OTU Only: Refined verses Unrefined Fuel

[Timerover51]

I may have missed it somewhere, but what is the difference between refined and unrefined fuel? I am not being facetious.

Refined fuel is Liquid Hydrogen. What is unrefined?

If you need refined Liquid Hydrogen for the Jump Bubble, what are you replacing the Hydrogen with if you cannot get refined fuel for the Jump Bubble?

Given that military and scout ships can use unrefined fuel, why are not all Free Traders and Far Traders equipped with the same gear, as they will be the civilian ships most likely to visit C, D, and E class star ports, where you cannot get refined fuel per the rules?

 

[creativehum]

What I am about to type applies only to Book 2/Basic Traveller rules.

Also, it may not address your question directly, but I think the following comments might be helpful.

One does not need unrefined fuel. One can use either refined fuel or unrefined fuel.

However, if one uses unrefined fuel:

1. There is a chance the drives will malfunction when using unrefined fuel in the 1977 rules. In the later editions using unrefined fuel is one of several modifiers to see if the drives fail. Note that scout and military ships have the same odds of drive failure as civilian ships.
2. The odds of a misjump go up. Using unrefined fuel is only one of several possible events/situations that can increase the odds of a misjump. (The moodiers vary between the 1977 edition and later edition of Basic Traveller.) Scout and Military vessels can ignore the unrefined DM for risk of misjum.

As to why the scout and military ships can dodge the DMs for possible misjumps, Book 2 does not say, and it is up to the Referee (along with many other apsects of Basic Traveller) to fill in the void as he or she sees fit.

For myself, I assume the technology for jumps, proprietary, secret, better, and expensive, of a large interstellar polity, gives them an edge over other ships. And I mean, it is really expensive stuff. Some sort of adjustments to the jump drives that make them less fragile to jump [insert babble-tech here] that allows them to risk using unrefined fuel. (But note that they are still at risk for drive failures with the same DMs as civilian ships when using unrefined fuel.)

That's my take. It has nothing to do with any books or cannon that follow the Basic Traveller rules. The distinction between the two types of ship is an interesting detail for the Referee to fill out and justify as desired.

 

[Enoki]

What I've always assumed is that "refined" liquid hydrogen is like the ultra-pure stuff. That is, it is 100% guaranteed hydrogen. It could even be one particular isotope of hydrogen if that's important.

The "unrefined" stuff is like technical grade or the like. That is it's like 99% hydrogen but contains impurities. Or it might be 99.5% hydrogen. That small amount of impurities in it is the problem. Nothing like getting some atoms of something else in your fusion reactor to make it go all squirrelly and explode...

It would also play to whether the ship using it is maintained properly or not. If you have a poor engineering staff or don't do the maintenance regularly, you could end up with more issues. Thus, warships and scouts are less likely to be in this situation and less likely to have issues other than just fuel that could mess up a jump.

So, the difference between a starport with refined fuel and one with unrefined fuel is a matter of quality control. It would be little different from getting avgas or jet fuel at a top notch airport while getting fuel from some small backwater airport means taking your chances it's not old, or has water in it, or some other issue.

 

[Timerover51]

The problem is that a lot of that Liquid Hydrogen goes into the Jump Bubble, and never is used in the power plant. That is one of the things that bugs me about it.

 

[BlackBat242]

Well, the "jump bubble" concept came along many years after the "refined vs unrefined" conflict - in the official published materials.

So MM et all were discussing and working out "refined vs unrefined" when all the fuel was assumed to be used by the powerplant/jump engine... long before someone said "hey, how about "jump bubble" or "cooling mass" for an idea".

 

[mike wightman]

The hydrogen being used to make a bubble is a misunderstanding of what was written in the MT SoM that became canonical in T4.
In SoM it talks of a bubble of normal spacetime, by T4 this has turned into using left over hydrogen from the jump procedure to maintain a 'bubble'.

MGT then went with this bubble of hydrogen.

Just a couple of things wrong with it:
most versions of Traveller and T5 do not have any hydrogen used to maintain a hydgrogen filled jump bubble
collector and antimatter powered jump drives don't use hydrogen at all.

One final factoid - in CT77 edition it is never referred to as hydrogen, it is always referred to as fuel.

 

[Spartan159]

Thanks, Mike, I had wondered where that bubble idea had come from. It has annoyed me more than any other quasi-fictional technobabble so far.

 

[AnotherDilbert]

One final factoid - in CT77 edition it is never referred to as hydrogen, it is always referred to as fuel.

What else could it be?

Unrefined fuel is often forced on a ship which must refuel without benefit of a starport. Unrefined fuel is available free to a ship by skimming a gas giant.

 

[mike wightman]

Helium3, deuterium...
any ship that just skims a gas giant is going to fill up with a very complex mix of gasses, not just 'helium contaminated hydrogen' - although the vast majority of the gas will be hydrogen. The upper atmosphere of Jupiter is very well documented.

 

[creativehum]

Frontier fuel skimming also changed from gas giants only in the '77 rules to gas giants and water in '81 -- which is when hydrogen was specified.

