Going Pirate

[Anthony]

Originally posted by Sigg Oddra:
Not many merchant designs carry fuel purifiers as standard; a bit silly IMHO since they pay for themselves so quickly. How many are going to run the risk of misjump?

Well, since there's no source for refined fuel in-system, ships without fuel purifiers will simply not visit Ianic.

Gas giants tend to have lots of moons, lots of places for pirates to hide to prey upon those merchants.

Yes, it is relatively easy to hide if you arrive before the patrol ship. Less easy to hide if you don't. Hiding after you attack the merchant is likely to be practically impossible, and running isn't going to be that easy given the large 100D on a gas giant.

Ianic is a rich world, so it must have something to trade.

The trade classifications in CT are useless beyond belief. There's no reason to think Ianic has anything of value.

 

[BetterThanLife]

But with, in OTU the per jump economic model the typical freighter and cargo ship is only Jump 1. Nothing else works, no matter the size, with a loan under the "jump every other week model from the OTU."

Originally posted by Anthony:
</font><blockquote>quote:</font><hr />Originally posted by rancke:
</font><blockquote>quote:</font><hr />Originally posted by Hal:
Take a look at Ianic in hex 1924.

No, it means that someone can make a profit from selling fuel at the starport, even if he has to import it from outside.</font>[/QUOTE]No, what it means is that ships will jump directly to the gas giant and not visit Ianic itself. Very little of the traffic you mention is actually headed for Ianic.

Also, I'd peg the traffic at roughly 0 ships per week. The major trade route in the area is Lunion to Abadicci, and that will be handled pretty much exclusively by J3 ships. </font>[/QUOTE]

 

[Nurd_boy]

I tend to think of things not as 'going pirate' but rather....

...commerce of opportunity

'pirate' is such a crude word, invoking too many centuries old stereotypes...besides, parrots don't do well in zero-gee.

 

[Straybow]

But parrots do just fine in AG and I-Comp.

 

[rancke]

Originally posted by Hal:
What it boils down to is that it is cheaper to make money spending 5 days in normal space than to give up a percentage of your cargo hold for fuel bladders. A Jump 1 craft utilizes roughly 30% of its cargo hold in order to carry enough fuel in its fuel bladder.

A jump-1 ship has a cargo bay of about 70% of its total volume. It will give up 14% of that to carry enough fuel in its bladder to get back.

Keep in mind that what I am discussing has to do with GURPS TRAVELLER, but the principle holds true in CT as well.

No, actually, the two situations are very different. (Which is why I have such a down on SJG for refusing to admit and correct the mistake). The 20% a streamlined ship loses comes straight of the ship's payload. But that doesn't really mean that a streamlined freighter will have that much less cargo space, that means that there won't hardly be any streamlined freighters.

A jump 2 ship has even less cargo space than a Jump 1 vessel. In GT, IIRC, a J-2 200 dton craft has only 49 Dtons cargo space. Utilizing 40 of those 49 is highly inefficient

Sure, but a jump-2 ship has enough fuel space to make two jumps-1, so it won't have to use its cargo bay.

Regards to the 50 ships per week - I should have added the following information...

1) those fifty ships all come from 16 different planets

2) those fifty ships are based on a "baseline" of 200 dton ships. For instance, some of the cargo carried from Lunion to Ianic could be carried by 400 dton ships because the incidental freight volume would be high enough.

2b) The fact that Ianic trades with 16 planets doesn't necessarily means that it is visited by ships from 16 planets. For instance, much of the cargo that comes from further to trailing than Lunion can be added to the trade from Lunion, since freight from (say) Mora can easily be offloaded at Lunion and transferred to another ship.

3) GURPS FAR TRADER has what amounts to two types of freight lots for tramp freighters to get their hands on. The first is the "incidentals". This freight market contains the last second freight that wasn't placed on the "freight liners" market for what ever reasons that might be. This stuff is never an absolute. The second is the "too low a volume to be worth our while" freight market. On worlds where the Bi-world Trade Value is 8+, regularly scheduled ships carry the trade with the "incidental last minute" cargo being available for tramps. On worlds with a BTN less than 8, it is wholely carried by tramps.

