Traveller: Jump Drive

[Steve]

This is my attempt at putting together a write-up for a Traveller Jump Drive. It actually works pretty well to model in Hero with the intersteallar hex mapping. I'm Megascaling it up to 1"=1 parsec instead of 10 LY/inch, which works quite nicely with Traveller scaling.

 

Jump Drive-2: Teleportation 2", MegaScale (1" = 1 parsec; +3 3/4) (19 Active Points); Extra Time (1 Week, -4 1/2), Increased Endurance Cost (x6 END; -2 1/2)

 

Am I missing anything? I'm also wondering if it would be book legal to take a separate Extra Time Limitation and use that to show the time needed to get the drive ready to enter Jump Space.

[Yansuf]

Re: Traveller: Jump Drive

 

As I remember Traveller (it's been years) I thought that the time required (1 week) was the time to prepare the jump; that the jump itself took negligible time.

[Peregrine]

Re: Traveller: Jump Drive

 

You misremember. A week (+/- a few hours) is spent in jumpspace.

[Nyrath]

Re: Traveller: Jump Drive

 

As I remember Traveller (it's been years) I thought that the time required (1 week) was the time to prepare the jump; that the jump itself took negligible time.

That turns out not to be the case.

 

Regardless of the distance of the jump, the ship spends about a week in hyperspace.

[shadowcat1313]

Re: Traveller: Jump Drive

 

Its a bit variable, 1 week give or take a few hours, if your off in travel time more than a day either way, you know you have probably misjumped, which presents a whole new set of problems.

 

heres one of the experimental builds for a traveller jump drive we've tossed around for the Traveller Hero book

 

8 1) Jump Drive-3: Teleportation 9", MegaScale (1" = 1 lightyear; +3 1/2) (81 Active Points); Extra Time (1 Hour, -3), 1 Charge which Recovers every 1 Week (-2 1/2), OIF Immobile (-1 1/2), Side Effects (Side Effect affects both character and recipient of Power's benefits; can cause misjump or damage to ship on failed skill roll; -3/4), Requires A Skill Roll (-1/2), Crew-Served (2 crew; -1/4), Difficult to Operate (-1/4) [Notes: Jump-3]

 

this may very well not be the final version, whats written above was fitted to a Broadsword class Merc Cruiser

[Manic Typist]

Re: Traveller: Jump Drive

 

Should it be a Bulky Focus? Or would that be inappropriate?

[shadowcat1313]

Re: Traveller: Jump Drive

 

I built it as immobile, its not going anywhere different on the ship, and with the accompanying fuel tankage, its pretty much hardwired

[AlHazred]

Re: Traveller: Jump Drive

 

Speaking of which, from a GMing perspective, what does Jump Space look like from the inside, canonically? I mean, I can make something up, but I'd like to know what other people have used, and why.

 

Just blank black space seems kind of dull and anticlimactic...

[Basil]

Re: Traveller: Jump Drive

 

This is my attempt at putting together a write-up for a Traveller Jump Drive. It actually works pretty well to model in Hero with the intersteallar hex mapping. I'm Megascaling it up to 1"=1 parsec instead of 10 LY/inch, which works quite nicely with Traveller scaling.

 

Jump Drive-2: Teleportation 2", MegaScale (1" = 1 parsec; +3 3/4) (19 Active Points); Extra Time (1 Week, -4 1/2), Increased Endurance Cost (x6 END; -2 1/2)

 

Am I missing anything? I'm also wondering if it would be book legal to take a separate Extra Time Limitation and use that to show the time needed to get the drive ready to enter Jump Space.

 

I think going to parsecs is better than staying with lightyears.

 

No, I wouldn't say a second XTime; put in a limit that you have to be X distance from any sizable body, and the getting to there will cover the time problem.

[BigJackBrass]

Re: Traveller: Jump Drive

 

Speaking of which, from a GMing perspective, what does Jump Space look like from the inside, canonically? I mean, I can make something up, but I'd like to know what other people have used, and why.

 

Just blank black space seems kind of dull and anticlimactic...

 

Your avatar might be a good look for it

[assault]

Re: Traveller: Jump Drive

 

Speaking of which' date=' from a GMing perspective, what does Jump Space look like from the inside, canonically? [/quote']

 

I don't think there is a canonical statement about this, but there was a novel published back in the early 90s that had a description of J-Space, IIRC. Of course I don't have it handy...

[Sir Ofeelya]

Re: Traveller: Jump Drive

 

I seem to remember reading that it was like a grey bubble with nothing to see, so viewports of ships in jumpspace were covered. There are canon references to people coming into contact with jumpspace, and at least one of someone surviving the experience.

