Fuel Bladders

[vargr1]

Methane is better than water (even though volumetric density does not equal energy density), the enthalpy is why we source 95% of hydrogen production from fossil fuels still. Even with things more efficient, it is still better to have the constituent parts. "Un-refined" could also mean that the protium ratio is too high.

I always likes the idea that refined fuel is chemically pure water without any of the heavier atoms of hydrogen. When cracked into H2, there no deuterium, no tritium. Separating out the heavy water (a difficult thing to do) could be used to explain the reason refined fuel is more expensive, even though it's 'just water.' I can see how the very picky jump bubble (which is hyper sensitive to mass) might have a problem when you toss molecules that are two or three times more massive than 1-proton H into the mix.

What would become of the dton? The 14 cubic meters is from liquid hydrogen.

Keep it as a cultural remnant. It probably started with the Vilani, and they never throw anything away.

 

[dragoner]

I always likes the idea that refined fuel is chemically pure water without any of the heavier atoms of hydrogen.

The energy is in the heavier atoms. Saying it is "just water" snaps my suspenders of disbelief.

 

[vargr1]

I always likes the idea that refined fuel is chemically pure water without any of the heavier atoms of hydrogen.

The energy is in the heavier atoms. Saying it is "just water" snaps my suspenders of disbelief.

Untrue. There are many types of fusion, it's just that using deuterium in your fusion is easier than proton-proton fusion. The energy is not in the heavier atoms. The energy is in all the atoms.

 

[phavoc]

Not quite, or, more accurately, not just 'exotic particles.'

Traveller Core Rulebook (MgT2) page 148
"To jump, a ship creates a bubble of hyperspace by means of injecting high energy exotic particles into an artificial singularity. The singularity is driven out of our universe, creating a tiny parallel universe which is then blown up like a balloon by injecting hydrogen into it."

Assuming that refined fuel = l-hyd, those exotic particles must be made from the l-hyd. The rest of the l-hyd is injected to form the jump bubble. Cracking H2 from water take very little time, probably less time than to pump slush hydrogen and heat it to a gas.

Yeah, the whole exotic particles is kind of another handwavium. I'm not sure how the hydrogen is converted into exotic particles (through the singularity generator (jump drive?) I guess).

But pumping the LHyd is easy - so long as you keep it chilled it pumps exactly like water. And making it to a gas is easy - pump it into space and it will turn to gas on it's own. In other words instantly. With water you would need to flash convert water to Hydrogen and Oxygen.

Agreed, however I prefer a game with as little handwavium required. Changing a technology to require more handwavium is a step in the wrong direction, IMHO.

Unfortunately we aren't going to get that in Traveller. 2300AD had fewer handwaviums than Traveller though.

 

[vargr1]

But pumping the LHyd is easy - so long as you keep it chilled it pumps exactly like water.

No, not quite. Pumping supercooled liquids like l-hyd comes with it's own mess of troubles. Just ask Space-X. Now, I fully agree that high tech can make it easier, but pumping water is and always will be much safer.

And again, its a lot safer for your starship and crew for a rupture to be in a tank full of water than in a tank full of l-hyd.

Exposing water to vacuum will also turn it into a gas.

Indeed - other than mass (a dton of water has about 10x the mass of a dton of l-hyd) - I have found no reason to prefer l-hyd to water as starship fuel. The reason mass doesn't matter is that Traveller starships are volume-limited, not mass-limited.

Agreed, however I prefer a game with as little handwavium required. Changing a technology to require more handwavium is a step in the wrong direction, IMHO.

Unfortunately we aren't going to get that in Traveller. 2300AD had fewer handwaviums than Traveller though.

It certainly seems that way, but one can always try.

 

[dragoner]

I always likes the idea that refined fuel is chemically pure water without any of the heavier atoms of hydrogen.

The energy is in the heavier atoms. Saying it is "just water" snaps my suspenders of disbelief.

Untrue. There are many types of fusion, it's just that using deuterium in your fusion is easier than proton-proton fusion. The energy is not in the heavier atoms. The energy is in all the atoms.

