Jump Time/Jump Variance/Astrogation skill?

[archhealer]

Ok, in the THB it states quite clearly that really good astrogators can get better results from Jump Travel, shaving off the average jump time and such. Does anybody know of any stats/tables/effect that a high astrogation skill actually HAS on jump travel?

 

[tjoneslo]

In MegaTraveller somewhere is a that states that if the computers of the ships can be linked (to calculate the jump), the time spread decreases from +/- 10% to +/-1%. This is used by the imperial navy to ensure their task groups come out of Jump Space at the same time, rather than spread over a day or more.

In JTAS issue 22 there is a discussion of using the astrogation skill to determine where in the system you arrive. (From Port to Jump-point by Leroy Guatney) While this doesn't alter the jump time per-se, it will alter the amount of time spent in normal space getting from the jump exit point to the planet. There is a further disucssion (but no new rules) regarding this in GT: Far Trader, if you follow through on the Jump Maksing rules.

 

[mike wightman]

It's Astrogator propoganda

In the skill description it mentions shaving a few minutes.
The reality is the jump time variable is measured in hours - 147 + 6d6 hours.

I'd be tempted to knock off an hour for each point over the DC the Astrogator makes his roll by.

 

[Spinward Scout]

This is what I've come up with for Plot Calculation and Travel Time. Hope it helps. You can drop the Distance Travelling and Rating of Drive if you'd like. It's not canon.

Dameon

JUMP PLOT CALCULATION
((( B + G + R + C ) X P ) / D ) X F )

Base DC ( B )
15

Fuel Used ( F )
2 - Unrefined ( Cr100 )
1 - Refined ( Cr500 )

Distance Traveling ( P )
In Parsecs

Jump Drive ( D )
Rating of Drive (i.e. J-5 drive, J-2 drive, etc...)

Gravity Disturbance ( G )
+15 - less than 10 diameters from gravity well
+5 - less than 100 diameters from gravity well
+0 - more than 100 diameters from gravity well

Destination Circumstances ( R )
-5 - Familiar Destination (negates other destination circumstances)
+5 - Fringe/Frontier region
+5 - Deep Space (empty hex)
+10 - Uncharted region

Other Circumstances ( C )
+15 - No Functioning Ship's Computer
+5 - Rushed, under fire
+5 - per month past annual maintenance
+5 - Using old Jump Tapes
-5 - Extra time taken for calculations and system cross-checks
-5 - Using a manual astrogation plotter to cross-check
-5 - Using recent Jump Tapes
+2 - Drop tanks used to fuel jump
+2 - per field repair since last annual maintenance
+1 - per major damage since annual maintenance
+1 - per rebuild of drive (as opposed to full replacement)


TRAVEL TIME CALCULATION
((( B + R ) - A

Base Time ( B )
147 hours

Randomizer Dice ( R )
roll 6d6

Astrogator's Modifier ( A )
This is the number the Astrogator's Jump Plot check succeeds by.

 

[tjoneslo]

I have a few questions about this:

Originally posted by Sir Dameon Toth:
This is what I've come up with for Plot Calculation and Travel Time. Hope it helps. You can drop the Distance Travelling and Rating of Drive if you'd like. It's not canon.

Dameon

JUMP PLOT CALCULATION
((( B + G + R + C ) X P ) / D ) X F )


Gravity Disturbance ( G )
+15 - less than 10 diameters from gravity well
+5 - less than 100 diameters from gravity well
+0 - more than 100 diameters from gravity well

Would you add any more modifiers to this category? (e.g. +30 for planetary surface).

Destination Circumstances ( R )
-5 - Familiar Destination (negates other destination circumstances)
+5 - Fringe/Frontier region
+5 - Deep Space (empty hex)
+10 - Uncharted region

Is there a +0 usual destination modifier?

While it may be clear to you what a "familiar" destination is, I'm unsure. Is the familiar to the astrogator on the ship, or to astrogators in general (i.e. a well travelled route)?

