the hulls are to be built out of wood, I presume the "1/4 BP" rule can be applied?


SMS Vulkan, Brandenburgian Fisheries Patrol Vessel laid down 1909

Displacement:
   983 t light; 1,014 t standard; 1,212 t normal; 1,370 t full load

Dimensions: Length overall / water x beam x draught
   219.82 ft / 213.25 ft x 34.45 ft x 13.12 ft (normal load)
   67.00 m / 65.00 m x 10.50 m  x 4.00 m

Armament:
      2 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1900 Model
     Quick firing guns in deck mounts
     on centreline ends, evenly spread
      1 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1903 Model
     Quick firing gun in deck mount
     on centreline amidships, 1 raised gun
      2 - 0.30" / 7.7 mm guns in single mounts, 0.01lbs / 0.01kg shells, 1909 Model
     Breech loading guns in deck mounts
     on side, all amidships
   Weight of broadside 48 lbs / 22 kg
   Shells per gun, main battery: 250

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

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,500 ihp / 1,119 Kw = 14.46 kts
   Range 10,000nm at 8.00 kts (Bunkerage = 356 tons)

Complement:
   102 - 133

Cost:
   £0.055 million / $0.221 million

Distribution of weights at normal displacement:
   Armament: 6 tons, 0.5 %
   Armour: 3 tons, 0.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 115 tons, 9.5 %
   Hull, fittings & equipment: 559 tons, 46.1 %
   Fuel, ammunition & stores: 229 tons, 18.9 %
   Miscellaneous weights: 300 tons, 24.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,234 lbs / 1,013 Kg = 107.4 x 3.5 " / 88 mm shells or 1.1 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 13.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.440
   Length to Beam Ratio: 6.19 : 1
   'Natural speed' for length: 14.60 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 30
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 6.56 ft / 2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.40 ft / 5.00 m
      - Forecastle (20 %):   13.12 ft / 4.00 m
      - Mid (50 %):      9.84 ft / 3.00 m
      - Quarterdeck (15 %):   10.66 ft / 3.25 m
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   11.58 ft / 3.53 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 62.6 %
      - Above water (accommodation/working, high = better): 93.9 %
   Waterplane Area: 4,649 Square feet or 432 Square metres
   Displacement factor (Displacement / loading): 209 %
   Structure weight / hull surface area: 71 lbs/sq ft or 347 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.44
      - Longitudinal: 5.30
      - Overall: 1.64
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[P3D]

Merchant standard ships cost 1/4 the BP and the same amount in $.

However, block coefficient is too low (0.440). Decrease draught and beam.

[swamphen]

The original design had 17.5' draft...which required the low BC to match the Jane's of the USCG Androscoggin (which it is based on). But with the lowered draft, here's a higher BC:

SMS Vulkan, Brandenburgian Fisheries Patrol Vessel laid down 1909

Displacement:
   1,191 t light; 1,227 t standard; 1,446 t normal; 1,621 t full load

Dimensions: Length overall / water x beam x draught
   219.82 ft / 213.25 ft x 34.45 ft x 13.12 ft (normal load)
   67.00 m / 65.00 m x 10.50 m  x 4.00 m

Armament:
      2 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1900 Model
     Quick firing guns in deck mounts
     on centreline ends, evenly spread
      1 - 1.97" / 50.0 mm guns in single mounts, 3.81lbs / 1.73kg shells, 1903 Model
     Quick firing gun in deck mount
     on centreline amidships, 1 raised gun
      2 - 0.30" / 7.7 mm guns in single mounts, 0.01lbs / 0.00kg shells, 1909 Model
     Breech loading guns in deck mounts
     on side, all amidships
   Weight of broadside 45 lbs / 21 kg
   Shells per gun, main battery: 250

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

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,500 ihp / 1,119 Kw = 13.96 kts
   Range 10,000nm at 8.00 kts (Bunkerage = 395 tons)