 

As far a ships go for Hero:Traveller, I have never felt the need to redsign them under the Hero Rules. I use my High Guard designs and also High Guard for ship combat. I make PCs make appropriate Hero system skill rolls (for instance, Gunner or Pilot) and apply the results as a +ve or -ve DM on the basis of +/-1 per 2 pts the roll was made/failed by.

[Steve]

Re: Traveller: Jump Drive

 

Its a bit variable, 1 week give or take a few hours, if your off in travel time more than a day either way, you know you have probably misjumped, which presents a whole new set of problems.

 

heres one of the experimental builds for a traveller jump drive we've tossed around for the Traveller Hero book

 

8 1) Jump Drive-3: Teleportation 9", MegaScale (1" = 1 lightyear; +3 1/2) (81 Active Points); Extra Time (1 Hour, -3), 1 Charge which Recovers every 1 Week (-2 1/2), OIF Immobile (-1 1/2), Side Effects (Side Effect affects both character and recipient of Power's benefits; can cause misjump or damage to ship on failed skill roll; -3/4), Requires A Skill Roll (-1/2), Crew-Served (2 crew; -1/4), Difficult to Operate (-1/4) [Notes: Jump-3]

 

this may very well not be the final version, whats written above was fitted to a Broadsword class Merc Cruiser

 

Part of the reason I went to 1"/parsec is because there are 3.26 light years in a parsec, and it was easier to work with the given Traveller jump drive ratings in Hero measurements that way. When I was running the numbers using inches as light years, the numbers I was getting were Jump-1 as 3", Jump-2 as 7" (6.52 lightyears rounding up to 7"), Jump-3 as 10" (9.78 light years rounding up to 10"), etc. I just finally said, screw it, an inch is a parsec, and the math worked fine. It was also cheaper points-wise to do it that way, an added bonus.

 

So setting up for a jump takes an hour? No Millenium Falcon style escapes then. I thought it was a faster process, but my memory is from games long ago.

 

The choice of one recoverable charge taking a week to recover is an interesting design. I didn't consider that one, but it kind of makes sense. My understanding of misjump is that it is a random thing not tied to skill rolling in Traveller, since in Traveller it occurs on a 2 on 2d6, modified by using unrefined fuel and other things. Maybe give the drive a 5- chance of misjump as a Limitation instead of tying it to a skill roll? A failed skill roll would then act as a modifier to the misjump chance.

 

Should the drives be able to scale down? I thought I read somewhere that you could jump much shorter distances that would still take a week to do, but the 1 parsec per drive rating number was the maximum.

[Eodin]

Re: Traveller: Jump Drive

 

Yes, jump drives can do a mini-jump within system. the rating is simply the maximum.

in large systems, a mini-jump may take less time that a 1G trip.

[Sir Ofeelya]

Re: Traveller: Jump Drive

 

Yes, jump drives can do a mini-jump within system. the rating is simply the maximum.

in large systems, a mini-jump may take less time that a 1G trip.

 

Nope. In Traveller Canon a mini-jump still takes a week plus/minus a few hours.

[Eodin]

Re: Traveller: Jump Drive

 

Sorry,

what I meant was that a mini-jump takes a week like a regular jump. It's just that the same trip at 1G may take more than a week.

[assault]

Re: Traveller: Jump Drive

 

No setting up for a jump takes an hour? No Millenium Falcon style escapes then. I thought it was a faster process' date=' but my memory is from games long ago.[/quote']

 

Millenium Falcon escapes can still happen. The "traditional" Traveller version is the run to the 100 Diameter limit, with everyone and their dog shooting at you. Usually all the jump preparation stuff happens while you are doing this.

 

As soon as you feel that the risk of misjump is less than the risk of being blown out of space, you jump...

 

It's been a long time since I've done one of these.

[Steve]

Re: Traveller: Jump Drive

 

I was reading in one of the BITS supplements (101 Religions) that there is a cult that worships jumpspace as being the naked face of God or somesuch. So they'll get drugged up and stare out open portals at naked jump space for hours on end. They also have their own ships, described as having a disturbingly large number of portals for viewing.

 

I'd forgotten that the jump drive has only one charge before needing to refuel. That sure makes scouting a new system a really risky enterprise. No gas giant or water world in the system, and you're stuck there.

 

Since the ships have fusion power plants, I'm wondering if an END reserve that gets mostly drained by a jump (leaving a little to run electrical power out to other systems) might better represent fuel reserves. I was thinking of having one main END reserve that represents overall fuel for the ship, and a second one for electrical power that is linked to the first. That second one would generate power for the ship's other systems, but costing END off the main END reserve in order to run.

