Ship Design questions

[JAFARR]

(1) For MT, does anyone know the formulae used to create the basic hull data in the craft design charts? I am trying to put it into an Excel spreadsheet without having to copy all the charts and then factor in the interpolations for hull sizes not given. Seems that if the charts can be reduced to a formula, it would be much easier to program.
(2) When using the powering down rule, I assume that in actuality there is only one power plant, but it is designed as seperate units for ease of designing. (The U.S. Navy nuclear power plants are routinely operated well below design power output. Power output is expressed as % of full power. Full battle load is much less than 100% giving a margin to allow for battle damage)
(3) What is the advantage of thrusters over anti-grav for maneuver drives? Thrusters cost more,weigh more, and require more power. There must be some reason to use them if they are the replacement technolngy?
(4) What use are the smaller chassis under the vehicle table? A UPC of .074? this is 1 liter or less than a large drink at most fast food joints (I work in one so I can call it a joint.) What possible use can that size or smaller vehicle have? I don't see any remote controls listed anywhere.

 

[BetterThanLife]

Originally posted by Andy Fralix:

(3) What is the advantage of thrusters over anti-grav for maneuver drives? Thrusters cost more,weigh more, and require more power. There must be some reason to use them if they are the replacement technolngy?
(4) What use are the smaller chassis under the vehicle table? A UPC of .074? this is 1 liter or less than a large drink at most fast food joints (I work in one so I can call it a joint.) What possible use can that size or smaller vehicle have? I don't see any remote controls listed anywhere.

For Item 3. Thrusters have one advantage over Anti-Grav. Anti-Grav require you to be in a Gravity Well. The farther you are from the source of Gravity the less well those thrusters work. Thrusters work regardless of Gravity Wells.

Item 4. Well I can think of a few reasons for the smaller chassis. The big reason is so you can add them to bigger ones, off the top of my head. Small Robots being another choice.

 

[jhulse]

Got to check with T20, not sure it really goes into it, but in at least the GURPS version of traveller, thruster plates (gravity drive) only work 1,000 diameters from a planetoid or larger sized object. On some of my schematic "adventure" ship designs, I usually have a combination of thruster plates and reaction drives. That way you can still at least accel/decel in deep space. If you only have gravity drives, you can still travel interplanetary, but you get to do it the old fashioned way! Accelerate until your 1,000 diameters away from your starting point, then drift until your 1,000 diameters away from your destination point at which time you can start to decelerate.
Don't ask me how to do the math on that one!

 

[BetterThanLife]

Originally posted by Jak Nazrith:
Got to check with T20, not sure it really goes into it, but in at least the GURPS version of traveller, thruster plates (gravity drive) only work 1,000 diameters from a planetoid or larger sized object. On some of my schematic "adventure" ship designs, I usually have a combination of thruster plates and reaction drives. That way you can still at least accel/decel in deep space. If you only have gravity drives, you can still travel interplanetary, but you get to do it the old fashioned way! Accelerate until your 1,000 diameters away from your starting point, then drift until your 1,000 diameters away from your destination point at which time you can start to decelerate.
Don't ask me how to do the math on that one!

Now that is a major difference between GURPS and MT. CT doesn't really get into what the Maneuver drives actually are and neither does T20. Though Since MT, Thruster Plates appear to be what was intended in CT. (At least the general consensus says that.)

 

[BetterThanLife]

Andy,
I picked up a spreadsheet for MT ship design a while ago. I am just trying to remember where I found it.

 

[jhulse]

Yeah that's what I figured. I guess in MT and T20 there is enough mass in a typical solar system for the grav-drives to work all the time. What happens if you jump into an empty parsec?
(shrug) I just tell myself
"It's I sci-fi futuristic space game engine doohickey"

 

[BetterThanLife]

Originally posted by Jak Nazrith:
Yeah that's what I figured. I guess in MT and T20 there is enough mass in a typical solar system for the grav-drives to work all the time. What happens if you jump into an empty parsec?
(shrug) I just tell myself
"It's I sci-fi futuristic space game engine doohickey"

WEll THruster plates were designed to be a reactionless Gravitic tech drive that would work in empty space. SOmething about the plate having the mass to push against, supposedly like a flywheel or something.

 

[jhulse]

Sounds logical to me.

 

[JAFARR]

Originally posted by Bhoins:
</font><blockquote>quote:</font><hr />Originally posted by Andy Fralix:

(3) What is the advantage of thrusters over anti-grav for maneuver drives? Thrusters cost more,weigh more, and require more power. There must be some reason to use them if they are the replacement technolngy?
.

