> Adam wrote:
> Good. It's not that I don't like the idea, it's just I think FT is
Okay, tell me what this "limited rotation" thing is all about. I've read the
Realistic Movement rules from Jon and Mike. Is this an addition? It did seem
to me that big ships with low thrust ratings should have a limited ability to
change facing with thrusters. Maybe the facing changes allowed would be equal
to the thrust rating?... How did you work it?
What about submunition packs, mines, and cloaking? Any changes or additions
generally accepted by the mailing list?
As you say, FT is pretty much perfect as is. After 25 years in this hobby I've
finally found a system I can stick with!
Date sent: 24-SEP-1996 08:56:25
> Adam wrote:
> Good. It's not that I don't like the idea, it's just I think FT is
... and adding
> Realistic Movement (with the addition of limited rotation) as
and Rob replied with:
> Okay, tell me what this "limited rotation" thing is all about. I've
It
> did seem to me that big ships with low thrust ratings should have a
Yes, thats how we changed it. You use the maneuvering thrusters to rotate
through a number of clock faces up to a maximum of the thrust power available.
Most ships end up with a thrust rate of 2, with a larger difference being seen
in the main drive.
I can tell you now, from what physics I know, that this is HIGHLY unrealistic
(In the scale we use, power to rotate is insignificant compared to the power
to accelerate over the distances we use) but it preserves the 'feel' of the
game, which I consider to be much more important.
> What about submunition packs, mines, and cloaking? Any changes or
There appears to be some confusion with Submunition packs concerning fire
arcs. You can only fit them in one arc (according to Jon).
I think everyone will agree that mines are too weak. I'd be tempted to treat
them as missile warheads without the engine. This would make them VERY
dangerous, possibly overpowering. It all depends on whether you want mines to
be a major factor, or simply a minor annoyance.
There are several variants of Cloaking that have been banded about.
> As you say, FT is pretty much perfect as is. After 25 years in this
As it has been pointed out earlier, the roumers of FT3 are just that. No
evidence that anything is planned.
> Date: Tue, 24 Sep 1996 09:14:57 +0100
I've read
...
> Yes, thats how we changed it. You use the maneuvering thrusters to
of
> the game, which I consider to be much more important.
And from the physics I know, economy of scale should make the larger
ships _faster_ since they can use more efficient drives. This dread-
naughts can only have a 2 thrust while escourts can have 6 is total bullshit.
I would concede that that same economy of scale would not help out with
thrusters to spin the ship around, as you would have limits of how much
jerking around crew and equipment could stand. There'd be far far greater
moment on the extreme ends of a dreadnaught flipping end over end to make a
turn, than you would feel in a corvette turning the same number of degrees in
the same time frame.
> On Tue, 24 Sep 1996, johnjmedway wrote:
> AdamD wrote:
> >> I can tell you now, from what physics I know, that this is HIGHLY
Hm. Doesn't the 'output increases as square, mass increases as cube' apply to
starships...?
In message
<Pine.SUN.3.91N2x.960924182447.16431A-100000@byse.nada.kth.se> you
wrote:
> On Tue, 24 Sep 1996, johnjmedway wrote:
> > ships _faster_ since they can use more efficient drives. This dread-
Someone else who sees sense...:)
> Hm. Doesn't the 'output increases as square, mass increases as cube'
But volume increases with the cube of linear dimensions, and surface area
increases with the square.
Mass of hull and armour increases slower than the amount of mass that can be
invested in drives. 25% volume of drives on a small ship might equate to 25%
mass, but on a big ship to only say 10% mass. So your thrust to mass ratio has
just gone up, so the ship is 'faster'.
This factor is reasonably easy to discover if you use vaguely realistic ship
creation rules.
It's also the case that big drives tend to be more efficient. If they're not,
you just use lots of small drives to get the same efficiency as small drives.
Hence, big ships are faster. It's counter intuitive to what people are used to
based on the ground, but there's no friction in space which increases with the
size of the ship (as you have in an atmosphere).
> johnjmedway wrote:
Maybe its just me, but I'm a hesitant fellow to make `how fast it can go' cost
determined by the `mass' of vehicle its mounted on, for this
and a handfull of other reasons. How much the /drive/ masses is
related, and that much mass will cost different amount for larger ships, but
adding in some kind of sliding scale starts getting just a bit too points
niggly for me.
I might build a 6 Thrust dreadnaught, but it should be points-intensive,
I think.
> I would concede that that same economy of scale would not help out
Considering that we're not exactly sure how long a FT Turn /is/, I'd
hesitate to start trying to calculate the moment of motion of a dreadnaught's
front as compared to an escort; it should probably be under the `noise' level
for getting shaken around.
