REF: Status: RO
TRUE VECTOR MOVEMENT AND THE ROTATION OF STATIONARY SHIPS
DEAR JON T. HAVING ASKED FOR COMMENTS ON THE 'TRUE VECTOR MOVEMENT' I AM
RESPONDING. (SOMEWHAT LATE, BUT RESPONDING) OVERALL THE RULES MAKE SENSE, AND
CAN BE PLAYED WITHOUT ANY GREAT ADJUSTMENT. THE ONE THING I NOTICED WHILE
READING THE RULES: THE 'TRUE VECTOR' CONCEPT DOES NOT FOLLOW THRU FOR THE
'ROTATION OF STATIONARY UNITS' AND THE 'SIDE SLIP' CONCEPTS. TO ROTATE A
STATIONARY SHIP 180 DEGREES WOULD REQUIRE A SHIP OF THRUST VALUE 24; 6 POINTS
OF THRUSTER TO TURN, 6 POINTS OF
THRUSTER TO STOP THE TURN. (THE SHIP COULD BE THRUST 12 IF A
STATIONARY SHIP WERE ALLOWED TO ALL OF ITS THRUST FOR ROTATION) THE SAME
PROBLEM SHOWS UP IN THE 'SIDE SLIP' MOVEMENT. IN 'TRUE VECTOR' ANY THRUST THAT
IS USED FOR ANY REASON MUST BE CANCELLED OR IT REMAINS A VECTOR ADJUSTMENT
FOREVER.
NOW TO THE TRUE PROBLEM; I FEEL THAT THE SYSTEM WILL TAKE TO LONG TO PLAY,
THIS WILL EASILY DOUBLE OR TRIPLE THE GAME
LENGTH. THE TRUE VIRTUE OF 'FULL THRUST' IS ITS SIMPLICITY AND
SPEED OF PLAY.
GOOD LUCK, TTFN.
Excerpts from FT: 4-Oct-97 Re: Vector Rules by John Leary@sj.bigger.net
Status: RO
> DEAR JON T.
^_^ 'S OK, anyone can respond, any time. Did you have to shout,
though?
> OVERALL THE RULES MAKE SENSE, AND CAN BE PLAYED WITHOUT ANY
Yup. They do all right, though turns take a bit longer to plan, I've found.
> THE ONE THING I NOTICED WHILE READING THE RULES:
I don't see this: my take on the rules (and the way I've played with them) is
that the points allocated for rotation are for both starting and stopping the
rotation, ie, you apply 3 points of rotation to port, then automatically stop
it once you've done so. This means you don't need to keep track of rotation
between turns. So you would need a ship of "only" thrust 12 to do a 180 in one
turn....
Alternately, I've played that you get rotation points *equal* to your thrust
value, and a "puch" takes two rotation points. This makes thrust 8 ships
*very* maneuverable, which is as it should be (IMO).
Incidentally, I don't think ships at "full stop" should be allowed to rotate
to any facing; if you've got rotation points, use them in all cases. (Either
that, or ignore them completely and just use the rotation points for pushes,
but I don't think SDNs can turn *that* fast,
so....)
> THE SAME PROBLEM SHOWS UP IN THE 'SIDE SLIP' MOVEMENT.
Actually, it's not a problem here, and it's accounted for in the way you
record your movement: if you pushed one inch to port, your final vector
includes that movement. If you want to cancel it, push one to starboard later.
Unlike rotation (if you don't consider it cancelled once you've used your
rotation points), pushes don't add any bookkeeping to the system.
> NOW TO THE TRUE PROBLEM; I FEEL THAT THE SYSTEM WILL TAKE
It's true that the vector movement does take some getting used to, and ships
with thrust 2 *do* have to move more slowly or they'll go off the board before
they can get turned around (my carrier did... whoops), but it also allows for
some rather amusing (and useful) tactics... like a SDN with massive broadsides
rotated off it's heading to bring the broadsides to bear, then rotating back
when it's in the middle of the enemy formation to bring *both* sides to
bear... heh heh heh heh.... <grin>
(Well, OK, it was amusing for *me*. I'm not sure how Mark Kochte took
it.)
(Actually, he took it on the chin, but that's another story. ^_^ )
<ahem>
Anyway, the vector movement works well once you get used to it. You need to be
a bit more cautious in your movement (it's not so easy to get turned about,
after all) but the range of tactics this opens up is well worth it IMO.
Later,
Status: RO
In response to Aaron's response to John Leary.....
[snip]
> OVERALL THE RULES MAKE SENSE, AND CAN BE PLAYED WITHOUT ANY
Just a note here for any newcomers to the list who may have missed earlier
discussions on this: I can state categorically that the Vector system is NOT
going to "replace" the original FT movement system; it will be presented as an
OPTION, for players to use or not as they wish. It will be possible to use any
given ship design with either the "Cinematic" (original FT) or Vector movement
without changing the ship's specs in any way, and it will even be possible to
combine both movement systems in the same game (eg: to reflect differing tech
levels between different races). Yes, the use of Vector movement changes the
feel of the game significantly, and does
require a bit more thought - but once the players are used to the system
it really does not take significantly longer to actually play out a vector
move than it does a cinematic one.
> THE ONE THING I NOTICED WHILE READING THE RULES:
Yes, Aaron, your interpretation is correct here.
> Alternately, I've played that you get rotation points *equal* to your
This is a very good suggestion - I think it will work well.
> Incidentally, I don't think ships at "full stop" should be allowed to
Agreed. With the adoption of the suggestion above re: rotation points, I think
this makes sense.
> THE SAME PROBLEM SHOWS UP IN THE 'SIDE SLIP' MOVEMENT.
Again, Aaron is 100% right here. A push simply changes the ship's vector
slightly, and this effect is then automatically carried over to subsequent
turns unless deliberately cancelled.
