Book 3: Scout - Terrapin Station Question

[EDG]

I have adopted a variation of EDG's/the GURPS rule: fusion power plants come with enough fuel for 200 years of operation (although for me there is a way to get fuel in and out). The power plant fuel has become fuel for manuever drives.

How? The usual reactionless M-drives just need power, that they can get from the fusion plant. So they don't need fuel of their own.

 

[captainjack23]

I have adopted a variation of EDG's/the GURPS rule: fusion power plants come with enough fuel for 200 years of operation (although for me there is a way to get fuel in and out). The power plant fuel has become fuel for manuever drives.

Ahhh ! I see. So....the fusion phase analyzer is used to invert the tritium to zero point phlogistem via a zero-point scalar electromagnetically induced Thiotomialine resublimation.

Excellent system.

 

[GypsyComet]

EDG is merely the loudest proponent of realistic fusion fuel rates at the moment. TNE (as in, an actual edition of Traveller) reduced power plant fuel requirements by two orders of magnitude almost 20 years ago.

 

[captainjack23]

EDG is merely the loudest proponent of realistic fusion fuel rates at the moment. TNE (as in, an actual edition of Traveller) reduced power plant fuel requirements by two orders of magnitude almost 20 years ago.

Good enough, but from what I recall, it also changed the M drive to reaction/HEPLAR,presumably to keep some continuity with ship designs that already had a bucket of H for the M drive in addition to doing away with reactionless drives.

I'm all in favor of some realistic description of the fusion plants -but as the rules stand now, it's the old standard. Nonetheless, I'm interested in Jame's solution becuase it moves the handwave to an already handwavy area: the M drive; and it doesn't require a change in the design sequence. As I see it, thats one less handwave to worry about.

So, seriously (well, sort of), Jame, do you have a rationale for the Hydrogen used in the M drive ? If not, well and good. Is it reaction mass, or somthing weirder -like, I don't know? Coolant for the Reactionless effector ? Perhaps food for the M-demon in the hamster wheel ?

 

[EDG]

Good enough, but from what I recall, it also changed the M drive to reaction/HEPLAR,presumably to keep some continuity with ship designs that already had a bucket of H for the M drive in addition to doing away with reactionless drives.

I don't know if people just have a blind spot here, but I'd swear that FF&S had rules for "traditional" Thruster Plates in it, as an alternative tech. IIRC they used 40MW per displacement ton? It was kinda hidden away in the rules, but it was there. Sure, the default technology was changed to HEPlaR but it wasn't the only option.


Either way, I don't see the point in sticking to the rules if they're just plain wrong. One ton of fusionable hydrogen isotopes will (realistically) keep a fusion reactor going for decades, period. If you want to keep the two week thing then say that it needs maintenance or flushing or whatever on that sort of timescale.

I can't see any reason for reactionless thrusters to require extra fuel tonnage either, since they draw power from the reactor (and even if you need more power for the drives, you just feed in a few more micrograms of hydrogen per second into the reactor).

Jump drives have that excuse of needing hydrogen for the jump bubble, which maybe works for the volumes involved (but then, it's not really a "bubble", because that just implies a hollow sphere... it's really got to be a filled volume of hydrogen around the ship, maintained for a week in jump), but AFAIK nobody's really calculated how many tons of liquid hydrogen convert into home many cubic metres of gaseous hydrogen that need to be replenished every second for about 15 million seconds.

 

[captainjack23]

Good enough, but from what I recall, it also changed the M drive to reaction/HEPLAR,presumably to keep some continuity with ship designs that already had a bucket of H for the M drive in addition to doing away with reactionless drives.

I don't know if people just have a blind spot here, but I'd swear that FF&S had rules for "traditional" Thruster Plates in it, as an alternative tech. IIRC they used 40MW per displacement ton? It was kinda hidden away in the rules, but it was there. Sure, the default technology was changed to HEPlaR but it wasn't the only option.

I haven't looked at FF&S in quite a while - and remember less of it. It was one of those "I can either learn this semester of Principle Components Analysis in grad school or FF&SE" kind of conflicts for brain space...

That said, granted they kept thruster tech, my main question is: did they have a use for the extra M drive Hydrogen ? Or did they just drop it ?

 

[EDG]

That said, granted they kept thruster tech, my main question is: did they have a use for the extra M drive Hydrogen ? Or did they just drop it ?

With HEPlaR the M-Drives used hydrogen as reaction mass, so it made sense to have hydrogen fuel being consumed there. But I don't recall seeing anything in the thrusters description that said that extra fuel was used for those.

 

[Jame Rowe]

I have adopted a variation of EDG's/the GURPS rule: fusion power plants come with enough fuel for 200 years of operation (although for me there is a way to get fuel in and out). The power plant fuel has become fuel for manuever drives.

