[MC+SS] Alternate TS Calculation

[Langy]

Originally Posted by Peter Knutsen

I haven't bought the #30 Pyramid, but it seems to me there are three classes of ship:

1. Short occupancy ships wth no FTL. These are able to devote many module slots to weapons and defence, and sensors and ECM and so forth, so they should have a high TS for their size.

2. Long occupancy ships with no FTL. Medium TS for their size.

3. Long occupancy ships with FTL. Low TS for their size.

All those things are well-covered by the multipliers for number of weapon batteries, ECM, and DR. As-is, a ship that costs ten more might provide only twice as much TS, even if it's built in the same exact fashion with the same exact modules (just 10 times as big). It only gets worse as the difference in SM (and thus price) goes up.

I'd suggest a different new formula than the one viera suggested, though. You could try:

Avg dDR*dHP*dHP*HF*WB*TF / 200

This would make the Battle-class frigate TS 729,000, which is much closer to the TS 768,000 you could get with two TL10 nuclear submarines for roughly the same price. Viera's formula would get a TS of 205,000, but is much more complicated.

Note that dDR*dHP*dHP scales almost directly with mass (and thus cost), and it makes the formula nice and pretty.

EDIT: After looking at how much Air vessels cost compared to other ones, I think spaceships being really expensive for their TS is appropriate - maybe divide by 1,000 or so instead of 200. It's still not appropriate for fighter-sized ships to be super-cheap for their TS compared with capital ships, though.

[vierasmarius]

Originally Posted by Langy

All those things are well-covered by the multipliers for number of weapon batteries, ECM, and DR. As-is, a ship that costs ten more might provide only twice as much TS, even if it's built in the same exact fashion with the same exact modules (just 10 times as big). It only gets worse as the difference in SM (and thus price) goes up.

I'd suggest a different new formula than the one viera suggested, though. You could try:

Avg dDR*dHP*dHP*HF*WB*TF / 200

This would make the Battle-class frigate TS 729,000, which is much closer to the TS 768,000 you could get with two TL10 nuclear submarines for roughly the same price. Viera's formula would get a TS of 205,000, but is much more complicated.

Note that dDR*dHP*dHP scales almost directly with mass (and thus cost), and it makes the formula nice and pretty.

That should work well for the most part, though DR is much more variable than HP (ranging from 5% to 70% of HP per armor system, or up to 300% for a Force Screen). I think including it there, rather than adding it to HP, might be weighting it too heavily.

I had another thought, while fiddling with the numbers for Carriers. If we go with TS = Mass, there's little to no reason to use fighters instead of just more guns. A single fighter of SM X-3 (ie, the largest fighter that will fit in a given hangar) weighs 1/30 of the capital ship, and replaces a gun emplacement that would weigh 1/20 of the capital ship. Assuming a heavy fighter loadout, it could have maybe 30% of it's systems devoted to weapons. Assuming good armor and handling it would have a TS of maybe 25%-30% of the gun that it's replacing. In this model the carrier would be better off just with another gun emplacement.

Under some conceptions of space warfare, this would work fine - Fighters would be a niche weapon for orbit-to-surface attacks or spacelane patrols. But it doesn't match the trope of "Space Superiority Fighters" as a key component of the larger battlescape. So perhaps a compromise. Instead of scaling TS with the linear dimension (the model presented in the article) or with the mass (my proposal above), instead scale with the surface area. This would give that heavy fighter I talked about above a TS equivalent to about 60%-80% of one capital ship weapon mount, which seems fair enough that carriers would be useful. And there's a very simple way to handle this formula too: Just multiply the TS calculated using the original formula by the ship's length divided by some constant, probably 20 (so a SM+6 fighter keeps it's original TS, the smaller fighters drop a bit, and everything above gets a boost). So that Battle-Class Frigate from the article would go from TS 68,580 to about 240,000. Capital Ships would still be more expensive than the same TS of Naval vessels, and larger ships would still be proportionally more expensive than smaller ones, but it's a bit less jarring a discrepancy, and it keeps Carriers in the ring.

