Changes made to Submarine rules

[Tanthalas]

They may now be simed to gat their fuel requirements (see Naval Technology thread and post questions here)

[snip]

A clarification:
We will now be simming subs in accordance with the folowing rules for design. Note we (the mod team) reserve the right to change aspects of these rules related to the technical performance of subs.

Submarines: Spring Style is designed for surface ships, and isn't really suited to sub sims. (Rolf Hoffman has created an excellent pencil-and-paper sub sim rule, which will be added to my website once formatted.) However, a fairly decent approximate sub sim can be done using Spring Style:

You will sim your sub in awash condition, just about to go under. Specify depth as about 2/3 of beam; this seems typical for subs of pre-nuke era. Provide "miscelleneous weight" of about 1/4 to 1/6 of normal displacement - this is your ballast tank. (Some nations' real subs had closer to 1/3, but this will not sim well.)

For freeboard, enter zero. (To avoid computer error, the program will adjust this to 0.1 ft (0.03 metre). You'll get a "horribly cramped" warning - ignore it. However, if your sub has stability less than 1.0, you'll have to redesign it. Always enter steadiness of 50 pct. (If you cheat to get more stability, whoever re-runs the sim will catch you!)

Multiply composite hull strength times 100 to get operational diving depth in feet. (Multiply by 30 for depth in metres.) Emergency diving depth is 1.6 times operational depth; crush depth is 2.5 times operational depth.

You will find that the smaller the ballast tank, the deeper your sub can dive. However, the ballast tank is your reserve bouyancy, and will determine how much depth-charging you can take and still make it back up!

Adjust your report file. Just delete all those warnings about lack of seaworthiness - a dived sub obviously isn't seaworthy by surface-ship standards. Specify crew as about half the listed minimum. Don't forget to list operational diving depth.

The limits that are stated in the tech rules for subs are just that, the lower limit that a given set of characteristics can be achieved on tech wise. The maximum displacement is still caped at the highest for that given tech level. IE, a sub constructed under the 1900 rules that has two tubes and two torpedos must weigh at least 125t light and cannot weigh more then 250t. All upkeep will be handeld as in surface ships. Questions?

[KWorld]

I'm not at all sure this is going to work out well in conjunction with the table.  As an example, I'm trying to similar to the historical USS Adder:


USS Adder, United States Submarine laid down 1900

Displacement:
   100 t light; 102 t standard; 108 t normal; 113 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (64.00 ft / 64.00 ft) x 11.50 ft x (10.00 / 10.34 ft)
   (19.51 m / 19.51 m) x 3.51 m  x (3.05 / 3.15 m)

Armament:
      Main Torpedoes
      1 - 18.0" / 457 mm, 12.00 ft / 3.66 m torpedo - 0.447 t total
   submerged bow tube
      2nd Torpedoes
      4 - 18.0" / 457 mm, 12.00 ft / 3.66 m torpedoes - 0.447 t each, 1.789 t total
   below water reloads

Machinery:
   Petrol Internal combustion generators plus batteries,
   Electric motors, 1 shaft, 162 shp / 121 Kw = 10.50 kts
   Range 1,000nm at 7.00 kts
   Bunker at max displacement = 11 tons

Complement:
   16 - 21

Cost:
   £0.009 million / $0.035 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 2.9 %
      - Weapons: 3 tons, 2.9 %
   Machinery: 37 tons, 34.0 %
   Hull, fittings & equipment: 32 tons, 29.8 %
   Fuel, ammunition & stores: 8 tons, 7.4 %
   Miscellaneous weights: 28 tons, 25.9 %
      - Hull below water: 28 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     18 lbs / 8 Kg = 0.2 x 6 " / 152 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 0.2 ft / 0.1 m
   Roll period: 10.0 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): 0.515 / 0.520
   Length to Beam Ratio: 5.57 : 1
   'Natural speed' for length: 8.00 kts
   Power going to wave formation at top speed: 62 %
   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): 179.8 %
      - Above water (accommodation/working, high = better): 0.6 %
   Waterplane Area: 479 Square feet or 45 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 37 lbs/sq ft or 180 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 2.02
      - Longitudinal: 6.31
      - Overall: 2.27
   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

        Below-water miscellaneous weight is ballast tankage.