How? The usual reactionless M-drives just need power, that they can get from the fusion plant. So they don't need fuel of their own.

In my house-rules, they do (this is a case of YMMV, I think :wink: ) - they're a very advanced reaction drive. Of course, I also like the hyperdrive rules, though for me they're the same size as jump drives; they also need fuel.

 

[DCAnsell]

In my house-rules, they do (this is a case of YMMV, I think :wink: ) - they're a very advanced reaction drive. Of course, I also like the hyperdrive rules, though for me they're the same size as jump drives; they also need fuel.

This is very interesting. Do you have any more details on the M-drives? I've been really considering shifting gravitics to something more along the lines of contragrav, in my game, along with artificial gravity and inertial compensation. On a starship, they'd be built into the hull cost, just to avoid having to worry about adding new equipment to keep track of.

Using your idea of power plant becoming M-drive reaction mass/fuel, I could keep using the stock ship designs as is, and assume that the fusion powerplants are being refueled as necessary during the annual maintenance. Or every tenth or twentieth, or whatever.

You could do the same thing with stock grav vehicles, using grav as contragrav, with motive thrust/power coming from advanced reaction drives or rotors or whatever is appropriate to the design.

 

[Jame Rowe]

The hydrogen is reaction mass, and the same tonnage provides enough reaction mass for four weeks of continuous thrust (it's sort of a no-radiation fusion drive; but as you can no doubt tell I haven't put much thought into actually describing it). Otherwise it works much as in the rules.

 

[DCAnsell]

The hydrogen is reaction mass, and the same tonnage provides enough reaction mass for four weeks of continuous thrust (it's sort of a no-radiation fusion drive; but as you can no doubt tell I haven't put much thought into actually describing it). Otherwise it works much as in the rules.

Would that be the same mass for one or two weeks of normal powerplant ops?

 

[BP]

...One ton of hydrogen fuel (the right isotopes) should be able to run a fusion reactor for decades. The massive fuel use in Traveller was rationalised (not particularly convincingly IMO) as hydrogen being used for jump bubbles, but if you just have a reactor on its own then you don't need to worry about that.

So that's were that silly 'jump bubble' dribble came in...

And I too have always (even in CT days) been bothered by the fusion fuel requirements. I rationalized that the fusion tech is not necessarily extremely efficient (or even self sustaining) - thus while past break even, a great percentage of the hydrogen generated power could be used to control and sustain the plant itself. This only works if you count the ready availability of hydrogen and enormous shipboard power requirements as determining factors. Qualifying shipboard power requirements really on becomes believable if the gravitics and M-drive somehow require significantly more power than the tech used in Grav-belts and G- vehicles. Again - these are just my weak rationalizations for broken Hard Sci-Fi.

Unfortunately, I feel that the Traveller game mechanics (frontier/colonial history style setting; fuel demands; gravity control) were initially met without regard to hard Sci-Fi - rather for desired effect. And this was not bad. The 'official' rationales tacked on later generally seem worse than having none (as they conflict with known science - at least without a rationalization there was no definitive conflict).

 

[GypsyComet]

I have no problem at all with the jump drive using huge amounts of hydrogen, "bubble filler" or not. Ripping holes in reality doesn't come cheap.

 

[BP]

I have no problem at all with the jump drive using huge amounts of hydrogen, "bubble filler" or not. Ripping holes in reality doesn't come cheap.

Me neither - the Jump drive can use all the H it wants - but the 'bubble filler' explanation rips a huge hole in Hard Sci-Fi believability and is definitely cheap.

 

[rust]

The 'official' rationales tacked on later generally seem worse than having none (as they conflict with known science - at least without a rationalization there was no definitive conflict).

Indeed, and this is one reason why I do not use the standard jump drive
in my setting - to me the "hydrogen jump bubble" makes about as much
sense as a means to enter jumpspace / hyperspace as a cup of clotted
cream or a geranium pot would do.

 

[BP]

... to me the "hydrogen jump bubble" makes about as much
sense as a means to enter jumpspace / hyperspace as a cup of clotted
cream or a geranium pot would do.

Hey - can I use that - you don't have any special license on that one do you?

Darn it Joey - we need to jump now! - where'd that cream go!... cut to Joey spilling coffee down front side...

 

[rust]

Hey - can I use that - you don't have any special license on that one do you?

With the sole exception of my name you can use whatever I post. :lol:

 

[Jame Rowe]

Would that be the same mass for one or two weeks of normal powerplant ops?

Yes. Yes it would. I dislike how they changed that, so I decided to change it back. :twisted: