Thoughts on refueling

phavoc

Emperor Mongoose
Pumping water into your tanks is pretty straightforward (as is getting raw or refined hydrogen straight from the tanker). So that leaves two methods that aren't quite defined - gas giant refueling and ice refueling.

The books have always stated that only streamlined or standard configurations may refuel from a gas giant (not to mention you have to have fuel scoops present). The assumption is (from my reading of the rules at least) that the ship has to drop down into the atmosphere of the gas giant to an altitude where the air pressure is undefined, and then using it's drives it flys through the atmosphere and 'scoops' up the gas, which is then cooled to a liquid format and stored in your fuel tanks. At some point your fuel purifiers can run the gas and 'refine' it to a more pure form.

But from what I can tell I can't find mention of much more information in any of the versions. I did find some interesting statistics across different versions regarding refueling:

T4 - 8hrs to skim fuel, regardless of tank size (4hrs in an ocean environment)
GURPS - 2hrs to skim fuel, regardless of tank size
MGT Core - 1-6hrs to skim fuel, regardless of tank size
MGT Starports - Ground fueling stations pump 60Dtons/hr

So we've got a wide spread for timing. There have been mentions of gas giant refueling and the hazards (pirates, SDB, the "high guard", mentions of the "danger") associated with this... but damn if I can find any more detailed information on what exactly constitutes the danger, how ships can lurk in the clouds undetected by sensors, why the ships are extra vulnerable doing refueling runs, etc.

Not to mention the HUGE potential variation in refueling times listed for MGT. Lets assume for a moment that pumping fuel from a tank is the most efficient way of transferring fuel. That seems a safe assumption to me because the fuel is already liquified and is simply being pumped. Doesn't get any more simpler than that. So if you were pumping 1,000 Dtons of Lhyd it would take 16hrs. But at MOST, refueling in a gas giant would take 6hrs. Those figures are wildly different.

I've got some ideas of my own but was interested in hearing what you guys think.
 
phavoc said:
Not to mention the HUGE potential variation in refueling times listed for MGT. Lets assume for a moment that pumping fuel from a tank is the most efficient way of transferring fuel. That seems a safe assumption to me because the fuel is already liquified and is simply being pumped. Doesn't get any more simpler than that. So if you were pumping 1,000 Dtons of Lhyd it would take 16hrs. But at MOST, refueling in a gas giant would take 6hrs. Those figures are wildly different.

Larger ships may have larger fuel scoops. But one would think they would also have more connections for fuel hoses.
 
"So if you were pumping 1,000 Dtons of Lhyd it would take 16hrs. But at MOST, refueling in a gas giant would take 6hrs. Those figures are wildly different. "

Assume first of all the ship dives into relatively dense atmosphere at very high speed so the gases are gathered and compacted quickly and these scoops are bigger relative to the size of the ship. The scoops aren't just gulping air, they pressurize it onto the tanks. Taking on water means cracking it to remove the oxygen component otherwise your tanks are mostly filled with 'waste', however, the material is denser to start. To keep it simple, the two processes can be considered comparable for game time. Ice refueling needs a ship's energy weapon to create a continuous pool of fluid to scoop.

The only reason I would think port refueling takes so long is safety. Hydrogen is very dangerous and the gear to transfer it must be built for extreme cold and hydrogen leakage. This isn't sticking a nozzle in a vehicle petrol tank. It could be comparable to fueling the tanks on a 21st century space vehicle.

"but damn if I can find any more detailed information on what exactly constitutes the danger, how ships can lurk in the clouds undetected by sensors, why the ships are extra vulnerable doing refueling runs, etc. "

The game doesn't get complex with such matters. The chaos of GG atmospheres especially with energy discharges (lightning) could causing jamming effects while flying through it. Not disabling but distracting. That chaos is also why there's a Pilot check during refueling.