[Nyrath]

Re: Traveller: Jump Drive

 

I'd forgotten that the jump drive has only one charge before needing to refuel. That sure makes scouting a new system a really risky enterprise. No gas giant or water world in the system, and you're stuck there.

 

Since the ships have fusion power plants, I'm wondering if an END reserve that gets mostly drained by a jump (leaving a little to run electrical power out to other systems) might better represent fuel reserves. I was thinking of having one main END reserve that represents overall fuel for the ship, and a second one for electrical power that is linked to the first. That second one would generate power for the ship's other systems, but costing END off the main END reserve in order to run.

 

Greg Costikyan did some calculation, and came to the alarming conclusion that with the smallest power plant used for starships, a single jump in Traveller uses about 160% of the energy the US produces in a single year.

 

http://www.costik.com/inttrav.html

[assault]

Re: Traveller: Jump Drive

 

I'd forgotten that the jump drive has only one charge before needing to refuel. That sure makes scouting a new system a really risky enterprise. No gas giant or water world in the system' date=' and you're stuck there.[/quote']

 

It's possible to build ships that have enough fuel for two or three jumps. Furthermore, aside from the very early silliness about "jump governors", it is usually assumed that ships jumping a shorter distance use less fuel than ships jumping their full distance. That is, a ship doing a J-1 uses less fuel than an identical ship doing a J-2. (In-system jumps count as J-1.)

 

That means that a type S scout ship can do two J-1 without refuelling.

 

Incidentally, it seems unlikely that there would be many systems without any fuel source at all. "Gas giants and water worlds" aren't the only potential sources. Of course a lot of the others aren't necessarily conveniently located, but that's another story.

 

As an aside, Traveller's gas giant refuelling would probably be a pretty silly idea in the real world. Oh well...

[Steve]

Re: Traveller: Jump Drive

 

I think it makes more sense to me to build a ship as having enough fuel for at least 2-3 jumps before needing to refuel, especially after reading the article Nyarth referenced. Being able to make only one jump on a full tank seems way too limiting to me.

 

Gas giant refueling doesn't bother me that much, although it does pose a fair element of risk in getting that close to such a heavy gravity well.

 

Perhaps some heavily-travelled systems have orbiting fuel depots that skim gas giants for supplies of refined fuel.

 

One thing I thought was interesting when I read it was that the amount of hydrogen used is not just to provide power through the engines for a jump. Some of it is used to fill the jump bubble created during jump, gradually bleeding off and lengthening the time before the bubble collapses and drops the ship back into normal space. I think I read that in T4, but I know I read it somewhere.

[shadowcat1313]

Re: Traveller: Jump Drive

 

orbiting fuel depots/stations arent uncommon, especially on lower tech worlds that maintain a basic presence in space. the Hard Times book for Megatraveller discusses a fuel harvester craft.

[Sir Ofeelya]

Re: Traveller: Jump Drive

 

I'd forgotten that the jump drive has only one charge before needing to refuel. That sure makes scouting a new system a really risky enterprise. No gas giant or water world in the system, and you're stuck there.

 

Not at all risky. First off, you use your flash TL telescopes to scan the next system to see if there is a gas giant in system (wobbling stars and all that stuff). We can do that now from Earth.

[assault]

Re: Traveller: Jump Drive

 

I think it makes more sense to me to build a ship as having enough fuel for at least 2-3 jumps before needing to refuel' date=' especially after reading the article Nyarth referenced. Being able to make only one jump on a full tank seems way too limiting to me.[/quote']

 

A lot would depend on the purpose of the ship. Most merchant ships would be fine with just one jump's worth of fuel. It would be wise for Exploratory vessels, on the other hand, to be capable of more than one jump on a single load of fuel. Naval vessels would vary, but would generally be capable of higher jump performance than most merchant ships anyway. A J-4 ship can do two J-2s by default.

 

(Obviously when I am talking about "one jump's worth of fuel" I mean one maximum distance jump for the ship.)

 

Generally speaking, the cost of Traveller ships is heavily influenced by their tonnage. More fuel means more tonnage, which means a more expensive ship. Or, alternatively, it means a ship with less effective payload for its size.

 

Obviously, it's generally a good thing for a freighter to be able to carry as much stuff as possible, relative to its size. There are exceptions, but they are exceptions.

[tytalan]

Re: Traveller: Jump Drive

 

maybe an endurance battery with the limit can only be recharged by refueling than you could take in the fact that with a jump gov jumps shorter than max only use the app amount of fuel. many cannon ships did this like the fury class gunboat had a jump rating of 4 but could make multiple jump 1s if needed with out refueling.