potential Bavarian DD

[Kaiser Kirk]

Intended to project force down the Illyrian coast, or, with tender/collier support, maintain station in the Med.

Never been good at designing DDs though :)


Raptor, Bavaria Torpedo Boat Destroyer laid down 1919 (Engine 1916)

Displacement:
   1,175 t light; 1,234 t standard; 1,408 t normal; 1,548 t full load

Dimensions: Length overall / water x beam x draught
   310.04 ft / 310.04 ft x 28.22 ft x 12.30 ft (normal load)
   94.50 m / 94.50 m x 8.60 m  x 3.75 m

Armament:
      4 - 4.72" / 120 mm guns in single mounts, 55.12lbs / 25.00kg shells, 1919 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread, 2 raised mounts
     Aft Main mounts separated by engine room
      2 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1919 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
   Weight of broadside 224 lbs / 101 kg
   Shells per gun, main battery: 250
   8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   1.18" / 30 mm            -
   2nd:   0.39" / 10 mm         -               -

   - Conning tower: 1.18" / 30 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 29,805 shp / 22,235 Kw = 31.25 kts
trial speed 32.08
   Range 3,660nm at 14.00 kts
   Bunker at max displacement = 313 tons (25% coal)

Complement:
   114 - 149

Cost:
   £0.365 million / $1.458 million

Distribution of weights at normal displacement:
   Armament: 27 tons, 1.9 %
   Armour: 25 tons, 1.8 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 22 tons, 1.5 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 3 tons, 0.2 %
   Machinery: 739 tons, 52.5 %
   Hull, fittings & equipment: 334 tons, 23.7 %
   Fuel, ammunition & stores: 234 tons, 16.6 %
   Miscellaneous weights: 50 tons, 3.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     290 lbs / 132 Kg = 5.5 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.25
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 11.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 0.89

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.458
   Length to Beam Ratio: 10.99 : 1
   'Natural speed' for length: 17.61 kts
   Power going to wave formation at top speed: 68 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   Bow angle (Positive = bow angles forward): -12.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      19.36 ft / 5.90 m
      - Forecastle (20 %):   16.21 ft / 4.94 m
      - Mid (50 %):      16.21 ft / 4.94 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:   12.46 ft / 3.80 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 188.8 %
      - Above water (accommodation/working, high = better): 41.3 %
   Waterplane Area: 5,617 Square feet or 522 Square metres
   Displacement factor (Displacement / loading): 55 %
   Structure weight / hull surface area: 28 lbs/sq ft or 139 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.62
      - Overall: 0.56
   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

[TexanCowboy]

With 25% coal, there isn't a point of retaining it. Just ditch the coal....

[maddox]

Bavaria has ample coal, but lacks domestic oil, only the expensive coal to oil program yields the homegrown oil.

[TexanCowboy]

Then add more coal. 25% coal is at the point of 'why even bother'.

[maddox]

25% is good for normal patrols. That saves the expensive oil.

[Guinness]

25% coal will provide ~900 miles at 14 knots. Probably good enough for most patrols.

Obligatory Guinness DD harping: Freeboard can probably afford to be lower, certainly if expected to operate in the Adriatic. More speed wouldn't hurt.

[Sachmle]

I'd say the armor is useless and just cost weight that could be speed. No need for 'weatherproofing" in the Med or Adriatic. 50mm is decent for stopping machine gun/rifle rounds and small naval guns like 88mm or smaller at range. Still shake the hell outta whoever's inside. Assume layout is supposed to be aBXy so why not use "Centerline Ends, 2 raised mounts superfiring" instead of Centerline distributed? If you're bothering w/ 10mm anti-mg armor you may as well have some mgs, so I'd add 4 7.7mm for 'deck policing" vessels if you stop them for inspection.

[maddox]

 900 miles @14 kts , that's almost across the whole Adriatic and back in 64 hours.

[Kaiser Kirk]

1.  25% coal means normal day to day operations can be completely coal fired. On 25% power they can make 22kts.  The entire coast line is only 70km anyhow and from Trieste to the Straits of Otranto is ~430nm....so they can make the round trip on coal.   As Maddox observed, oil is somewhat precious, so it's essentially reserved for sprints.

2. In the event of extended ops outside the Adriatic, coal will be commercially available in far more ports than oil.

3. The freeboard can be lower, but these are also intended to operate with tender support in the Med. Roughly adding +0.5 to seakeeping would make these good seaboats by DD standards, and with a paucity of friendly ports to hide in, thats the goal.

4. Actually I was figured A, Q, X,Y, with Q and X being raised and tubes flanking Q.  The two 37mm would be on the searchlight platform like the brits.

5. Armor...I agree, it's somewhat of a deliberate error to add splinter armor to the vessel, gunshields should be 20-30mm and nothing on the bridge...but I figured it was a reasonable error to make and didn't hurt overly in the weight category.

edit :
4x 8mm MGs...doable.
More speed... I think she'd have to be ~1500t to make 32+ knts, hard to recall the permutations, but I got to a point where a smidge over 31 seemed pretty good.

[Kaiser Kirk]

Ok, here's a 32 knot version.
Slightly longer range, slightly less seakeeping, though still +.5 = 1.2
For the gain of 0.85kts, there was a size increase of 200 tons, or 18%.
Which means I can buy 8 of the original design...or 6.6 of the new.
Misc weight may be high, but gives a large reserve for the future.