Climbing up a gravity well is an energy strain. Fighter pilots of all eras will attest. A ship deeper in a gravity well should lose a maneuver action per combat phase to reflect this. This is why military (and possibly convoy) operations have ships guarding the highpoint while others refuel.
 
ShawnDriscoll said:
Don't most players fast-forward through this action anyway?

Time still elapses, and can have an effect on other events, like the closing or escaping of another ship, the alibi for a murder, the health of a passenger or live cargo...
 
AndrewW said:
Larger ships may have larger fuel scoops. But one would think they would also have more connections for fuel hoses.

They would have to, especially since their tanks are so much larger. And yes, I thought of that as well (i.e. multiple fittings). Though if we use our real-world examples of vehicles, that's usually not the case. An aircraft may have port and starboard fueling access points, but typically only a single one is used. Same goes for fueling rockets (though each tank usually has an individual fitting - Lox and Lhyd shouldn't be mixed except at the end...). Multiple places to refuel would require a larger ground crew.

ShawnDriscoll said:
Don't most players fast-forward through this action anyway?

Yes, most do. I'm one of those players that likes to know the background of things. Knowing the details lets me make better adventures or play better as a character. Plus, as I mentioned, there have been numerous references to the vulnerability a ship is placed in when refueling in a gas giant. But why exactly? We all could (and most do) fill in the blank with house rules, but when you have a gaming system then the ideal is to have a common rule upon which to modify or use as you choose.

Reynard said:
Assume first of all the ship dives into relatively dense atmosphere at very high speed so the gases are gathered and compacted quickly and these scoops are bigger relative to the size of the ship. The scoops aren't just gulping air, they pressurize it onto the tanks. Taking on water means cracking it to remove the oxygen component otherwise your tanks are mostly filled with 'waste', however, the material is denser to start. To keep it simple, the two processes can be considered comparable for game time. Ice refueling needs a ship's energy weapon to create a continuous pool of fluid to scoop.

The only reason I would think port refueling takes so long is safety. Hydrogen is very dangerous and the gear to transfer it must be built for extreme cold and hydrogen leakage. This isn't sticking a nozzle in a vehicle petrol tank. It could be comparable to fueling the tanks on a 21st century space vehicle.

Taking on gases from the atmosphere of a gas giant also means taking on impurities in the gas, and liquid at least will flow better through pipes without having to keep pressure baffles in place so a gas would not flow out. I don't know enough about the physics of gas vs. a liquid to state categorically which is easier to deal with. The liquid wouldn't need to be pressurized and liquified like the gas would.

Refueling is dangerous, but most risks can be reasonably mitigated with the proper equipment. The gear built for refueling need to be built no differently than what is present for gas giant refueling. I'm thinking the difference in fueling may lie in the same reason we see other differences in the books - different authors with different perspectives and no individual or group that is tasked with keeping things more or less the same. It's a problem that bedevil's all game systems. Some do a better job at it than others.



Reynard said:
The game doesn't get complex with such matters. The chaos of GG atmospheres especially with energy discharges (lightning) could causing jamming effects while flying through it. Not disabling but distracting. That chaos is also why there's a Pilot check during refueling.

Climbing up a gravity well is an energy strain. Fighter pilots of all eras will attest. A ship deeper in a gravity well should lose a maneuver action per combat phase to reflect this. This is why military (and possibly convoy) operations have ships guarding the highpoint while others refuel.

Ah, yes. Those hazards of refueling. The core rulebook states refueling requires 1-6hrs and requires a successful pilot check. Most failed pilot checks mean the action failed, some fail with dire results. But if you are fueling and you fail your pilot check it means.... what exactly? You just wasted 1d6hrs and you have to try again? There's no table of hazards or even negative effects associated with failing your refueling check. I'm just looking for some clarity and options here upon which to spring upon the unsuspecting player.

Thanks for the responses thus far everyone.
 
