Idea for a smallish subchaser-type ship

[P3D]

Nice. I'd argue for a single shaft, and dispense with the 25mm armor on the bridge, but all of them are cosmetic changes and won't affect the ships' ability to any degree.

[Sachmle]

Nice. I'd argue for a single shaft, and dispense with the 25mm armor on the bridge, but all of them are cosmetic changes and won't affect the ships' ability to any degree.

Actually just going to 1 shaft gave me 0.01 overall strength extra, the 25mm armor on the bridge gave me another 0.01. So I upped the speed a little and cut 25nm from the range.

J-101, Deutsche Reich U-bootenjäger laid down 1920 (Engine 1916)

Displacement:
   75 t light; 79 t standard; 86 t normal; 92 t full load

Dimensions: Length overall / water x beam x draught
   108.91 ft / 104.99 ft x 13.94 ft x 5.41 ft (normal load)
   33.20 m / 32.00 m x 4.25 m  x 1.65 m

Armament:
      1 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline forward
      4 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1920 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 22 lbs / 10 kg
   Shells per gun, main battery: 200

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   2nd:   0.59" / 15 mm         -               -

Machinery:
   Petrol Internal combustion motors,
   Direct drive, 1 shaft, 750 shp / 559 Kw = 17.25 kts
   Range 1,050nm at 12.00 kts
   Bunker at max displacement = 13 tons

Complement:
   13 - 18

Cost:
   £0.021 million / $0.082 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 3.0 %
   Armour: 2 tons, 2.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 2.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 28 tons, 32.5 %
   Hull, fittings & equipment: 39 tons, 45.8 %
   Fuel, ammunition & stores: 11 tons, 13.1 %
   Miscellaneous weights: 3 tons, 3.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     69 lbs / 31 Kg = 3.3 x 3.5 " / 88 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 10.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.36
   Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.380
   Length to Beam Ratio: 7.53 : 1
   'Natural speed' for length: 10.25 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   Bow angle (Positive = bow angles forward): 14.20 degrees
   Stern overhang: 1.64 ft / 0.50 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      9.02 ft / 2.75 m
      - Forecastle (20 %):   7.38 ft / 2.25 m (7.22 ft / 2.20 m aft of break)
      - Mid (50 %):      5.74 ft / 1.75 m
      - Quarterdeck (15 %):   5.74 ft / 1.75 m
      - Stern:      5.74 ft / 1.75 m
      - Average freeboard:   6.42 ft / 1.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 133.1 %
      - Above water (accommodation/working, high = better): 75.1 %
   Waterplane Area: 842 Square feet or 78 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 21 lbs/sq ft or 102 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.81
      - Longitudinal: 6.83
      - Overall: 1.00
   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

3t 9 1916 Depth Charges w/ racks

[TexanCowboy]

Eh....I know this is about to sound like a broken record.....do it enough anyways, though, so....

I'm not really a huge fan of the very low BC.

[Sachmle]

Eh....I know this is about to sound like a broken record.....do it enough anyways, though, so....

I'm not really a huge fan of the very low BC.

It's a narrow supersized motor boat w/ guns with the same dimentions as an OTL ship. If I make the BC any higher, what pray tell, should I due with the extra tonnage? Faster's not really useful, neither is more range. P3D has already pointed out that more guns make little sense as does more armor.

[TexanCowboy]

Shrink the other dimensions?

[Sachmle]

Shrink the other dimensions?

Fair enough.

J-101, Deutsche Reich U-bootenjäger laid down 1920 (Engine 1916)

Displacement:
   75 t light; 80 t standard; 87 t normal; 93 t full load

Dimensions: Length overall / water x beam x draught
   102.35 ft / 98.43 ft x 13.07 ft x 4.92 ft (normal load)
   31.20 m / 30.00 m x 3.99 m  x 1.50 m

Armament:
      1 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline forward
      4 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1920 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 22 lbs / 10 kg
   Shells per gun, main battery: 200

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   2nd:   0.59" / 15 mm         -               -

Machinery:
   Petrol Internal combustion motors,
   Direct drive, 1 shaft, 850 shp / 634 Kw = 17.32 kts
   Range 1,000nm at 12.00 kts
   Bunker at max displacement = 13 tons

