Brandenburg War Emergency Torpedobooten

[Sachmle]

S-101, Brandenburg Torpedobooten laid down 1917 (Engine 1916)

Displacement:
   500 t light; 517 t standard; 611 t normal; 686 t full load

Dimensions: Length overall / water x beam x draught
   229.65 ft / 225.66 ft x 22.57 ft x 10.33 ft (normal load)
   70.00 m / 68.78 m x 6.88 m  x 3.15 m

Armament:
      1 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1906 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, all amidships
      2 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1905 Model
     Machine guns in deck mounts
     on side, all forward, all raised mounts - superfiring
   Weight of broadside 30 lbs / 14 kg
   Shells per gun, main battery: 250
   4 - 19.7" / 500 mm above water torpedoes

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18,000 shp / 13,428 Kw = 30.19 kts
   Range 5,000nm at 12.00 kts
   Bunker at max displacement = 169 tons

Complement:
   60 - 79

Cost:
   £0.121 million / $0.482 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0.6 %
   Machinery: 327 tons, 53.6 %
   Hull, fittings & equipment: 155 tons, 25.4 %
   Fuel, ammunition & stores: 111 tons, 18.1 %
   Miscellaneous weights: 14 tons, 2.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     135 lbs / 61 Kg = 6.5 x 3.5 " / 88 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 57 %
         - Recoil effect (Restricted arc if above 1.00): 0.08
   Seaboat quality  (Average = 1.00): 0.71

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.406
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 15.02 kts
   Power going to wave formation at top speed: 72 %
   Trim (Max stability = 0, Max steadiness = 100): 80
   Bow angle (Positive = bow angles forward): 14.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.01 ft / 4.88 m
      - Forecastle (20 %):   12.01 ft / 3.66 m
      - Mid (40 %):      12.01 ft / 3.66 m (8.01 ft / 2.44 m aft of break)
      - Quarterdeck (15 %):   8.01 ft / 2.44 m
      - Stern:      8.01 ft / 2.44 m
      - Average freeboard:   9.93 ft / 3.03 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 180.3 %
      - Above water (accommodation/working, high = better): 48.4 %
   Waterplane Area: 3,147 Square feet or 292 Square metres
   Displacement factor (Displacement / loading): 44 %
   Structure weight / hull surface area: 23 lbs/sq ft or 113 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.33
      - Overall: 0.58
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is extremely poor
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

4t = 4 Torpedoes
10t = 30 Depth Charges

[The Rock Doctor]

Like most emergency designs, it's okay.  It'll certainly do for screening your larger units.

Did you consider a L:B ratio of around 11:1 and slighter deeper draught?  Or do you prefer 10:1 as a design feature?

[Sachmle]

Design Specifications:
1.) Must fit in Type 0 Slipway
2.) 30kts or greater speed
3.) 5000@ 12kts or better range
4.) 500t or less

If I decrease beam to get 11:1 it kills the steadiness, but w/ the deeper draft does improve sea keeping, but only to 0.78.

[The Rock Doctor]

Steadiness will suffer, but shooting at stuff is probably third on her to-do list behind depth-charging stuff and torpedoing stuff. 

[Sachmle]

Steadiness will suffer, but shooting at stuff is probably third on her to-do list behind depth-charging stuff and torpedoing stuff.  

Actually it's fifth. Behind Depth-Charging stuff, Torpedoing stuff, scouting stuff, and running away from stuff.  ;)

[Guinness]

with one gun she's not going to hit much at medium or long range anyway...

still better than the 5cm armed DKB GTBs though :)

[Sachmle]

S-101, Brandenburg Torpedobooten laid down 1917 (Engine 1916)

Displacement:
   499 t light; 516 t standard; 611 t normal; 687 t full load

Dimensions: Length overall / water x beam x draught
   229.65 ft / 225.66 ft x 20.51 ft x 10.83 ft (normal load)
   70.00 m / 68.78 m x 6.25 m  x 3.30 m

Armament:
      1 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1906 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, all amidships
      2 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1905 Model
     Machine guns in deck mounts
     on side, all forward, all raised mounts - superfiring
   Weight of broadside 30 lbs / 14 kg
   Shells per gun, main battery: 250
   4 - 19.7" / 500 mm above water torpedoes

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18,000 shp / 13,428 Kw = 30.19 kts
   Trial Speed = 32.65 kts
   Range 5,000nm at 12.00 kts
   Bunker at max displacement = 171 tons