> NOW TO THE TRUE PROBLEM; I FEEL THAT THE SYSTEM WILL TAKE
This is not what we've found with our playtesting (both in-house and
"blind" tests). Once the players are comfortable with the new system, play
proceeds at much the same speed as basic FT. At the end of the day, which
movement system you choose will depend entirely on personal preference and on
what specific background you're trying to simulate.
Thanks to both of you for the feedback - ALL comments are read and
noted, and everything helps in some way to shape what we are doing in the
future.
TO: AARON T.
CC: JON T.
IN RESPONSE TO YOUR SAT. 04OCT97 MESSAGE.
ROTATION OF ...: I FEEL THAT THE ROTATION VECTOR SHOULD BE
CARRIED FORWARD AS A PART OF THE MOVEMENT UNTIL
CANCELLED. ANY SORT OF 'GIMME' REDUCES THE VALUE
OF THE 'TRUE VECTOR' CONCEPT. THE SOLUTION TO THE ROTATION PROBLEM IS SIMPLE,
DO AWAY WITH IT! ALLOW ANY SHIP TO FACE AS IT DESIRES AND USE THE "FULL
THRUST" TO ALTER THE TRAVEL VECTOR.
Status: RO
I BEG EVERYONES PARDON, THE USE OF CAPS IS A JOB RELATED 'BAD' HABIT I HAVE
PICKED UP AND I AM NOT REALLY TRYING HARD ENOUGH TO BREAK AWAY. (THIS I TRUST
IS THE SHOUTING.)
I DIDN'T CATCH THAT THE 'SIDE SLIP' WOULD ROLL INTO THE 'NEW' END OF TURN
VECTOR. OOPS!
I HAVE FOUND THAT MOST GAMES I RUN HAVE A FAIR NUMBER
OF LEARNING PLAYERS. THE LARGEST NUMBER OF SHIPS I'LL
HAND OUT IS ABOUT SIX. THREE OF THESE WILL BE ESCORTS AND I GENERALLY HAVE
THESE PEOPLE USE A KIND HEARTED FORM OF
SQUADRON MOVEMENT. MY THOUGHTS ON TIME DURATION WERE
BASED ON MY NORMAL SITUATION.
I SUSPECT THAT THIS IS ALL PART OF A PLOT TO MAKE MISSILES
EFFECTIVE! (WELL, I SELDOM DESIGN A SHIP WITH A THRUST LESS
THAN FIVE.)
BY FOR NOW, DINNER CALLS
Excerpts from FT: 6-Oct-97 Re: Vector Rules by John Leary@sj.bigger.net
> ROTATION OF ...: I FEEL THAT THE ROTATION VECTOR SHOULD BE
> CARRIED FORWARD AS A PART OF THE MOVEMENT UNTIL
Well, I dunno about that; all you'd have to do is *double* your thrust
for maneuver points, and then work from there. ^_-
Actully, though, a (possibly) more serious problem is using the main engines
while you're rotating. Technically, you'd have to integrate the thrust from
the mains over the arc you crossed while firing, which seems
to be a bit complex for a (hopefully) quick game. ^_- Assuming you
rotate, stop, and *then* fire goes much faster. (Unless you want to introduce
the thrust as intentaneous, but that's even *less* realistic
IMO.)
> THE SOLUTION TO THE ROTATION PROBLEM IS SIMPLE,
I *really* can't see this. Granted I've been reading lots of Honor Harrington
recently, but even *before* I thought of battleships in the millions of tonnes
range I couldn't see it. There's just *way* too much inertia there to ignore,
and making behemoths rotate at the same rate as destroyers is just too much of
an injustice to the lil' dudes.
> I BEG EVERYONES PARDON, THE USE OF CAPS IS A JOB RELATED
Er, yes, it is... it'd be *really* nice if you would try and stop; just
for your information, I know several people who will delete -- without
reading -- messages that are all in caps, just because it's annoying.
None of 'em are on this list, but it *is* considered 'rude' in the realm of
netiquete. (Not a word I've heard recently, but given the handful of chain
letters I've gotten just today I wish more people paid
attention....)
[snip]
> I SUSPECT THAT THIS IS ALL PART OF A PLOT TO MAKE MISSILES
Ow, doesn't htat get expensive with capital ships? Anyway, yes, vector
movement *does* make missiles more effective, as well as fighters if you use
the More Thrust rules where fighters move after orders are written, but before
ships are moved. <shrug> One solution is to make PDAFs more
effective vs. missiles -- I never saw why they're so ineffective, really
-- while another is to just smack anyone who uses too many missiles. ^_-
G'night,
Status: RO
Does the Space Shuttle use its main engines to rotate???
No! It uses lots of small little manuevering thrusters to do so. There
is no reason why a billion ton supper-battleship couldn't rotate, stop
rotating, and then fire its main engines in one turn. Remember
micro-gravity. It doesn't take that much thrust to rotate and stop
rotating a billion to supper-battleship.
Rotating should cost ZERO thrust. The little guys will still be able to out
manuever the big guys because they have more (often much more) thrust. For
game play I would limit rotating to once per turn, either before or after main
engine fire.
A more time consuming method would be that each ship has one free rotation and
can purchase more rotations for one thrust each. This would allow a thrust 8
destroyer to rotate (free) thrust for 2, rotate (1), thrust for 4, and rotate
(1). The thrust cost for each extra rotations is for the main engines NOT
thrusting while the ship is rotating. In other words, this is the loss of
thrust the main engines could have generated while the ship is rotating.
> Imre A. Szabo writes:
@:) Does the Space Shuttle use its main engines to rotate???
@:)
@:) No! It uses lots of small little manuevering thrusters to do so.
@:) There is no reason why a billion ton supper-battleship couldn't
@:) rotate, stop rotating, and then fire its main engines in one turn.