Complement:
   116 - 152

Cost:
   £0.063 million / $0.250 million

Distribution of weights at normal displacement:
   Armament: 6 tons, 0.4 %
   Armour: 3 tons, 0.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 115 tons, 8.0 %
   Hull, fittings & equipment: 768 tons, 53.1 %
   Fuel, ammunition & stores: 255 tons, 17.6 %
   Miscellaneous weights: 300 tons, 20.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,010 lbs / 1,365 Kg = 144.8 x 3.5 " / 88 mm shells or 1.4 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 12.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.525
   Length to Beam Ratio: 6.19 : 1
   'Natural speed' for length: 14.60 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 30
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 6.56 ft / 2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.40 ft / 5.00 m
      - Forecastle (20 %):   13.12 ft / 4.00 m
      - Mid (50 %):      9.84 ft / 3.00 m
      - Quarterdeck (15 %):   10.66 ft / 3.25 m
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   11.58 ft / 3.53 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 52.8 %
      - Above water (accommodation/working, high = better): 89.0 %
   Waterplane Area: 5,009 Square feet or 465 Square metres
   Displacement factor (Displacement / loading): 250 %
   Structure weight / hull surface area: 92 lbs/sq ft or 451 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.88
      - Longitudinal: 6.10
      - Overall: 2.11
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[P3D]

The original vessel's draught could have been deep not normal.

[swamphen]

The second half of the Island Patrol types planned for 1909. Uses "full cost" (military-grade) materials throughout.

(This started out as one of my Lake Victoria designs but has been modified.)

SMS Constantine, Brandenburgian Kanonboot laid down 1909

Displacement:
   1,118 t light; 1,200 t standard; 1,352 t normal; 1,473 t full load

Dimensions: Length overall / water x beam x draught
   237.86 ft / 229.66 ft x 38.06 ft x 10.83 ft (normal load)
   72.50 m / 70.00 m x 11.60 m  x 3.30 m

Armament:
      2 - 5.91" / 150 mm guns in single mounts, 99.21lbs / 45.00kg shells, 1909 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread
      8 - 4.13" / 105 mm guns in single mounts, 35.27lbs / 16.00kg shells, 1905 Model
     Quick firing guns in casemate mounts
     on side, evenly spread
     8 guns in hull casemates - Limited use in any sea
      1 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1903 Model
     Anti-airship gun in deck mount
     on centreline amidships
      4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
      4 - 0.30" / 7.7 mm guns in single mounts, 0.01lbs / 0.01kg shells, 1909 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts

   Weight of broadside 491 lbs / 223 kg
   Shells per gun, main battery: 175

   1 - 17.7" / 450 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.97" / 50 mm   229.66 ft / 70.00 m   9.84 ft / 3.00 m
   Upper:   0.79" / 20 mm   229.66 ft / 70.00 m   5.74 ft / 1.75 m
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -         0.79" / 20 mm
   2nd:   1.97" / 50 mm         -               -
   3rd:   0.79" / 20 mm         -               -

   - Armour deck: 0.98" / 25 mm, Conning tower: 1.97" / 50 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 2,250 ihp / 1,678 Kw = 15.77 kts
   Range 4,200nm at 10.00 kts (Bunkerage = 273 tons)

Complement:
   110 - 144

Cost:
   £0.116 million / $0.463 million

Distribution of weights at normal displacement:
   Armament: 62 tons, 4.6 %
   Armour: 357 tons, 26.4 %
      - Belts: 203 tons, 15.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 43 tons, 3.2 %
      - Armour Deck: 106 tons, 7.8 %
      - Conning Tower: 5 tons, 0.4 %
   Machinery: 173 tons, 12.8 %
   Hull, fittings & equipment: 475 tons, 35.2 %
   Fuel, ammunition & stores: 234 tons, 17.3 %
   Miscellaneous weights: 50 tons, 3.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,208 lbs / 1,002 Kg = 21.4 x 5.9 " / 150 mm shells or 0.9 torpedoes
   Stability (Unstable if below 1.00): 1.44
   Metacentric height 2.2 ft / 0.7 m
   Roll period: 10.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 75 %
         - Recoil effect (Restricted arc if above 1.00): 0.26
   Seaboat quality  (Average = 1.00): 1.87