> johnjmedway wrote:
> then Alexander Williams wrote:
AFAIK all ships are capable of a max thrust of 8, if designed that way. It is
more costly to build a thrust 6 capable DN than a thrust 2 for obvious
reasons(namely more energy required to push a larger body of mass, increasing
as acceleration needs increase).
> Date: Tue, 24 Sep 1996 14:00:00 -0400
Isn't there already a sliding scale? Though in reverse?
> I might build a 6 Thrust dreadnaught, but it should be
My argument is that it shouldn't be any more points-intensive than 2
ships os half its size added together.
[MUNCH]
> Samuel Penn wrote:
This is assuming that a thrust to mass ratio is important in the type of drive
system you're using. Since FT is so wonderfully vague, it could very well be
that the effeciency of the drive depends only on the mass of the ship that
you're trying to move. Remember, we might not be using Newtonian concepts in
terms of movement.
For example- I develop an inertialess drive. Problem: The power curve
goes up asymptotically versus mass. In this case, big ships WILL be slower
than small ships, because, even though I can cram more power generation units
into the big ships (hamsters on treadmills, let's say
(8-) ), my demand for power for a given thrust grows even faster.
I won't do the math, but I think I've made my point. (8-)
"Captain, the hamsters canna take it!"
Sorry. (8-)
J.
> On Tue, 24 Sep 1996, Samuel Penn wrote:
> > Hm. Doesn't the 'output increases as square, mass increases as cube'
> > apply to starships...?
Uh - no, more likely the other way round, unless your engines are
considerably lighter than most weaponry! I'd rather say that engines equates
10% of the volume but 25% of the mass...
While ship masses don't necessarily increase by the cube of the length scale,
it does (approximately) if you fill the extra volume with
additional equipment - like engines, weapons, shields etc. Of course, a
troop transport will have lots of empty space inside rather than weapons...
Furthermore, the bigger ships need stronger structural supports if they are to
be able to manouver as fast as smaller ships, which increases the
mass even more.
> This factor is reasonably easy to discover if you use vaguely
What is realistic depends on your assumptions about engine masses, of course.
As long as we use standard rocket drives, we can make reasonable assumptions,
but what about ion engines? Photon drives? Whatever?
> It's also the case that big drives tend to be more efficient. If
Unless, of course, you lose more trying to make the smaller engines cooperate
than you do by increasing the scale. I know too little
> Hence, big ships are faster. It's counter intuitive to what people
> Oerjan wrote:
> On Tue, 24 Sep 1996, Samuel Penn wrote:
Or 80%+ of the mass if we're talking about reaction drives, but
yes you're probably right - I just plucked two random figures
out of thin air for that example.
> What is realistic depends on your assumptions about engine masses, of
There was some guy at NASA who had some research done on this, and big rockets
worked out cheaper and more efficient than smaller ones. Of course, we're
talking chemical rockets here,
but ion drives etc all work on the same principle - you apply
energy to some reaction mass, and chuck it out the back, so the same theory
should apply to all reaction drives (I would have thought).
Of course, FT uses reactionless drives, which screws up everything. It also
uses shields heavily, which also causes complications. Assuming armour though
(shields are for wimps!), you're going to be wanting as much of it as you can
get away with. And it's mass is going to go up with the square of linear
dimension, while drive volume will go up with the cube. So in theory, big
ships end up
with a higher thrust/mass ratio.
Though as someone else pointed out, FT drives could work in any way you damn
well wanted, and end up being slower as they get larger.
My feelings on the matter are that big ships should be fast, but having them
as slow lumbering hulks fits in with a lot of science fiction much better.
On Wed, 2 Oct 1996, Samuel Penn wrote, in reply to a post I thought I had
cancelled:
> > What is realistic depends on your assumptions about engine masses,
Appearently not when it comes to lifting off from planets; or else we wouldn't
have any problems in launching huge space stations... I think.
(I don't think air resistance would be that important - would it?)
> Of course, we're talking chemical rockets here,
Depends on how much extra mass you have to allocate to cooling systems,
supports and suchlike. I don't know enough to say anything very intelligent
about it, but a big drive has less area per volume than a
small drive - and because of that it has that much bigger problems to
get rid of excess heat. You could probably come up with other PSB factors to
improve small drives:)
...
> My feelings on the matter are that big ships should be fast,
Fast but unmanouvrable would certainly be an interesting option. Sure,
you have lots of main drive thrust - but it turns much slower than the
smaller ships <g>
Excerpts from FT: 7-Oct-96 RE: FT3, details of needed .. by Oerjan
Ohlson@nada.kth.s
> > There was some guy at NASA who had some research done on this,
Um, yes it would; you get air friction on the way up, too. For most craft it's
not a problem, but something large & unaerodynamic (as most stations are) is
gonna hurt.