Unless talking nucleosynthesis and stellar density, it's very true, D-T fusion has the largest cross section by Lawson criterion. It simply is the most plausible.

 

[vargr1]

The energy is in the heavier atoms. Saying it is "just water" snaps my suspenders of disbelief.

Untrue. There are many types of fusion, it's just that using deuterium in your fusion is easier than proton-proton fusion. The energy is not in the heavier atoms. The energy is in all the atoms.

Unless talking nucleosynthesis and stellar density, it's very true, D-T fusion has the largest cross section by Lawson criterion. It simply is the most plausible.

For current tech, yes. For Traveller, where the Vilani have been using fusion for 10,000 years and there is tech to manipulate gravity and the strong nuclear force (nuclear damper), it's highly believable that their fusion reactors are proton-proton or even CNO cycle.

 

[dragoner]

Untrue. There are many types of fusion, it's just that using deuterium in your fusion is easier than proton-proton fusion. The energy is not in the heavier atoms. The energy is in all the atoms.

Unless talking nucleosynthesis and stellar density, it's very true, D-T fusion has the largest cross section by Lawson criterion. It simply is the most plausible.

For current tech, yes. For Traveller, where the Vilani have been using fusion for 10,000 years and there is tech to manipulate gravity and the strong nuclear force (nuclear damper), it's highly believable that their fusion reactors are proton-proton or even CNO cycle.

Not really, no, because the Vilani reached a technological plateau, and that fusion tech is "current" at TL 8. While at one time I played around with it in my head that it could be similar to nucleosynthesis, that opens more questions than it answers. It would change the tech paradigm quite a bit.

It is simply easier to say that the D-T reaction is affected by protium in unrefined fuel, then shut the drawer. Otherwise it is going towards a total rewrite of the game, and at that point, better to just start new. Nothing wrong with that, it's a lot of work, however, the market could probably bear a new hard SF-ish game.

 

[vargr1]

Unless talking nucleosynthesis and stellar density, it's very true, D-T fusion has the largest cross section by Lawson criterion. It simply is the most plausible.

For current tech, yes. For Traveller, where the Vilani have been using fusion for 10,000 years and there is tech to manipulate gravity and the strong nuclear force (nuclear damper), it's highly believable that their fusion reactors are proton-proton or even CNO cycle.

Not really, no, because the Vilani reached a technological plateau, and that fusion tech is "current" at TL 8. While at one time I played around with it in my head that it could be similar to nucleosynthesis, that opens more questions than it answers. It would change the tech paradigm quite a bit.

It is simply easier to say that the D-T reaction is affected by protium in unrefined fuel, then shut the drawer. Otherwise it is going towards a total rewrite of the game, and at that point, better to just start new. Nothing wrong with that, it's a lot of work, however, the market could probably bear a new hard SF-ish game.

So refined fuel is deuterium and tritium? What is the other 99.9% of the hydrogen in unrefined fuel used for? Is it just discarded?

And the 3I uses a fusion reactor design from TL8? The Vilani had at least TL11 for jump 2.

Now that really breaks my suspension of disbelief. Much more so that using water as my starship's fuel.

 

[dragoner]

For current tech, yes. For Traveller, where the Vilani have been using fusion for 10,000 years and there is tech to manipulate gravity and the strong nuclear force (nuclear damper), it's highly believable that their fusion reactors are proton-proton or even CNO cycle.

Not really, no, because the Vilani reached a technological plateau, and that fusion tech is "current" at TL 8. While at one time I played around with it in my head that it could be similar to nucleosynthesis, that opens more questions than it answers. It would change the tech paradigm quite a bit.

It is simply easier to say that the D-T reaction is affected by protium in unrefined fuel, then shut the drawer. Otherwise it is going towards a total rewrite of the game, and at that point, better to just start new. Nothing wrong with that, it's a lot of work, however, the market could probably bear a new hard SF-ish game.

So refined fuel is deuterium and tritium? What is the other 99.9% of the hydrogen in unrefined fuel used for? Is it just discarded?