Size is about right, and it fits into the 100 ton size class from the table.  But it's too fast, it's too long ranged, carries too many torpedoes, and can dive too deeply.  Not to mention that there's no way to specify the amount of batteries carried, or how large the electric motors are.

If we're going to design subs instead of using them from the table, I'd suggest using SubSim (www.geocities.ws/greglocock/subsim.xls) instead, as it's designed for the task and produces mostly plausible results.  It's main flaw is that it doesn't allow you to put in multiple guns directly, which can be worked around easily enough.  Another advantage of subsim is that since you specify the amount of batteries a boat has, and battery maintenance/replacement is an important expense on these vessels, the battery tonnage could be included in the fuel calculations.

[Tanthalas]

You do realise we still have players that view Spread Sheats as Black Magic right? Ok so im not sure about "now" but I know we did... Seriously we dont need to get that detaild though (we have discussed the Dive Depth issue but the answer isnt finalised).  We may never get them perfect but we decided to go with good enough to get yall started and tweak from there.  Here is my first stab at a 100 ton Jober based on the A class and using the chart as a referance (I didnt deleat the bad boy warnings however)

Test Submarine using my proposed rule changes (its based off the USA A class subs and our 100 ton 1900 submarine).  I didnt deleat all the bad boy warnings but comparing it to the A class I say it hit fairly close (good enough for goverment work anyway)

GMS Experimental sub, GMS Forum Submarine test ship laid down 1900

Displacement:
   100 t light; 102 t standard; 104 t normal; 106 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (64.00 ft / 64.00 ft) x 11.80 ft x (10.50 / 10.64 ft)
   (19.51 m / 19.51 m) x 3.60 m  x (3.20 / 3.24 m)

Armament:
      Main Torpedoes
      1 - 17.0" / 432 mm, 12.00 ft / 3.66 m torpedo - 0.403 t total
   submerged bow tube

Machinery:
   Petrol Internal combustion generators plus batteries,
   Electric motors, 1 shaft, 53 shp / 40 Kw = 8.00 kts
   Range 250nm at 8.00 kts
   Bunker at max displacement = 4 tons

Complement:
   16 - 21

Cost:
   £0.005 million / $0.021 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.8 %
      - Weapons: 1 tons, 0.8 %
   Machinery: 12 tons, 11.6 %
   Hull, fittings & equipment: 59 tons, 56.3 %
   Fuel, ammunition & stores: 4 tons, 4.3 %
   Miscellaneous weights: 28 tons, 26.9 %
      - Hull below water: 28 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     79 lbs / 36 Kg = 0.7 x 6 " / 152 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.36
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 8.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 2 %
         - 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): 0.459 / 0.461
   Length to Beam Ratio: 5.42 : 1
   'Natural speed' for length: 8.00 kts
   Power going to wave formation at top speed: 45 %
   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): 77.4 %
      - Above water (accommodation/working, high = better): 0.6 %
   Waterplane Area: 463 Square feet or 43 Square metres
   Displacement factor (Displacement / loading): 200 %
   Structure weight / hull surface area: 67 lbs/sq ft or 326 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 3.57
      - Longitudinal: 13.14
      - Overall: 4.06
   Excellent 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

Dive limit 400 foot

[KWorld]

The problem with that design (just like mine) is that it can dive WAY, WAY too deeply, because it has far too much strength.  The historical boats had a test depth of under 75 feet, as opposed to over 400 for yours and over 200 for mine.


The good thing about using Subsim for spreadsheet-phobes is 1) they don't have to create anything, the sheet's already done, and 2) the only things to enter are in one blue column: date, main gun bore size, length, beam, and draft (in meters), number of torpedo tubes, number of "mines" (used for torps as well), tons of oil, batteries, and hydrogen peroxide (if needed), and above water and submerged cruise speeds.  If res bouyancy if over 40%, you probably have bigger ballast tanks than you need, if res buoyancy is below 15-20%, your sub will take a long time to dive. 

