mike wightman
SOC-14 10K
Yup, Traveller has needed an explanation of heat dissipation for a long time now. There is an actual canon reference to the heat radiator fins on the AHL.
Resource Scarcity in the Far Future
- Thread starter Bartleby
- Start date
Badenov
SOC-12
Using the helium to dump heat is a very clever and useful idea. I like it!Point of order ... space (vacuum) is a notoriously poor heat sink to dump thermal loads into.
Just a reminder.
Actually, the helium would be useful for a variety of things, including thermal transfer. Heat the helium up and dump it overboard.
High energy uses of this sort of thing would amount to HEPlaR maneuver drive types of reaction thrust propellant gas applications.
Low energy uses of this sort of thing would functionally be a means of waste heat rejection out of the craft (via venting of helium).
And let's not forget that helium has its uses as a refrigerant working fluid for things that need to be kept cold.
So although the helium would "not be useful" in the power plant for fusion reactions, there are plenty of OTHER uses that skimmed helium could be put to if it can be separated out from gas giant atmospheric gases by a refining process onboard. Have engineering, will travel(ler).
mike wightman
SOC-14 10K
A great big cloud of expanding hot helium gas ends the stealth in space argument I suppose 
A great big cloud of expanding hot helium gas ends the stealth in space argument I suppose
But, your ship could be stealthily obscure within the volume of the big expanding cloud of hot helium . . . .
(posts quoted as representation of others too)
Please stop this kind of condescendent/pedantic/insulting posts. This kind of comments insinuating (if not outright saying) the other one is stupid, has low understanding capacity, or anything like it will no longer be tolerated, and we will enforce rule 1 without the slightest tolerance from now on
A mol is the expression in g of the atomic/molecular mass.
As the atomic mass of hydrogen is 1, each ton (14 kl) of Lyd has 1 million mols of hydrogen atoms (half a million of molecular hydrogen, as it is diatomic).
So a liter holds 1000000/14000, so 71.43 mols of atomic, or 35.71 mols of molecular hydrogen
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From MT;RM, page 83 (ITTR CT had something like this, but I was unable to find it):
So it seems the volume they need when empty is considered irrelevant...
Not clear... I guess the one that simplifies rules (but that's only my guess)
Yup, sort of. Reality says YES. FUSION PP says "maybe". [like FTL Travel]
We shouldn’t ask if jumpspace is an insulator or can accept radiated heat. Ugly weirdness either way.Yup, sort of. Reality says YES. FUSION PP says "maybe". [like FTL Travel]
Ammonia and water would have nitrogen and oxygen as waste products from fuel purification, so you could have smaller tanks for processed LH2, O2, and N2, and wouldn't need bulk high pressure/cryogenic vessels for LH2 (which can pass through a lot of materials under pressure).
Note that ammonia vented into a breathable atmosphere would produce ammonium hydroxide which is corrosive and inimical to human life. Maybe the NH3 storage tanks are behind a bulkhead and vented to vacuum, or external. Or maybe we stick with H2O.
Ammonia and water seem like really good things to round up in-system when you're scavenging CHNOPS for a station or colony.
Why wouldn't 3cm be enough? Maybe it's too much? Isn't this 'supposed' to be some kind of amazing technology in the Far Future of the Traveller universe?
Collapsible Fuel Tanks are a part of the Far Future of Traveller. Now, for some reason, they are mentioned in T20, but with no details. I eventually looked in the Traveller Wiki and decided to use the info there. Not only that, but originally, I didn't really care about them, but @Spinward Flow used them in so many of his multipurpose star ships threads that I wrote up a few of my own. They're not for every ship, but a good option for those that could use them.
I bet there are some Prospecting ships that have Collapsible Fuel Bladders so they can get to some difficult to reach place that has some small amount of raw scarce resources.
Spinward Flow
SOC-14 5K
Being able to double jump is just TOO USEFUL of a capability!
I would argue that the LBB S7 Type-J would be better off with collapsible fuel tanks rather than the internal demountable tanks that actually got used in LBB S7. Being able to "flex" 10 tons of cargo hold in/out when needed would be quite the awesome thing to do. After all, you hardly need a J2 worth of fuel "in reserve" while prospecting, most of the time.
