Just how does a Jump Drive work re: Power/Fuel

[DickNervous]

I think the distinction he is making is the difference between the Jump Drives using the fuel directly in some way, versus the Power Plant using the said fuel at a high consumption rate in order to power the drive.

That actually sums it up better than I did, thank you.

If the Jump Drives get power from the Power Plant, then the amount of fuel needed to execute a jump is directly related to the efficiency and type of power plant you have.

On the other hand, if the Jump Drives actually consume the fuel directly (and have their own specialized reactor in them) then the it doesn't matter what your power plant is. However, if this is the case then why would be required (in CT and MgT1/2) to have a Power plant the same, or larger, class as the Jump Drive? After all, if the jump drive provides it's own power, couldn't a ship with a Class A M-Drive and Class C J-Drive have a Class A Power Plant?

 

[kilemall]

Could be the jump drives need BOTH- the fuel feeds the superreactor and/or bubble/jump maintenance, the power plant powers the jump drive to keep the superreaction sustained, and if you drive it all off the jump superreactor you have to use that much more initial fuel.

Then the tradeoff is saving expense on the plant and it's fuel vs. not having that power when you need it for maneuver and weapons.

The capacitor timing explanation just means some folks would go looking for more stable batteries. A 10 EP per ton battery set would like do just fine for a low power plant/battery hybrid setup.

Which suits me just fine, more engineering drama.

 

[aramis]

Could be the jump drives need BOTH- the fuel feeds the superreactor and/or bubble/jump maintenance, the power plant powers the jump drive to keep the superreaction sustained, and if you drive it all off the jump superreactor you have to use that much more initial fuel.

Then the tradeoff is saving expense on the plant and it's fuel vs. not having that power when you need it for maneuver and weapons.

The capacitor timing explanation just means some folks would go looking for more stable batteries. A 10 EP per ton battery set would like do just fine for a low power plant/battery hybrid setup.

Which suits me just fine, more engineering drama.

The bubble theory can be nullified by the stated fact that an antimatter plant ship can operate without hydrogen fuel, albeit at high expense in fuel. (A 5 year slug for the PP is one jump... similar relationship in TNE and T4 for hydrogen use. ) Mega and T20 don't allow jumping on pure antimatter, tho'.

 

[phavoc]

As I recall, CT had the powerplant rapidly using up all the fuel to power the jump drive (old-school Lanthanum grids). The old SOG had an image of a Free Trader with grid lines on it as it was phasing into, or out of, jump.

If you had Black/White globes you could use the power generated by the shield absorption to also power your ship and your jump drive.

So it used to be the hydrogen was simply the method by which the power was generated.

And then along came MGT, which changed it to the hydrogen was utilized to build a exotic bubble universe that after it decayed you popped back into real space. No lanthanum grids required, or zuchai crystals I guess.

And now we have a new variations on the old themes. It still kind of comes down to two distinct models - one where the jump is powered by something, and the other where you have the jump bubble. Accumulators have appeared in MGT 2nd edition, but that's kind of breaking the old canon rule of hydrogen being the primary method by which the jump bubble is created. I suppose they sidestep that oversight by having the accumulators collect 'exotic particles' from space....

Personally I prefer the power to the jump drive model. This allows you some variations (such as having capacitors power it), and doesn't deviate from previous materials.

 

[BlackBat242]

I've never seen a PP requirement for Jump drives. TNE doesn't have one, HG doesn't have one. Can't speak to MgT[12]

CT Book 2 Starships (1981 edition): page 13

A starship must have a jump drive and a power plant; a maneuver drive may also be installed, but it is not required. In all cases the power plant letter must equal or exceed either the maneuver drive letter or the jump drive letter, whichever is higher.

CT Book 5 High Guard (1980 edition): page 22

All ships require power plants.
.....
On any given ship the power plant number must at least equal the jump number or the maneuver number, whichever is higher.

 

[aramis]

the only edition which doesn't require a PP is CT 1E, and only if you don't have High Guard. But even there, if it goes anywhere, it logically should.