[Tanthalas]

thats one of the things we will be changing from the wesworld rules.  However im waiting for the other 2 mods to check off on it before I make the change I feal ok saying however that its likley to be somthing like this.  instead of *100 for depth it will likley be *33.  This proposal came from my 100 ton job (we all agreed that it could dive way to deap).  Perfect Historical accuracy isnt realy necessary(after all look at the Proliferation of AQY ships vs OTL), what is necessary is a good enough solution that everyone can use.  I personaly am against getting into a diferent program for every ship type.

The problem with that design (just like mine) is that it can dive WAY, WAY too deeply, because it has far too much strength.  The historical boats had a test depth of under 75 feet, as opposed to over 400 for yours and over 200 for mine.

[KWorld]

thats one of the things we will be changing from the wesworld rules.  However im waiting for the other 2 mods to check off on it before I make the change I feal ok saying however that its likley to be somthing like this.  instead of *100 for depth it will likley be *33

The problem with that design (just like mine) is that it can dive WAY, WAY too deeply, because it has far too much strength.  The historical boats had a test depth of under 75 feet, as opposed to over 400 for yours and over 200 for mine.

Be careful with that, because it will likely cause problems later on, though a sliding scale as submarine tech improves might work.

I suppose my question is is what's the point of having both the detailed limits in the table and being able to design our own vessels?  In general, we have either a detailed table (like for MTBs, or subs), OR a set of design parameters to stay within. 

[Tanthalas]

the table is going to get changed to outline only tonage limits, it just hasnt got changed yet because how is still under discussion.  A sliding scale is likley to be what we come up with (like I said its still under discussion) and it will proly be a part of the "new" table.

thats one of the things we will be changing from the wesworld rules.  However im waiting for the other 2 mods to check off on it before I make the change I feal ok saying however that its likley to be somthing like this.  instead of *100 for depth it will likley be *33

The problem with that design (just like mine) is that it can dive WAY, WAY too deeply, because it has far too much strength.  The historical boats had a test depth of under 75 feet, as opposed to over 400 for yours and over 200 for mine.

Be careful with that, because it will likely cause problems later on, though a sliding scale as submarine tech improves might work.

I suppose my question is is what's the point of having both the detailed limits in the table and being able to design our own vessels?  In general, we have either a detailed table (like for MTBs, or subs), OR a set of design parameters to stay within.

[KWorld]

If SS3 did a better job with submarines, I'd have no issues with using it, but it doesn't handle rather important parts of them (the "electric" part of "diesel-electric") at all.

[KWorld]

the table is going to get changed to outline only tonage limits, it just hasnt got changed yet because how is still under discussion.  A sliding scale is likley to be what we come up with (like I said its still under discussion) and it will proly be a part of the "new" table.

thats one of the things we will be changing from the wesworld rules.  However im waiting for the other 2 mods to check off on it before I make the change I feal ok saying however that its likley to be somthing like this.  instead of *100 for depth it will likley be *33

The problem with that design (just like mine) is that it can dive WAY, WAY too deeply, because it has far too much strength.  The historical boats had a test depth of under 75 feet, as opposed to over 400 for yours and over 200 for mine.

Be careful with that, because it will likely cause problems later on, though a sliding scale as submarine tech improves might work.

I suppose my question is is what's the point of having both the detailed limits in the table and being able to design our own vessels?  In general, we have either a detailed table (like for MTBs, or subs), OR a set of design parameters to stay within.

Ah, OK, that will help.  I still have reservations, because of SS3's lack of handling the electric side of submarines, but I can deal with them.

