FFS3 for T5

[GypsyComet]

Originally posted by robject:
The 20-ton bridge will probably be whacked. Don't ask me what this does to the X-boat; I don't know.

The X-boat has a stated purpose for any "waste" volume. It's effectively all "computer", though much of it is simple storage and a *hefty*-bandwidth laser-comm. The X-boat is a special case, but so long as the volume/cost/power of the "payload" is clearly stated instead of glossed, it's all good. It's the CT "storage banks" with no further details that drives people nuts...

Since they don't like losing X-boats, it wouldn't surprise me to hear that the little beggars carry a commo suite to make a Tigress envious, but the ultra-high-bandwidth laser comm is a given.

 

[GypsyComet]

Being able to make B2 drives work in a strictly defined system is doable, but you pretty much need to make either core technology, maintenance access, or symbiotic drive assumptions. Any of these work for me, and the latter can go a long way to explaining the Vilani tradition of Jump Dimming.

Where the relationship between the two breaks badly is in Maneuver drives. I can make a technology assumption to cover this, but that solution doesn't appeal to everyone.

 

[Anthony]

There are ways to define M-drives that are plausibly volume-based; a field effect drive might well be volume-based, and gets grav compensation as a side effect of the drives, making grav pong less relevant.

 

[whartung]

I looked at FF&S1 last night, and it was quite straightforward to create an M Drive table that listed hulls down the left side, and "drive models" (for lack of a better word) across the top.

Then at the intersection, of the drive and hull, you got a G rating.

There was a simple assumption that basically mass scales with volume, and then from there each dTon of drive provides a certain amount of thrust. This all followed the formula derived from the book.

DV = SV * 10 / 40 / 14 * G

DV = Drive Volume, in dtons
SV = Ship Volume, in dtons
G = G rating of the drive.

So, what you end up with is pretty straightforward.

If you have a 200 ton ship, and 6 drives (A, B, C, D, E, F) that give M1-6 respectively, then you can put those same drives in other hull sizes with varying performance.

Put a B drive in a 400dTon ship, and it gets M1. Put it in a 200dTon ship, and it gets M2, and put that in a 100dTon ship, you get M4. The volume stays the same, the power stays the same, but you can see how the drive scales with the ship.

So, it's simple to extend the chart and come up with stock M Drives for stock hulls, yet still be in sync with the detailed design sequence. The hard part is choosing reasonable hull sizes and rounding the volumes properly. I think at most I rounded off 10% of one drive to fit in my contrived table.

The next trick would be to somehow come up with stock Power Plants to provide enough energy. In FF&S, the Thruster Plate drives (which I used for this, not HePLAR), require basically 14MW/dton of drive. Meanwhile, a Laser Turret takes about 5MW of poiwer. Other than that, 1MW/100 dTons of power is probably enough power to handle the housekeeping on the ship.

It would be reasonable to scale this down using "energy points", where each EP = 5MW, and then come up with stock drives.

This will break down when you want power hungry weapons (i.e. large heavy energy weapons). But what's nice there is that you can introduce "military grade" power plants to give more power that are required for larger weapons.

In FF&S, Thruster plates don't change via TL at all, they arrive at TL 11 and that's it. Jump Drives get lighter at TL improves, but not much. And Fusion Power plants get more efficient for their volume.

TL9-12 - Efficiency 1
TL13-14 - Efficiency 1.5
TL15 - Efficiency 2

So, a TL 15 plant will produce twice as much power as a TL9 plant for the same volume.

The thinking is use the MDrive table to choose a G Rating, Jump Drive is a simple percentage calculation, and a list of stock power plants each with an enery output that, essentially, overpowers the ship, just not greatly. Then bolt on hardpoints, some fuel, and a bridge. Boom. Starship.

I would skip the hull shape difference, ignrore surface area, and come up with some simple control guidelines. Sensors are plug and play, like weapons. The work out crew requirements (FF&S engineering requirements are crazy).

But for a small ship, Book 2, casters, missiles and lasers Lego design system, I think it's straight forward. And it can all be table driven.

 

[robject]

Originally posted by GypsyComet:
The X-boat has a stated purpose for any "waste" volume. It's effectively all "computer", though much of it is simple storage and a *hefty*-bandwidth laser-comm. [...]

Since they don't like losing X-boats, it wouldn't surprise me to hear that the little beggars carry a commo suite to make a Tigress envious, but the ultra-high-bandwidth laser comm is a given.

Good point about the commo suite. There's probably a specialized commo system whose primary purpose is to broadcast data, perhaps a large battery of powerful transmitters.

Originally posted by whartung:
I looked at FF&S1 last night, and it was quite straightforward to create an M Drive table that listed hulls down the left side, and "drive models" (for lack of a better word) across the top.