And the 3I uses a fusion reactor design from TL8? The Vilani had at least TL11 for jump 2.

Now that really breaks my suspension of disbelief. Much more so that using water as my starship's fuel.

Most of the other hydrogen is used for inflating the jump bubble, you can also burn it with oxygen and get water (NASA engineers like this). As for reactor designs, tech does plateau in the real world, it has in the past, and we are heading for one now with a limitation of how many scientists we can support.

Water has other issues: mass, it is corrosive, and easily polluted biologically (things grow in it).

 

[vargr1]

Not really, no, because the Vilani reached a technological plateau, and that fusion tech is "current" at TL 8. While at one time I played around with it in my head that it could be similar to nucleosynthesis, that opens more questions than it answers. It would change the tech paradigm quite a bit.

It is simply easier to say that the D-T reaction is affected by protium in unrefined fuel, then shut the drawer. Otherwise it is going towards a total rewrite of the game, and at that point, better to just start new. Nothing wrong with that, it's a lot of work, however, the market could probably bear a new hard SF-ish game.

So refined fuel is deuterium and tritium? What is the other 99.9% of the hydrogen in unrefined fuel used for? Is it just discarded?

And the 3I uses a fusion reactor design from TL8? The Vilani had at least TL11 for jump 2.

Now that really breaks my suspension of disbelief. Much more so that using water as my starship's fuel.

Most of the other hydrogen is used for inflating the jump bubble,

Yes - for jump fuel. Does jump fuel also need to be deuterium and tritium?

As for reactor designs, tech does plateau in the real world, it has in the past, and we are heading for one now with a limitation of how many scientists we can support.

Traveller designs show that fusion reactors get better as TL increases. They do not plateau at TL8. (MgT2 High Guard pg 15)

Water has other issues: mass, it is corrosive, and easily polluted biologically (things grow in it).

Quite. Except Traveller starships - as I've pointed out earlier - are volume-limited, not mass-limited. Is water more or less corrosive than l-hyd? Are the issues of having water in your starship tanks greater than having l-hyd?

I think not.

 

[snrdg121408]

Hello all,

Silly question time: What does all of this have to do with the original topic of "I seem to remember a thing from Mug-A-Traveller callleda fuel bladder that would store away in the ship until needed after skimming. I can't seem to find it in this edition. Or am I missing something?" was posed by Cpt Black Thorne.

Hopefully the following from MgT HG 2e Chapter 3: Spacecraft Options p. 36 answers the subject of this thread

"Collapsible fuel tanks (also called fuel bladders) are large flexible bladders which expand when filled with hydrogen fuel. They take up cargo space in a ship and are used to extend range without the need to fit demountable tanks. Fuel cannot be pumped directly from these tanks to the jump drive, and so a ship must complete a jump before it can use fuel stored in collapsible tanks.

When empty, collapsible tanks take up 1% of the tonnage they use when full. They cost Cr500 per ton."

Here is the information from CT Adventure 5 TCS pp. 13-14:

"Large fuel bladders can be used to hold additional fuel, the collapsible tanks are filled with fuel and take up space in the ship's main cargo hold. It must have a hold equal to or greater than the tonnage required for the collapsible tanks, and the tanks displace tonnage in the cargo hold.

When not in used, collapsible tanks collapse and are stored in the cargo hold; they take up 1% of their filled tonnage

Fuel from collapsible tanks must be pumped into the normal fuel tanks before it can be used; thus a jump made using collapsible tanks may not use more fuel than the capacity of the normal interior fuel tanks. Pumping fuel before a jump takes about three hours."

The typical use for collapsible tanks is to allow a short-jump ship to cross a gap in two or more jumps. For example, to cross between two worlds located 4 parsecs jump 4 drives are needed. With collapsible tanks, a ship with a jump-2 drive could negotiate the distance in two sequential jumps, the first into deep space half way across, where the collapsible tanks provide the fuel for the second jump.

Collapsible tanks may not be used to enable a ship to satisfy minimum jump parameters in Trillion Credit Squadron. The may be installed at any Class A or B starport in one week and cost Cr500 per ton."

