Power plant fuel usage

[parmasson]

The scenario is a scout/courier is stranded on a trace atmosphere world with burnt-out maneuver drives. The power plant is functional and a ton or two of fuel is left in the tanks.

How much hydrogen would a starship's power plant need to run the ship's basic systems excluding maneuver drives and the J-drives in a realistic setting?

 

[mike wightman]

Which version of Traveller?

Power plant fuel usage is one of those things that changes between every edition

 

[Andrew Boulton]

Yup. In CT, you might get a few months; in T4, maybe a couple of years.

 

[Anthony]

Originally posted by Parmasson:

How much hydrogen would a starship's power plant need to run the ship's basic systems excluding maneuver drives and the J-drives in a realistic setting?

Realistically, you'll need on the order of 10 kilowatts to run life support and passive sensors. We might as well go with 100 kilowatts, to cover incidental requirements.

One kilogram of hydrogen, fused to helium, yields approximately 6x10^14J, or 19 megawatt-years. The efficiency of the fusion plant may, of course, be less than 100%; we'll go with 20%. Therefore, you will need 25 grams of hydrogen per year.

Basically, in a realistic setting, fuel expenditures for fusion power plants are negligible.

 

[far-trader]

As long as the design of the fusion powerplant allows operation at less than peak output the above is good. And of course if it's what the game needs then you should make it so. If the plot requires that the ship survive for X years then allow that, if you only need Y months then go with that.

Actually in the above scenario, unless the cargo hold has extra provisions or the native biosphere can support life (as we know it) the power will probably last longer than the crew. Unless of course the situation is that there is no crew left, just the ship waiting to be found.

 

[parmasson]

One kilogram of hydrogen, fused to helium, yields approximately 6x10^14J, or 19 megawatt-years...need 25 grams of hydrogen per year.

Basically, in a realistic setting, fuel expenditures for fusion power plants are negligible.

The edition is the LBBs.

Holy hydrogen! 25 grams per year, is there anything that hydrogen cannot do!
Fuels your stars, jump drive, power plants, fuel cells and plots. I was afraid that there would not be enough fuel.

I was going to make it a scout ship on the surface of a world but the plot was messed up.

They are going to encounter a 2000 ton colony ship that experiences some alien/malfunction/Hal 9000 problem that kills off the crew. The automated maintenance robots on the ship continue to maintain the power plant and other systems under the direction of the central computer but are unable to repair the damaged jump drives. I just wanted to know if it was plausible that the ship could have enough fuel to "idle" for a couple of years.

 

[mike wightman]

Ahh, in that case you should take a look at the fuel use table in the CT boxed module Beltstrike.

 

[Fritz_Brown]

Yeah, robotic "crew" and all the systems running would eat up a bit more of your fuel....

 

[parmasson]

Yep . . . the ship is almost out of time.

The colony ship Ortigal has 200 settlers and crew in low berths, seed and other knickknacks in it. It is the victim of a misjump into an empty hex. It took three years for the distress call to reach the characters in an uninhabited star system. Aboard the ship backup power is damaged, sensors are shot, thruster plates are blown, the J drives are slag, most of the fuel was lost, and the ship's remaing systems are being maintained by six fixobots. Now the ship only has a few days before it runs out of power and dies. The characters have an old Seeker named the Lodestone with enough fuel for one more jump. What will the characters do? I love writing adventures with those kinds of choices.

 

[far-trader]

Sounds grand it does

It has classic adventure written all over it, and I mean that as a good thing. Oh and you gotta add the name to Liam's list if it's not already part of it, it's got my own muse whispering sweet somethings in my ear too

 

[Anthony]

Note that fuel requirements in most versions of traveller are quite unrealistic. Still, you can basically handwave the endurance of a ship to whatever number seems useful (if you want to shorten it, mechanical breakdown might occur fairly quickly).

 

[parmasson]

Thanks Far-Trader, sent Lord Gen. Liam the submission.
Along with the names of the other ships in the mission
The Imperial Cruiser Oberon (100,000 tn capital ship)
Colony ship: Ortigal (Missing and presumed destroyed.)
Colony Ship: Blue Heaven
Colony Ship Providence

My next question is what caused the misjump and killed the warm crew members still sitting at their posts?

Perhaps venting too much drive fuel caused the accident. A much larger than normal charge builds during the ramp up to jump. The inexperienced pilot hits the jump switch and KABLAM!

The grid overloads, blows out half of the systems sends a massive shock of something through the hull and kills everybody not in a protected low berth. A week later the ship transitions to N-space and automatically sends out a distress call.

 

[far-trader]

You missed putting the Lodestone on the list. Or I missed it or forgot it if it's already there

Well, how messy do you want it? A severe enough misjump could make the crew so ill (jump sickness) that they are quickly incapacitated with little or no warning until the jump drive is engaged. There would have to be something seriously wrong with the drive or the jump plot for that though.

Any electrical event that would do that to the crew would also toast every electrical device aboard including the low-berths, so the popsicles would melt and there'd be no distress beacon. Oh and the bots would probably be fried too.

Or the misjump could have been one that affected the minds of the crew who weren't in cold sleep so that they go nutters or just catonic. Stuff like sleeping or sitting till they starve, or taking a stroll out the airlock in their skivvies.

Just a couple thoughts

 

[parmasson]

The Lodestone already appears as the "S.S. Lodestone"

Thanks, I love the idea of them sitting at their stations until they starve to death. I don't want any monsters on this ship. They just got done escaping from the old mining colony full of zombies so we need some suspense now.

I think this disaster is due to of the non-standard design of the ship. It was constructed so that it could be disassembled and used for parts to build the colony at the end of the journey. Being built on the cheap certain safety devices and shielding were left out. The jump charge load monitors only measured the average charge per cubic meter not total charge. The energy pulse on entering J-space traveled through the grid back into the jump initiator and zapped the J-drive. Because of poor electrical system design the maneuver drives and few other systems were hit before tripping the breakers. One system that was hit was the artificial gravity net. It went nuts and caused deck plates to buckle, interior partitions to twist and some rather nightmarish interior rearranging to occur. What took out the minds of the crew was a momentary incursion of jumpspace into the ship that wiped their minds clean.

It is a little technobabbleish but there are two more ships of this design out there and the characters will find themselves on one in a later adventure!

 

[far-trader]

Very nice descriptive, I especially like the twisting and buckling and nightmarish interiors the "rescuers" will find. Spooky and dangerous to move around in.

Technobabble has a valid place in sci-fi, just so long as it's not overused imo.