In general I prefer the more opaque logic of '77 which a) kept gas giants as the center of refueling and b) left the fuel to the Referee to define.

And, yeah... "bubbles" come later. And as we've discussed most of the canon of Traveller is a melange of half-thought through ideas used to justify other half-thought through ideas. Working backward from the final results to make it all make sense will, in my view, lead to a soup that runs through one's fingers.

 

[McPerth]

Just a couple of things wrong with it:
most versions of Traveller and T5 do not have any hydrogen used to maintain a hydgrogen filled jump bubble
collector and antimatter powered jump drives don't use hydrogen at all-

This happened also with Annic Nova (something I know it's always controversial to bring to bear).

OTOH, CT:HG (and MT, that is nearly a carbon copy) clearly specified that fuel is needed to jump even if the jump capacitors are already full from the Black Globe...

Also, in MT, even a higher TLs (the only version I know to have them before T5) where antimatter is used, the jump drives need fuel to work (albeit at dwindling quantities).

 

[aramis]

One final factoid - in CT77 edition it is never referred to as hydrogen, it is always referred to as fuel.

Maybe not explicitly, but it's noted as being skimmable from gas giants' atmospheres.

Wilderness Refuelling: Unrefined fuel may be obtained by skimming the atmosphere of a gas giant if unavailable elsewhere. Most star systems have at least one gas giant; the presence of a gas giant can be predicted from a distance of Jump-1, or determined from the ship’s library. Throw 10+ for a system to not have a gas giant present.

 

[mike wightman]

It doesn't say you are skimming hydrogen, it says you are skimming for unrefined fuel. You and I both assume they mean hydrogen, which is the most abundant gas present but not the only potential fuel for a nuclear reactor, fusion rocket reaction mass and jump coolant.

 

[Ulsyus]

.... You and I both assume they mean hydrogen, which is the most abundant gas present but not the only potential fuel for a nuclear reactor, fusion rocket reaction mass and jump coolant.

Fair point. TNE's FF&S p64, when referring to fuel use in fusion reactors, only refers to the use of fuel, not which type of fuel. LHyd is listed as one of the types though on p63.

 

[ffilz]

Frontier fuel skimming also changed from gas giants only in the '77 rules to gas giants and water in '81 -- which is when hydrogen was specified.

In general I prefer the more opaque logic of '77 which a) kept gas giants as the center of refueling and b) left the fuel to the Referee to define.

And, yeah... "bubbles" come later. And as we've discussed most of the canon of Traveller is a melange of half-thought through ideas used to justify other half-thought through ideas. Working backward from the final results to make it all make sense will, in my view, lead to a soup that runs through one's fingers.

Yea, I like this distinction myself. Combine the small and not very costly fuel refineries from Book 5 with specifying the fuel as hydrogen and allowing water as a source (which should also include ice...) and the whole risk disappears.

I have put some house rules in place on unrefined fuel and misjumps because I don't want the situation to be a random chance of campaign ending (though some have pointed out that one COULD purchase enough refined fuel and carry it in one's cargo hold to avoid wilderness refueling). Even with my rules, that's still an option. I also made some house rules on drive/fuel system flushing that make it totally reasonable to carry the capability to do a flush or two.

 

[Timerover51]

The problem with the massive amount of fuel specified is that it vanishes with a Jump. What is it used for? Whether hydrogen or some other unspecified substance, it is needed for a Jump. What happens to it when you Jump? Given the amount of energy in a kilogram or so or hydrogen when fused, a power plant is not going to be using tens to hundreds of tons of hydrogen. The energy release boggles the mind.

 

[mike wightman]

Coolant and carrying away waste products:

When the jump drive is activated, a large store of fuel is fed through the ship power plant to create the energy necessary for the jump drive. In the interests of rapid energy generation, the power plant does not work at full efficiency, and some of the fuel is lost in carrying off fusion by-products, and in cooling the system. At the end of a very brief period (less than a few minutes), the jump drive capacitors have been charged to capacity. Under computer control, the energy is then fed into appropriate sections of the jump drive and jump begins.

 

[BRJN]

I've never worked this through in any detail, but have wondered: I wilderness refuel at a GG and head out to jump. My fuel refiners will be done just before I reach the jump point. If I have a really nasty scoop and get lots of contaminants rather than lots of fuel, and refine the crud out ... could I reach the jump point with not-enough fuel for the jump? How can I tell before I leave the GG in the first place?

 

[mike wightman]

You can extract enough hydrogen from the water, methane and ammonia to make up any difference.
Water, methane and ammonia in their liquid or solid states are a more efficient way to bulk carry hydrogen than liquid hydrogen.

 

[aramis]

You can extract enough hydrogen from the water, methane and ammonia to make up any difference.
Water, methane and ammonia in their liquid or solid states are a more efficient way to bulk carry hydrogen than liquid hydrogen.

Only by volume, not by mass. Water is 9x the mass for the same amount of hydrogen. Sure, 1/14th the volume, but a LOT more mass.