That's all true, provided said battleship had enough fuel to spin Status: RO
itself up and slow itself down again.
@:) Remember micro-gravity. It doesn't take that much thrust to
@:) rotate and stop rotating a billion to supper-battleship.
How about "remember mass"? Or maybe "remember Newton". It DOES take that much
thrust to rotate and stop rotating a billion ton super battleship. If you
aren't worried about turning around any time soon, you can use the Space
Shuttle's technique. If you have to point at something before it kills you,
you're going to start thinking about vectoring the thrust coming from your
main engines. That's a cheap and easy way of rotating without attaching
additional engines to your ship.
@:) Rotating should cost ZERO thrust. The little guys will still be @:) able
to out manuever the big guys because they have more (often @:) much more)
thrust. For game play I would limit rotating to once @:) per turn, either
before or after main engine fire.
Not only do I think that this idea ignores physics in a large way (and
remember physics is what the vector movement system is trying to represent)
but I think it changes the feel of the game significantly. Suddenly everyone
is always in everyone else's front arc all the time. Enormous super ships can
coast through the middle of a battle and flip from one direction to another to
pick off targets. I prefer a system that more closely matches the original FT
"cinematic" system, in which large ships are slow and clumsy and small ones
are manouverable.
However, I do think your next idea has some merit.
@:) A more time consuming method would be that each ship has one free @:)
rotation and can purchase more rotations for one thrust each. @:) This would
allow a thrust 8 destroyer to rotate (free) thrust for @:) 2, rotate (1),
thrust for 4, and rotate (1). The thrust cost for @:) each extra rotations is
for the main engines NOT thrusting while @:) the ship is rotating. In other
words, this is the loss of thrust @:) the main engines could have generated
while the ship is rotating.
I think this makes some sense but I still don't like the idea of ships
rotating freely. I would say instead that ships have thrusters, like those
found on the Space Shuttle, and they can use them to make one heading change
per turn at no thrust cost. So ships with thrust two can actually turn three
headings per turn, and even ships with no engines left can very slowly
reorient themselves.
Excerpts from FT: 7-Oct-97 Re: Vector Rules by "Imre A. Szabo"@sprintma
Status: RO
> Does the Space Shuttle use its main engines to rotate???
I never implied main engines were used to rotate....
> No! It uses lots of small little manuevering thrusters to do so.
Well, not that many (only a couple clusters, I imagine warships would have
lots of backups...).
> There
Exactly my point, re: 1 rotation point starts and stops one arc of rotation.
(I *am* kinda assuming you're replying to my last message... you don't really
make it clear.)
> Remember
Gravity is irrelevant. We're talking *mass* here, and inertia.
(Remember, acceleration = Force/mass. No gravity term....) An eight
million tonne SDN (Honor Harrington universe) can *not* turn on a dime. They
even have some trouble rotating on their axis to bring up their impeller
wedges instead of their sidewalls, fer chrissake!
And even if you're using smaller ships, all you need to do is bring down the
time scale a bit, which isn't really stated anyway, as the big ships will
still 'react' more slowly than the small ships.
> Rotating should cost ZERO thrust. The little guys will still be able
Hmm. Not always, and this would make superships *much* more powerful in a
vector universe. One of the only things stopping my SDN from going and killing
all the smaller ships was that it couldn't turn put it's
guns on target after the initial pass -- the little ships kept dancing
away.
It also keeps the supserships down to a fairly low velocity, as you'll
otherwise drift off the map.
Actually, something I wouldn't mind seeing is the ability to purchase seperate
main engine and maneuver ratings, ie you can have a ship with
*huge*... maneuvering jets and roughly the same-size engines. Your
ability to "push" should be maxxed out to your engine power, though. (Of
course, there was always that one ship, in Frontier: Elite II, that had larger
retros than mains....)
> For game play I would limit rotating to once per turn, either
Yeech. No, thank you: the ability to turn, thrust away from something, and
then turn back and fire is a wonderful thing. Though I guess you can't allow
that if you have free turning, which is another point in the
favor of limited rotation in my book. ^_^
> A more time consuming method would be that each ship has one free
Hmm, not bad, but I don't think it adds much to what the seperate points
system can do.
> On Tue, 7 Oct 1997, Imre A. Szabo wrote:
Status: RO
> No! It uses lots of small little manuevering thrusters to do so.
There
> is no reason why a billion ton supper-battleship couldn't rotate, stop
Ehhhhhhhh, what?
Tell you what, let's go down to the nearest lake. To you, I'll float a
8'
long, 1' thick oak log. I'll take a 8" long, 1" thick oak twig. You turn yours
in the water, I'll turn mine. One rotation, then stop. Reverse that motion.
Repeat a hundred times. Let's see who's out of breath and
wishing he hadn't been sitting hip-deep in the lake.
Entropy always wins and Inertia is His Handmaiden. It takes a /huge/
amount of thrust to rotate a billion tonne super dreadnaught. Don't be silly.
It takes just as much thrust to sweep it through one complete
rotation as to move it one ship-length, I'd imagine. One of our
numericists can crank the exact numbers.:)
> On Tue, 7 Oct 1997, Joachim Heck - SunSoft wrote:
> Imre A. Szabo writes:
Status: RO
> That's all true, provided said battleship had enough fuel to spin
I had a similar arguement with someone during a FTIII playtest session. I had
a dickens of a time trying to convince him that the bigger the starship, the
more mass it would need to dedicate to engines if it wanted to go at a ceratin
speed. Since this is the "thrust 8
super-dreadnought" crowd, they found the idea of paying 40% of their
mass for a thrust 8 ship as opposed to just 10% for a thrust 2 ship appalling.
"Big ships don't need to go slow," I was told. "That idea is so... British,"
said another.
Later,
Status: RO
> Does the Space Shuttle use its main engines to rotate???
