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FFS3 for T5

Originally posted by robject:
At first, I thought the Book 2 M-drive volumes could be retained as-is, but they're too powerful on the low end: M-drive A pushes a Free Trader at 1G, yet it's only 0.5% of the ship's volume.

So, I suggest 2% per G is a nice, happy-sounding number.

I also suggest that there will probably be jumps in the drive power sequence, but volume and price should jump appropriately.
All else being equal, that nets a Free Trader 3 tons less cargo capacity. Does that dramatically hurt the financial performance of the ship overall?

I agree that 2%/G is a nice, round, easy number. And I also think direct compatability with B2 numbers shouldn't be a goal, rather it should just be an inspiration in terms of mechanics of design.
 
Originally posted by whartung:
So, you want to change the actual technology of the drive, not how the drive ratings are ascertained.
Well, HG drives behave as if they're volume-based. If we assume drives and weapons are 1T/m^3 (14T/dton), a Tigress weighs 50-60 tons/dton, an unarmored Fer-de-Lance weighs 7-8 tons/dton, and both need 17% maneuver drive for 6 Gs. Changing the drive tech also allows bypassing some historical problems such as near-C rocks.

I don't see that happening at all. We already have a volume based drive system -- jump drive. Using a mass based drive system fits all in to acceleration and vectors and all of the other OTU idioms.

But what's wrong with a mass based drive system?

Complexity and incompatibility with High Guard.
 
Originally posted by whartung:
</font><blockquote>quote:</font><hr />Originally posted by robject:
I suggest 2% per G is a nice, happy-sounding number.
All else being equal, that nets a Free Trader 3 tons less cargo capacity. Does that dramatically hurt the financial performance of the ship overall?

I agree that 2%/G is a nice, round, easy number. And I also think direct compatability with B2 numbers shouldn't be a goal, rather it should just be an inspiration in terms of mechanics of design.
</font>[/QUOTE]We're going to trash the bridge, so we've got room.
 
Heck, HG used ((3 x G)-1)% for maneuver and (1 + Jn)% for Jump.

Being mass-based is fine for our purposes provided the only users who have to worry about it are the ones that want to. If the simple side *looks* volume-based, Book 2 simplicity is achieved.

Trashing the "Bridge" means mentioning all the things that used hide in that volume, which otherwise have to magically appear and take up previously unaccounted for volume when we jump to the complex level. "Book 2" becomes unattainable at that point, unless we're building all those infrastructure bits into Bridge packages or summarily removing the required volume from the hull before the user gets there (ala QSDS). This becomes a headache to write AND use pretty quickly unless boiled down to a simple relationship which, funny, looks a lot like "2% of the hull volume with a minimum of 20 tons".
 
Originally posted by robject:
At first, I thought the Book 2 M-drive volumes could be retained as-is, but they're too powerful on the low end: M-drive A pushes a Free Trader at 1G, yet it's only 0.5% of the ship's volume.

It's not just the low end.

I still think it's doable, but only by making technology and/or accessibility assumptions about the package M-drive. Remember, the numbers don't necessarily represent the drive, but rather what it takes to put that drive into a starship. If the package M-Drives are "old-but-reliable" tech with no maintenance spaces of their own, the reductions of up to 80% over (or would that be "under"?) their HG equivalents start to make a little more sense.

And for the record, I don't necessarily want to see such drive options at a *new* "Book 2" level. Possible yes, required no. Nothing like unexplained penalties ("What do you mean all the Engineering tasks are 'Impossible' in this ship?") in the basic system to drive people away...
 
Originally posted by Anthony:
Well, HG drives behave as if they're volume-based. If we assume drives and weapons are 1T/m^3 (14T/dton), a Tigress weighs 50-60 tons/dton, an unarmored Fer-de-Lance weighs 7-8 tons/dton, and both need 17% maneuver drive for 6 Gs.
It behaves that way for the same reason my contrived B2 sytem behaves that way -- the system designers didn't change the drive tech, they assumed some standard average density for all ships. They simply didn't want to expose the player to that detail.

