Bavarian Torpedo Boat

[Kaiser Kirk]

Having run into unforseen considerations with the cruiser, my attention turned to the other Bavarian warcraft, the Torpedo boats.

Currently, the Bavarians have 10 TB-1 model boats. 520tons, 28kts, 3x 88mm, 4x20" TT.

So this is meant as an improvement- faster, heavier armed, a touch shorter ranged, about the same size.  Overall suitable for scurrying around the Adriatic or raiding ships just off the short Bavarian coast.

I was worried about the BC, and could not find a specific rule like in WW, but I did find the CSA torpedo rams which have lower.

TB-11, Bavaria Torpedo boat laid down 1912 (Engine 1909)

Displacement:
   520 t light; 542 t standard; 586 t normal; 622 t full load

Dimensions: Length overall / water x beam x draught
   226.38 ft / 226.38 ft x 21.00 ft x 10.66 ft (normal load)
   69.00 m / 69.00 m x 6.40 m  x 3.25 m

Armament:
      3 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1912 Model
     Breech loading guns in deck mounts
     on centreline ends, majority aft, 1 raised mount aft
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1912 Model
     Machine guns in deck mounts
     on side ends, evenly spread
   Weight of broadside 106 lbs / 48 kg
   Shells per gun, main battery: 180
   4 - 20.0" / 508 mm above water torpedoes

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 16,815 shp / 12,544 Kw = 30.00 kts
   Range 1,100nm at 12.50 kts
   Bunker at max displacement = 80 tons (100% coal)
     Caution: Delicate, lightweight machinery

Complement:
   59 - 77

Cost:
   £0.073 million / $0.294 million

Distribution of weights at normal displacement:
   Armament: 13 tons, 2.3 %
   Machinery: 315 tons, 53.7 %
   Hull, fittings & equipment: 188 tons, 32.0 %
   Fuel, ammunition & stores: 67 tons, 11.4 %
   Miscellaneous weights: 4 tons, 0.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     138 lbs / 63 Kg = 3.9 x 4.1 " / 105 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 10.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - 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: 0.405
   Length to Beam Ratio: 10.78 : 1
   'Natural speed' for length: 15.05 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      16.57 ft / 5.05 m
      - Forecastle (20 %):   10.83 ft / 3.30 m
      - Mid (50 %):      10.83 ft / 3.30 m
      - Quarterdeck (15 %):   10.83 ft / 3.30 m
      - Stern:      10.83 ft / 3.30 m
      - Average freeboard:   11.29 ft / 3.44 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 191.4 %
      - Above water (accommodation/working, high = better): 48.6 %
   Waterplane Area: 2,935 Square feet or 273 Square metres
   Displacement factor (Displacement / loading): 33 %
   Structure weight / hull surface area: 24 lbs/sq ft or 119 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 4.38
      - Overall: 0.62
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is extremely poor

The TB1 class managed 27 knots and mounted 3x 88mm.  The little ram bowed TB11 attempts to improve on that with 30 knots, 3x 105mm and a slightly shorter range, but still suitable for the defense of the Northern Adriatic.

Misc wieght : 4 tons for 4 x 20" torpedo (Advanced +1)

[Korpen]

I think she suffers from too shorth range, 1100nm is just about 3h at full speed. Considering it will take a ship at least 30-40 minutes to reach top speed it makes her combat radius (30-40nm) i bit low IMO.
Around 70-80nm would be the minimum I would recomend, as that would allow for operations as far south as the end of Istria, and intercepting traffic to Venice.

[Kaiser Kirk]

Good observation Korpen. I had been thinking in terms of darting out to discourage shore bombardment and supply of amphibious beachheads, so 3hrs is likely acceptable. However as you pointed out, it doesn't take much more range to make the ship more useful.

So I have two versions. Version TB-11A can do 180nm at 30knts allow that 70-80nm combat radius.  Version TB-11B is a larger craft with 8.5 hrs endurance at 29knts.  Bavarian Destroyer tech allows 750t, so TB-11B is about as large as they can manage.