There
> is no reason why a billion ton supper-battleship couldn't rotate, stop
There is a big, big, big, BIG difference between the shuttle and the ships
used in FT. That difference is primarily Mass. The more massive something is,
the more energy and effort it is going to take to move
it *any*where - even just to rotate it. You gotta get that bulk moving
somehow, and a dinky thruster that would rotate a 10 ton thing ain't
gonna do squat to a 10,000 ton thing. Micro-gravity only reduces your
weight; it does nothing to your mass.
That or you need a hell of a lot of dinky thrusters! More than what are
feasible to imagine. Much less mount on a ship.
There are Laws which govern this.
And once you got something going, it's going to take a heck of a lot of energy
to stop it again! Inertia. In both cases. You need to overcome it.
> Rotating should cost ZERO thrust.
Why? You need to spend energy from somewhere to rotate something; why should
it cost '0'?
I think the rules, as written, and the vector rules, do a reasonable job of
simulating the thrusters and account for rotations well enough to work. That
you are using Thrust to rotate your ship does *not* mean you are using your
main engines. Simply the power output is redirected to side thrusters.
Mk
> On Tue, 7 Oct 1997, Imre A. Szabo wrote:
Status: RO
> Rotating should cost ZERO thrust. The little guys will still be able
I disagree -- it would take too much effort to rotate a battleship at
the same speed as a corvette. The key question is "how far can you rotate the
ship in a single game turn?" I can't see how a 60-ton capital ship could
possibly maneuver/rotate at with the same degree of "agility" as a 6-ton
escort ship. Of course, given enough time, a single retro-rocket can
spin a battleship like a top, but it would take forever to get up to speed.
> On Tue, 7 Oct 1997, Imre A. Szabo wrote:
Status: RO
> No! It uses lots of small little manuevering thrusters to do so.
There
> is no reason why a billion ton supper-battleship couldn't rotate,
You seem to be forgetting that there is a major difference between trying to
rotate an object in space Vs rotating it in water fighting the resistance of
the liquid. You should be able to maneuver the big ships quite quickly, the
only drawback is that the further you are away from the point of rotation, the
more inertia you will have to deal with. Captains take note... make no
surprise high speed maneuvers, lest your forward gunners become salsa.
Status: RO
I have been away and missed the beginning of this thread. If I repeat someone
else's opinion, please forgive me.
Two options appeal to me:
1) The easiest is that if a ship has 1 point of thrust left (unused) it can
face any single direction for firing purposes.
2) Each point of thrust that is left (unused) will permit a 3 point facing
change. Thus an average thrust 4 battleship could only apply 2 points of
thrust to change course if it needed to target to the rear.
> Stuart Ford writes:
@:) You seem to be forgetting that there is a major difference between @:)
trying to rotate an object in space Vs rotating it in water @:) fighting the
resistance of the liquid. You should be able to @:) maneuver the big ships
quite quickly
This mailing list reminds me of a Dilbert poster in my manager's office: "The
Boss Zone, where time and logic no longer apply!" Status: RO
Except it would be physics and logic.
Anyway, yes water causes drag but the fact is that massive things
are hard to move anywhere, in space, in water, in air, wherever - if
they have mass they have inertia and they're hard to move. The more massive
they get, the harder it is to move them.
> On Tue, 7 Oct 1997, Stuart Ford wrote:
Status: RO
> You seem to be forgetting that there is a major difference between
make no
> surprise high speed maneuvers, lest your forward gunners become salsa.
There's no forgetting whatsoever. Suspend both wooden objects by a chain
connected to their middles, balanced. You run around the 8' log as hard
as you can push it, one rotation, then /stop/ it and rotate it back the
other way. I'll to the same one with the 8" cylinder. Who do you think is
going to be exhausted and sloppy when the exercise is done?
This holds even in /axial/ rotations. Put both on a lathe. Let's time
how many times I can get opposite rotations out of our respective wooden
objects. Mine spins trivially with a flick of my finger and stops just
the same. Yours will require both hands and some sweat and /stopping/
it will be as hard as, if not harder than (because you're trying to do it
faster), starting it!
How much the peas in the pod rattle around is a legitimate concern, but is
/just/ as important when considering linear axial thrust.
Status: RO
I'll assume that's why a 10 ton ship has at least 1 ton of engine, and a 100
ton ship 10 (at least under the house rules we use here.. 10% for engine, 15%
for structure)
Based on the current rules, it seems as if the ships have equivalent
thrust/mass ratio at the same thrust levels. Thrust 4 FFG = Thrust 4
SND.
Stuart F. (wow, two posts in the same day...)
[quoted original message omitted]
On Oct 7, 1997 at 11:53:21 AM, Rick Rutherford <rickr@ss4.digex.net> wrote:
> On Tue, 7 Oct 1997, Imre A. Szabo wrote:
Status: RO
> > Rotating should cost ZERO thrust. The little guys will still be
And there are a couple of other things to remember:
1) You have a force of acceleration in the direction of rotation, meaning that
if the thrusters are firing to rotate to the left, everyone is being pushed up
against the right-hand bulkheads. This lasts as long as the thrusters
are firing.
2) In addition, you have inertia (i.e., centrifugal force) effects pushing you
out away from the axis of spin. This effect continues as long as the shio is
*rotating*.
This subject came up one of the Traveller lists. I forget the details of the
specific conversation, but the final calculation was that the people in the
nose and tail of the ship were pulling a LOT of gees.
Peoiple aren't the only concern -- these things affect the ship, too.
Firing engines on the back pushes the back into the front, i.e., compresses it
-- a *
lot* different than the type of stress you get when you want to rotate a long
ship.
This is not to say that you can't rotate large ships, but it is to say that
you can't assume that doing so is easy.
