T20 and Drop tanks

[shadowdragon]

would you need to modify the ships fuel processors to deal with ammonia? how would you convert it to Lhyd fast enough for the jump drives to burn it?
would it basically be unrefined fuel then?

Water and gasses sucked off a planet are one thing but does ammonia split as easily as water, say in an electric current?
Otherwise a free 40% reduction in fuel mass (T20)is way too generous to give to players.

 

[Fritz_Brown]

Aramis, you are right. Not that contradictions prove alot....

 

[mbrinkhues]

Originally posted by shadowdragon:
would you need to modify the ships fuel processors to deal with ammonia? how would you convert it to Lhyd fast enough for the jump drives to burn it?
would it basically be unrefined fuel then?

Water and gasses sucked off a planet are one thing but does ammonia split as easily as water, say in an electric current?
Otherwise a free 40% reduction in fuel mass (T20)is way too generous to give to players.

I doubt that you can skim pure Hydrogen or even the extremly dangerous Di-Hydrogen Monoxide from a gas giant. You get the "whole cocktail" and the processors crack and seperate the stuff.

So IMHO the processors should already be set to do the cracking. IRL Jupiters outer athmosphere is H, H2, H2O and other traces with multiple Ammonia layers below (Saturn has even more ammonia in the outer athmosphere)

 

[shadowdragon]

Darn that pesky Di-Hydrogen Monoxide. it gets into EVERYTHING!

 

[TheEngineer]

Refering to shadowdragons questions...

I would consider Ammonia to be unrefined fuel (just as Water, Methane or any other Hydrocarbons), as it needs a reforming process to free hydrogen. Liquifying is not a time consuming process, so I see no problem here.
Reforming is likely to be done using thermal methods (above 1600-1700 degrees Celsius). Here its quite neglegtable, which kind of C-H configuration is feed into the process. Compounds of the Cocktail (TM MB) break up and can be separated.

IMTU I consider another more simple operation mode of standard fuel scoops as staged "freezing traps". The first trap is used to strip of other compounds than hydrogen and helium (because of the fairly low freezing points) and the second stage is used strip out hydrogen via liquification, while helium runs thru the exhaust

Despite of the sometimes problematic surface gravity on some gas giants and radiation effects, I see no problem in skimming fuel here.

 

[Jeff M. Hopper]

What if you just used the dirty ice itself as the exterior fuel tank? You'd still have to use internal fuel tankage for jumps, but by hauling ice on the outside - you could crush it and purify it in the internal tankage for travel. The ice would have to be taken from cometary bodies and not skimmed obviously.

What would be the Armor Factor for cometary ice?

I'm picturing a ship with a jump-6 drive, imbedded in an ice shell of a displacement equal to five times its original displacement (giving the ship jump-1), but allowing extreme range of travel without stopping. A jump net or jump web like the one described in Supplement 9: Fighting Ships would be needed to cover the ice shell - or the ship's hull would have to built with the jump grid on the outside of where the ice will be stored.

 

[TheEngineer]

Ho, ho, the scout on the rocks idea is pretty cool, indeed

Guess, thats a variation of collapsable exterior tanks.

Armor factor ?
Dont know, but ice around a few kelvin is perhaps pretty tough...

Anyway, the hydrogen density might not be as good as using LHyd directly (1 m³ of ice only contains around 10 kg hydrogen). So one has to carry ten times the volume if using ice as fuel source

 

[Jeff M. Hopper]

Ah, but each ton of ice is considered to be a ton of unrefined fuel (I know, implausible, but not against the rules). Also a ship like this, doing jump-1 all the way to use the most conservative jump fuel expenditure could do 17 parsecs straight-line course with a jump-6 at the end.

 

[RainOfSteel]

Originally posted by Liam Devlin:
"Icing:The use of solidified Hydrogen, stored in external mountings, as jump and reaction mass. Fuel is the largest consumer of space aboard a ship, with even a j-1 ship giving about 50% of its displacement to fuel tankage."-Peter Gray/ Science in the regency

This must be some TNE-FFS calculation I'm not familiar with (I have the book, but have only read bits and pieces).

How does a J-1 ship consume 50% of its displacement in fuel tankage?

Something about TNE's fuel consumption rates being different is running around in the back of my mind . . .

 

[GypsyComet]

Peter Gray has been dominating the TNE-RCES mailing list with his view of the New Era for years, and has done a staggering amount of work in support of that view. That MJDs work on 1248 not only has Marc Miller's blessing but Dave Nilsen's as well at this point apparently holds no water with Mr Gray, from what I've heard, so don't bring up the subject around him.

The above quote is likely refering to the swap in tonnage dominance under TNE. The lumping of jump fuel in that statement is a simplification. TNE jump drives are in line with normal Traveller usage, and power plants require a small fraction of what they needed under CT or MT. However, HEPlaR drives are *incredibly* hungry drives from a Traveller point of view, and any ship capable of long hauls or high acceleration will indeed need to dedicate a high percentage of its volume to fuel.

 

[RainOfSteel]

Originally posted by GypsyComet:
[...] However, HEPlaR drives are *incredibly* hungry drives from a Traveller point of view [...]

Given that normal zero-fuel manuever drives appear at what, TL-8, why would anyone bother developing heplar drives?

It is a thrust in the direction of "enlightened retcon", where given the wiping out of the past, the technology of that past can be replaced with something that lends additional SF realism?

 

[GypsyComet]

The HEPlaR and Contragravity pair was created for TNE for reasons that Dave Nilsen has gone into before, and retained in T4 alongsside Thrusters for reasons that trace back to MT: All the zero-reaction-mass drives (A-G and Thrusters) have a gravity horizon inherent to their physics, beyond which they drop to almost useless. As such, Thrusters don 't work worth a darn if you feel like exploring the Oort Cloud. The solution for deep-space operations is some form of reaction drive. By Thruster standards, HEPlaR requires some design compromises most players aren't used to, but the presence of HEPlaR in the Third Imperium setting alongside Thrusters doesn't bother me in the slightest.