For Item 3. Thrusters have one advantage over Anti-Grav. Anti-Grav require you to be in a Gravity Well. The farther you are from the source of Gravity the less well those thrusters work. Thrusters work regardless of Gravity Wells.

</font>[/QUOTE]That make me feel like a dunce, which I deserve.
Should have figured that out for myself!

 

[JAFARR]

Originally posted by Bhoins:
Andy,
I picked up a spreadsheet for MT ship design a while ago. I am just trying to remember where I found it.

That is what I am trying to do now as an exersise to learn Excel programming. Book 2 and High Guard were fairly easy. Now I am trying to redo my first attempt which was MT. I learned better ways of doing things and want it to be a professional, user friendly speedsheet.

 

[Andrew Boulton]

"Got to check with T20, not sure it really goes into it, but in at least the GURPS version of traveller, thruster plates (gravity drive) only work 1,000 diameters from a planetoid or larger sized object."

I'm trying to remember where that idea first appeared. I *think* it was TNE.

 

[aramis]

Not TNE, but the pre-release discussions on the TNE-dominated TML while FF&S 2 was being worked upon.

and a URP of 0.074 is 999L (effectively, 1kL, or 1 cubic meter)
Big enough to be R2D2

 

[Andrew Boulton]

Aha. Thanks. I'm sure it appeared in print somewhere, though.

 

[BetterThanLife]

It isn't in T20. T20 doesn't really discuss what a maneuver drive actually is. (Neither did CT for that matter.) MT defined it as Thruster Plates. And defined the difference between Anti-Grav drive
and thruster plates. It states that Thruster Plates work outside of gravity wells, which is why they are needed instead of Anti-Grav drive for spacecraft and starships.

Originally posted by Andrew Boulton:
"Got to check with T20, not sure it really goes into it, but in at least the GURPS version of traveller, thruster plates (gravity drive) only work 1,000 diameters from a planetoid or larger sized object."

I'm trying to remember where that idea first appeared. I *think* it was TNE.

 

[aramis]

Andrew: FF&S2 included those limits, and IIRC, so did T4 base book.

 

[daryen]

Originally posted by Jak Nazrith:
Got to check with T20, not sure it really goes into it, but in at least the GURPS version of traveller, thruster plates (gravity drive) only work 1,000 diameters from a planetoid or larger sized object.

Not quite. In GURPS Traveller, the maneuver drive is a "reactionless thruster". As such, it is not gravitic dependent and will work just as well in deep space as deep in a gravity well.

MT is the system that had the gravitic based thrusters.

 

[GypsyComet]

If I recal correctly, it wasn't that Thrusters "stopped working" beyond that radius, but that their input to output ratio went to heck, dropping to only a couple percent of their normal efficiency.

 

[jhulse]

You guys may be correct. I'll have to read it again in the next night or so. But I definitely remember a "1,000 diameter limitation" on some portion of thruster plate design.

 

[BetterThanLife]

Originally posted by Jak Nazrith:
You guys may be correct. I'll have to read it again in the next night or so. But I definitely remember a "1,000 diameter limitation" on some portion of thruster plate design.

If that is correct that there is a 1000D limit on Thruster plates, how do you get from Earth to Neptune before the invention of Jump Drive? Maneuver Drive clearly filled that role in the OTU before someone decided to call maneuver drive thruster plates. And before TNE.

Thinking about it, how in FF&S, does one explore and exploit their own solar system without jump drive? Clearly HEPLAR drives are not efficeint enough to do the job.

 

[aramis]

MT's early anti-grav thrusters had a 1000D limit. They are TL9. How do you get to neptune with them?

1) You accelerate on an elliptical orbit until break-free, and continue on a drifting, probably hohman transfer orbit, course.

2) You leave the planet, then do a long sun-dive to attain a parabolic intercept

in either case, you then make final corrections and orbital insertion thrusting upon reaching.

T4's limit was a specific gravity gradient, which was solar limited to about saturn, but you could easily "Aim for the well" of a further out world. If I remember correctly, that gradient was 0.001 G, but I'm too lazy to look it up right now. It was to prevent the planet shattering "Near-C Rocket" attack with a 10 ton launch wiping out capital. With said limit, you need a 6G 100Td 7J1 custom designed assault ship. (Start in solar ellipse, accelerate through the solar well, jump so that you come back at the well, repeat.)

Remember, in space, if you have the momentum, you can coast almost forever. (The femptonewtons {1E-12N} or smaller of drag per square meter are a factor, however, and sooner or later, you will match speed with the interstellar medium.)