Cracking water in TRAVELLER

[Anaraxes]

The point of cracking water was that it was commonly available in the "wilderness" (which is to say, away from a starport). Ice from asteroids, moons, icecaps, or even the occasional liquid water source. You wouldn't normally store it in ship fuel tanks; you'd crack it at the source and keep the hydrogen (liquified) and possibly some of the oxygen (for life support, or simply resale as an industrial gas).

It's possible to find ammonia, but it's more scarce than water.

[hal]

Originally Posted by Anaraxes

The point of cracking water was that it was commonly available in the "wilderness" (which is to say, away from a starport). Ice from asteroids, moons, icecaps, or even the occasional liquid water source. You wouldn't normally store it in ship fuel tanks; you'd crack it at the source and keep the hydrogen (liquified) and possibly some of the oxygen (for life support, or simply resale as an industrial gas).

It's possible to find ammonia, but it's more scarce than water.

In my current campaign set in the year 98 (Milieu Zero), the Deneb Sector and the Spinward Marches sector are a little less populated and/or industrialized then their 1105 counterparts will eventually become. The mad race to reach Mora and colonize it - along with the surrounding worlds nearby - has to trace a route through areas that are lacking in facilities.

Now, if I were to have a Jump 1 scout that for what ever reason, was designed to carry extra fuel for two parsecs worth of jumps before refueling, it would be possible to carry 10 dTons of Hydrogen Fuel along with 7 dTons of tankage that carries water. If said ship were to be discovered floating about somewhere as a derelict, then it might be an "interesting" aspect to the ship's design.

Yes, the ship can crack the water itself, but without fuel tankage to hold onto the oxygen that it cracks free from the water, chances are good that it either outgasses while on the world surface, or it is dumped directly into space - because I can't see the crew being willing to bleed it directly into their ship's atmosphere - thereby increasing the ratio of Oxygen to other gases mixture.

Later on, perhaps in the 600's or so, the route directly leading to Mora from Vland will be more heavily populated and the like, but until then, the route is going to be somewhat primitive.

[malloyd]

Originally Posted by hal

Ammonia MIGHT be the other alternative route to go - in that if the Liquid Hydrogen is Cryogenic in nature, it (the tanks) should also be able to handle the Ammonia. By chance, would you know how much liquid Hydrogen one can obtain from Liquid Ammonia? If not, no biggie. If yes - well, might be interesting!.

In general take the density of the material, and multiply by the number of hydrogens in the formula, divided by its total molecular weight

So for liquid hydrogen you have 0.071 * (2/2) = 0.071
For water you have 1.00 * (2/18) = 0.111
For liquid ammonia you have 0.68 * (3/17) = 0.120 around boiling
Chilled liquid ammonia can get denser, so up to 0.74 * (3/17) = 0.131 for that.
For chilled diborane you have 0.48 * (6/25.6) = 0.113

The real unbalancing concept for Traveller is metallic hydrogen, which given the existence of materials like bonded superdense should be *easy* with existing tech. Estimates of densities vary, by 0.85 is about the minimum estimate, leading to 10-fold or more smaller fuel tanks.

[hal]

Originally Posted by malloyd

...The real unbalancing concept for Traveller is metallic hydrogen, which given the existence of materials like bonded superdense should be *easy* with existing tech. Estimates of densities vary, by 0.85 is about the minimum estimate, leading to 10-fold or more smaller fuel tanks.

Thank you for the how-to on the weights and such. :)

The last bit is an oucher in that it would transform Traveller in a big way. I guess the law of unintended consequences strikes yet again.

One of the reasons I like Traveller overall is the very limitation that the fuel tank imposes on ship design and ability to travel. Any time I am tempted to run a sci-fi campaign, I look for ways to keep FTL travel compact. The reason being - I don't want to have to try and detail millions of worlds simply because FTL allows for mankind to go anywhere and everywhere quickly.

T5 tosses in the added complication of having to roll against Navigation with the number of dice being rolled, incrementing the further your ship jumps. Thus, a Jump-5 is that much more difficult to engage in as compared against a Jump-2.