Unless it is carried ten times a year by a 1000 T ship instead of 50 times a year by 200 T ships.

as for route protectors?

well, Ianic has no real port, and is unable to maintain regularly scheduled maintenance of military forces.

Not a problem: A patrol ship can jump to Lunion, get maintained, and jump back to Ianic. A better question is what GWP Ianic has. That will show what it can do for itself.


Hans

 

[rancke]

Originally posted by Hal:
The thing to remember is this: Ships that *MUST* go to the Ianic main world don't have any choice but to go to the Gas Giant if they want to get home. The world has a hydrology rating of Zero.

That doesn't mean that there is no water on Ianic. It just means that there is less than 5% free-standing water on Ianic. There could be a small ocean next to the colony, or underground water or ice.

The inhabitants has to get water from somewhere. Wherever the Ianic Public Waterworks gets its water (even if it imports it from Adabicci), it must be possible to increase the production a bit and get some fuel out of it. The profits would certainly warrant it.


Hans

 

[Anthony]

Originally posted by Hal:
Apparently Anthony, you've not bothered to look at the traffic flow for Ianic deeply. Considering that it was you who forced me to look more closely - I am a little surprised

I seem to have been hit by my house rules, which put a cap a bit lower than Far Trader (Jim MacLean came out with a similar variant on max route size, but neither has made it into any errata). However, given the actual economy of Ianic, I think my house rules are more plausible than the standard rules...

 

[Straybow]

"Sure, but a jump-2 ship has enough fuel space to make two jumps-1, so it won't have to use its cargo bay."

The original LBB2 said that a J-2 or higher drive uses the full fuel required even if jumping below its rating. A supplement cut the jump fuel in half from the value in LBB2. I suppose that may have been changed as well, hmmm?

IMTU there is no such thing as fuel scoops and on-board refining. Fusion requires Deuterium, which is only 0.015% of natural hydrogen. That means you'd need to scoop and process 6600 times the amount of hydrogen as the fuel required. Hope you brought a very long book to read.

 

[far-trader]

Originally posted by rancke:
Sure, but a jump-2 ship has enough fuel space to make two jumps-1, so it won't have to use its cargo bay.

True enough but a J2 ship is likely to just do a J2 right by Ianic (in this specific case) unless they have some extremely valuable cargo, which is gonna raise the interest of, erm, certain interested parties

The premise here is what does all the J1 traffic, and I for one see plenty*, do about fueling? Rather than mess with changing the starport to include fuel I think it's either skim or melt ice for yourself, or carry it in with you. Most ships have the scoops even if they don't have purifiers and might decide to risk the small chance of a misjump this once.

The Subbies would of course use cargo carried fuel tanks for their own use through Ianic, being less concerned with profits and more concerned with schedules and safety.

Now if I were a nervous nelly of a Free-Trader I'd buy a 20T lot on the next Subbie and ship myself some fuel to Ianic for cr20,000 and use my own cargo hold for something more valuable. Once you refuel you can sell the containers locally or reuse them for cargo to your next destination.

*This is a major trade subsector, the crossroads of the Marches, and the J1 Main (to the Border Worlds, Sword Worlds, Darrian, Five Sisters and Glisten) runs right through Ianic. Granted not every Free-Trader is gonna run the whole Main regularly but a few will, and I expect there would be a stop at Ianic by a Subsidized Merchant or two.

Originally posted by Straybow:
The original LBB2 said that a J-2 or higher drive uses the full fuel required even if jumping below its rating. A supplement cut the jump fuel in half from the value in LBB2. I suppose that may have been changed as well, hmmm?

Yep, the LBB did say all your fuel regardless of acutal jump but that was changed in High Guard. First by the inclusion of a Jump Governor conversion and then by simply saying all ships already included it. Not sure which supplement said halve the J fuel but as far as I know it's only been an optional (and very not OTU) rule.