> On Tue, 7 Oct 1997, <Mark Andrew Siefert> wrote:
> On Tue, 7 Oct 1997, Joachim Heck - SunSoft wrote:
Status: RO
> > Imre A. Szabo writes:
Odds are, your playtesters are among those who confuse MASS and WEIGHT.
Sure, in micro-grav a SDN doesn't weigh anything, but it sure as hell
has mass and the inertia that goes along with mass.
And as for thrust 8 SDNs, give me a break. I can think of far better ways to
spend your fleet points that on SDNs with destroyer thrust...
Its not a 'British' idea (love that phrase...!) its physics and points
cost...
Regards,
> @:) You seem to be forgetting that there is a major difference between
> This mailing list reminds me of a Dilbert poster in my manager's
*grin*
> Anyway, yes water causes drag but the fact is that massive things
How 'bout a better example! ;-)
Let's take, say, a 1 metric ton beam of steel, and a 1 lb shaft of wood. Set
them on a pivot point in such a manner that they will not fall off (we assume
they won't for sake of arguement;). As in the following illustration:
============================
| | -----------
============================ ^
^ / \
/ \ / \
/ \ | |
| | | |
------- -------
Assume in this system that air friction is negligible, and that the friction
between the pivots and the beam/shaft is negligible (there's really
really good oil on there). Now try and rotate them (and stopping them after
they've gone a half turn). Just go up there and give that ol' steel beam a
good push!
Impart the *same* push/force to the shaft of wood.
Better, give the shaft of wood a push to move it, then give the *same* push
to the steel beam. Okay, now push harder. ;-)
You can practice this in real life (kids! do this at home! WITHOUT parental
consent - but I take no claims for any messes you make in the mean
time!) Get a 10' section of PVC pipe, fill it with a material of your choice
(dirt, water, whatnot), cap both ends. That'll represent the steel beam above.
Get a straw. That'll represent the shaft of wood.:) Put both on a 'lazy
susan'. Now...try and rotate them. No, really. This will work, and *ought* to
demon-
strate the basic principles trying to be shown above.
Mk
> On Tue, 7 Oct 1997, Stuart Ford wrote:
> >On Tue, 7 Oct 1997, Imre A. Szabo wrote:
Status: RO
> >
There
> >> is no reason why a billion ton supper-battleship couldn't rotate,
Reverse
> >that motion. Repeat a hundred times. Let's see who's out of breath
make no
> surprise high speed maneuvers, lest your forward gunners become salsa.
You seem to be getting a bit confused regarding inertia...although you do have
a point about the centrifuge (sp?) effect of turning, a big ship has inertia
all over, not just at the extreme bow and stern ends. You need to push the
WHOLE mass of the ship around on its axis to rotate it, not only the bow and
stern ends.
For SDNs and other big ships, mass and inertia stop them from spinning like
tops. For little ships, destroyers and the like, it may indeed be the
salsa-ed crew problem that stops them from pulling 360s and stuff - the
crew and possibly the ship's frame would be damaged...
The as-written costs of rotation seem to work - I've not playtested
them, but they read well. The inertia of big ships cannot be forgotten.
Status: RO
The debate is very interesting, but unlimited rotation has a profound
difference on tactics compared to the current limited rotation in use. The
current PBeM, Battle for Nimrod Station, has certainly shown me the difference
this has on tactics. If you allow unlimited rotation, fire arcs become
pointless as it becomes always possible to aim the maximum amount of guns at
your target.
'Neath Southern Skies
> On Wed, 8 Oct 1997 09:35:08 +1000, "ROBERTSON,Brendan" writes:
Status: RO
> The debate is very interesting, but unlimited rotation has a profound
As another player in the Numrod Station game, I want to concur with this. If
we had unlimited facing changes, it would take a lot of the tactics and
maneuvering out of the game. I know I spent a LOT of time on the last turn
trying really hard to end up with my guns baring on the enemy, and his guns
not hitting me. I failed:), but it was a good try.
Please don't allow unlimited turns. And make the bigger ships turn slower. It
really does effect the feel of the game negitively to allow big ships to spin
on a dime.
Corridor of Endless Winding Leader of the Assult on the Nimrod Station
ps. If people would like to see some bits of a game actually played with a
vecotr system, and none of the onther players mind, I can try to put up the
maps and turn summeried on a web page when the game is over.
> Aaron P Teske wrote:
Status: RO
> Actually, something I wouldn't mind seeing is the ability to purchase
Our group has talked about purchasing additional rotation at the same
cost of the Main Thrust, but only for rotating - not accel. BTW we use a
house rule of actually using up 2 Thrust for each point of rotation (a ship
with a Thrust of 4 may make a 4 pt. accel; a 1 pt turn and 2 pt
accel; or a 2 pt turn - not a 2 pt turn and 2 pt accel as the FT
rulebook indicates). You can only purchase additional rotation to give a max
of your ships Thrust Rating.
Status: RO
> As another player in the Numrod Station game, I want to concur with
> Corridor of Endless Winding
Hey there.
This is Chuk[former pilot of ThunderTird]. That game was pretty fun
[short for me though]. I agree fully about the spin and turning though.
If you let it play like that you will end up with battle barges that drift
along and just rotate and blast everything that gets close. Not much fun.
That
Chuk Guy
PS- those drones really suck :). Hope I caused a little discomfort to
you bug wankers.
> Alexander Williams wrote:
Status: RO
> Tell you what, let's go down to the nearest lake. To you, I'll float
If you ignore friction, I'll take you on; but I want someone ten times taller
then you to turn my log. You are using same size engines to turn different
size objects. Get real. If I have a ship 10 times bigger, I'll have 10 times
bigger manuevering thrusters...
> Entropy always wins and Inertia is His Handmaiden. It takes a /huge/
I'm not being silly; simply making a point.
