[technology] Imperial starship propulsion (sub-light)

[Dragon Lord]

Some discussions we've been having regarding the Venturer lead to me think it might be a good idea to have a more general discussion about the propulsion systems used by Imperial starships.

Warp drive is not so much of a problem as the warp is defined as a place where the laws of physics do not exist and as such we don't have to worry about breaking them it is with the realspace engines (usually referred to in the background as 'Plasma drives' that we run into problems.

In the past the canonical picture has been to have the warp jump point of a system quite a long way out, probably not as far out as Pluto but maybe somewhere around Uranus or Neptune considering the Sol system as an example.
It was also I'm sure though stated that it took around 4 or 5 weeks to reach the system jump point from a typical habitable world.
Assuming that it is necessary to get out to ~20 AU (just past Uranus) for a Sun like star that would require a constant velocity of 10^6m/s, or 0.003c to reach the jump point from Terra in 5 weeks, or a constant acceleration of 0.6m/s, assuming you don't mind entering the warp travelling at 0.006c.  If you would like to slow to a near halt before entering the warp then you would need to be able to maintain an acceleration of 1.2m/s for 5 weeks.

I'll come back to this and flesh out the numbers a little later but I have to go now.

[Kage2020]

Some discussions we've been having regarding the Venturer lead to me think it might be a good idea to have a more general discussion about the propulsion systems used by Imperial starships.

At the moment, the Venturer is being modelled as having a fusion drive (actually three of them for a combined acceleration of 0.015G) and with a total of 180 mps of delta-v.  If we work on the principle that you want to reach 50mps, then the time to do this is:

T (hrs) = 50*(0.0455/0.015) = 15.17 hrs

During which the ship would have travelled:

D = (15.17)^2 * 0.015 * 0.00042 = 0.001449175 AU

Cruise time would then be:

T (days) = (18.26-0.001449175) * (1076/50) = 392 days

Of course, that's just using 50 mps of fuel.  You could almost double that (90 mps) if you really wanted, reducing the travel time to 218 days, but you're not leaving lot of "space" (fuel, deceleration) on the other end...

Warp drive is not so much of a problem as the warp is defined as a place where the laws of physics do not exist and as such we don't have to worry about breaking them it is with the realspace engines (usually referred to in the background as 'Plasma drives' that we run into problems.

Please note that in the warp ships do not use their sublight drives but, rather, utilise the Geller Field as "warp sails," for want of a better term.  At least, that is the justification that Anargo uses and, I feel, the one that we're going to stick with.

It was also I'm sure though stated that it took around 4 or 5 weeks to reach the system jump point from a typical habitable world.

In the 'fluff' it was suggested that it took about a year.  The five week figure was Anargo trying to blend the various editions, but personally I don't have a problem with it taking a year to get to the jump point.

If you want faster, then you're going to essentially have to turn in reaction-based drives and go superscience into reactionless thrusters, just with a limited speed and acceleration (to give it that "slow and lumbering" impression), and some form of made up "endurance" based on whatever you want it to be based on... coolant, or whatever.

Kage

[JRaup]

So I decided to jump in with both feet.  Dang this water is deep!

I'm not going into the whole mathematical and scientific aspect of this (there's a reason I transferred out of engineering), and go more with a "narrative" POV.

While I will not dispute that the various formulas and such produce "realistic" numbers for flight times, I'm not so sure they work in the setting as intended.  By that I mean, when it comes to actual play, will taking 5-6 weeks to reach a jump point, followed by an indeterminate period of time in the warp be conducive to a good game?  Yes, it may work for some people, but I'd venture that a greater majority of players/GMs, will find it a hinderence to the flow of the game.  Speaking as one of those who hate "blipping time" in game, I can attest to this.

Now I will also agree that this leaves us in a bit of a quandry.  How to reconcile the "science" and the game play?  I see no problem with going to Kage's "super-science" route.  If anything, I find it fits better.  It will need limits and caps of course, even for G/DAoT stuff.  So using reactionless drives works for me, it makes a degree of sense to me.  Probably due to too much "outside" influence, but still.  Or perhaps I'm just over estimating how far humanity will progress in these fields over time.  Either way, I think it's the way to go.  And as a last note here, it does not exempt the "snazzy" drive ships from Newtonian laws, like momentum.   

Well, let me clarify that a bit.  Let's instead this is the way to go for "high end" vessels.  That is to say, Imperial warships, vessels of the Inquisition, the Astartes, Administratum, etc.  "Civilian" vessels can use the more "standard" reaction drives, which would serve not only as a balancing aspect, but would be "fluffy" in that it would give the Imperial authorities a bit more "control" over the flow of civilian populations.  Splitting hairs and not really making a decision?  Maybe.   