[...]

drive vol = hull vol * 10 / 40 / 14 * G

[...]

If you have a 200 ton ship, and 6 drives (A, B, C, D, E, F) that give M1-6 respectively, then you can put those same drives in other hull sizes with varying performance.

Put a B drive in a 400dTon ship, and it gets M1. Put it in a 200dTon ship, and it gets M2, and put that in a 100dTon ship, you get M4. The volume stays the same, the power stays the same, but you can see how the drive scales with the ship.

[...]

The thinking is use the MDrive table to choose a G Rating, Jump Drive is a simple percentage calculation, and a list of stock power plants each with an enery output that, essentially, overpowers the ship, just not greatly. Then bolt on hardpoints, some fuel, and a bridge. Boom. Starship.

Thank you for looking into this. Your suggestions sound reasonable to me, and so it looks like a very simple system is do-able.

drive vol = hull vol * 10 / 40 / 14 * G

This looks like M-drive volume is appx 1.8% hull volume per G in FFS. Yes?

Close to B2 and HG. It could steal the "symbiotic drives" concept to support B2, or alternately steal the "modular and easy and a little clunkier" concept to support HG.

 

[Anthony]

Originally posted by robject:
This looks like M-drive volume is appx 1.8% hull volume per G in FFS. Yes?

For a ship at the standard 10 tons per dton, sure. Unfortunately, 10 tons per dton is a totally irrational assumption, realistic designs can range from about 1 ton/dton to about 50 tons/dton.

 

[GypsyComet]

Originally posted by robject:

Close to B2 and HG. It could steal the "symbiotic drives" concept to support B2, or alternately steal the "modular and easy and a little clunkier" concept to support HG.

The key to running this back into the complex is to keep the "Letter Drives" simple-but-legal, so that compatibility between the two complexity levels is simply a matter of "showing your work".

I'm plugging away at the Book 2 numbers now to see what sort of "symbiote" ratios will be needed.

 

[GypsyComet]

Originally posted by Anthony:
</font><blockquote>quote:</font><hr />Originally posted by robject:
This looks like M-drive volume is appx 1.8% hull volume per G in FFS. Yes?

For a ship at the standard 10 tons per dton, sure. Unfortunately, 10 tons per dton is a totally irrational assumption, realistic designs can range from about 1 ton/dton to about 50 tons/dton. </font>[/QUOTE]"Totally"? Not so much. FF&S(TNE) hits 10 tons/dTon as a good average for civilian ships, which is really what a simple system is aimed at. If we were feeling productive, a second M-Drive chart could be produced for a "standard armored" hull size range. Jigger the base table to assume roughly twice the civilian average density (or more, if hockey pucks are what we would consider "standard"), so a 200 ton armored ship is using the MDrives that would go into a 400 or 600 ton "thin-skin" ship. If the drives map the same way they do in Book 2, the powerplant would have to follow the M Drive, but that sounds about right for a military ship anyway...

The overpower at the low density end is a simple price to pay for standard modularization. If the user really cares, he'll dig into the complex appendices and figure out what that standard M-Drive can *really* push his featherweight around at, but if the ship is that light, the internal structure may crumple under the higher available thrust...

 

[Anthony]

Originally posted by GypsyComet:
</font><blockquote>quote:</font><hr />Originally posted by Anthony:
</font><blockquote>quote:</font><hr />Originally posted by robject:
This looks like M-drive volume is appx 1.8% hull volume per G in FFS. Yes?

For a ship at the standard 10 tons per dton, sure. Unfortunately, 10 tons per dton is a totally irrational assumption, realistic designs can range from about 1 ton/dton to about 50 tons/dton. </font>[/QUOTE]"Totally"? Not so much. FF&S(TNE) hits 10 tons/dTon as a good average for civilian ships, which is really what a simple system is aimed at.</font>[/QUOTE]Even for civvy ships, it doesn't work very well. Fuel and passengers are very low density; a passenger carrier can be under 2 tons/dton, and for other ships on average a J4 ship will weigh about 25% less than a J1 ship.

 

[atpollard]

If your goal is to produce a FFS3 that is backwards compatible with the old Book 2, the old High Guard and the old FFS1/2, your task will be nearly impossible. If your goal is to produce a FFS3 that includes/is compatible with a “high resolution” system LIKE FFS1/2, a “medium resolution” system LIKE High Guard, and a “low resolution” system LIKE Book 2, then the task will be relatively easy.

The defining characteristic of Book 2 is that it is a quick and simple way to design common civilian ships. The price paid for this simplicity is that most of the decisions have been made for you. There is only 1 TL for all ships. There are a limited number of hulls to choose from and the variables (like shape modifiers to cost) are built into the limited choices. There are only a limited number of weapons to choose from.

Book 5 (High Guard) allows more choices and complexity, but still lumps many small items into big categories (like the bridge including sensors). High Guard allows a broad variety of ships without executing minute detail.

Striker and FFS are based on a maximum level of detail and offer the opportunity to create “Millennium Falcon” like ships (I’ve made a lot of special modifications, myself.)

It is my opinion that you should focus on a balanced “high resolution” system for FFS3 and THEN modify it by combining some items into a “medium resolution” system (which will automatically be compatible with the “high resolution” system since the medium resolution components are just common assemblies of high resolution components). Once the “medium resolution” system works, strip it down to a bare bones “low resolution” system (which will automatically be compatible with the “high resolution” system since the low resolution components are just common assemblies of medium resolution components).

That’s the way I see it. Do whatever makes you happy.

 

[robject]

Doesn't FFS1 and FFS2 both make that assumption for the low end of ship density, though?

 

[whartung]

So the quibbling continues.

Here's a fundamental aspect of a "simple design system". The entire foundation is "assumptions".

Since 2tons/dton is less that 10tons/dton as the TNE baseline suggests, then a 10tons/dton drive will work hunky dory. It may work REALLY WELL, and have untapped potential. "Ask the engineer if we can push the reactor to 105%."

But as you fill the ship with cargo and not passengers, your mass/dton goes up.

It's kind of implied that most folks simply don't want to run cargo and load calculations to determine their drive rating, and if you're the type that wants a simple Lego design, you're probably even more inclined to not want to care about how many m/s^2 your drive goes down when you add in an extra dTon of people, wheat, booze, or gold bricks.

See, that's the entire point of the simple system. For those folks that don't care about such details, they can throw a hull together, bolt on a drive, some guns, staterooms, and radar, paint it red, name it "Big Sister" and party in to the stars.

But if some day, some how, some where, somebody DOES want to know the exact potential of the drive or thickness of the hull, or how many cubic meters of bolts and screws are in the thing, then assuming it's a straightforward conversion to the advanced system, then they can get those numbers readily.

If you don't want to keep track of mass or effects of armor, or how much power a plasma mount takes, then you can augment the system with "military M-Drives" and "military Power Plants". If you want armor, get a military drive as it's built to compensate for heavier, armored ships. A military power plant has extra capacity for high powered weapons over and above the life support and built in ice maker on standard, civilian designs.

There are always going to be holes and gaps. The simplicity of the system comes from using coarse, blocky parts vs custom designed and cut to fit pieces.

And if you think 10 tons/dTon is too dense or not dense enough, then simply propose a different average, generic rating and recalc the drives. No big deal.

 

[Anthony]

My actual proposal is to just have volume-based maneuver drives. A generic gravity drive (wraps the ship in an artificial gravity field, the ship is in freefall within the field) is plausibly volume-based, has a natural reason for limited peak acceleration/field strength, and has an additional side benefit that you can make use of the drive bubble to cheat on kinetic energy concerns.

This would result in some pretty ridiculously armored ships, though; a Tigress really would be 16% bonded superdense by volume, meaning a hull 670cm thick with an armor value of 9,400 cm steel (Striker/MT armor value of 105).

 

[robject]

Originally posted by Anthony:

This would result in some pretty ridiculously armored ships, though; a Tigress really would be 16% bonded superdense by volume, meaning a hull 670cm thick with an armor value of 9,400 cm steel (Striker/MT armor value of 105).

Gadzooks!

(Grabs calculator)

IMTU, that's a UAV of 16,750, displacing 67,000 tons!! 80,000 tons would yield 800cm of BSD, for a UAV of 20,000... egads...

 

[robject]

Originally posted by robject:

drive vol = hull vol * 10 / 40 / 14 * G

That's FFS1, isn't it? Isn't FFS2 more like

drive vol = hull vol * 14 / 40 / 14 * G

In other words, 2.5% per G?

Sounds like there's plenty of leeway here. But really, as noted, any value would work, since the volumes are simple multiples.

 

[whartung]

Originally posted by Anthony:
My actual proposal is to just have volume-based maneuver drives.

Well, the drive table I'm talking about IS a volume based M-Drive system.

If the mass and volume relationship is linear (which it is if you assume N tonnes/dton density), then the larger the volume of the ship, the larger the M-drive you need.

Also, the M-Drive itself (as noted in FF&S1 for Thruster Plate technology vs HEPLaR) is also volume based. 40 tonnes of thrust for each cubic meter of drive.

So, a 1 dTon of M-Drive == 40 * 14 m^3/dTon == 560 Tonnes of thrust/dTon.

Assuming the TNE density of 10 tonnes/dTon mass, a 100 dTon ship masses 1000 tonnes, and requires 1000 tonnes of thrust for 1G. So, a 1G drive is 1000/40 m^3, or 25 m^3. 25 m^3/14 = 1.8(ish) dTons. Rounded up, you get 2 dTons for 1G drive for a 100 dTon ship. Crank that up to 4 dTons for a 2G drive, as twice the drive gives twice the thrust. Place that 4 dTon displacement M-Drive in to a 200 dTon ship, and that same drive becomes a 1G drive because a 200 dTon ship masses twice what a 100 dTon ship does, so it gives 1/2 the performance.

So, this M Drive, is totally volume based already. As robject observerd, 1.8% of hull/G.

The "hard" part of the drive letters is simply that those letters are basically arbitrary when you start making up a table.

Observe this contrived table hulls, drive letters and G ratings:
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> A B C D E F G H J K L M
100 2 4 6
200 1 2 3 4 5 6
400 1 2 3 4 5 6
800 1 2 3 4 5 6</pre>[/QUOTE]If you look at the actual volumes (which I don't show), the volumes for drives A-F follow a linear track, based on G rating.

So do the volumes for drives G-J, for the same reason. But the bump from E to F is different than the bump from F-G, because the G drive is designed for the 400 ton ship.

You'll notice that the G ratings get spread out until you run out of drives suitable for earlier ships, then you simple stack the drives together.

This is fine if you doing what I'm doing with 100, 200, 400, 800. But when you start adding other hull sizes, the columns become less clean as you try and jam similar drives together in to the same column in order to limit the number of the Drive Letters.

But that's simply a side-effect of trying to limit drive letters and fit different hulls on to the same table. But judicious use of a belt sander to round off the corners, eventually you get all the square pegs in to the rounder holes, and it works out. My first rough cut came up with 28 drive letters (yes, I know), for hulls between 100 and 5000 tons. 100, 200, 400, 600, 800, 100, 1200, 1500, 2000, 2500, 3000, 4000, 5000.

It would take a bit more work to try and squeeze that table in to 24 drive letters, but it could be done and stay within 10% margin for some drives vs their actual FF&S volumes. No big deal, frankly.

 

[whartung]

Originally posted by robject:
</font><blockquote>quote:</font><hr />Originally posted by robject:

drive vol = hull vol * 10 / 40 / 14 * G

That's FFS1, isn't it? Isn't FFS2 more like

drive vol = hull vol * 14 / 40 / 14 * G

In other words, 2.5% per G?
</font>[/QUOTE]Yea, I don't have FF&S 2 (well I do, somewhere, but I was so off put by the printing I've never used it.).

But, yea, I don't care about the numbers, just the overall concept of making the simple ship system use numbers derived from the detail design system in tabular form and the factors and assumptions documented so anyone so motivated could convert a "B2" ship to an "FF&S" spec ship readily.

 

[Anthony]

Originally posted by whartung:
</font><blockquote>quote:</font><hr />Originally posted by Anthony:
My actual proposal is to just have volume-based maneuver drives.

Well, the drive table I'm talking about IS a volume based M-Drive system.</font>[/QUOTE]Um, no. Assuming a linear relation between mass and volume gets into the situation of "but that's clearly not true". Stating that the drive doesn't care about mass eliminates that objection.

 

[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.

 

[whartung]

Originally posted by Anthony:
Assuming a linear relation between mass and volume gets into the situation of "but that's clearly not true". Stating that the drive doesn't care about mass eliminates that objection.

So, you want to change the actual technology of the drive, not how the drive ratings are ascertained.

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?

Recall that we're talking about a design system here, not operations or physics. The goal is to have a system the produces "reasonable ships" with "reasonable" operational parameters. Ships that work for a large chunk of the role-playing population and role-playing tasks.

If you want to worry about edge cases, then you can use the more detailed design system. Or you can use the "B2" system to bolt together your ship, and then get the "real numbers" from the detailed system to get the "real" performance.

The idea is to throw complexity of desgn out, but not necessarily complexity of "real world". If a ships drive run at "roughly" 1, 2, or 3 Gs, etc, then nobody cares if it's "really" running at ".9G" or "2.1G". That's the "price" you pay for a lego based ship vs a custom model.

There's also Stutterwarp, which is also volume based (actually it's power and volume based), but I don't see that happening any time soon.

So, no, I don't see the base technology changing from a thrust/mass based sublight system any time soon, but robject may know better than that. Far as I know they're sticking with Thruster plates and J Drives.