The G-forces arguement doesn't hold water. The crew would be stationed
at the center of the ship where the effects will be minimum, and the equipment
will be designed to handle it. If you think there will not be enough room for
the crew in the center of the ship, you are wrong.
Contrary to Star Wars and many sci-fi novels, crew sizes will be very
small. Men don't man most naval gun turrets directly now (men physically in
the turret); what will it be like in 200 years???
Absolute maximum crew size for ships would be 2 men per mass and 1 to 2 men
per fighter (assuming fighters are manned), not more. Probably 0.5
to 1 man per mass with un-manned fighters is a better number. Most
damage control, maintence, repair, etc. will be done by machines. This
may make boring sci-fi, but is a bit more likely to be what will
happen.
One last point just in case no one has made it yet (I'm fairly knew to the
list). There is only one reason why the shuttle and other current technology
spacecraft use vector movement instead of "cinematic movement," fuel.
Spacecraft CAN manuever just like you see in Star Wars (hyperspace jumps
ommitted). It just takes lots of fuel to do so and at $1,000's per pound to
orbit, every pound of fuel, or anything else for that matter, counts.
Status: RO
> One last point just in case no one has made it yet (I'm fairly knew
Not with only one big engine sticking out the back they can't.
A plane moves in direction x, banks and is moving in direction y with the same
speed as before. The air has nicely converted velocity in one direction to
velocity in other. Nice air.
A spacecraft moves in direction x, banks and is facing direction y with some
speed in that direction. At no point has its engine pointed along its former
course, its speed along x can't have been cancelled and so it still has speed
in the dirextion x. It's velocity will be towards some direction between x and
y.
An X-wing would need engines just as big as those pointing backwards
to be pointing in all other directions if it wanted to fly like a plane. Same
holds for the FT ships. The basic movement system requires engines pointing
all round to cancel out the motion in direction x. This is possible to build
but why bother?
With warp/gravity/inertialess drives with don't use thrust but
instead manipulate the fabric of space-time to pruduce propulsion,
then you can have whatever movement system you like.
Without pseudo-science engines, some form of fluid medium surrounding
you, or big thrusters facing each direction you can not ly like a plane, no
matter how much fuel you expend. The first probably doesn't exist, the second
doesn't exist in space by definition, and the third is a very poor way of
designing a spacecraft.
> On Wed, 8 Oct 1997, Imre A. Szabo wrote:
Status: RO
> If you ignore friction, I'll take you on; but I want someone ten times
You're changing the grounds of the argument /and/ introducing a new
fallacy at the same time. To address both:
a) The whole point is that the larger vehicle /requires more thrust to
turn at the same rate/. First and foremost. Secondarily,
b) You assume a linear increase in engine efficency with engine mass. If
the drive is based on conventional technology, this will /definitely/
not hold, in fact, efficency will probably fall off fairly sharply with size
if conventional means of acceleration are used, whether that be
reaction-mass throwers or ion drives. If you're using some
ultra-science
wave-surfing pulse hyper-skipper as your thrusters, all bets are off,
but
you might as /well/ have 0 rotation time since you're firmly in the
realm of fantasy anyway.
> The G-forces arguement doesn't hold water. The crew would be
I won't even deign to list the number of assumptions you're pulling from some
obscure crevasse in this paragraph.
What I /will/ state is that were I designing the space-based defense
forces of 200 to 2000 years in the future, there'd be no people at /all/
involved. Flocking algorithms and emergent behavioural and reactive systems
are quite good enough today to build contingency planning cores
around which you craft a cheap and small weapon-beriddled hull and small
(and thus efficent) thruster array. Put them in stationkeeping positions or on
patrol orbits. They're cheap enough to lose tonnes of them to accident and
malfunction and, unlike humans, don't get bored and are intrinsically better
combatants. If you really need the human elements, or have humans on site for
some reason, they can act as 'strategic control' for the drone craft,
directing inputs into their overall
behaviour from /well/ behind the battle lines.
Of course, it'd be boring as hell to game out but it'd make an intriguing
computer game on the scale of UNNATURAL SELECTION or SIMLIFE.
Mind you, in 200 years we /might/ have humans in fighters that don't use
reaction mass zipping through space like WWII pilots and talking into cheap
radios. Humans are funny about war; sometimes its a step forward to go back.
> One last point just in case no one has made it yet (I'm fairly knew to
Actually, there's another reason: physics.
Spacecraft that look like X-wings and TIEs cannot maneuver like you see
in SW. They'd have to be oblate or spheroid with thruster ports covering 80%
of their exterior to pull off maneuvers that mimic the motion of winged
vehicles in an atmosphere to move like that. Worse, beyond inefficent, motion
like that makes you a prime target for weaponry.
Want to see realistic vector movement in space? Watch the Star Furies on
B5; non-combat motion is point - thrust - coast x Xmin - reorient -
thrust
- coast - repeat. Combat motion significantly shortens the coast period
because its trivial to plot the vector of a non-accelerating vehicle in
0g outside of a gravity well (and not too hard in one). A good set of vector
movement rules that capture this are the space combat rules from DP9's JOVIAN
CHRONICLES.
ObGZG: The real problem at the heart of the matter is /what is the
relative scale of distance and time/? If each inch is 15km and each
Turn 5min, it makes sense for a massive battleship to take significant Turns
to turn around. If inch is 5k km and a Turn is 2hrs, then it makes far
/less/ sense; in a tactical scope, turning the ship about /would/ be
free at that scale.
> Gravity is falling in a. good way today writes:
@:) You can practice this in real life (kids! do this at home! WITHOUT
@:) parental consent - but I take no claims for any messes you make in
@:) the mean time!) Get a 10' section of PVC pipe, fill it with a @:) material
of your choice (dirt, water, whatnot), cap both @:) ends. That'll represent
the steel beam above. Get a straw. That'll @:) represent the shaft of wood.:)
Put both on a 'lazy susan'. @:) Now...try and rotate them. No, really. This
will work, and *ought*
@:) to demon- strate the basic principles trying to be shown above.