Flipside to that is that the Type-J "kinda obviously" wants to be crewed by 2 shift of 2 people each (total: 4 crew). That way you can do the "belter life" of 12 hours on/12 hours off with shift crews of 2 on an infinite rotation (until life support and fuel reserves are exhausted and you have to return to base).
Right.
And if you look at the drive mishap rules (separate from the misjump rules) in LBB2 2nd edition, they clearly go back to 1st edition, as any drive can be broken by unrefined fuel, including the maneuver drive. (How could that happen if it's a grav drive rather than a "rocket exhaust nozzle" for the power plant anyhow? It'd never be directly affected by fuel quality in that case!)
Can't go below 30Td in hard tanks if it is to jump at all, and all 40Td must be in hard tanks to enable J2, per R.A.W. (must have 20Td for power plant, plus jump fuel). No, I don't like it either.
With the TCS/JTAS#14 power-down rule available, 20Td hard-tanked fuel allows J1/1g/Pn-1.
[Edit: just devil's advocating, here ]
On the other hand, 30Td tanks do allow J1/1g with up to 100Td of external cargo (elaborate sacks full of rocks?) because the Pn drops to 1. Go figure.
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Badenov
SOC-12
How can either drive be affected by impurities in the fuel when only the power plant touches the fuel? The RAW are misleading because there's a bit that says 'Ships in Traveller use the same fuel – hydrogen – to power both the Jump drive and the power plant –' (LBB5 has a very similar quote) implying that the J Drive does something with fuel on its own rather than accumulating power from the power plant, but if that were the case, it wouldn't matter if you had a power plant that had a smaller rating than the jump drive, but it's a requirement that the power plant is a minimum of the greater of the M-drive or the J-drive, so in either case, the PP must supply all the power. There is a quote later in MgT1 that says 'A Jump drive requires a tremendous amount of power to function which must be supplied by the ship’s power plant,' which confirms this is the case. I don't have all the LBBs so I can't compare.
I am assuming then (in both cases), the vulnerability is due to the uneven power availability. When the plant sucks in something other than hydrogen, the power output falls until there is no more non-fuel getting sucked into the power plant. The unsteady energy build then must be the cause of misjumps (if you fail the roll to jump with unpurified fuel) and (in that version) apparently also results in premature wear on either drive, which makes as much sense as anything, though I would offer a capacitor to even those vagaries out rather than allowing the systems themselves to degrade. Or maybe it's the capacitor that degrades, but the engine can't run without that protective capacitor in place.
Older US Navy gear had protective circuits, and a switch called "Battle short" which in an emergency would allow you to bypass the protection and keep running, though that would damage the gear.
Condottiere
SOC-14 5K
Has anyone considered fuel grades?
mike wightman
SOC-14 10K
In CT 77 the power plant is implied to be a fusion power plant, the maneuver drive is a reaction drive (in 79 high guard confirmed as a fusion drive) and of course the jump drive requires fuel.
By the way nowhere in LBB:2 77 does the word hydrogen appear, so the "fuel" could be something other than liquid hydrogen.
We are told that the power plant uses fuel, the jump drive uses fuel, we are not told these two types of fuel are the same.
We are told that unrefined fuel can cause any of the three drives to fail.
We are told that military and paramilitary drives can be made rugged enough to use unrefined fuel (no cost increase, no size increase, just referee declaration).
By the way nowhere in LBB:2 77 does the word hydrogen appear, so the "fuel" could be something other than liquid hydrogen.
We are told that the power plant uses fuel, the jump drive uses fuel, we are not told these two types of fuel are the same.
We are told that unrefined fuel can cause any of the three drives to fail.
We are told that military and paramilitary drives can be made rugged enough to use unrefined fuel (no cost increase, no size increase, just referee declaration).
I have never read the 77 version, but I guess if it also allowed frontier refuelling ,in GG or oceans, this implies the fuel is hydrogen, even if not explicited...
mike wightman
SOC-14 10K
There are other substances that could be extracted from skimming a gas giant --> deuterium, helium3, even antimatter.
'77 doesn't mention fuel scoops either.
'77 doesn't mention fuel scoops either.