Originally posted by Straybow:
IMTU there is no such thing as fuel scoops and on-board refining. Fusion requires Deuterium, which is only 0.015% of natural hydrogen. That means you'd need to scoop and process 6600 times the amount of hydrogen as the fuel required. Hope you brought a very long book to read.

So of course all my blather about such is pointless for your game

I do agree that it should take a lot longer, and involve more than a little hazard (at least GG skimming). I always figured the skimming rate should be dependant on the purifier rate* and figured that such fuel should be called unrefined with all the negatives it implies. Refined fuel costs so much more imo because it goes through further steps that can't be easily done on a starship.

*Unless you have enough tankage to first skim a full load (or more since it must be reduced by the purifier process imo) and then pump it into another clean tank (big enough for your Jump) through the purifier at your leisure. Just the way I feel it should be handled.

 

[Straybow]

The difference between Hydrogen and Deuterium is one of those gratingly unscientific things that reaches the point of being broken in Traveller and needs to be fixed. I'm mystified at why it wasn't fixed decades ago&#133

 

[Hal]

Originally posted by Straybow:
The difference between Hydrogen and Deuterium is one of those gratingly unscientific things that reaches the point of being broken in Traveller and needs to be fixed. I'm mystified at why it wasn't fixed decades ago&#133

Shhhhhhh - don't say that, you never know who might be listening

 

[jfwking]

Originally posted by Hal:
</font><blockquote>quote:</font><hr />Originally posted by Straybow:
The difference between Hydrogen and Deuterium is one of those gratingly unscientific things that reaches the point of being broken in Traveller and needs to be fixed. I'm mystified at why it wasn't fixed decades ago&#133

Shhhhhhh - don't say that, you never know who might be listening </font>[/QUOTE]/looks outside at howling mob with pitchforks and torches. Points in opposite direction and says "he went thataway" then ducks

 

[TheEngineer]

Hi,

guess the H/D topic was just neglected because it was not considered as really important for actual gameplay.

Thinking about skimming....:
The time consuming part of the skimming procedure surely might not be to pump a few cubic meters water around.
Its the breaking down into gasous H2/D2 via electrolytical/catalytical means.
D2 could be - at least technically - derived in that way, too.

So, IMHO skimming an amount of "unpurified" H/D mix could take as long as the skimming / purification to D2 in a plant designed and optimized to do that.
Perhaps Traveller puri-plants are just as fast as scoops.

Just a thought...

Regards,

Mert

 

[Straybow]

Well, yes, if you want to allow fuel skimming then the H vs D distinction must be ignored. The ratio of D is what makes the purification a lengthy process requiring bulky equipment. Or you create a Traveller-friendly universe where D is naturally 10% of hydrogen, allowing unrefined fuel to be used in fusion with lower power output.

Maybe a ship would have an emergency purifier, so that water or scooped gas could be processed into sufficient D2 to allow minimal life support while awaiting rescue. No manuevering except emergency O2/H2 rockets (sufficient for orbit maintenance and docking) and no jump.

Fuel skimming would be a viable commercial enterprise, with massive equipment in orbit around a gas giant or on the surface of a world with volatiles so that 6600 tons hydrogen/unit of fuel can be economically processed.

 

[mike wightman]

Straybrow said:

Fusion requires Deuterium

Not quite .
The version of fusion reactor that we have been trying to build (unsuccessfully so far after nearly fifty years of r&d and who knows how much money) relies on D+D fusion. This is because the temperatures and pressures required for the "cleaner" forms of fusion (4P-He, or 3He+H, or 3He+3He) are way beyond current technology.
Fusion power is achieved at TL9, it could be the breakthroughs in grav technology that lead to controllable fusion reactions involving hydrogen as the fuel in the Traveller Universe.
Development of nuclear damper tech (strong force manipulation) at TL12 could lead to its incorporation in TL13+ reactors which is why you get the increased EP output.