CT HG -80 requires it as noted above.
CT-79 has the following, which implies a requirement to have an MD, and thus a PP:

Initially, a hull is selected, and a configuration specified; either built-up metal hulls or hollowed-out asteroids or planetoids may be used. Maneuver drives, power plants, and jump drives are selected; planetary navies need not install jump drives, but may elect to do so. (HG-79, page 21)​

Note that it makes the JDrive explicitly optional, but as worded requires an MD and a PP be installed.

MT requires a PP, but not matched to the JD, in order to provide computers, controls, and LS.

Ibid TNE, T4.

GT abstracts the PP into the modules... but actually notes that there is a PP and it's needed for everything BUT the jump drive.

T20 is essentially CT HG-2003...

MGT 1E requires a PP mated to the rating of both JD and MD... easiest quote is from the design checklist.

Choose a Power Plant, ensuring that it can provide enough
power for the Jump and Manoeuvre Drives. (MGT 1E, p105)​

 

[Brandon C]

It is clear, though, that a jump requires a great deal more of fuel than a power plan consumes for routine operations. I am not opposed t the idea of a jump drive with an antimatter powerplant using antimatter rather than liquid hydrogen, but it should use a great deal of antimatter to initiate the jump and the various Traveller rules sets have no "tons equivalent" for fuels other than liquid hydrogen.

 

[whulorigan]

It is clear, though, that a jump requires a great deal more of fuel than a power plan consumes for routine operations. I am not opposed t the idea of a jump drive with an antimatter powerplant using antimatter rather than liquid hydrogen, but it should use a great deal of antimatter to initiate the jump and the various Traveller rules sets have no "tons equivalent" for fuels other than liquid hydrogen.

It can also be said that Antimatter power is a revolutionizing technology, and that you can therefore get many more jumps/hops, etc. out of an equivalent volume of antimatter as compared to LHyd fuel. That perhaps is one of the things that will give the Galaxiad/M:1900 era a different look and feel to the M:1100 era, as the galaxy is vastly opened up.

 

[whartung]

In HG Jump drives do not require energy points, while most every other system on the ship does. So, while perhaps the ship has some arbitrary power plant requirement, the Jump drive does not, apparently, put any load on the power plant.

In TNE, the Jump Drives do not have a megawatt rating either.

 

[mike wightman]

If you mean CT HG2 there is this little passage:

Jumping: A ship which breaks off by jumping must have a destination and
enough fuel to get there. It must expend energy points equal to two turns output
from a power plant whose number is equal to the jump being attempted (EP
required = O.O1MJn). If it can do this in two turns, it jumps at the end of two turns.
If it can do this in one turn or less, it jumps at the end of one turn (in the pursuit
step). A ship which cannot summon the required energy in two turns may not jump
at all.

 

[Condottiere]

Apparently, jump capacitors can only retain the charge over two turns.

Wonder if Mongoose plans to incorporate this feature.

 

[Claretcraig]

Power Plant is the initiator that enables the jump drive to kick in (as well as do the mundane things like life support, ships power, lighting, recycling, etc) and use all the fuel in one hit to make the required jump distance. That makes having a power plant AT LEAST equal to the jump rating essential.

 

[phavoc]

It used to be that power, from any source, was required to power the jump drives. Then it became an issue of having a power plant equivalent to your jump drive number to power it. The jump fuel was burned at the time of jump in a very rapid fashion to generate enough power to cycle your jump drive (later we got lanthanum grids and zuchai crystals as part of the overall jump tech). You could also, if you had one, use your black globe generator to take enemy fire, absorb the energy and shunt it to your jump drive for a free jump (power wise at least).

These rules stayed more or less true till MGT came around. Then the jump tech was changed to a jump bubble, and your hydrogen was used to create exotic particles that created a pocket universe through which you moved through space. Same basic idea, just implemented differently. Which caused some headaches when they re-released some older material the described jump in the CT/MT fashion.

Annic Nova-style accumulators were alien tech, and stepped around the issue with alien tech! It was just supposed to be a one-off, so easily discarded.

I know T5 uses some other tech, but I haven't gotten into it that much to offer more of a comparison. I'm not sure if the various jump techs consume different amounts of fuel, or they are just variations on the same theme.