Or you could suspend the thing from a string tied around the Status: RO
middle. Might be cheaper than going out and buying a lazy susan.
Imre A. Szabo said: Status: RO
> The G-forces arguement doesn't hold water. The crew would be
Even discounting crew effects, 1) the ship still masses a tremendous amount,
suggesting that idly assuming that they can spin like tops is inaccurate, and
2) such rotation is still putting a *lot* of stress on the frame of the ship.
Pick up a naval ship design manual sometime -- while not spacecraft
design, it will explain what happens when you put stress on large hulls, and
it will talk about some of the scaling affects that you run into.
> Absolute maximum crew size for ships would be 2 men per mass and 1 to
This
> may make boring sci-fi, but is a bit more likely to be what will
Really? And what are these numbers based on? _FT_ is far too generic
to make any such determination: we have no idea concerning computer
capability, robotics, etc. Heck, this vision might not happen purely on the
basis of human crews being *cheaper* (which we can't determine because of lack
of
info).
> One last point just in case no one has made it yet (I'm fairly knew to
> the list). There is only one reason why the shuttle and other current
> that matter, counts.
No; with a sufficient amount of fuel and sufficiently powerful thrusters
pointing from every conceivable surface, a ship might be able to perform
*
some* of the maneuvers in question, *provided they were not anywhere near the
limits of their performance capbilities*. The different types of
vehicles at the limits of their performance capbilities would have radically
different course profiles. Since military vehicles have a tendency to push the
envelope, when it counts, vector movement doesn't look like Star Wars. I
don't think the shuttle could do it under any circumstances -- I don't
think the engines are powerful enough.
> @:) You can practice this in real life (kids! do this at home! WITHOUT
Status: RO
> Or you could suspend the thing from a string tied around the
Hey!! Stop being so practical! Geez...
Mk
Status: RO
> > If you ignore friction, I'll take you on; but I want someone ten
Here's the problem. In normal everday conversation thrust is used in a sense
that means Force to a physciist. In FT, Thrust is actually an acceleration.
Thrust 1 will have the same effect on a Mass 6 ship as it does on a Mass 60
ship. It must be acceleration then, not force.
1 thrust point for the Mass 6 ship represents a much smaller force than for th
Mass 60 ship. 10 times smaller. (Newton's Second Law: Force = Mass x
Acceleration).
For rotation, things get a bit more complicated. Now the shape of the ship and
the position of the thrusters will play a part.
The fact that Thrust points used for rotation and acceleration are identical
even under the proposed Vector systems is a simplification. I don't think we
would want to play a game that did not make that simplification. (Sure, I'd
love to calculate the moment of inertia for a Kra'Val super dreadnaught about
its vertical axis...)
Status: RO
Incorrect. It takes the same amount of force to rotate a million ton ship in
microgravity as next to a black hole. We are talking force vs. inertia, not
gravity.
> Chan Faunce wrote:
Status: RO
> house rule of actually using up 2 Thrust for each point of rotation (a
Greetings Chan,
I feel you and your group are doing the best with rotation
that can be done. It is simple and does not wander away from the
current 'FULL THRUST' (2nd Edition) rules. (best of all, no
"gimme" free thrust.) THANKS,
> Alexander Williams wrote:
Status: RO
> [quoted text omitted]
ObGZG: The real problem at the heart of the matter is /what is the
> relative scale of distance and time/? If each inch is 15km and each
Alexander, A dead center hit on the top of the nail. (I personally do not like
to play with large logs in water. So, I will stay out of that part of the
continued exchange.) Good day,
On Tue, 7 Oct 1997 16:24:22 -0400 (EDT), Alexander Williams
> <thantos@alf.dec.com> wrote:
> On Tue, 7 Oct 1997, Stuart Ford wrote:
Status: RO
> How much the peas in the pod rattle around is a legitimate concern, but
Agree with the inertia comments. I'm going to throw something else in the mix:
structural integrity. Making a starship that can handle high amounts of linear
acceleration is a given. However, in order to handle high amounts of
rotational acceleration would require extra stressing. It's not just a matter
of bigger engines taking up more mass. The internal structure would have to be
reinforced to handle the acceleration. This adds mass. How much mass? Don't
know, how massive is durasteel, plaststeel, metallic hydrogen reinforcing
rods, etc? But, it would be more mass than if you designed the ship for only a
small amout of angular acceleration.
How does this affect the game? Probably not at all; this is a fast paced
wargame, not an engineering lesson. However, if you're thinking of homegrown
rules to handle angular acceleration, you may want to think about giving fast
turning ships a slight penalty in mass to handle this effect.
On a tangential note, I'd like to be able to make brittle ships by getting a
bonus for taking less than the calculated hull boxes and make tougher ships by
buying extra hull boxes.
> Allan Goodall writes:
@:)... if you're thinking of homegrown rules to handle angular @:)
acceleration, you may want to think about giving fast turning @:) ships a
slight penalty in mass to handle this effect.
@:)
@:) On a tangential note, I'd like to be able to make brittle ships by @:)
getting a bonus for taking less than the calculated hull boxes and @:) make
tougher ships by buying extra hull boxes.
I like that idea. Here's a thought on how to handle damage from rotational
stresses:
A space ship experiences stress whenever it changes COURSE. The Status: RO
amount of stress is proportional to the size of the turn. Each ship also has a
"maximum stress factor"; if this amount of stress is exceeded, the ship may
take damage. The maximum stress factor is measured in COURSEs per turn. It is
calculated, at ship construction time, by the following formula:
SFmax = floor(1 + 60/mass)
This means that ships have the following maximum stress factors:
Mass SFmax <=20 4 <=30 3 <=60 2
> 60 1
If a ship changes course by a number of COURSEs greater than its maximum
stress factor, that ship immediately suffers 1d6 points of damage.