TB-11A

TB-11A, Bavaria Torpedo boat laid down 1912 (Engine 1909)

Displacement:
   670 t light; 697 t standard; 797 t normal; 877 t full load

Dimensions: Length overall / water x beam x draught
   255.91 ft / 255.91 ft x 23.29 ft x 11.15 ft (normal load)
   78.00 m / 78.00 m x 7.10 m  x 3.40 m

Armament:
      3 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1912 Model
     Breech loading guns in deck mounts
     on centreline ends, majority aft, 1 raised mount aft
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1912 Model
     Machine guns in deck mounts
     on side ends, evenly spread
   Weight of broadside 106 lbs / 48 kg
   Shells per gun, main battery: 180
   4 - 20.0" / 508 mm above water torpedoes

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 19,063 shp / 14,221 Kw = 30.00 kts
   Range 2,150nm at 12.50 kts
   Bunker at max displacement = 181 tons (100% coal)

Complement:
   74 - 97

Cost:
   £0.096 million / $0.383 million

Distribution of weights at normal displacement:
   Armament: 13 tons, 1.7 %
   Machinery: 437 tons, 54.8 %
   Hull, fittings & equipment: 215 tons, 27.0 %
   Fuel, ammunition & stores: 127 tons, 15.9 %
   Miscellaneous weights: 5 tons, 0.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     187 lbs / 85 Kg = 5.3 x 4.1 " / 105 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.41
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 9.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 52 %
         - Recoil effect (Restricted arc if above 1.00): 0.24
   Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.420
   Length to Beam Ratio: 10.99 : 1
   'Natural speed' for length: 16.00 kts
   Power going to wave formation at top speed: 68 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      18.04 ft / 5.50 m
      - Forecastle (20 %):   10.83 ft / 3.30 m
      - Mid (50 %):      10.83 ft / 3.30 m
      - Quarterdeck (15 %):   10.83 ft / 3.30 m
      - Stern:      10.83 ft / 3.30 m
      - Average freeboard:   11.40 ft / 3.48 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 190.4 %
      - Above water (accommodation/working, high = better): 60.1 %
   Waterplane Area: 3,715 Square feet or 345 Square metres
   Displacement factor (Displacement / loading): 40 %
   Structure weight / hull surface area: 25 lbs/sq ft or 120 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.71
      - Overall: 0.59
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped

The TB1 class managed 27 knots and mounted 3x 88mm.

The little ram bowed TB11 attempts to improve on that with 30 knots, a 6hr @ 30kt endurance, 3x 105mm, still suitable for the defense of the Northern Adriatic.

Misc wieght : 4 tons for 4 x 20" torpedo (Advanced +1)

TB-11B
TB-11B, Bavaria Torpedo boat laid down 1912 (Engine 1909)

Displacement:
   750 t light; 783 t standard; 917 t normal; 1,024 t full load

Dimensions: Length overall / water x beam x draught
   269.03 ft / 269.03 ft x 24.61 ft x 11.15 ft (normal load)
   82.00 m / 82.00 m x 7.50 m  x 3.40 m

Armament:
      4 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1912 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1912 Model
     Machine guns in deck mounts
     on side ends, evenly spread
   Weight of broadside 141 lbs / 64 kg
   Shells per gun, main battery: 180
   4 - 20.0" / 508 mm above water torpedoes

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 17,660 shp / 13,174 Kw = 29.00 kts
   Range 255nm at 29.00 kts
   Bunker at max displacement = 242 tons (100% coal)

Complement:
   83 - 108

Cost:
   £0.108 million / $0.434 million

Distribution of weights at normal displacement:
   Armament: 18 tons, 1.9 %
   Machinery: 481 tons, 52.4 %
   Hull, fittings & equipment: 228 tons, 24.9 %
   Fuel, ammunition & stores: 167 tons, 18.2 %
   Miscellaneous weights: 24 tons, 2.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     217 lbs / 99 Kg = 6.2 x 4.1 " / 105 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.43
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 9.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 53 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.435
   Length to Beam Ratio: 10.93 : 1
   'Natural speed' for length: 16.40 kts
   Power going to wave formation at top speed: 66 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      18.04 ft / 5.50 m
      - Forecastle (20 %):   10.66 ft / 3.25 m
      - Mid (50 %):      10.66 ft / 3.25 m
      - Quarterdeck (15 %):   10.66 ft / 3.25 m
      - Stern:      10.66 ft / 3.25 m
      - Average freeboard:   11.25 ft / 3.43 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 186.9 %
      - Above water (accommodation/working, high = better): 63.5 %
   Waterplane Area: 4,172 Square feet or 388 Square metres
   Displacement factor (Displacement / loading): 47 %
   Structure weight / hull surface area: 25 lbs/sq ft or 122 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.04
      - Overall: 0.58
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped

The TB1 class managed 27 knots and mounted 3x 88mm.  The little ram bowed TB11 attempts to improve on that with 29knts, a theoretical endurance of 8.5 hours at that speed, 4x 105mm.

Misc wieght :
10t spare
10t for Marconi
4 tons for 4 x 20" torpedo (Advanced +1)
[/b]

[Jefgte]

Short range for Adriatic actions.

Are you going to built some Atlantic ships, a kind of High Sea Fleet for action with Allies ?



Jef  ;)

[Borys]

Bavarian battleship have to wait until 1916-21. But that would suck up all officers.
Hmm, the New Swiss could be pouched - Bavaria holds the Old Country and all that.

Borys

[Kaiser Kirk]

Short range for Adriatic actions.

Are you going to built some Atlantic ships, a kind of High Sea Fleet for action with Allies ?



Jef  ;)

Well I forgot to adjust the second one back to a 12.5knot cruise speed. Range at that speed is 2,690 @ 12.5kts-- substantially greater than the 255nm @ 29 shown :)


Probably not for many years. Right now the biggest "need" for an Atlantic capable vessel is to simply show the flag.  The Bavaria of 1912 has no overseas territories, no overseas bases or allies, little or no merchant marine, and does most of her maritime trade down the Rhine through the Netherlands.

So defense of the tiny coastline via mines and torpedo boats, and some localized raiding capacity. More will depend on what stories develop... and the development of more Bavarian naval personnel. As Borys observes, Bavaria simply lacks the qualified personnel to even field major combatants at this time, though recruitment is possible.

[Kaiser Kirk]

Well after more consideration, I think I should change the vessel slightly.
First, at 269ft/82m fitting in 4x105mm + 2 x TT2 on centerline would seem borderline. The OTL IJN Kuri class has similar dimensions and 3x4", 2xTT2. 

Add in the desire for Mount & hoist and a 3 gun ship seemed advisable. Added minerails on the fantail for offensive laying. Took the figures from Fox.

Not sure if I still need weight for the Marconi.

So, which is better- the 4x105mm version non hoist, or 3x 105mm hoist with mines. ?

TB-11C, Bavaria Torpedo boat laid down 1912 (Engine 1909)

Displacement:
   750 t light; 780 t standard; 914 t normal; 1,021 t full load

Dimensions: Length overall / water x beam x draught
   269.03 ft / 269.03 ft x 24.61 ft x 11.15 ft (normal load)
   82.00 m / 82.00 m x 7.50 m  x 3.40 m

Armament:
      3 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1912 Model
     Quick firing guns in deck mounts
     on centreline ends, majority forward, 2 raised mounts - superfiring
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1912 Model
     Machine guns in deck mounts
     on side ends, evenly spread
   Weight of broadside 106 lbs / 48 kg
   Shells per gun, main battery: 200
   4 - 20.0" / 508 mm above water torpedoes

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 17,600 shp / 13,130 Kw = 29.00 kts
   Range 2,675nm at 12.50 kts
   Bunker at max displacement = 241 tons (100% coal)