Other Circumstances ( C )
+15 - No Functioning Ship's Computer
+5 - Rushed, under fire
+5 - per month past annual maintenance
+5 - Using old Jump Tapes
-5 - Extra time taken for calculations and system cross-checks
-5 - Using a manual astrogation plotter to cross-check
-5 - Using recent Jump Tapes
+2 - Drop tanks used to fuel jump
+2 - per field repair since last annual maintenance
+1 - per major damage since annual maintenance
+1 - per rebuild of drive (as opposed to full replacement)

Where do you get the jump tapes? Is there a modifier for no jump tapes? In CT the few mentions of jump tapes were as a replacement for the Astrogator. Buy a jump tape, plug it into the computer and off you go. All of the complex calculations had already been done.

How long does the extra time for cross checks take?

I think the familiar system modifier is too large. I would go with a log jump count modifier for each jump route. For example, Astrogator plots a course between System A and System B 10 times, they get a +1 from now on. Do it 100 times and the bonus grows to +2. 1000 times and the bonus is +3.

 

[Spinward Scout]

Gravity Disturbance

Would you add any more modifiers to this category? (e.g. +30 for planetary surface).

I personally wouldn't. What's on there is canon and ties in with chance of misjump.

Is there a +0 usual destination modifier?

Not that I'm aware of. Familiar destination is just one that you've been to before as far as I'm aware. If it makes it make more sense to you, just make it +0.

Where do you get the jump tapes? Is there a modifier for no jump tapes? In CT the few mentions of jump tapes were as a replacement for the Astrogator. Buy a jump tape, plug it into the computer and off you go. All of the complex calculations had already been done.

How long does the extra time for cross checks take?

To be honest with you, Jump Tapes were from CT as far as I know. You can modify this to however it fits YTU. You can get Jump Tapes from the local TAS office, I think. Or maybe the starport has it. Personally, I always saw jump tapes as a replacement for the Generate Program. The Navigator still has to modify the results of the Generate Program for the current Jump. Generate just does the major calculations. I might be wrong on this. Can somebody double check that?

I've lost my Starship Operator's Manual, so I don't remember how long cross-checks take. It might be in the MegaTraveller Imperial Encyclopedia, tho.

Later,

Dameon

 

[Whipsnade]

Originally posted by Sir Dameon Toth:
+15 - No Functioning Ship's Computer

Dameon,

Nifty list. Consider it stolen!

I'll let some of the other stuff go; especially the various gravity and deep space modifiers that smack of requiring that a vessel contact a jump limit in order to exit jump space, but jumping without a computer?

Going by the explanations of space combat damage results, you can't jump without a functioning computer in CT, MT, TNE, T4, or G:T. Why can you jump without a computer in T20?


Have fun,
Bill

 

[Spinward Scout]

Maybe that should be changed to No Generate Program or Jump Tapes. I can't remember what web page I got some of this from. I worked it up just after T20 came out.

Glad you like it,

Dameon

 

[Whipsnade]

Originally posted by Sir Dameon Toth:
Maybe that should be changed to No Generate Program or Jump Tapes.

Dameon,

Now that's a delightfully fun/wonderful/different idea to spice up any personal TU! You're definitely firing on all cylinders with this thread.

You can't generate your own jump plot without a computer BUT you can jump if you have jump tapes!

I've recently been re-reading a lot of Andre Norton's old, old stuff. Got it from Baen's free library and its all good reading. I love the idea of jump tapes in CT and am sorry I didn't do more with them in my GMing days. Having a good number of merchantmen reliant on what are essentially a 57th Century equivalent of rutters leads to all sorts of fun and plots.

Thanks again!


Have fun,
Bill

 

[Spinward Scout]

You've got to read Star Rangers. Very Traveller-esque. Or at least I thought so. I never got to read any of her other stuff, tho. Not sure why since I really liked Star Rangers. Let me know what other ones you like so I can check them out at the library.

Dameon