Afternoon from WA Phil,
On Thursday, June 18, 2020, 09:59:23 PM MST, Rupert Boleyn <xxxxxx@gmail.com> wrote:
On 19Jun2020 1606,
xxxxxx@gmail.com wrote:
> Even in MT, they are mentioned in text and on a table, but there's no
> detail of whether fuel goes into the main fuel tank (and the main fuel
> tank feeds the jump drive)... or for that matter how the Jump Drive
> consumes the fuel - all at once? in a metered way? How long does that
> take?
As far as I'm concerned, it's 'all at once', or nearly so. We know jump
tanks work. We also know that there's no requirement to have any extra
tankage on board, and that the jump drive's volume is very small
compared to the fuel used (so it can't be stored there). So it's all
used in some way in that short time between jump initiation and actual
jump. IMTU some is used in a really inefficient fusion process to power
the system, more is used as coolant, and most goes into creating a 'jump
bubble' for the ship to sit in during jump.
On jump exit the burst of hot hydrogen from the bubble bursting back
into normal space-time is one of the signatures of a jump emergence (the
other main one is the sudden gravity wave from a massive object suddenly
coming into existence where there was nothing before). Analysis of how
much hydrogen there is and how hot it is can give insight into the size
of the ship and how far it came (especially if you've also got data of
the gravity spike).
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hasn't there also been mention of "charging the jump capacitors"?
GDW JTAS 2 1979 p. 14 mentions "...Commercial vessels equipped with the new generation of long-storage jump capacitors carry jump fuel in specially designed L-Hyd drop tanks in excess of their rated tonnage. Upon conversation of the fuel to the massive energy required for jump, the drop tanks are explosively jettisoned through the use of break-away connections and explosive bolts. Jump is executed when the remains of the tanks are a safe distance from the vessel."
I'd be much happier with this quote if the words 'long-storage' were present. It seems like the time you actually store the power is very short. That would not merit 'long-storage' and if they were 'long-storage', would I not use them to dump Black Globe energy into or to have on-hand power for emergency evasion or any other number of things?
I think the passage is fine without the 'long-storage'.
GDW JTAS 6 1980 p. 5:"...Less than a month ago, the 800 ton liner Trimkhana Brilliance was lost with 217 lives due to a jump capacitor discharge immediately prior to jump. While the four survivors of the disaster are still under intensive medical care, interviews with the one surviving crew member indicates that the capacitor discharge may have been do to a delay in jump after full charging due to a failure of the port side L-Hyd drop tank to separate completely...."
And this one seems to suggest they aren't long-storage because the delay may have caused the unplanned discharge event.
GDW JTAS 24 1985 pp. 34-38 has the article on Jumpspace by Marc W. Miller. Under the section of Required Items on p. 35 "Energy Storage Nodes: Once power is generated, it must be stored until the instant of jump. Capacitors or fast-discharge batteries fit this requirement...."
My opinion is that the this is "charging the jump capacitors."
Okay, that process is still a magic black box (because it obviously is consumed at a rate that FAR, FAR, FAR exceeds normal power plant consumption rates). That's not 100% satisfactory, but putting some 'handwavium' in here to explain the magic of super fast 'poof' - fuel gone now - is I suppose okay. You'd need more 'handwavium' to explain why this isn't used more generally though.
ISTR also a mention the the jump drive includes a special purpose power plant that, somehow, manages to convert all that fuel w/i a very short period of time.
In CT LBB 2 1977 the power plant type letter had to be at least the same as the maneuver drive. My conclusion was that the jump drive was a specialized power plant.
That's a very odd requirement.
MT Referee's Manual 1987 p. 58 "...Jump drives are themselves a special high-yield power plant linked to an integral net in the craft's hull for initiating and maintaining a jump field. Because a jump drive is also a power plant, it must be allocated fuel separate and distinct from the craft's power plant...."
Tom Rux
If I WERE FIXING THIS (and not worried about all details of canon, including the somewhat contradictory ones):
1. Jump fuel would be more like the amount needed in MT. That could be split between more living space (so people can survive a lifetime of banging around trade lanes without going crazy) and more cargo capacity (or other interior appointments) which might make smaller ship trade more viable.
2. Jump modules and their attached fuel tankage would really be one unit, just existing separately just to allow differing fuel loads for any given jump module install. The two would work together and the fuel tankage would not be part of larger non-jump fuel (Plant/M-Drive fuel) although probably some transfer piping would exist for emergency pump-overs.
When the jump engine was energized, it would create a containment field for the fuel and then trigger a field effect that quickly (as fast as instant or as slow as a few mintues) convert the J-fuel to power stored in the zuchaii crystals. Those are effectively the 'jump capacitors' and the risk of an accidental discharge increases with the length of hold time so generally you go quickly from fuel conversion to jump. (And if I were looking for a place to make small ships more common than big, I'd say the net amount of fuel involved would also increase the odds of an accidental discharge.)
3. The Jump drive is not formally a power plant. It is an energy conversion system and a jump interface generator.
4. M-Drive and plant fuel would be contained in more mundane storage. There would be no M-drive requirement for J-Drives.
5. The reasons that the high-storage capacitors are not used elsewhere are several-fold: Limited supply of zuchaii crystals, cost of zuchaii crystals and thus of jump drive modules, the instability of zuchaii crystals that are highly charged (time from conversion to use is normally a matter of minutes at most, often seconds) and if you try to hold anything longer, their instability is a big risk which is deemed inadvisable in other ship's system (Jump systems are the only game in town to move strategically at decent speed, so they must be suffered in that role).
6. The Lanthanum grid is part of how ships jump and it forms a field essentially conformal to the ship (as a rule, it can be adjusted in case a space walk is needed in Jump though that's a dangerous operation at best!).
7. Drop tanks for regular M-Drives would be just simple outside fuel storage. For Jump Drives, they would be more expensive units because they would substitute for the internal J-fuel tankage and thus have the same field creation bits in their construction (you want to recovery these as they are expensive!).
Now, could you use regular drop tanks for Jump? Yes... but...
Yes you can, but it works best on ships that are using it for limited fuel volumes because a) they would face less risk of holding their capacitors at full charge for a bit longer than a larger ship would and b) you could more feasibly pump fuel rapidly into the main tanks in that extended window. The larger ships would be screwed in two ways: Larger ships have shorter hold times and they need to transition a LOT more fuel for larger hulls and generally longer J-legs. A big battlewagon will thus tend to use the specialized 'Jump Drop Tanks' that are pricey so they can get the full benefits. But smaller ships can use the more mundane tankage and hold their caps at full charge longer and still not blow up.
That's my solution.