I'm not actually sure that the original poster (the quote above Oerjan's) is
correct; I think he may be referring to Truax at Aerojet General in the
sixties. He did some research and discovered that
development costs actually decrease with increasing size -- take Agena
vs. Thor. Thor was several times larger than Agena, but cost far less
to develop. Ditto on the Titan I two-stage launch vehicle; the smaller
upper stage cost more than twice as much to develop than the lower stage, in
spite of the fact that the upper stage was a virtual copy,
just re-scaled down from the lower stage.
Basically, the cheapest rockets are big dumb boosters (BDBs) that don't push
the state of the art, are reusable (though with a big enough production base,
and enough launches, they don't have to be), don't push safty margins, and do
*not* mix people and cargo. If you need to lauch people, make something small
and reusable and expensive and safer than anything, but lauch the cargo in the
BDB.
Anyway, if anyone wants a copy of an article on this, just let me know.
(Or I could post it; it's only 4-5K or so.)
Later,
> On Mon, 7 Oct 1996, Aaron P Teske wrote:
> Anyway, if anyone wants a copy of an article on this, just let me
Yes please! It's always nice to check fantasy with facts <g>
-------------------- Begin Original Message --------------------
Message text written by Oerjan Ohlson
"Fast but unmanouvrable would certainly be an interesting option. Sure,
you have lots of main drive thrust - but it turns much slower than the
smaller ships <g>"
-------------------- End Original Message --------------------
Fast but unmanoverable is what we have. Any ship can travel any speed. Its
trying to stay in the play area that is hard.
Try starting a game on a standard table (approx 3x6' or 1x2m) at a starting
velocity of 24 or 600mm).
By the way what is the standard metric conversion for this game? My best guess
was 1" coverts to 25mm (adjusted apporximation for playability).
> On 8 Oct 1996, Brian Bell wrote:
> Fast but unmanoverable is what we have. Any ship can travel any speed.
Its
> trying to stay in the play area that is hard.
No, we have fast and manouvrable (thrust 8 escorts) and slow and unmanouvrable
(thrust 2 capitals). Fast but unmanouvrable is easier to implement with a Real
Thrust variant (...look at Mark's FT page) where large ships have very
powerful main thrusters but are unable to turn more than
one clock facing or so per turn, while small ships have relatively weaker main
thrusters, but can change facing faster.
> Try starting a game on a standard table (approx 3x6' or 1x2m) at a
I use the conversion 1 M.U. (Measuring Unit) = 1 M.U. If you measure in
inches, then 1 M.U. = 1"; if you measure in cm, 1 M.U. = 1 cm. I measure in
cm, and have no problem at all manouvreing my thrust 8 escorts at speed 40 and
stay on my 120cm * 80cm table. The capitals are more difficult; but even so
speeds around 20 are the norm with the normal FT movement rules.
Regards,
Date sent: 9-OCT-1996 12:22:08
> "Fast but unmanouvrable would certainly be an interesting option. Sure,
> you have lots of main drive thrust - but it turns much slower than the
You use the Realistic Movement rules Mike and Jon posted, plus my little
addition don't you? Give a ship a great big main drive with
tiny weeny thrusters 8-). Alternatively for the core rules use a
simple modification like, only 1/4 thrust can be used to turn.
> By the way what is the standard metric conversion for this game? My
That's close enough, but you can use any conversion you like. Try 1cm == 1"
for a larger play area.
> Date sent: 9-OCT-1996 12:22:08
> You use the Realistic Movement rules Mike and Jon posted, plus my
Okay, I give up. What is your little addition to the Realistic Movement rules?
Every bit helps!
Date sent: 10-OCT-1996 14:53:46
> You use the Realistic Movement rules Mike and Jon posted, plus my
> Okay, I give up. What is your little addition to the Realistic
> Rob
In the original version, a ship could either thrust for direction, or rotate
to ANY facing. Whilst from a Physics point of view this is correct, from a
game point of view, it's pretty damn dull. So I proposed some time ago (and I
think several others were already doing the same thing, you know how good
ideas are seldom original) that you limit rotation to a maximum of (thruster
power) clock faces. Simple, neat, elegant but unrealistic.
Realistic can go blow itself out of the airlock 8-)
oops - missed this one:
> >Date sent: 9-OCT-1996 12:22:08
[in reply to my post]
> >You use the Realistic Movement rules Mike and Jon posted, plus my
How did you find out? ;-) Yes, for all except Ether-sail ships... and
your suggestion below is exactly what I had in mind!
> > Give a ship a great big main drive with
Later,