[Peter Knutsen]

Can GURPS Spaceships even give a cost discount for short-occupancy ships? I forgot...

[Langy]

Originally Posted by Peter Knutsen

Can GURPS Spaceships even give a cost discount for short-occupancy ships? I forgot...

Yes. They require significantly fewer systems for life support or habitats, possibly all the way down to 'none' if the 'short-occupancy' bit means something more like a fighter than a patrol boat.

That should work well for the most part, though DR is much more variable than HP (ranging from 5% to 70% of HP per armor system, or up to 300% for a Force Screen). I think including it there, rather than adding it to HP, might be weighting it too heavily.

This is intended. If something has twice as much DR, then they get twice as much TS, etc. I suppose you could do (HP+DR)^3, but I like HP*DR more.

I had another thought, while fiddling with the numbers for Carriers. If we go with TS = Mass, there's little to no reason to use fighters instead of just more guns. A single fighter of SM X-3 (ie, the largest fighter that will fit in a given hangar) weighs 1/30 of the capital ship, and replaces a gun emplacement that would weigh 1/20 of the capital ship. Assuming a heavy fighter loadout, it could have maybe 30% of it's systems devoted to weapons. Assuming good armor and handling it would have a TS of maybe 25%-30% of the gun that it's replacing. In this model the carrier would be better off just with another gun emplacement.

This matches the general Spaceships system rather well - there's little point to using fighters in it. Still, if you do want to make it scale with surface area, do DR*HP instead of DR*HP*HP.

[OldSam]

Originally Posted by vierasmarius

And there's a very simple way to handle this formula too: Just multiply the TS calculated using the original formula by the ship's length divided by some constant, probably 20 (so a SM+6 fighter keeps it's original TS, the smaller fighters drop a bit, and everything above gets a boost). So that Battle-Class Frigate from the article would go from TS 68,580 to about 240,000. Capital Ships would still be more expensive than the same TS of Naval vessels, and larger ships would still be proportionally more expensive than smaller ones, but it's a bit less jarring a discrepancy, and it keeps Carriers in the ring.

With original formula you mean the one David Pulver used in the article, don't you?
If so, that sounds like a very good upgrade for me! :) Good job!

It would be really strange to have fleets with large ships being much too expensive and thus not cost-effective. On the other hand it would be boring to have big fleets without any fighters, just because simple weapon batteries are cheaper, I think the flexibility offered by fighters should make them useful, too.

[vierasmarius]

Originally Posted by OldSam

With original formula you mean the one David Pulver used in the article, don't you?
If so, that sounds like a very good upgrade for me! :) Good job!

Yeah, I meant David's original formula.

It would be really strange to have fleets with large ships being much too expensive and thus not cost-effective. On the other hand it's boring to have big fleets without any fighters, just because simple weapon batteries are cheaper, I think the flexibility offered by fighters should make them useful, too.

One advantage that fighters have, even if their TS is lower, is superior Air mobility. This can extend a space-bound fleet's influence into a gravity well. Additionally, winged fighters gain around +40% TS in an atmosphere due to their Handling bonus, making them even better suited for this role compared to the clumsy atmosphere-capable capital ships.

[Tyneras]

There are also a number of design switches and specific systems that should be included in that calculation. Having Hardened Armor or Shields, or IT:DR would improve the TS of a ship, or maybe give it the Armor class. I'd look for more, but I'm away from my books right now.

I don't know about you guys, but I would love a Spaceships #: Fleet Warfare supplement that covered everything in worked detail.

[vierasmarius]

Originally Posted by Tyneras

There are also a number of design switches and specific systems that should be included in that calculation. Having Hardened Armor or Shields, or IT:DR would improve the TS of a ship, or maybe give it the Armor class. I'd look for more, but I'm away from my books right now.