[Kage2020]

While I will not dispute that the various formulas and such produce "realistic" numbers for flight times, I'm not so sure they work in the setting as intended.

Well, from the 'fluff' they work as written, or at least as written back in - what? - 1991?  It did take a year for a ship to get to the warp zone.

By that I mean, when it comes to actual play, will taking 5-6 weeks to reach a jump point, followed by an indeterminate period of time in the warp be conducive to a good game?

Time in the warp is determined by how far you're jumping, but is the impatience of players of an RP a valid reason for reducing the travel time--and therefore requiring the use of fantasy "superscience" that breaks conservation of momentum?

Of course, GW's answer - the whole "speed of the plot" - is to say, "Yes, that is a valid reason."

Well, let me clarify that a bit.  Let's instead this is the way to go for "high end" vessels.  That is to say, Imperial warships, vessels of the Inquisition, the Astartes, Administratum, etc.  "Civilian" vessels can use the more "standard" reaction drives, which would serve not only as a balancing aspect, but would be "fluffy" in that it would give the Imperial authorities a bit more "control" over the flow of civilian populations.  Splitting hairs and not really making a decision?  Maybe.   

I'll leave this up for the masses to decide, and is a solution that I have used before, but still requires a great deal of hand waving to make it work.

Kage
[/quote]

[CELS]

The background seems to suggest that ships need fuel, so I'm afraid we're stuck with that. Though I seem to recall that we talked earlier about using rules for reactionless thrusters with a fudged fuel use.

I think ships should be able to reach a system's mainworld from the warp zone in weeks rather than years. Note that the Gothic War, involving hundreds of ships fighting over a whole sector, involving what seems like a very large number of battles, was resolved in something like 15 years. Indeed, the events in the Gothic War seem to be happening so quickly that it seems impossible for the travel time from the warp zone to the mainworlds to be more than months. In my opinion, the BFG history articles are more credible sources in regards to the time and scale of space travel, compared to, say, Black Libary novels who briefly mention travel times as a plot device. I'm sure Dan Abnett would say that it takes only a few days to go from Pluto to Sol

PS: We've sometimes taken the approach that the old background from the early 90's could be seen as describing earlier years in the 40k universe, while new background represents how things work in M41. Especially in regards to the Inquisition, Space Marines, the Imperial approach to Chaos and the Imperial Guard. We could consider a similar approach to technology... except that the old background seems to suggest more primitive technology than the new background

[JRaup]

While I will not dispute that the various formulas and such produce "realistic" numbers for flight times, I'm not so sure they work in the setting as intended.

Well, from the 'fluff' they work as written, or at least as written back in - what? - 1991?  It did take a year for a ship to get to the warp zone.

Yeah, but it's also been one of those aspects that has never been "definitively" stated anywhere.  IIRC, even the old WD articles were more "suggestions" and "guidelines" than this is it sort of things.

By that I mean, when it comes to actual play, will taking 5-6 weeks to reach a jump point, followed by an indeterminate period of time in the warp be conducive to a good game?

Time in the warp is determined by how far you're jumping, but is the impatience of players of an RP a valid reason for reducing the travel time--and therefore requiring the use of fantasy "superscience" that breaks conservation of momentum?

Of course, GW's answer - the whole "speed of the plot" - is to say, "Yes, that is a valid reason."

Well, one of the "rules" of game design is "The plays the thing."  It's what has killed more than a few budding systems over the years.  Now, I do not agree with GW's approach.  It's too haphazard and ad hoc for my tastes.  Got a neat idea?  Cool, we'll just bolt it on and issues with it be darned!  No, what I'm aiming for is a "happy medium" of sorts.  I think that we can reconcile it all, fluff wise and mechanics wise, to have a logical flow to it, and have it work not only from a "pure science" perspective (even if making some huge presumptions), but from an actual game play perspective. 

It won't do any good to establish set route times and such if no one ends up using them.  Hyper-detailing things like this may actually work against the concept.  On the converse, not detailing them enough leads to all sorts of problematic inconsistencies and a lack of focus. 

And can I just point out that there's a bit of inconsistency in your argument?  Sure, it's a small thing, but it kind of made me chuckle.  You're arguing for strict Newtonian "real physics" with the sublight drives, and against "super-science," but are perfectly willing to accept "warp drives" as envisioned in 40K fluff?  Wouldn't that qualify as "super-science?"