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.500
   Length to Beam Ratio: 6.03 : 1
   'Natural speed' for length: 15.15 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 40
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 8.20 ft / 2.50 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      13.12 ft / 4.00 m
      - Forecastle (5 %):   12.30 ft / 3.75 m (11.48 ft / 3.50 m aft of break)
      - Mid (50 %):      10.66 ft / 3.25 m
      - Quarterdeck (15 %):   10.66 ft / 3.25 m
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   11.01 ft / 3.36 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 86.1 %
      - Above water (accommodation/working, high = better): 109.8 %
   Waterplane Area: 5,823 Square feet or 541 Square metres
   Displacement factor (Displacement / loading): 108 %
   Structure weight / hull surface area: 55 lbs/sq ft or 267 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.66
      - 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

[P3D]

A waste of steel. Get at least 20-21kts out of her so she could catch a 14kts merchant ship or a dual-use pirate/trawler boat. 3 shafts, with two turbines on the sides.

[swamphen]

20-21 is too much without a complete redesign. However 18.2 is doable, which is acceptable as it's a colonial gunboat, not a cruiser. If it runs into something faster that's causing problems, then there's trouble in River City and the big guys get called in.

SMS Constantine, Brandenburgian Kanonboot laid down 1909

Displacement:
   1,155 t light; 1,229 t standard; 1,352 t normal; 1,450 t full load

Dimensions: Length overall / water x beam x draught
   237.86 ft / 229.66 ft x 38.06 ft x 10.83 ft (normal load)
   72.50 m / 70.00 m x 11.60 m  x 3.30 m

Armament:
      2 - 5.91" / 150 mm guns in single mounts, 99.21lbs / 45.00kg shells, 1909 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread
      8 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1905 Model
     Quick firing guns in casemate mounts
     on side, evenly spread
     8 guns in hull casemates - Limited use in all but light seas
      1 - 1.97" / 50.0 mm guns in single mounts, 3.81lbs / 1.73kg shells, 1903 Model
     Anti-airship gun in deck mount
     on centreline amidships
      4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
      4 - 0.30" / 7.7 mm guns in single mounts, 0.01lbs / 0.00kg shells, 1909 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts

   Weight of broadside 491 lbs / 223 kg
   Shells per gun, main battery: 150

   1 - 17.7" / 450 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.57" / 40 mm   229.66 ft / 70.00 m   9.84 ft / 3.00 m
   Ends:   Unarmoured
   Upper:   0.79" / 20 mm   131.23 ft / 40.00 m   8.20 ft / 2.50 m
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -         0.79" / 20 mm
   2nd:   1.57" / 40 mm         -               -
   3rd:   0.79" / 20 mm         -               -

   - Armour deck: 0.79" / 20 mm, Conning tower: 1.97" / 50 mm

Machinery:
   Coal and oil fired boilers, reciprocating cruising steam engines plus steam turbines,
   Direct drive, 3 shafts, 4,000 ihp / 2,984 Kw = 18.23 kts
   Range 3,500nm at 10.00 kts (Bunkerage = 221 tons)

Complement:
   110 - 144

Cost:
   £0.126 million / $0.505 million

Distribution of weights at normal displacement:
   Armament: 62 tons, 4.6 %
   Armour: 296 tons, 21.9 %
      - Belts: 170 tons, 12.6 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 36 tons, 2.7 %
      - Armour Deck: 85 tons, 6.3 %
      - Conning Tower: 5 tons, 0.4 %
   Machinery: 240 tons, 17.8 %
   Hull, fittings & equipment: 506 tons, 37.5 %
   Fuel, ammunition & stores: 197 tons, 14.6 %
   Miscellaneous weights: 50 tons, 3.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,901 lbs / 862 Kg = 18.5 x 5.9 " / 150 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.32
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 11.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.32
   Seaboat quality  (Average = 1.00): 1.52