Obviously, the system let players get out to some pretty wide parameters, if the same drive can accelerate 50t/dt as well as 7 t/dt.


Changing the drive tech also allows bypassing some historical problems such as near-C rocks.
The only way that's going to happen is if you change the tech dramatically or limit the duration of acceleration. Stutterwarp goes the first route, since the ships really aren't moving at all in normal space (thus no C rocks), or with HEPLaR where you simply run out of fuel.

But as far as I know they're sticking with Thruster Plates.


Complexity and incompatibility with High Guard.
The complexity is only within the higher end FF&S system, not in the simple system. When creating the simple system, you can impose rules that prevent the player from inadvertantly creating a ship that's too heavy: limited armor amounts, more powerful "military" drives, or "if armor > X, reduce G performance by Y". There are all manners that can be used to hide that complexity and still create ships compatable with the FF&S sytem.

And I don't know if HG compatability is a driving force anyway.

The complexity in FF&S comes in several places. One, its formulae -- it uses cube roots I think. Hard to do cube roots with a pencil.

Two, is in its presentation (and I'm talking FF&&S 1 here, not even FF&S 2 which I feel was a complete disaster). A "cheat" sheet documenting step by step the ship design process (vs the vehicle or weapon design process), along with page numbers would help early designers simply navigate the book.

Three, they need to provide an "ironmongery" of pre-built weapons with set performance, power, mass and volumes that designers could readily plug in to their designs. A table of laser turrets, energy weapons, some spinal mounts, etc. For a combat vessel that relieves a large burden from the designer, who can then later build their own weapons. But for a first time designer, it can be a non-starter having to design EVERYTHING.

Finally, I do think that they can create a more HG like system on top FF&S. Basically that's done by focusing on a starship design (vs vehicle or aircraft design -- I don't want to read about propellers and jet engines when I'm trying to look up Maneuver Drives, but they're stuffed together in the book under Sub Light drives) and adding yet again some more tables to free up some of the math.

I mean, the tables have to come from SOMEWHERE, so they may as well come from the forumlae in the FF&S books. As long as you stick with the numbers and are judicious with the round off errors, the end results will inevitably be compatable throughout all of the design sequences.

Finally, I think it's unfair to burden the new system with trying to be compatable with HG. Yea, there are a lot of designs out there, but it's not like HG didn't have problems of its own and I see no reason to keep that albatross.

I don't necessarily suggest that FF&S 3 be perfectly compatable with FF&S 1 or 2 either, but since they're based more upon and expose more fundamental aspects of design, I think they'll be widely compatable.

FF&S (in some form) is basically a collection of engineering and materials formulae used to design all manner of things. With its flexibility come complexity, but also power. One of the powers of theses fundamentals is creating simpler design systems that have built in assumptions pre-calculated in to the various tables.

As long as those assumptions are documented (like, say, PPlants include Life Support and G Compensation), then you have mobility of designs across the various system. Where you have aerodynamic and smooth flowing ships designed with FF&S, they get a bit more blocky and pedestrian and you move towards an B2 system, but at the core they're the same.

So, if you want a "volume" based M drive, supply constraints to the simpler system where its difficult to violate the mass/volume assumptions determined at the begining. Then you have a mass based M Drive that behaves from a designer point of view as a volume based one.
 
Originally posted by Anthony:
Well, HG drives behave as if they're volume-based...
Or not
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I've long pondered if the original CT/HG intent wasn't massed based. There are hints in the rules that can be seen to point that way. If so all components are calculated and measured in metric tons and any displacement is only vaguely implied. At least this way all those badly broken deckplans are not nearly so broken and the 20% fudge rule for deckplans makes a lot more sense.

Oh, and btw, we can't assume drives and weapons are 1T/m^3 (14T/dton) in CT. We only know in CT that fuel is 1T/dton and the only example we have for anything else suggests that everything is limited to 1T/dton, and that's from the calculation of cargo density in the example for speculative cargo breakdown. To the best of my recollection at least.

Example: Two 400ton ships are built with identical drive section sizes (23%) but different performance and other features.