Well, let me clarify that a bit.  Let's instead this is the way to go for "high end" vessels.  That is to say, Imperial warships, vessels of the Inquisition, the Astartes, Administratum, etc.  "Civilian" vessels can use the more "standard" reaction drives, which would serve not only as a balancing aspect, but would be "fluffy" in that it would give the Imperial authorities a bit more "control" over the flow of civilian populations.  Splitting hairs and not really making a decision?  Maybe.   

I'll leave this up for the masses to decide, and is a solution that I have used before, but still requires a great deal of hand waving to make it work.

Kage

I don't think you need a lot of hand waving to make it work.  There just has to be a valid back story to it. 

In this instance, the government having better drives than civilians, it's not that big of a stretch.  IMO, it's not a stretch at all, more so in the context of the 40K universe. 

In my mind (a very scary place), it goes something like this:
We begin with the Great Crusade's inception.  All production is turned over to arming and equipping this endeavor.  Civilian needs, beyond the basics are put on hold.  It's all for the military and its support.  We then proceed through the various stages of the Crusade, concluding with the fall of Horus, and the founding of the Imperium we all know and love.

This is the key period for this little bit of back story.  Is it unreasonable to think that at this time, a policy decision, one which restricts who gets those "super-science" drives is implemented?  It would be a conscious decision by the High Lords to limit unofficial access to this technology, perhaps to appease the Mechanicum as well as to help control the flow of humanity, and information.  That would be a far reaching decision would it not?  We also have to look at the personalities involved, including the not yet entombed Emperor.  This would be exactly the sort of thing that the Emperor would think of.  Not to mention the Sigilite, Rogal Dorn, and Roboute Guilliman.  Even once the immediacy of such strict controls would have passed, it can be assured that the Mechanicum would jealously guard the secret of such drives, and would only be giving them to the Imperials grudgingly.  So, even if you say that the initial reason was as a "temporary emergency measure," it would become de facto policy after a short period of time.

The background seems to suggest that ships need fuel, so I'm afraid we're stuck with that. Though I seem to recall that we talked earlier about using rules for reactionless thrusters with a fudged fuel use.

Does this count as a heretical double post?   

I see no reason not to have a fuel requirement with reactionless drives.  Why wouldn't they have some sort of fuel requirement?  It would still need to generate power to work, so there must be something that gets used.  Just because the drives aren't generating "thrust" in the traditional sense (ie expelling something to create a reaction to move the vessel), doesn't mean that there isn't something being consumed to generate the field or whatever.

My question here would be, what is the fuel in question?  My admittedly surface reading and understanding here leads me to believe that there's a premise of some sort of combustible fuel at work.  Or at least in terms of conceptualization.  Yes, even nuclear/fission reactors use fuel, but the amount needed to generate power is significantly less than fossil fuels.  (Bad analogy I know). 

I think ships should be able to reach a system's mainworld from the warp zone in weeks rather than years. Note that the Gothic War, involving hundreds of ships fighting over a whole sector, involving what seems like a very large number of battles, was resolved in something like 15 years. Indeed, the events in the Gothic War seem to be happening so quickly that it seems impossible for the travel time from the warp zone to the mainworlds to be more than months. In my opinion, the BFG history articles are more credible sources in regards to the time and scale of space travel, compared to, say, Black Libary novels who briefly mention travel times as a plot device. I'm sure Dan Abnett would say that it takes only a few days to go from Pluto to Sol

In general I'd agree.  Though I haven't read the BFG materials, they probably are better sources to start with.

PS: We've sometimes taken the approach that the old background from the early 90's could be seen as describing earlier years in the 40k universe, while new background represents how things work in M41. Especially in regards to the Inquisition, Space Marines, the Imperial approach to Chaos and the Imperial Guard. We could consider a similar approach to technology... except that the old background seems to suggest more primitive technology than the new background

That little hobgoblin of inconsistency has plagued many a person over the years.     There have been times when the older fluff does indicate it was an earlier period, yet others where it indicates the current period.  Sometimes in the same fluff piece!  It takes a bit of hip wading to get through it all, and even then you usually end up short.

Removed the double post (as you realise, try not to do this unless it is absolutely necessary) and modified the quotes so that they reflect who posted the quoted text.

[Kage2020]

The background seems to suggest that ships need fuel, so I'm afraid we're stuck with that. Though I seem to recall that we talked earlier about using rules for reactionless thrusters with a fudged fuel use.

This is the fudge that I mentioned elsewhere.  I do not find it particularly pleasing since it buys into the inconsistency rather than sorting it out, which if we recall was one of the little goals that we had with the project.