Raptor II, Bavaria Destroyer laid down 1919 (Engine 1916)

Displacement:
   1,385 t light; 1,450 t standard; 1,665 t normal; 1,837 t full load

Dimensions: Length overall / water x beam x draught
   339.57 ft / 339.57 ft x 29.53 ft x 11.48 ft (normal load)
   103.50 m / 103.50 m x 9.00 m  x 3.50 m

Armament:
      4 - 4.72" / 120 mm guns in single mounts, 55.12lbs / 25.00kg shells, 1919 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread, 2 raised mounts
     Aft Main mounts separated by engine room
      2 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1919 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1919 Model
     Machine guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
   Weight of broadside 224 lbs / 101 kg
   Shells per gun, main battery: 250
   8 - 21.0" / 533.4 mm above water torpedoes

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

   - Conning tower: 0.98" / 25 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 35,499 shp / 26,482 Kw = 32.00 kts
Trial speed 32.74
   Range 4,120nm at 14.00 kts
   Bunker at max displacement = 387 tons (25% coal)

Complement:
   129 - 169

Cost:
   £0.433 million / $1.732 million

Distribution of weights at normal displacement:
   Armament: 27 tons, 1.6 %
   Armour: 18 tons, 1.1 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 15 tons, 0.9 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 3 tons, 0.2 %
   Machinery: 911 tons, 54.7 %
   Hull, fittings & equipment: 354 tons, 21.3 %
   Fuel, ammunition & stores: 280 tons, 16.8 %
   Miscellaneous weights: 75 tons, 4.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     315 lbs / 143 Kg = 6.0 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.35
   Metacentric height 1.4 ft / 0.4 m
   Roll period: 10.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 46 %
         - Recoil effect (Restricted arc if above 1.00): 0.22
   Seaboat quality  (Average = 1.00): 0.71

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.506
   Length to Beam Ratio: 11.50 : 1
   'Natural speed' for length: 18.43 kts
   Power going to wave formation at top speed: 67 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): -12.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      20.28 ft / 6.18 m
      - Forecastle (20 %):   15.72 ft / 4.79 m
      - Mid (50 %):      15.72 ft / 4.79 m (7.71 ft / 2.35 m aft of break)
      - Quarterdeck (15 %):   7.71 ft / 2.35 m
      - Stern:      7.71 ft / 2.35 m
      - Average freeboard:   12.08 ft / 3.68 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 194.5 %
      - Above water (accommodation/working, high = better): 50.9 %
   Waterplane Area: 6,718 Square feet or 624 Square metres
   Displacement factor (Displacement / loading): 55 %
   Structure weight / hull surface area: 28 lbs/sq ft or 136 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.03
      - Overall: 0.53
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

[Sachmle]

I think if you adjust trim to raise steadiness (46% currently) in exchange for stability (1.35 currently) you MAY see a slight increase in seakeeping as well (Like 0.74 instead of 0.71). Other than that, I like it.

[Kaiser Kirk]

whoops, I had that fixed at one point and then went and toyed with hull form some. .. it solves at 0.78 seakeeping, 66 trim and 50 stability.

In the mean time, I explored what it would take to get to 34 kts..and came up with this behemoth.

Raptor III, Bavaria Destroyer laid down 1919 (Engine 1916)

Displacement:
   2,190 t light; 2,272 t standard; 2,553 t normal; 2,778 t full load

Dimensions: Length overall / water x beam x draught
   380.58 ft / 380.58 ft x 33.46 ft x 15.58 ft (normal load)
   116.00 m / 116.00 m x 10.20 m  x 4.75 m

Armament:
     4 - 4.72" / 120 mm guns in single mounts, 55.12lbs / 25.00kg shells, 1919 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread, 2 raised mounts
     Aft Main mounts separated by engine room
     2 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1919 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
     4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1919 Model
     Machine guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
   Weight of broadside 224 lbs / 101 kg
   Shells per gun, main battery: 250
   8 - 21.0" / 533.4 mm above water torpedoes

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

  - Conning tower: 0.98" / 25 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 54,958 shp / 40,998 Kw = 34.00 kts
   Range 4,130nm at 14.00 kts
   Bunker at max displacement = 506 tons (25% coal)

Complement:
   179 - 233

Cost:
   £0.703 million / $2.811 million

Distribution of weights at normal displacement:
   Armament: 27 tons, 1.0 %
   Armour: 19 tons, 0.7 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 15 tons, 0.6 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 4 tons, 0.2 %
   Machinery: 1,592 tons, 62.4 %
   Hull, fittings & equipment: 502 tons, 19.6 %
   Fuel, ammunition & stores: 363 tons, 14.2 %
   Miscellaneous weights: 50 tons, 2.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     391 lbs / 177 Kg = 7.4 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.50
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 10.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 45 %
         - Recoil effect (Restricted arc if above 1.00): 0.12
   Seaboat quality  (Average = 1.00): 0.69

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.450
   Length to Beam Ratio: 11.37 : 1
   'Natural speed' for length: 19.51 kts
   Power going to wave formation at top speed: 66 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): -12.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.46 ft / 6.54 m
      - Forecastle (20 %):   16.70 ft / 5.09 m
      - Mid (50 %):      16.70 ft / 5.09 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:   12.73 ft / 3.88 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 211.7 %
      - Above water (accommodation/working, high = better): 58.9 %
   Waterplane Area: 8,126 Square feet or 755 Square metres
   Displacement factor (Displacement / loading): 57 %
   Structure weight / hull surface area: 32 lbs/sq ft or 157 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.01
      - Overall: 0.54
   Hull space for machinery, storage, compartmentation is extremely poor
   Room for accommodation and workspaces is cramped
   Caution: Lacks seaworthiness - very limited seakeeping ability