The first is a TL12 fast liner with J3 M3 P3. It's final mass with a full load is limited to 400tons. A large part of the load is the passenger staterooms which are far larger in displacement than the listed mass (rooms being generally air). It's final displacement might be well over 400dt.

The second is an TL15 SDB design with M5 P7. It's final mass with a full load is limited to 400tons. A large part of that load is armor with an actual displacement being a small fraction of the listed armor mass (armor being very dense). It's final displacement might be well under 400dt.

So the two ships are both designed based on identical mass, and the performace of each is rated on loaded mass, however the first is much larger than the second.

Originally posted by Anthony:
Changing the drive tech also allows bypassing some historical problems such as near-C rocks.
It does? How? The only way to avoid that old problem is limit the maximum speed (not thrust) of the drives or maybe restrict them to operating only in a gravity well. Or is that what you mean by changing the drive tech?


Originally posted by whartung:
But what's wrong with a mass based drive system?


Absolutely nothing in my opinion, as seen above.

The complexity issue is avoided by treating the design as built for fully loaded mass. Traveller doesn't use rockets that burn massive amounts of fuel so we don't have to keep calculating the thrust to mass ratio to get to orbit. If someone wants to do the extra (minimal math) to recalculate the performance of drives for flying lighter or heavier well more power to them. It'll be rare though, most traders are going to be flying with a full cargo hold and few other designs will stray far enough from the design load to matter. The rules should allow it though and the formula should be obvious from the design.

As for imcompatibility with HG, there is none. If everything you believe HG says is a displacement ton I say I believe is a mass ton and we both build a ship with the same stats they will be the same. Mine will not have the same displacement as yours, and yours will not have the same mass as mine, but they will be, from a game rules perspective, identical.
 
Originally posted by whartung:
So, if you want a "volume" based M drive, supply constraints to the simpler system where its difficult to violate the mass/volume assumptions determined at the begining. Then you have a mass based M Drive that behaves from a designer point of view as a volume based one.
Okay, and sort of doable, but it involves big changes to FF&S2. There are basically three standard densities for Traveller components:
Fuel/Passenger: 1 ton/dton
Mechanical: 14-28 tons/dton
Armor: 200 tons/dton

For a simple system, I would suggest:
1) This system does not support armored ships. Treat ships as either unarmored, or as having some fixed-weight hull. About 1 ton per dton is fair.
2) Give empty fuel tanks a weight; 1 ton/dton is plausible. This means full fuel tanks weigh 2 tons/dton.
3) Make staterooms heavier, probably by adding a substantial chunk of life support to the weight.
4) Reduce the density of mechanical components. Most RL machines, if you include access space, are less dense than water, often by quite a bit. Typical cargo spaces are also less dense than water. A figure of 5 tons/dton is not hard to justify.

These three, combined, give a density of 3-6 tons/dton, and almost all ships will be in the middle somewhere.
 
From High Guard, power plants were MCr3 per ton, with 1 to 4 tons per EP (from TLs ranging from 7 up to 15). 4 tons per EP is relegated to TL7 and TL8, which is probably not "fusion"-based -- but High Guard doesn't bother to explain itself, which is fine.

From Book 2, power plants were MCr2 per ton, with 1 to 2 tons per EP.

FFS2 seems to say (at TL12) that a 250MW power plant displaces 3.5 tons and costs appx KCr38 per ton (maybe a serious error here!). Cheap power indeed.

FFS1 says (TL12 again) that a 250MW power plant displaces around 9 tons and costs appx MCr2.5 per ton.


The price consensus seems to rest within MCr2-3 per ton. If FFS1 has similarly scaled back power requirements with all of its equipment, then I'd not be surprised if 1 to 3 tons per "EP" was reasonable, with "EP" not being defined at this time.

If "Book 2-like" components are designed at a somewhat high tech level, then I can see 1 ton per EP. It's also extremely easy to remember. I don't care whether the price is MCr2, MCr2.5, or MCr3 per ton.


Please note that I'm really just playing numbers games here. I have no authority over starship design or FFS in T5.
 
