High Guard TL 7 M-Drive Errata?

[smiths121]

Hi All,

Although unlikely it is possible to for a class B starport to only be tech level 7. Interesting world from a social point of view (would need to be a Ga world to avoid most of the TL pluses).

Anyway I aside - a world with a class B starport can build their own system defense. At TL7 the Gravatic drive is not available, so you have to use a Solar Sail or Reaction Drive. Solar Sail is defined OK (but as this is system defense is not interesting anyway). The reaction drive is defined well for small ships (so your class C starport is taken care of), it is mentioned even with an example on page 42 in High Guard.

The text says they are the same size as a normal TL 12 M-drive, but cost less. I cannot see anything to calculate their cost, the High Guard Errata has no errata for page 42.

Whilst rare statistically, it is possible to generate a tech level 7 world in MGT, they cannot use gravatic drives, limited to good old reaction drives - so how much do they cost?

I am going with the cost of a gravatic drive for now, as I cannot see the formula used on the small craft table on page 58 of high guard for any clues.

Anyone come across it/have some thoughts?

 

[DFW]

The way I look at it is thus: We are currently at TL 7 (US and some other advanced countries) so, how much would a drive with the performance specs
cost? Shouldn't be too hard to find some data...

 

[Egil Skallagrimsson]

I doubt it is an errata, think the idea is that the R drive is less efficient, and so cheaper.

The TL 7 bit is interesting, if it is an isolated world with no wider galactic community, fine.

But if connected in to a higher tech galactic economy (eg the Imperium), its hard to see why they would not buy M drives on the open market, if they have enough money, especially for military applications.

Egil

 

[smiths121]

Thanks Guys for your quick response. not sure they help me much (sorry, because you both tried to help really quick)

Bit of context. Having a week off from work, though I would look at the changes High Guard Errata did in a little more detail (all look good). Fired up the pdf of Adventure 5 Trillion Credit Squadron and took option 1 from the Billion Credit Squadron section on page 28.

Option is TL-7, Jump-0, 20 pilots Orbital refuelling. I have built a number of reaction drive equipped small craft, no probs - there is a table. Came a bit unstuck with starships.

Both are very interesting suggestions but rather cover over the problem there is a hole in the MGT rule-set, other version of Traveller has scaled down to TL 7 (or at least MT and CT with which I am familiar).

Not sure where I would start to research current fuel requirements, as we have never built a 2000 ton starship with reaction drives on Earth (Terra!)- Avenger did a good job covering current technology for smaller craft in Golden Age Starships 5. Its 101 tons to 2000 I am struggling with. You cannot build 2001 tons or above because of the computer table on page 65 of high guard.

Think it is things missed in the High Guard Errata when we put in the errata a few months ago.

Two things stood out when trying to use Core Rulebook to produce a 2000 ton TL-7 (actually the problem is at 8 as well as there is no Gravatic drive at TL 8 either).

1) Fission Drive fuel use was not extended for the AA to DA drives, and the rules do not limit their availability. Assumed you can extend the same way as the fusion table. The table on 109 of TMB looks the same to me as the fusion drive fuel use on page page 107. Probably needs to be stated though in the errata.
2) No cost for reaction drive - but comment they cost less and evidence of this from the small ship table . My view is just use the m-drive table, the major penalty is the fuel cost if you actually want to dog fight.

Would rather keep this on the rules level. Given there is an example of the fuel use in High Guard, I would hope there is a table somewhere that has not been printed.

 

[phavoc]

Keep in mind reaction drives are going to require mass. It's horribly ineffecient (but entirely possible) to do that sort of thing today and send up more fuel.

If you are trying to minimize things you might look at some of the hybrid drives, like say the Ion drive, that would be your standard for orbital craft. You are still stuck with boosters to get to orbit though. But Ion drives in the lab provide about 10x the specific impulse as a chemical drive. But they do have their limitations.

You could also go the route of using big dumb boosters (ala Russian rockets or the Sea Dragon design) to get cargo to orbit. You can read more about Sea Dragon on the wikia site here - http://en.wikipedia.org/wiki/Sea_Dragon_(rocket)

 

[Rikki Tikki Traveller]

In the Small Craft Drive Table, a Reaction M-Drive is 1/2 the cost of a Gravitic M-Drive.

I would extend that up to the 101-2000 ton range as well. Just half the cost of the listed M-Drive on the tables in the TMB.

While not explicitly stated, it makes logical sense to extend that percentage.

 

[Mithras]

That's a powerful reaction drive! What kind of rocket is that?

 

[smiths121]

In the Small Craft Drive Table, a Reaction M-Drive is 1/2 the cost of a Gravitic M-Drive.

I would extend that up to the 101-2000 ton range as well. Just half the cost of the listed M-Drive on the tables in the TMB.

While not explicitly stated, it makes logical sense to extend that percentage.

Nearly works, but it is only half the cost until sF, the cost then begins to fall to below half the cost of a Gravatic Drive - not graphed it out yet.

Thanks to all for your input - it is an edge case as a class B starport is need to develop a tech level of 6 or less. Which is statistically quite unlikely. Given Nuclear Misssiles exist at TL6, it would seem a TL6 populated world, that is part of a interstellar community, but not necessarily part of the big interstellar good guys or bad guys would need to consider world to orbit, which is why I asked the question.

 

[simonh]

TMB page 179:

"The Technology level measures the average technology presence on the planet, and gives an idea of local production and repair capability. Trade with offworlders may bring in advanced technology; on average, a rich individual can afford technology two or more levels higher than the planetary average. The government may also have access to higher-technology items."

Highlight added. So there is no problem whatever with that TL7 world having limited availability of some TL9 technologies, such as gravitic drives.

Simon Hibbs