Improvement: Structural Stiffening Mass: 0 Cost: 10% of hull cost This system
makes the ship more resistant to the stresses encountered during rotational
motion. Ships with this system add one point to their maximum stress factor.
System: Adaptive Structures Mass:0 Cost: 30% of hull cost
Symbol: ____
/ /
| A |
/___/
This system of computer-controlled hydraulic stiffening systems
allows the ship to twist bend as it is manouvered. The increased flexibility
allows more violent manouvers to be performed without damage. Ships with this
system add two points to their maximum stress factor. Unlike structural
stiffening, this system is actively controlled by a computer, which can be
destroyed. This system cannot be combined with structural stiffening.
Status: RO
In message <199710071453.KAA29797@sparczilla.East.Sun.COM>
> Joachim Heck - SunSoft <jheck@East.Sun.COM> wrote:
> Imre A. Szabo writes:
I know I've had this argument (sorry, we're all friendly here
aren't we? - discussion :) ) on this list before, but small
does not necessarily mean fast.
If 50% of your mass is devoted to engines and propellant, then (assuming equal
technology for both ships) a big ship is going to be as 'fast' as a small
ship. In fact, some things work out
more mass-efficient on big ships, allowing the big ship to be
faster, given the same proportion of drive systems.
Of course, a lot of people like the 'cinematic' idea of small is fast, big is
slow though.
> I think this makes some sense but I still don't like the idea of
I sort of like the idea of having two drive systems - a primary
drive which thrusts in one direction, and a manouevre drive which can thrust
in any direction, and also be used for turns. Then you can have damn fast
ships, which can't turn to save themselves (literally).
Realistically, it all depends on the length of the turn. If you're assuming 15
minute turns, most ships should be able to complet a 360 degree rotation in a
turn. If turns are 15 seconds long, then this won't be so.
Status: RO
In message
<Pine.OSF.3.96.971007115245.1520C-100000@zeorymer.alf.dec.com>
> Alexander Williams <thantos@alf.dec.com> wrote:
> Tell you what, let's go down to the nearest lake. To you, I'll float
Not quite a fair comparison - the oak log has much greater
friction acting on it. In space, there is none of that.
You've also got moments of inertia to factor in - the log
is longer, so it's a better lever.
In fact, if you want to be picky, both the log and the twig would take exactly
the same amount of effort.
Of course, while a push on the twig rotates it at 90 degrees a second, the
same push on the log starts it rotating at maybe 1 degree a second. It takes
longer, but no more effort.
> Entropy always wins and Inertia is His Handmaiden. It takes a /huge/
You could always use damn big fly wheels (rotate wheels one
way, ship rotates the other). Then you don't need _any_
thrust.:)
Status: RO
In message
<Pine.OSF.3.96.971008065731.2299B-100000@zeorymer.alf.dec.com>
> Alexander Williams <thantos@alf.dec.com> wrote:
> On Wed, 8 Oct 1997, Imre A. Szabo wrote:
If
> the drive is based on conventional technology, this will /definitely/
My understanding is that bigger drives are actually more efficient, though
that comes from many similar discussions over in rec.arts.sf.science, rather
than from personal experience.
Anyway, for the sake of argument, let's say that a mass 10 engine gives a
thrust of X, and a mass 30 engine gives a thrust of 2X. Obviously with this
sort of relationship between engine size and mass, big ships are going to be
slow.
Wrong!
The big ship does not mount a mass 30 engine. Instead, it
mounts 3 mass 10 engines, giving it a thrust of 3X - just
as efficient as the smaller ship.
If big engines are inefficient, you mount lots of smaller ones. There is added
complexity, which leads to less efficiency, but such disadvantages are
probably far outweighed by the advantages of big designs.
If ships carry armour (I don't like magical shield technology),
then a big ship has _far_ less surface area to armour than
a small ship does, proportional to their volumes.
A ship eight times as big, has only four times as much armour mass, but has
eight times as much drive space.
So if armour is non-negligable, big ships can easily
be faster.
> Samuel Penn writes:
@:) I know I've had this argument (sorry, we're all friendly here
@:) aren't we? - discussion :) ) on this list before, but small does
@:) not necessarily mean fast.
@:)
@:) If 50% of your mass is devoted to engines and propellant, then @:)
(assuming equal technology for both ships) a big ship is going to @:) be as
'fast' as a small ship. In fact, some things work out more
@:) mass-efficient on big ships, allowing the big ship to be faster,
@:) given the same proportion of drive systems.
Nevertheless, the problems of structual integrity, to borrow a Status: RO
phrase, scale up quickly with volume. No matter what kinds of engines they can
mount, larger ships will be forced to move more slowly or they will tear
themselves apart. The penalty for greater stability is greater (proportional)
mass.
@:) Of course, a lot of people like the 'cinematic' idea of small is @:) fast,
big is slow though.
That, too.
@:) Realistically, it all depends on the length of the turn. If you're @:)
assuming 15 minute turns, most ships should be able to complet a @:) 360
degree rotation in a turn. If turns are 15 seconds long, then @:) this won't
be so.
This is true.
> On Wed, 8 Oct 1997, Alexander Williams wrote:
Status: RO
> a) The whole point is that the larger vehicle /requires more thrust to
Yes, but the requirement increases linearly. I don't think anyone seriously
suggested fixed engine thrust.
> b) You assume a linear increase in engine efficency with engine mass.
If
> the drive is based on conventional technology, this will /definitely/
The problem with thrust is that it's simply additive.
Whether you have one 2 MN thruster or 2 1 MN thrusters or even 2000000 1
Newton thrusters, the total thrust is 2 MN.
> From the design standpoint this means that after your ship gets big
Even today, practically all ships mount multiple engines.