Complement:
   60 - 79

Cost:
   £0.121 million / $0.482 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0.6 %
   Machinery: 327 tons, 53.6 %
   Hull, fittings & equipment: 155 tons, 25.3 %
   Fuel, ammunition & stores: 112 tons, 18.3 %
   Miscellaneous weights: 14 tons, 2.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     131 lbs / 60 Kg = 6.3 x 3.5 " / 88 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 11.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 53 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 0.78

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.427
   Length to Beam Ratio: 11.00 : 1
   'Natural speed' for length: 15.02 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 68
   Bow angle (Positive = bow angles forward): 14.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.01 ft / 4.88 m
      - Forecastle (20 %):   12.01 ft / 3.66 m
      - Mid (40 %):      12.01 ft / 3.66 m (8.01 ft / 2.44 m aft of break)
      - Quarterdeck (15 %):   8.01 ft / 2.44 m
      - Stern:      8.01 ft / 2.44 m
      - Average freeboard:   9.93 ft / 3.03 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 180.3 %
      - Above water (accommodation/working, high = better): 40.5 %
   Waterplane Area: 2,899 Square feet or 269 Square metres
   Displacement factor (Displacement / loading): 44 %
   Structure weight / hull surface area: 22 lbs/sq ft or 109 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.69
      - Overall: 0.59
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is extremely poor
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

4t = 4 Torpedoes
10t = 30 Depth Charges

[Sachmle]

Upgunned, and probably final version.

S-101, Brandenburg Torpedobooten laid down 1917 (Engine 1916)

Displacement:
   500 t light; 524 t standard; 611 t normal; 681 t full load

Dimensions: Length overall / water x beam x draught
   229.65 ft / 225.66 ft x 20.51 ft x 10.83 ft (normal load)
   70.00 m / 68.78 m x 6.25 m  x 3.30 m

Armament:
     2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1906 Model
     Quick firing guns in deck mounts
     on centreline ends, evenly spread
     2 - 1.97" / 50.0 mm guns in single mounts, 3.86lbs / 1.75kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, all amidships
     2 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1905 Model
     Machine guns in deck mounts
     on side, all forward, all raised mounts - superfiring
   Weight of broadside 78 lbs / 36 kg
   Shells per gun, main battery: 250
   4 - 19.7" / 500 mm above water torpedoes, 2 sets of twin launchers, stacked amidships.

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18,000 shp / 13,428 Kw = 30.19 kts
   Trial Speed = 32.57 kts
  Range 4,600nm at 12.00 kts
   Bunker at max displacement = 157 tons

Complement:
   60 - 79

Cost:
   £0.128 million / $0.510 million

Distribution of weights at normal displacement:
   Armament: 10 tons, 1.6 %
   Machinery: 317 tons, 51.9 %
   Hull, fittings & equipment: 159 tons, 26.0 %
   Fuel, ammunition & stores: 111 tons, 18.2 %
   Miscellaneous weights: 14 tons, 2.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     128 lbs / 58 Kg = 3.6 x 4.1 " / 105 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 11.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 52 %
         - Recoil effect (Restricted arc if above 1.00): 0.29
   Seaboat quality  (Average = 1.00): 0.78

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.427
   Length to Beam Ratio: 11.00 : 1
   'Natural speed' for length: 15.02 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 67
   Bow angle (Positive = bow angles forward): 14.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.01 ft / 4.88 m
      - Forecastle (20 %):   12.01 ft / 3.66 m
      - Mid (40 %):      12.01 ft / 3.66 m (8.01 ft / 2.44 m aft of break)
      - Quarterdeck (15 %):   8.01 ft / 2.44 m
      - Stern:      8.01 ft / 2.44 m
      - Average freeboard:   9.93 ft / 3.03 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 183.2 %
      - Above water (accommodation/working, high = better): 40.5 %
   Waterplane Area: 2,899 Square feet or 269 Square metres
   Displacement factor (Displacement / loading): 43 %
   Structure weight / hull surface area: 23 lbs/sq ft or 112 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.77
      - Overall: 0.59
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is extremely poor
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

4t = 4 Torpedoes
10t = 30 Depth Charges

[The Rock Doctor]

I'm liking that last one better.

[maddox]

Hmm, the ant approach.   A 100 of these are a menace to the world.

[Jefgte]

...Shorter range is not a problem...
...Speed is also enough to work with the fleet...

because, this class is made for coastal operations.

Good concept

;)