"Taking on gases from the atmosphere of a gas giant also means taking on impurities in the gas, and liquid at least will flow better through pipes without having to keep pressure baffles in place so a gas would not flow out. I don't know enough about the physics of gas vs. a liquid to state categorically which is easier to deal with. The liquid wouldn't need to be pressurized and liquified like the gas would."

PV=T is the Ideal Gas Law. Pressure, volume and temperature in relation. You make a gas liquid by reducing the temperature or increasing pressure. GG atmosphere is partially under high pressure and low temp (they're clouds) but the scoop mechanism will compress it more will chillers drive the temp down. There are probably highly efficient heat sinks in the scoop machinery bleeding the heat away as the gases are quickly brought down to 20.28 Kelvin. Traveller technology is hand-wavey, high-techy but it works in the game. Obviously, water is already in liquid state so other machinery will 'crack' and separate the liquid then either storing the oxygen for ship use and/or expelling it from the ship as waste. Again, hand-waviness all around and who cares how EXACTLY it works.

"no table of hazards or even negative effects associated with failing your refueling check."

As with many RPGs, it would become unwieldy to have effects tables for every possible result. That's what the Ref is for. The ref sees how much the result passed or failed and comes up with something imaginative with possible related game mechanic. If the pilot rolled well with wilderness refueling there may be a description how calm the region was allowing a smooth ride with a view of the unusual color pattern of the gas clouds seldom observed. A bad roll could mean the operation is interrupted with only a limited maybe insufficient portion gathered as the ship was rocked about by strong currents or the pilot had miscalculated. These would mean another run. A zero effect failure could have the refueling complete but the ship is thrown off course. Use the number rather than depending on them.
 
Reynard said:
PV=T is the Ideal Gas Law. Pressure, volume and temperature in relation. You make a gas liquid by reducing the temperature or increasing pressure. GG atmosphere is partially under high pressure and low temp (they're clouds) but the scoop mechanism will compress it more will chillers drive the temp down. There are probably highly efficient heat sinks in the scoop machinery bleeding the heat away as the gases are quickly brought down to 20.28 Kelvin. Traveller technology is hand-wavey, high-techy but it works in the game. Obviously, water is already in liquid state so other machinery will 'crack' and separate the liquid then either storing the oxygen for ship use and/or expelling it from the ship as waste. Again, hand-waviness all around and who cares how EXACTLY it works.

All good points - especially about hand-wavium being a foundation upon a lot of playing is built upon. Usually if you find a couple of lines giving a basic explanation it's enough for most players and refs to build upon.

Reynard said:
As with many RPGs, it would become unwieldy to have effects tables for every possible result. That's what the Ref is for. The ref sees how much the result passed or failed and comes up with something imaginative with possible related game mechanic. If the pilot rolled well with wilderness refueling there may be a description how calm the region was allowing a smooth ride with a view of the unusual color pattern of the gas clouds seldom observed. A bad roll could mean the operation is interrupted with only a limited maybe insufficient portion gathered as the ship was rocked about by strong currents or the pilot had miscalculated. These would mean another run. A zero effect failure could have the refueling complete but the ship is thrown off course. Use the number rather than depending on them.

Again, no disagreement with you. This is where I think supplements come in handy because they can flesh out the gaming universe and allow for more plot points. I'm currently refereeing a Shadowrun campaign and while the gaming mechanics are different, there are parts of it where I'm trying to put more detail into things so it's not all about shooting/stabbing/magic melee. For example I was trying to add a dragon into the character mix and found that the core book basically says dragons are the ultimate billy-badasses... except for my storyline to work out the dragon was essentially a younger, up-and-comer and I had nothing to go on in order to develop his backstory and prepare for my players to trash my plot line and go along their own damn merry way.

Which is why, for me at least, having a broader explanation actually makes it easier for me to handle things.

And yes, the hand-wavium effect occurs on a regular basis. Then again I love to roll the dice when the players get a soda from the machine. Just to keep them on their toes.... :)
 
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