The discussion of the fuel and fuel purification appears to be a secondary topic and probably should have a thread of its own.

Updated 10/27/2016 3:26 PM PDT or 10:26 PM forum time added the word should to the last sentence.

 

[dragoner]

So refined fuel is deuterium and tritium? What is the other 99.9% of the hydrogen in unrefined fuel used for? Is it just discarded?

And the 3I uses a fusion reactor design from TL8? The Vilani had at least TL11 for jump 2.

Now that really breaks my suspension of disbelief. Much more so that using water as my starship's fuel.

Most of the other hydrogen is used for inflating the jump bubble,

Yes - for jump fuel. Does jump fuel also need to be deuterium and tritium?

As for reactor designs, tech does plateau in the real world, it has in the past, and we are heading for one now with a limitation of how many scientists we can support.

Traveller designs show that fusion reactors get better as TL increases. They do not plateau at TL8. (MgT2 High Guard pg 15)

Water has other issues: mass, it is corrosive, and easily polluted biologically (things grow in it).

Quite. Except Traveller starships - as I've pointed out earlier - are volume-limited, not mass-limited. Is water more or less corrosive than l-hyd? Are the issues of having water in your starship tanks greater than having l-hyd?

I think not.

Jump fuel is the main part of the fuel, no power plant, no jump. The oxygen in the water is the most corrosive part, most corrosion is oxidization. Just because mass isn't directly mentioned, doesn't necessarily mean it doesn't count, the problem is one of simplification, nobody wants to be doing calcs for the three masses of spaceflight. With mass there are also the issues of steam and ice expansion, juddering uncovering intakes, which mass exacerbates. NASA prefers liquid hydrogen to water, and if handling issues are the issues with hydrogen , technology to the rescue. It always has come to the rescue as far as that is concerned, eg technical issues.

 

[dragoner]

Fuel cannot be pumped directly from these tanks to the jump drive...

What? When is fuel pumped to the jump drive ever?

 

[vargr1]

Jump fuel is the main part of the fuel, no power plant, no jump. The oxygen in the water is the most corrosive part, most corrosion is oxidization.

Last I checked, cryo fuels are quite touchy to handle and store. Much more so than water. Ask SpaceX about that.

Just because mass isn't directly mentioned, doesn't necessarily mean it doesn't count, the problem is one of simplification, nobody wants to be doing calcs for the three masses of spaceflight. With mass there are also the issues of steam and ice expansion, juddering uncovering intakes, which mass exacerbates.

True,however, even those versions of Traveller that do take into account mass average your ship as 10 tons mass per displacement ton when calculating thrust, That's not too awful off the mass of a dton of water (13.5 tons mass).

NASA prefers liquid hydrogen to water

This is a non sequitur, and has be refuted earlier in this thread. NASA is not using jump drives and fusion reactors. Jump drives are not rocket science.

and if handling issues are the issues with hydrogen , technology to the rescue. It always has come to the rescue as far as that is concerned, eg technical issues.

Agreed, yet handling water instead of l-hyd is always going to be easier and safer.

Also, again, which is more dangerous - a breech of a l-hyd tank into your spaceship or the breech of a tank of water? Which is safer - fueling a starship with l-hyd on a planet with a standard atmosphere, or filling it with water?

 

[dragoner]

Jump fuel is the main part of the fuel, no power plant, no jump. The oxygen in the water is the most corrosive part, most corrosion is oxidization.

Last I checked, cryo fuels are quite touchy to handle and store. Much more so than water. Ask SpaceX about that.

Just because mass isn't directly mentioned, doesn't necessarily mean it doesn't count, the problem is one of simplification, nobody wants to be doing calcs for the three masses of spaceflight. With mass there are also the issues of steam and ice expansion, juddering uncovering intakes, which mass exacerbates.

True,however, even those versions of Traveller that do take into account mass average your ship as 10 tons mass per displacement ton when calculating thrust, That's not too awful off the mass of a dton of water (13.5 tons mass).