[Nobody]

A big part of the problem is that SpringSharp ignores the fact that these petroleum engines are several times less efficient than Diesels. That becomes less of a problem later on.
The other part is indeed the electric equipment, maybe we could represent the biggest part of that - the battery by misc weight? E.g. 1 ton per electric horsepower? Although that ignores the range issue and obviously wouldn't work with say a type XXI* without being modified over time.


*)the type's XXI 236 ton battery (~15% of the subs total weight) was capable of driving the ~5000 hp_e at nearly full power.

[KWorld]

A big part of the problem is that SpringSharp ignores the fact that these petroleum engines are several times less efficient than Diesels. That becomes less of a problem later on.
The other part is indeed the electric equipment, maybe we could represent the biggest part of that - the battery by misc weight? E.g. 1 ton per electric horsepower? Although that ignores the range issue and obviously wouldn't work with say a type XXI* without being modified over time.


*)the type's XXI 236 ton battery (~15% of the subs total weight) was capable of driving the ~5000 hp_e at nearly full power.

Miscellaneous weight could be used to sim the weight of the batteries, yes, but SS3 wouldn't give us any way to determine the range on those batteries at different speeds, nor would it give us any way to sim the electric motors that used those batteries.

[Darman]

Enter ship name, Enter country Enter ship type laid down 1900

Displacement:
   231 t light; 236 t standard; 250 t normal; 261 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (140.00 ft / 140.00 ft) x 12.50 ft x (11.00 / 11.36 ft)
   (42.67 m / 42.67 m) x 3.81 m  x (3.35 / 3.46 m)

Machinery:
   Petrol Internal combustion generators plus batteries,
   Electric motors, 1 shaft, 172 shp / 128 Kw = 10.00 kts
   Range 2,000nm at 6.00 kts
   Bunker at max displacement = 25 tons

Complement:
   30 - 40

Cost:
   £0.014 million / $0.054 million

Distribution of weights at normal displacement:
   Armament: 0 tons, 0.0 %
   Machinery: 39 tons, 15.6 %
   Hull, fittings & equipment: 136 tons, 54.5 %
   Fuel, ammunition & stores: 19 tons, 7.5 %
   Miscellaneous weights: 56 tons, 22.4 %
      - Hull below water: 56 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     179 lbs / 81 Kg = 1.7 x 6 " / 152 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.15
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 9.8 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): 0.455 / 0.460
   Length to Beam Ratio: 11.20 : 1
   'Natural speed' for length: 11.83 kts
   Power going to wave formation at top speed: 27 %
   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): 75.8 %
      - Above water (accommodation/working, high = better): 0.7 %
   Waterplane Area: 1,069 Square feet or 99 Square metres
   Displacement factor (Displacement / loading): 186 %
   Structure weight / hull surface area: 68 lbs/sq ft or 331 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 3.42
      - Longitudinal: 2.91
      - Overall: 3.03
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is extremely poor
   Ship has quick, lively roll, not a steady gun platform
   Caution: Lacks seaworthiness - very limited seakeeping ability

[Darman]

Sorry, it was based on the B-class

[Nobody]

A big part of the problem is that SpringSharp ignores the fact that these petroleum engines are several times less efficient than Diesels. That becomes less of a problem later on.
The other part is indeed the electric equipment, maybe we could represent the biggest part of that - the battery by misc weight? E.g. 1 ton per electric horsepower? Although that ignores the range issue and obviously wouldn't work with say a type XXI* without being modified over time.


*)the type's XXI 236 ton battery (~15% of the subs total weight) was capable of driving the ~5000 hp_e at nearly full power.

Miscellaneous weight could be used to sim the weight of the batteries, yes, but SS3 wouldn't give us any way to determine the range on those batteries at different speeds, nor would it give us any way to sim the electric motors that used those batteries.

It doesn't have to. Simplest case: you use the power requirement for cruise speed as the power of the electric motors (and therefore the submerged speed*) from that determine the battery weight (motor wight is neglectible in comparison to the battery). A normal battery should be able to give full power for about an hour or two (much longer if you go slower).


*)in reality most subs before 1945 would require more power underwater to reach the same speed