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.500
   Length to Beam Ratio: 6.03 : 1
   'Natural speed' for length: 15.15 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 8.20 ft / 2.50 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      14.76 ft / 4.50 m
      - Forecastle (5 %):   13.94 ft / 4.25 m (13.12 ft / 4.00 m aft of break)
      - Mid (50 %):      12.30 ft / 3.75 m
      - Quarterdeck (15 %):   12.30 ft / 3.75 m
      - Stern:      13.12 ft / 4.00 m
      - Average freeboard:   12.65 ft / 3.86 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 102.0 %
      - Above water (accommodation/working, high = better): 126.4 %
   Waterplane Area: 5,823 Square feet or 541 Square metres
   Displacement factor (Displacement / loading): 102 %
   Structure weight / hull surface area: 56 lbs/sq ft or 274 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.26
      - 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

[The Rock Doctor]

I'd like to see a line drawing - it looks rather crowded on deck with all those medium caliber guns.

[swamphen]

Except for the 150s, the layout is the same as USS Nashville PG-7:

[The Rock Doctor]

Aha...missed the hull casemate bit.  I can't say I'd be really keen to have hull casemates on that freeboard, but so long as you're not out in rough weather, you should be okay.

[swamphen]

And now, the third leg of the Brandenburgian island-patrol-fleet troika.
(AKA something I just noticed in Jane's WWI today that was (a) built in 1909 (b) in Germany.)


SMS Teleute, Brandenburgian Torpedo Gunboat laid down 1909

Displacement:
   1,043 t light; 1,080 t standard; 1,177 t normal; 1,255 t full load

Dimensions: Length overall / water x beam x draught
   278.87 ft / 278.87 ft x 30.84 ft x 11.98 ft (normal load)
   85.00 m / 85.00 m x 9.40 m  x 3.65 m

Armament:
      2 - 5.91" / 150 mm guns in single mounts, 99.21lbs / 45.00kg shells, 1901 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread
      4 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1903 Model
     Quick firing guns in deck mounts
     on side, all amidships
      6 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, evenly spread, 4 raised mounts

   Weight of broadside 223 lbs / 101 kg
   Shells per gun, main battery: 100

   2 - 15.7" / 400 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:      0.79" / 20 mm         -               -
   2nd:      0.59" / 15 mm         -               -

   - Armour deck: 0.79" / 20 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 8,000 shp / 5,968 Kw = 23.14 kts
   Range 3,000nm at 10.00 kts (Bunkerage = 175 tons) (75% coal)

Complement:
   99 - 130

Cost:
   £0.115 million / $0.461 million

Distribution of weights at normal displacement:
   Armament: 29 tons, 2.4 %
   Armour: 85 tons, 7.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 8 tons, 0.6 %
      - Armour Deck: 77 tons, 6.6 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 390 tons, 33.2 %
   Hull, fittings & equipment: 519 tons, 44.1 %
   Fuel, ammunition & stores: 134 tons, 11.4 %
   Miscellaneous weights: 20 tons, 1.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     999 lbs / 453 Kg = 9.7 x 5.9 " / 150 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 11.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0.47
   Seaboat quality  (Average = 1.00): 1.56

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.400
   Length to Beam Ratio: 9.04 : 1
   'Natural speed' for length: 16.70 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 46
   Bow angle (Positive = bow angles forward): -10.00 degrees
   Stern overhang: -3.28 ft / -1.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:         18.37 ft / 5.60 m
      - Forecastle (20 %):      16.40 ft / 5.00 m
      - Mid (50 %):      14.76 ft / 4.50 m (8.20 ft / 2.50 m aft of break)
      - Quarterdeck (15 %):   8.20 ft / 2.50 m
      - Stern:         8.20 ft / 2.50 m
      - Average freeboard:      12.21 ft / 3.72 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 127.6 %
      - Above water (accommodation/working, high = better): 107.6 %
   Waterplane Area: 5,294 Square feet or 492 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 52 lbs/sq ft or 252 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.17
      - Overall: 1.00
   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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[P3D]

A ship that has
a/ no speed to get within torpedo launch range without shot into pieces
b/ not enough torpedoes to make any impact
c/ two guns that has chance to do any damage
d/ not enough QF guns to scare away torpedo boats
e/ no range to the to the next port without refueling
f/ inferior to a 750t DD in almost every aspect, and also more expensive.

