Changes made to Submarine rules

[Tanthalas]

ill go ahead and post this here, but I have simed 5 diferent subs so far today.  Post 1900 (aka 1905 tech and on) composite times 100 is fairly accurate, for the 1900 jobs its times 35 (roughly I got a range from 33 to 37 depending on the sub so I averaged it out to 35).  One thing I did however find was that to reach the speeds listed for them they all required more SHP than OTL, so that is making up for the weight of the batteries etc.  using the system outlined however I was capable of producing subs very close (if not exact) to OTL equivilants.

[Walter]

One thing I did however find was that to reach the speeds listed for them they all required more SHP than OTL

That is because you sim the sub about to go under while the speed listed is when the submarine is surfaced. So it is only natural that you end up needing more SHPs.

As for SubSim, I tried it in the past and did not like it so I won't use it.

[snip]

Let me just chime in with this.

Whatever we come up with may not be prefect to OTL results, but all players will be held to the same standards of design. As SpringSharp is the metric we use for every other ship, we will be using it for subs. It may not be prefect, but it will be the same for all which is the most important thing.

[Tanthalas]

My latest Effort (note its intentionaly broken by adding the 3" gun it cost me almost 90' of dive depth

P Class, Italia Submarine laid down 1900

Displacement:
   235 t light; 240 t standard; 250 t normal; 258 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (105.00 ft / 105.00 ft) x 15.00 ft x (10.00 / 10.25 ft)
   (32.00 m / 32.00 m) x 4.57 m  x (3.05 / 3.12 m)

Armament:
      1 - 3.00" / 76.2 mm 45.0 cal gun - 13.00lbs / 5.90kg shells, 30 per gun
     Quick firing gun in deck mount, 1900 Model
     1 x Single mount on centreline, forward deck forward
      Weight of broadside 13 lbs / 6 kg
      Main Torpedoes
      2 - 17.0" / 432 mm, 12.00 ft / 3.66 m torpedoes - 0.403 t each, 0.807 t total
   submerged bow tubes

Machinery:
   Petrol Internal combustion generators plus batteries,
   Electric motors, 2 shafts, 258 shp / 192 Kw = 11.00 kts
   Range 570nm at 9.00 kts
   Bunker at max displacement = 18 tons

Complement:
   30 - 40

Cost:
   £0.017 million / $0.068 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 1.7 %
      - Guns: 3 tons, 1.0 %
      - Weapons: 2 tons, 0.6 %
   Machinery: 59 tons, 23.4 %
   Hull, fittings & equipment: 109 tons, 43.7 %
   Fuel, ammunition & stores: 15 tons, 6.0 %
   Miscellaneous weights: 63 tons, 25.2 %
      - Hull below water: 63 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     104 lbs / 47 Kg = 7.7 x 3.0 " / 76 mm shells or 0.6 torpedoes
   Stability (Unstable if below 1.00): 1.31
   Metacentric height 0.5 ft / 0.1 m
   Roll period: 9.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 1 %
         - Recoil effect (Restricted arc if above 1.00): 0.00
   Seaboat quality  (Average = 1.00): 0.00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.556 / 0.559
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 10.25 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  0.10 ft / 0.03 m,  0.10 ft / 0.03 m
      - Forward deck:   30.00 %,  0.10 ft / 0.03 m,  0.10 ft / 0.03 m
      - Aft deck:   35.00 %,  0.10 ft / 0.03 m,  0.10 ft / 0.03 m
      - Quarter deck:   15.00 %,  0.10 ft / 0.03 m,  0.10 ft / 0.03 m
      - Average freeboard:      0.10 ft / 0.03 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 118.3 %
      - Above water (accommodation/working, high = better): 0.7 %
   Waterplane Area: 1,105 Square feet or 103 Square metres
   Displacement factor (Displacement / loading): 134 %
   Structure weight / hull surface area: 66 lbs/sq ft or 320 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 3.09
      - Longitudinal: 3.48
      - Overall: 3.13
   Cramped machinery, storage, compartmentation space
   Extremely poor accommodation and workspace room
   Ship has quick, lively roll, not a steady gun platform
   Caution: Lacks seaworthiness - very limited seakeeping ability

Operational Diving Depth 105'
2 tons misc weight Torps

[Tanthalas]

Oh I realised that mate, I was just pointing it out.  I downloaded sub sim just to have a look at it... I think the WesWorld rules are fine for subs, outside the issue with 1900 subs.

One thing I did however find was that to reach the speeds listed for them they all required more SHP than OTL

That is because you sim the sub about to go under while the speed listed is when the submarine is surfaced. So it is only natural that you end up needing more SHPs.

As for SubSim, I tried it in the past and did not like it so I won't use it.

[Walter]

Perhaps a modifier is needed just like a modifier is used for the passenger weights on ocean liners to get more realistic diving depths.

[Tanthalas]

thats what we are "discussing" in the mod forum right now.  once it gets hammerd out *wonders if he will actualy have to use a hammer on someone* we will post it in here.

Perhaps a modifier is needed just like a modifier is used for the passenger weights on ocean liners to get more realistic diving depths.

[KWorld]

I suppose another question is: is the tonnage for ballast tanks subtracted from the light displacement of the submarine to get the cost?

[snip]

No

[KWorld]

Works for me.

[Nobody]

Technically I would say yes, but subs are supposed to be expansive, so no.

[Darman]

So 1905 rolls around and I have the 1905 submarine tech.  The lay down date is still the year it was layed down but the engine year is unknown.  Should the engine year be the year of the tech?  Or should it be the year of our relevant engine tech?

[Walter]

I was rereading this thread since Snip is posting his sub things in his encyclopedia without this matter having been concluded yet regarding submarines.

Technically I would say yes, but subs are supposed to be expansive, so no.

I was thinking about this. Should this not be reflected in the cost? I would think that to build the submarine, it would cost less BP (because your ballast tank is water and not building materials), but more $ (because, as you said, they're more expensive). Maybe something simple like the ballast tank should be subtracted from the weight to get the BP cost and multiply that by 2 to get the $ cost.

[Walter]

... anything? ???

[Darman]

I suspect that other than TB/DD rules (which I think the cost in cash part should apply to submarines as well) the mods are hesitant to add more rules.