What I also liked about Travller was that ships couldn't engage in combat while in jump space. Star Trek allows for combat in warp, Star Wars does not. Therein lies the difference for me in Traveller and Star Wars. In Star Wars, ships could be forced out of Hyperspace by masses in normal space. CT didn't have that.

In any event - the water/ammonia/metallic Hydrogen issues can change Traveller to some extent, or to a major extent. I don't think I want to see Metallic Hydrogen in my campaigns any time soon (if at all).

[Anthony]

I mean, one option that gets rid of most of the shenanigans is to just toss the concept of volume-based drives and use mass-based.

[hal]

Originally Posted by Anthony

I mean, one option that gets rid of most of the shenanigans is to just toss the concept of volume-based drives and use mass-based.

The implication from that is - it would also favor the small ship universe. Armor being mass, it would also favor ships whose armor levels were as sparse as possible and still get the job done.

Something to think about.

[whswhs]

Originally Posted by hal

The implication from that is - it would also favor the small ship universe. Armor being mass, it would also favor ships whose armor levels were as sparse as possible and still get the job done.

I don't see why it would do the former. If the cost of a jump is proportional to mass, and it doesn't make any difference if the mass takes up 1000 cubic meters or 10,000—why make any effort to economize on room? Any time a little extra space would make things easier, you just design it in.

[Anthony]

Originally Posted by hal

The implication from that is - it would also favor the small ship universe. Armor being mass, it would also favor ships whose armor levels were as sparse as possible and still get the job done.

It favors less armor that CT had, but you can still have armor, and it simplifies ship building quite a bit. You might want a dual limit (a J-drive has both a mass limit and a volume limit) to avoid shenanigans with extremely low density ships.

[hal]

Originally Posted by whswhs

I don't see why it would do the former. If the cost of a jump is proportional to mass, and it doesn't make any difference if the mass takes up 1000 cubic meters or 10,000—why make any effort to economize on room? Any time a little extra space would make things easier, you just design it in.

I wasn't thinking along the lines of volume per se, but that in general, the larger ships tend to become more massive. If I'm to avoid the issues of ships being able to zip along lickety split - I need to have something similar to the limitations imposed by the original Traveller.

As I pointed out in a GURPS SPACESHIP thread elsewhere - I'd like to see it happen where the smaller ships by mass/volume end up being able to travel slightly faster than average, with larger heavier ships being slowed dramatically. This makes it such that heavy battle fleets are ponderously slow, but when they arrive, they settle things on the spot so to speak.

When you get right down to it, I'm thinking that unconsciously - I'm wishing I could emulate to some extent, the age of sail. Smaller ships can sort of skip along, but the larger ships can pile on more canvas to bear down on the really small ships. Frigates would end up with the sweet spot with both firepower and speed, but still unable to take on a ship of the line.

I largely suspect that Traveller would kind of stink in that kind of environment. :(

[Fred Brackin]

Originally Posted by hal

I

As I pointed out in a GURPS SPACESHIP thread elsewhere - I'd like to see it happen where the smaller ships by mass/volume end up being able to travel slightly faster than average, with larger heavier ships being slowed dramatically. This makes it such that heavy battle fleets are ponderously slow, but when they arrive, they settle things on the spot so to speak.
:(

For Spaceships you would have to add a modification factor after the design was complete. You couldn't embed it in the middle of the design sequnce because of the way Spaceships uses sliding scales. I spemtimes don't choose how large a ship is going to be until I've nailed down everything else and that works in Spaceships.

You could try something as simple as a modifer to speed of +0.1 for every SM below 9 and -0.1 for every SM above 9. I think that would give you x 1.5 for SM+4 and x.4 for SM+15.

Those are not necessarily the exact numbers you'd want but I would recommend that level of arbitrary non-complexity. Creating a complex mathematical formula would be wasted effort in a system where ships alwasy get larger by a power of 3 as they increase in size.