NASA prefers liquid hydrogen to water

This is a non sequitur, and has be refuted earlier in this thread. NASA is not using jump drives and fusion reactors. Jump drives are not rocket science.

and if handling issues are the issues with hydrogen , technology to the rescue. It always has come to the rescue as far as that is concerned, eg technical issues.

Agreed, yet handling water instead of l-hyd is always going to be easier and safer.

Also, again, which is more dangerous - a breech of a l-hyd tank into your spaceship or the breech of a tank of water? Which is safer - fueling a starship with l-hyd on a planet with a standard atmosphere, or filling it with water?

If the cabin is open to anything, that is the problem. Water vs hydrogen is moot at that point. Once again, NASA prefers filling ships with hydrogen, just don't smoke. Planets might have an issue with cross contamination of water supplies too, transferring biologicals to different worlds, not that the game deals with it; it is a real life issue with ships and ballast tanks, that is how the Baltic Mussels contaminated the great lakes. Safety does not override efficiency, more vehicles run on gasoline than diesel, yet diesel is safer handling.

 

[dragoner]

Apt picture from Space Hipsters today:

 

[vargr1]

Apt picture from Space Hipsters today:

As soon as Traveller thrusters are defined as chemical rockets that burn l-hyd and an oxidizer, I'll take that point into consideration. NASA does not operate jump drives nor fusion reactors on board starships.

Also, if that tank was full of water, would you need that warning label?

 

[snrdg121408]

Hello dragoner,

Fuel cannot be pumped directly from these tanks to the jump drive...

What? When is fuel pumped to the jump drive ever?

The material provided is a copy and paste from the PDF copy of MgT HG 2e and until you pointed out the line of text was something I apparently filled in with the "fuel tank."

"Fuel cannot be pumped directly from these tanks to the jump drive fuel tank, and so a ship must complete a jump before it can use fuel stored in collapsible tanks."

As a guess the reason the transfer of fuel from the collapsible tank to the jump drive's tank is that tank is not empty until they ship exits jump space.

In CT 1977 LBB 2 the power plant must be at least the same size/rating as the maneuver drive. My understanding at the time suggested that the jump drive was a specialized power plant which needed refined fuel which is the reason for a separate fuel tank. Back then the information suggested that the power plant could use unrefined fuel without a problem.

With the release of CT LBB 5 the jump drive has been linked with the power plant which has pretty much shredded my understanding to the point I do not think about how they work or why they require refined L-Hyd in any of the Traveller rule sets.

 

[vargr1]

If the cabin is open to anything, that is the problem. Water vs hydrogen is moot at that point.

Again - which is more dangerous when it spills into your starship - water or l-hyd? I fyou take yourstarship into combat, there's a good chance it will happen.

Once again, NASA prefers filling ships with hydrogen, just don't smoke.

This makes about as much sense as saying that NASA does not put unleaded gasoline in their rockets, so you should not put it in your car. And once again, your statement is a non sequitur, and has be twice refuted earlier in this thread. NASA is not using jump drives and fusion reactors. Jump drives are not rocket science.

Planets might have an issue with cross contamination of water supplies too, transferring biologicals to different worlds, not that the game deals with it; it is a real life issue with ships and ballast tanks, that is how the Baltic Mussels contaminated the great lakes.

I am aware of this, however, I believe the process of wilderness refueling of water can easily be used to disinfect that water. Disinfecting wilderness-water is much easier and less handwavey than refining that water into l-hyd using the same tanks (which is how Traveller fuel purifiers have to work). Here on TL8 Earth, we can easily disinfect water and store it for arbitrarily long periods and not have things growing in it. And that's sill easier than storing l-hyd.

Safety does not override efficiency, more vehicles run on gasoline than diesel, yet diesel is safer handling.

It varies according to the circumstances, so you cannot use that as a blanket statement.

Mind you, it varies according to the circumstances, so you cannot use that as a blanket statement. However, we see that a refueling accident with a spaceship using l-hyd can easily result in the loss of the craft - an incident that cannot happen when you're refueling with water.

I again maintain that handling water is much much much safer and much less handwavey than handing l-hyd.