Complement:
   83 - 108

Cost:
   £0.105 million / $0.420 million

Distribution of weights at normal displacement:
   Armament: 13 tons, 1.5 %
   Machinery: 483 tons, 52.9 %
   Hull, fittings & equipment: 218 tons, 23.8 %
   Fuel, ammunition & stores: 164 tons, 17.9 %
   Miscellaneous weights: 35 tons, 3.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     197 lbs / 89 Kg = 5.6 x 4.1 " / 105 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 0.9 ft / 0.3 m
   Roll period: 10.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.433
   Length to Beam Ratio: 10.93 : 1
   'Natural speed' for length: 16.40 kts
   Power going to wave formation at top speed: 66 %
   Trim (Max stability = 0, Max steadiness = 100): 68
   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:      18.04 ft / 5.50 m
      - Forecastle (20 %):   10.50 ft / 3.20 m
      - Mid (50 %):      10.50 ft / 3.20 m
      - Quarterdeck (15 %):   10.50 ft / 3.20 m
      - Stern:      10.50 ft / 3.20 m
      - Average freeboard:   11.10 ft / 3.38 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 186.4 %
      - Above water (accommodation/working, high = better): 62.5 %
   Waterplane Area: 4,166 Square feet or 387 Square metres
   Displacement factor (Displacement / loading): 48 %
   Structure weight / hull surface area: 24 lbs/sq ft or 118 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.90
      - Overall: 0.57
   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

The TB1 class managed 27 knots and mounted 3x 88mm.  The little ram bowed TB11 attempts to improve on that with 29knts, a theoretical endurance of 8.5 hours at that speed, 3x 105mm.  The aft 105mm is raised to have a clear field over the rear mine deck.

Misc wieght :
20 tons:  30 x 350-kg mines and rails
10t for Marconi
4 tons for 4 x 20" torpedo (Advanced +1)
1 ton spare

[Borys]

3x4" better

[Korpen]

The 4x10 is superior, and the ten ton reserve could be used for mines.
The 3x10 is inferior in firepower to all Italian DDs, and no better then the austrian ones.

[Kaiser Kirk]

Hmm , two differing answers. Appreciate both though.

Let me rephrase.

1. 82m hull- folks fine with 4 x 105mm and 2 twin TT fitting?
If so, then that remains a viable option.

2. I can have 4 QFs with only local ammo,  or 3 QF with steady ammo.  As such the 4 guns may put out fewer shells in the long run than the 3 guns...but more in the short run.  Which is more valuable?

3. Somewhere I think I read that separate misc weight for Marconis becomes unnecessary in 1912, is that so?

[Borys]

1 - as always I say - NEDS;

2 - you are unliely to be in extended firefights - in such context 4 guns is better; and P3D established that in WWI destroyers had one or two hoists - if at all, for all their guns.

Borys

[Korpen]

1 - as always I say - NEDS;

That is incorrect, there is plenty of space for four, or even five guns.

http://www.warshipsww2.eu/lode.php?language=E&period=&idtrida=2332

Or six guns for that matter:
http://www.warshipsww2.eu/lode.php?language=E&period=&idtrida=2338

And even seven was possible:
http://www.warshipsww2.eu/lode.php?language=E&period=&idtrida=2339

Let me rephrase.

1. 82m hull- folks fine with 4 x 105mm and 2 twin TT fitting?
If so, then that remains a viable option.

Defiantly fine, you could even consider reducing the misc weight some and add a fifth gun.

2. I can have 4 QFs with only local ammo,  or 3 QF with steady ammo.  As such the 4 guns may put out fewer shells in the long run than the 3 guns...but more in the short run.  Which is more valuable?

4 guns, not much point with using hoists. The ship is unarmoured so the magazines are not all that much better protected then the deck lockers, so there is not much drawback in having large deck lockers. With 1/3 of the ammo in lockers, it allows for something like six minutes of rapid fire, which should be enough under most circumstances. Hoists are really only usefully if it allows the ammo to stay in a protected magazine, if one expects very long engagements with rapid fire (not likely before the AA mission) or if using twin mounts (were they are a must by our rules).

[Borys]

Indeed .. these Italian boats are impressively overgunned - I wonder how useful were those 6x4".

Is this some Italian abberation? British and German ships were much light armed. Was it the seas they were designed to operate? Was it because the Regia Marina was a "sortie fleet?

Borys

[Korpen]

Indeed .. these Italian boats are impressively overgunned - I wonder how useful were those 6x4".

Is this some Italian abberation? British and German ships were much light armed. Was it the seas they were designed to operate? Was it because the Regia Marina was a "sortie fleet?

Suspect the fact that the British and German DDs had speeds of 33-36kts, compared to the italians 30kts (16 000shp vs. ~25 000shp).

One could say it was the Germans who were undergunned rather then the other way around.

[Kaiser Kirk]

Thanks for the feedback, I will keep the 4 gun version then !