I don't know about you guys, but I would love a Spaceships #: Fleet Warfare supplement that covered everything in worked detail.

Definitely. I've been adding Force Screen DR to the average, but it would make sense for Hardened to have an impact too. Perhaps a x1.5 to the armor DR on that facing? I like the idea of giving it the Armor class, but perhaps that should be based on a ship having an exceptional average DR instead (ie, twice hull HP). Recon and Cav classes would make sense in a space opera setting where FTL travel, dense asteroid belts and short engagement ranges make detection and tactical maneuvering more of a concern. Artillery could represent a ship with long-range missiles, especially if it lacks heavy armor or close-in weapons. Neutralize C3I for ships with jammers, and Neutralize Armor for weapons like Graviton beams and Disintegrators.

Most of the classes don't make sense for a realistic sci fi battle, but space opera tends to be "Naval Battles IN SPACE" so I think a little divergence could suit the genre well.

[vierasmarius]

Okay, I ran some comparisons of capital ships and fighter-equipped carriers using David's formula and the two alternates we've been discussing. Got some interesting results, based on several combinations of Carrier and Fighter at a couple TLs. (The top line, 2*SM X-3 etc, indicates the number and relative size of fighters carried in a 2-hangar ship)

Relative TS of SM X Carrier + Fighters vs SM X Capital Ship
Formula		2*SM X-3	20*SM X-5	200*SM X-7	2K*SM X-9
Linear		x1 - x1.5	x2 - x3		x10		x30
Area		x2/3		x2/3 - x1	x1		x1
Mass		x1/2 - x1/3	x1/2 - x1/3	x1/2 - x1/3	x1/2 - x1/3

Based on this, I really like the Area-based formula, since it makes carriers and other capital ships pretty equal in terms of overall power.

[terranstrider]

Originally Posted by vierasmarius

Instead of scaling TS with the linear dimension (the model presented in the article) or with the mass (my proposal above), instead scale with the surface area. This would give that heavy fighter I talked about above a TS equivalent to about 60%-80% of one capital ship weapon mount, which seems fair enough that carriers would be useful. And there's a very simple way to handle this formula too: Just multiply the TS calculated using the original formula by the ship's length divided by some constant, probably 20 (so a SM+6 fighter keeps it's original TS, the smaller fighters drop a bit, and everything above gets a boost). So that Battle-Class Frigate from the article would go from TS 68,580 to about 240,000. Capital Ships would still be more expensive than the same TS of Naval vessels, and larger ships would still be proportionally more expensive than smaller ones, but it's a bit less jarring a discrepancy, and it keeps Carriers in the ring.

OK, so the formula becomes:
TS = (average dDR (x1.5 if hardened) + dST/HP) x WB x HF x TF. x SA/20
WB = number of weapons batteries + ECM systems
HF = 10 + Handling. If no Handling; HF = 4.
TF = the tech level constant: 0.01 for TL3 or less, 0.02 for TL4,
0.05 for TL5, 0.25 for TL6, 0.5 for TL7, 1 for TL8, 2.5 for TL9,
5 for TL10, 10 for TL11, or 20 for TL12. Double TF if the craft
uses superscience weapons or multiply by 20 if it uses cosmic.
SA = approximate Surface Area - Length in Yards divided by 20

Question: Does this still make sense when we take into account the difference in surface area by Hull Shape?
For example; the Battle Class Frigate is streamlined and therefore probably has a length closer to 130 meters as a streamlined wedge rather than the 70 yards assumed for an unstreamlined cylinder. A Sphere would have a length (diameter) of 18 meters.
I calculate the surface area for the above 3 options as 1,010 m2, 1,670 m2 & 2,250 m2. Wings are not included.
Sorry about the metric; I never use imperial in my calculations.

Anyway the example Frigate would have a TS of approximately 480,000. All streamlined fighters and ships would have double the TS of unstreamlined versions. Note that armour protection for streamlined ships is 2/3 unstreamlined.