To summarize: very nice ships, something the REpublic of Orange wants DKB to build in large quantities :P

[swamphen]

A ship that has
a/ no speed to get within torpedo launch range without shot into pieces
b/ not enough torpedoes to make any impact
c/ two guns that has chance to do any damage

This is a patrol boat, intended to police the various and sundry islands of The Empire, from Fiji to Pitcairn. It is not entended to engage enemy warships, if it does then something has gone seriously wrong. The torpedoes are there to quickly scuttle merchies who have run afoul of the law without wasting ammo.*

c/ two guns that has chance to do any damage
d/ not enough QF guns to scare away torpedo boats

Now I can fit 6x105mm on her**...

e/ no range to the to the next port without refueling

I did some poking around - for a Island Patrol Boat, 3000/10 should work. (And I intend to build a fair number of cheapo Type 0 Ports in those islands over the next five-ten years.)

f/ inferior to a 750t DD in almost every aspect, and also more expensive.

Can't dispute the latter part of that assessment. But the former - better seakeeping, better endurance in the patrol role - no need for a mothership or port visit each and every night lest the crew start shooting each other.

* - The Uruguayans, who bought the historical version, apparantly disagreed.
** - Normally Germanic ships are male. But given the name of this one...

6x105mm version, with bigger fish:

SMS Teleute, Brandenburgian Torpedo Gunboat laid down 1909

Displacement:
   1,042 t light; 1,080 t standard; 1,177 t normal; 1,255 t full load

Dimensions: Length overall / water x beam x draught
   278.87 ft / 278.87 ft x 30.84 ft x 11.98 ft (normal load)
   85.00 m / 85.00 m x 9.40 m  x 3.65 m

Armament:
      2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1905 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread
      4 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1900 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships
      2 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 215 lbs / 98 kg
   Shells per gun, main battery: 100
   2 - 17.7" / 450 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.59" / 15 mm         -               -

   - Armour deck: 0.79" / 20 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 8,000 shp / 5,968 Kw = 23.14 kts
   Range 3,000nm at 10.00 kts (Bunkerage = 175 tons)

Complement:
   99 - 130

Cost:
   £0.114 million / $0.455 million

Distribution of weights at normal displacement:
   Armament: 27 tons, 2.3 %
   Armour: 86 tons, 7.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 9 tons, 0.7 %
      - Armour Deck: 77 tons, 6.6 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 390 tons, 33.2 %
   Hull, fittings & equipment: 514 tons, 43.7 %
   Fuel, ammunition & stores: 135 tons, 11.5 %
   Miscellaneous weights: 25 tons, 2.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,002 lbs / 454 Kg = 28.4 x 4.1 " / 105 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 11.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.49
   Seaboat quality  (Average = 1.00): 1.55

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.400
   Length to Beam Ratio: 9.04 : 1
   'Natural speed' for length: 16.70 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 46
   Bow angle (Positive = bow angles forward): -10.00 degrees
   Stern overhang: -3.28 ft / -1.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      18.37 ft / 5.60 m
      - Forecastle (20 %):   16.40 ft / 5.00 m
      - Mid (50 %):      14.76 ft / 4.50 m (8.20 ft / 2.50 m aft of break)
      - Quarterdeck (15 %):   8.20 ft / 2.50 m
      - Stern:      8.20 ft / 2.50 m
      - Average freeboard:   12.21 ft / 3.72 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 127.0 %
      - Above water (accommodation/working, high = better): 104.8 %
   Waterplane Area: 5,294 Square feet or 492 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 51 lbs/sq ft or 250 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.11
      - Overall: 1.00
   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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[P3D]

- I'd think ammo is cheaper than a torpedo, but true, they sink the merchies faster.
- Neither Uruguay nor Germany had an extended archipelago like DKB. Also, making mixed-firing does not make much sense. Either coal, or oil, but not both. You increase cruising speed to 13kts and the endurance is down to 5 days.
- Seakeeping is not better than a destroyer that is steaming only with 23kts. Also, 2.5m aft freeboard is a bit on the low side for pacific service

The armament makes a bit more sense now.

[Desertfox]

Hey don't help him ;) The more of the original design he builds, the less BPs available for truly useful ships.