 

[jfwking]

To admit to following non cannon herasy here but I tend to ignore the whole H/D thing. Fuel purification is simply to get all the rubbish out of it before use or it clogs up your drives. Gas from a giant or space ice or sea water all have loads of impurities which need filtering out before they can be used. Imagine landing on a coast, sucking on board a full full load for your far trader (45 odd tons). In that lot are going to be fish/plants/disolved metals and minerals etc. You could maybe sell some of it on like the half ton of salt you would get from salt water ocean refueling.

Besides which a misjump due to unpurified fuel caused by a fish jammed into the fuel flow pipe strikes my evil GMs heart as realy funny.

 

[TheEngineer]

Regarding security aspects I would be glad with tanks full of water, too

 

[Hal]

Originally posted by Captain Jonah:
</font><blockquote>quote:</font><hr />Originally posted by Hal:
</font><blockquote>quote:</font><hr />Originally posted by Straybow:
The difference between Hydrogen and Deuterium is one of those gratingly unscientific things that reaches the point of being broken in Traveller and needs to be fixed. I'm mystified at why it wasn't fixed decades ago&#133

Shhhhhhh - don't say that, you never know who might be listening </font>[/QUOTE]/looks outside at howling mob with pitchforks and torches. Points in opposite direction and says "he went thataway" then ducks </font>[/QUOTE]/pulls on a mask that makes him look like Captain Jonah saying "He went that way and looks like a fuzzy blue thing - kept talking like a real live furby too. "

 

[Straybow]

Well, I surprised myself. The 0.015% D naturally occuring in hydrogen could be enough, if we assume that Traveller fusion techniques can do that. There are some other hard figures given that turn out, well, realistic.

1 EP (250MW) can accelerate a 100 dTon (assume 500 ton mass) starship at 1G. Normally a conservation of momentum equation does the trick, but with gravitics (exchange of momentum with the rest of the universe via distortion of space-time) we'll have to approximate.

250MW = Energy/sec
250MW = m·a·d/sec = m·a·v (averaged over 1 sec)
250MW = m·a·(0+a·t)/2 = ½m·a²·t
a² = 250MW/(½m·t)
a² = 250MW/(½500ton·1s) = 250MW/.25Mkg·s = 1000W/kg·s
a = 31.6 m/s²

Gravitics are operating at a reasonable 30% efficiency of input energy.

So let's see how we're doing in the fusion department. One dton (2 tons mass) D2 can produce 0.006355·2000kg·c² = 1.14e+18 Joule. That's 250MW for 145 years! D2 occurs naturally at 0.015% abundance, so if we throw that factor in we still get 1 EP from 1 ton of natural hydrogen for 7.9 days assuming complete fusion of all D2.

Traveller allows 2 days acceleration (288 10 min maneuvers in LBB2). Allowing a 50% efficiency converting raw thermal/gamma energy into electrical power, that means Traveller fusion power needs only 50% of fusionable mass used up from the 1 ton of hydrogen fuel requirement per EP.

So, yes, refining would just be removing all the heavy nuclei that suck up the power you're using to reach criticality and the power you get out of the reactions.

On the other hand, a pure D2 engine could operate with proportionately lower fuel requirements, and thus hold fuel for hundreds of jumps (being very conservative). That could be a better option than fission for those willing to spend the extra cost up front for concentrated fuel.

(See High Guard 3 thread)

 

[Anthony]

Um...
Power requirement of gravetics, assuming perfect efficiency, is thrust * velocity, where velocity is relative to whatever you're pushing on (unknown in this case). Assuming a 100dton ship is 100T (unlikely), that's 1 million newtons, so at velocities exceeding 250 meters/second you're breaking conservation of energy.

As for being able to match the power output of a fusion plant with the amount of D in the amount of fuel the plant uses, we have a problem because it implies you can purify your fuel to, oh, 15% D by volume and use 0.001 tons of fuel per energy point per month, instead of 1 ton. The effects on jump drives are particularly noteworthy.