Ideally, the costs for components would be fixed to deal with TL differences; components which aren't as efficient would be cheaper. For example, under high guard, you might set it so TL 15 PPs are 3 MCr/dton, TL 13-14 are 1 MCr/dton (2 MCr/EP), TL 9-12 are 0.5 MCr/dton (1.5 MCr/ep), TL 7-8 are 0.3 MCr/dton (1.2 MCr/ep).
 
Originally posted by far-trader:
It does? How? The only way to avoid [the near-C rock] problem is limit the maximum speed (not thrust) of the drives or maybe restrict them to operating only in a gravity well.
Marc is seriously thinking about slashing M-drive thrust outside of a gravity well to something painfully low.

To solve the NCR problem, I guess that would have to be something around 1/1000 of the original performance, or less.

Would that help?
 
Well, yes and no. It helps with the NCR problem, but it creates a new problem: we have plenty of canon for sublight interstellar voyages, which reach a significant chunk of lightspeed. We also have canon for people going from mainworld to gas giant via M-drive, and the 1% of c you get from 3.5 days at 1G is more than enough to create problems.

The only method that fits established canon on what ships can do (e.g. settling the Islands Cluster at an apparent velocity of 0.4c), and doesn't support near-C rocks, is that a 'maneuver drive' is in large part some form of normal-space warp drive (it needs some ability to generate real delta-V, but that can be fairly limited).
 
Originally posted by Anthony:
Well, yes and no. It helps with the NCR problem, but it creates a new problem [...]
In other words, further reconciliation, explanation, or redaction is necessary. OK.
 
Originally posted by robject:
Marc is seriously thinking about slashing M-drive thrust outside of a gravity well to something painfully low.
He already has: beyond 2000AU they drop to 1% (FF&S2 p65).
 
Nope, that still doesn't really fix the NCR problem. Reducing the performance (even to some small fraction) just means a longer time to achieve the velocity (near C) needed. That won't stop a determined enemy from planning to destroy a know target that can't change it's knowable position (like your homeworld).

The only way to fix it is to say (for example): 1G drives are capable of accelerating at 1G but limited to a maximum speed of 100,000kph (just a number pulled out of the vacuum). It could be explained as efficiency drops off as speed increases and eventually more energy in doesn't result in more acceleration.
 
Note that discarding dtons and saying a ton is a ton and that J-drives are mass-based would certainly simplify the design sequence, at a cost of being a gigantic departure from what every design sequence has said, and invalidating every deckplan ever published.
 
Originally posted by Anthony:
Note that discarding dtons and saying a ton is a ton and that J-drives are mass-based would certainly simplify the design sequence, at a cost of being a gigantic departure from what every design sequence has said, and invalidating every deckplan ever published.
Nope, no real departure from CT, or even much from T20 beyond the semantics. A bit of a departure perhaps for other systems, where complications like density and mass were given a nod.

If that's what is being aimed for (realistic thrust equations factoring gravity and mass) then will the rules be tossing out the use of reactionless thrusters, contragrav, antigrav, artigrav, inertial compensators, grav focussed lasers, repulsors, and tractor beams, to name but a few of the technologies that would make any mass based calculations completely pointless?

And it would hardly invalidate every deckplan ever published when most (if not all) published deckplans never (or at best rarely) held to the rules as published anyway and typically showed huge departures from any supposed realistic depiction of volumes
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If you could accept them as they were this wouldn't change anything for the worse, in fact it would probably make them more acceptable.
 
Scott is trying to reconcile FFS against volume-based thrust. I don't know if he's gotten approval from Marc on that -- but perhaps the reconciliation will be based on the assumption of X mass tons per displacement ton.
 
Originally posted by robject:
Scott is trying to reconcile FFS against volume-based thrust. I don't know if he's gotten approval from Marc on that -- but perhaps the reconciliation will be based on the assumption of X mass tons per displacement ton.
X mass tons per displacement ton isn't that unreasonable. Yes it looses some accuracy, but who wants different performance ratings for a ship with full jump tanks vs empty jump tanks, full vs empty cargo hold, and all of the possible combinations.
 
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