Spinward Flow
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Otherwise known as "powered down to Power Plant-1" minimum power performance.
If you have a higher Pn, then you need more fuel to keep that power plant running at a higher output.
The Xboat is a HG2 design
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If you have a higher Pn, then you need more fuel to keep that power plant running at a higher output.
Nope. Read literally, fuel consumption is a flat 1%. Not "powered down", just 1% across the board. I'm pretty sure that's not what they meant, of course.
AnotherDilbert
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Quite, they presumably fumbled the words a bit.
Perhaps this is where the "powered down" rule originated?
HG'79, p24 says the usual:
Perhaps this is where the "powered down" rule originated?
HG'79, p24 says the usual:
mike wightman
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But we also know that the 79 HG maneuver drive is a fusion rocket so some of that fuel used during 'cruising' is reaction mass - which they neglect to mention and probably gives rise to the reactionless drive interpretation for HG80.
Spinward Flow
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When "could be done better" transitions into "was done better" ...
AnotherDilbert
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@AnotherDilbert it says the same thing in HG '80 regarding "inconsequential".
mike wightman
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That's power plant consumption, reaction mass would be maneuver drive consumption...
AnotherDilbert
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M-drives has no fuel requirement or fuel consumption:
Only the power plant and jump drive needs fuel, anything else is inconsequential.
AnotherDilbert
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Quite, but HG'80 does not say anything about attacking with fusion drives, there is no hint of any need for reaction mass unlike LBB2'77 and HG'79.
HG'80, and later, M-drives use a lot of power, but no reaction mass; hence "reactionless" drives.
mike wightman
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So there needs to be a section added, a clarification, that the rest of the 'power plant fuel' is used as reaction mass for the maneuver drive, since that is the only way a fusion rocket could work.
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Spinward Flow
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Things get a lot more interesting if there's more than one point of view ... or in this case, more than one context for maneuver drives to be operating within. Specifically, the idea (that I postulated over here) that within 1000 diameters of nearby gravity wells, maneuver drives can operate "electrically" as reactionless drives (link provided to wiki page) ... but beyond 1000 diameters the reactionless thrust of maneuver drives is reduced to 1% (or less), at which point you need to have reaction drives (link provided to the wiki page again) which does require additional fuel consumption above and beyond nominal power plant fusion fuel demands.
So within 1000 diameters, reactionless drives "work" just fine ... but in deeper space environments more than 1000 diameters away from gravity wells (and this can easily include deep space hexes on subsector maps) you'll need to use reaction drive engineering for propulsion (and station keeping). Since most "adventuring" with ships happens within 1000 diameters of somewhere more than 98% of the time, it's rare for the distinction to need to be made.
Remember, Traveller put a LOT more work into making travel (and trade!) interstellar ... while leaving interplanetary trade and travel as basically an afterthought (if that). No wonder maneuver drives are so "woefully underdeveloped" in terms of their importance to starship design and freedom of navigation in normal space (as opposed to hex maps for jump space that are reasonably well defined). For the longest time, Traveller was a 1+1 worlds per star game system ... you had the "mainworld" and you had the gas giant (if present) ... and nothing else represented through the UWP. In such a simplified system, you don't NEED maneuver drives other than to get out 100 diameters and a jump point. There was "nowhere else to go" so why bother going anywhere else?
AnotherDilbert
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That is explicitly addressed:
You can accelerate for weeks and the fuel consumption is inconsequential.
HG'79 says nothing about "fusion rockets", but "fusion drives". Those fusion drives needs a lot of power, but negligible fuel or reaction mass; presumably they are not rockets, but something like an ion drive.
mike wightman
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It is not explicit since it isn't addressed at all, reaction mass for the maneuver drive isn't mentioned.
All we are told is the power plant consumption is inconsequential regardless of maneuver, what we are not told is how much reaction mass is used by the fusion rocket maneuver drive.
About fusion drive/fusion rocket - how can the drive be used as a fusion gun if it is not a fusion rocket?
All we are told is the power plant consumption is inconsequential regardless of maneuver, what we are not told is how much reaction mass is used by the fusion rocket maneuver drive.
About fusion drive/fusion rocket - how can the drive be used as a fusion gun if it is not a fusion rocket?
AnotherDilbert
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Those newfangled ideas were not in CT. CT (at least 1980+) defined M-drives as just producing acceleration everywhere. The game Imperium explicitly discussed interstellar travel by manoeuvre drive.
Traveller was never limited to a single world per system.
LBB3'77 says:
The UWP describes the main world, not the entire system.
AnotherDilbert
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Agreed, reaction mass is not discussed by name, but we do know that ships no not need any tanks or storage for reaction mass, nor do they need to acquire reaction mass for normal operation.
My conclusion is that it's not needed at all, any more than unicorn farts. Unicorn farts are not mentioned by the rules either.
I have no idea what a HG'79 "fusion drive" is. If it is something like an ion drive it must eject particles at very high velocity to accelerate a ship.
A small amount of very energetic particles (the imagined ion drive) would do damage just as well as a larger amount of particles at lower velocity, lower energy (the imagined fusion rocket).
What does it matter? That concept is gone. Elided. De-Stalinized.
GDW went through great effort to remove HG '79 from the public consciousness by not just re-releasing the rules, but by giving it away as part of JTAS. "Hey, yea, ya'll remember that HG book we published? Yea, it's all wrong. Here's the new one."
Discussing it is right up there with talking about how the Articles of Confederation govern the United States. An historical curiosity to be sure, but no more germane than that.
Spinward Flow
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LBB5.79 was the first draft and somewhat obviously rushed to publication.
LBB5.80 was a more finished version with fewer flaws (although there were still some here and there).
LBB5.80 was a more finished version with fewer flaws (although there were still some here and there).
mike wightman
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They are very different, I have long sought the answer to the question why was HG79 replaces so quickly with HG80?
They brought it back with HEPLAR drives, kind of.