Complement:
   13 - 18

Cost:
   £0.022 million / $0.087 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 3.0 %
   Armour: 2 tons, 2.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 2.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 31 tons, 35.7 %
   Hull, fittings & equipment: 37 tons, 42.6 %
   Fuel, ammunition & stores: 11 tons, 13.1 %
   Miscellaneous weights: 3 tons, 3.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     59 lbs / 27 Kg = 2.8 x 3.5 " / 88 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 10.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.43
   Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.480
   Length to Beam Ratio: 7.53 : 1
   'Natural speed' for length: 9.92 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 14.20 degrees
   Stern overhang: 1.64 ft / 0.50 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      9.02 ft / 2.75 m
      - Forecastle (20 %):   7.38 ft / 2.25 m
      - Mid (50 %):      5.91 ft / 1.80 m
      - Quarterdeck (15 %):   5.91 ft / 1.80 m
      - Stern:      5.91 ft / 1.80 m
      - Average freeboard:   6.55 ft / 2.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 143.1 %
      - Above water (accommodation/working, high = better): 73.8 %
   Waterplane Area: 807 Square feet or 75 Square metres
   Displacement factor (Displacement / loading): 97 %
   Structure weight / hull surface area: 20 lbs/sq ft or 97 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.80
      - Longitudinal: 7.71
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped

3t 9 1916 Depth Charges w/ racks

[TexanCowboy]

That one I, personally, like a lot better.

[Sachmle]

And the big sister:

G-Klasse, Deutsche Reich Küstenpatrouilleboot laid down 1920

Displacement:
   550 t light; 569 t standard; 654 t normal; 722 t full load

Dimensions: Length overall / water x beam x draught
   229.67 ft / 226.67 ft x 22.97 ft x 9.02 ft (normal load)
   70.00 m / 69.09 m x 7.00 m  x 2.75 m

Armament:
      1 - 5.12" / 130 mm guns in single mounts, 66.14lbs / 30.00kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1920 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
      6 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1920 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 69 lbs / 31 kg
   Shells per gun, main battery: 150
   3 - 19.7" / 500 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0.98" / 25 mm   166.50 ft / 50.75 m   5.74 ft / 1.75 m
   Ends:   Unarmoured
     Main Belt covers 113 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   2nd:   0.59" / 15 mm         -               -
   3rd:   0.39" / 10 mm         -               -

   - Armour deck: 0.79" / 20 mm, Conning tower: 0.98" / 25 mm

Machinery:
   Petrol Internal combustion motors,
   Direct drive, 2 shafts, 5,800 shp / 4,327 Kw = 22.69 kts
   Range 5,000nm at 12.00 kts
   Bunker at max displacement = 152 tons

Complement:
   64 - 84

Cost:
   £0.130 million / $0.520 million

Distribution of weights at normal displacement:
   Armament: 9 tons, 1.3 %
   Armour: 93 tons, 14.3 %
      - Belts: 38 tons, 5.9 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.5 %
      - Armour Deck: 50 tons, 7.6 %
      - Conning Tower: 2 tons, 0.2 %
   Machinery: 203 tons, 31.0 %
   Hull, fittings & equipment: 235 tons, 36.0 %
   Fuel, ammunition & stores: 104 tons, 15.9 %
   Miscellaneous weights: 10 tons, 1.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     645 lbs / 293 Kg = 9.6 x 5.1 " / 130 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.18
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 11.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.18
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.487
   Length to Beam Ratio: 9.87 : 1
   'Natural speed' for length: 15.06 kts
   Power going to wave formation at top speed: 61 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   Bow angle (Positive = bow angles forward): 10.35 degrees
   Stern overhang: -2.46 ft / -0.75 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.40 ft / 5.00 m
      - Forecastle (15 %):   16.40 ft / 5.00 m
      - Mid (20 %):      16.40 ft / 5.00 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:   9.84 ft / 3.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.8 %
      - Above water (accommodation/working, high = better): 58.4 %
   Waterplane Area: 3,429 Square feet or 319 Square metres
   Displacement factor (Displacement / loading): 113 %
   Structure weight / hull surface area: 35 lbs/sq ft or 170 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.75
      - Overall: 1.00
   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

4t - 12 DC
6t - 3 50cm Torpedoes in Triple Launcher amidships

[Logi]

What is the point of the belt and armored deck? It's too small a ship to be of much use and too thin to protect it from anything.

[Sachmle]

What is the point of the belt and armored deck? It's too small a ship to be of much use and too thin to protect it from anything.

Machine gun fire. For some reason some people don't like it when you order them to heave too and allow you to board. They like to shoot back and I like to not have my boat full of little holes.

[mentat]

For Policing actions I can see it's needed for the Bridge (add some splinter armour?), CT and Guns - not so sure about the deck or belt ...

- alternative to make it smaller + cheaper??