With that said, if this is the only way to solve the issue then, yes, I'm willing to go forwards with it.  I would, however, rather not go down the route whereby the military has the reactionless thruster fudge-drive and the poor schleps only get a reaction-based drive.  That's one of the reasons why, in the RPG statistics for the Venturer, I selected the fusion drive as the "current" 40k version, and the "fusion torch" (limited "superscience" drive) as the one from the past--that they each had a strength and a weakness in comparison to each other.

I think ships should be able to reach a system's mainworld from the warp zone in weeks rather than years.

This is the determination that we had previously made as well.  I believe it was something like 6 weeks to the warp zone for the average ship, though quicker ships could obviously make it in less time.

Note that the Gothic War, involving hundreds of ships fighting over a whole sector, involving what seems like a very large number of battles, was resolved in something like 15 years.

I think that one of the reasons that GW might have taken a step back from this approach is because they realised their wars are going to take a rather long time to prosecute.  There's no "running in to save the day" for the Space Marines when everyone can see them coming for a year.

If you reduce the warp zone too much, though, you lose the admittedly small buffer zone that transit time represents.  So, in short, buggered if you do, buggered if you don't.

In my opinion, the BFG history articles are more credible sources in regards to the time and scale of space travel, compared to, say, Black Libary novels who briefly mention travel times as a plot device. 

And an article which expressly talks about the "average" journey?  Bugger... I cannot find it in the documents that I have to hand, but it's a pull-out box on the right hand page at the top of WD139/140.

I know, I know.   I'm just throwing that out for completeness.  Whatever we do we'll going to be invalidating some 'fluff.'  If it were just me I would select the longer transit time.  Why?  Because it suits my sense of "scale" of the 40k universe.  Since, however, this is obviously not an individual project I'm more than willing to bend. 

(It's strange to note, though, that GW has spent much of its time "compressing" the size of the universe by making it quicker to reach the warp zone, but also seems to have partially "uncompressed" it by making warp travel longer... Guess it gives them more time to talk about daemons scratching on the hull and inside the minds of psykers, or some such.)

I'm sure Dan Abnett would say that it takes only a few days to go from Pluto to Sol

While some of the other authors might have them landing on it and taking a stroll around.

PS: We've sometimes taken the approach that the old background from the early 90's could be seen as describing earlier years in the 40k universe...

That's actually a good reminder, so thanks for that CELS.  If it wasn't for the fact that the 'fluff' specifically talks about plasma engines and "superheated gas for thrust" it wouldn't be so bad.  About the only other way of handling the situation would be to increase the fuel efficiency by a thousand or so.

We could consider a similar approach to technology... except that the old background seems to suggest more primitive technology than the new background 

That's one of the reasons that I selected the fusion drive and fusion torch drive...

Yeah, but it's also been one of those aspects that has never been "definitively" stated anywhere.  IIRC, even the old WD articles were more "suggestions" and "guidelines" than this is it sort of things.

It was mentioned as the "average warp trip," so... take that as you will.  It's from the same couple of articles that "defined" warp travel time, which is equally contentious given the figures that GW come out with.

No, what I'm aiming for is a "happy medium" of sorts.  I think that we can reconcile it all, fluff wise and mechanics wise, to have a logical flow to it, and have it work not only from a "pure science" perspective (even if making some huge presumptions), but from an actual game play perspective. 

Consistency in producing a "framework of interpretation" is something that I prefer, yes.  That and the longer transit time would certainly give CELS a bit more of a reason to have his cryostasis units in the Venturer! 

And can I just point out that there's a bit of inconsistency in your argument?  Sure, it's a small thing, but it kind of made me chuckle.  You're arguing for strict Newtonian "real physics" with the sublight drives, and against "super-science," but are perfectly willing to accept "warp drives" as envisioned in 40K fluff?  Wouldn't that qualify as "super-science?"

That's not an inconsistency by a recognition of the parameters of the 40k universe and the lens through which one observes it.    There's a difference, for example, between realising the context of the warp and the means by which the fictional characters interface with it, and then using that as an argument for pulling whatever argument that you want out of the 'ole derriere. 

I don't think you need a lot of hand waving to make it work.  There just has to be a valid back story to it. 

On the technological standpoint there is more of a problem, in my mind at least.  Again, it's not one that I'm unwilling to go beyond, I just find that the more you do this then the more "fantasy" that your universe gets, which is fine if that's what you want, but... Ah well.

It's one of the reasons that I normally hit a wall when dealing with Philip S's technology interpretations.  Need a Thunderhawk to be aerodynamic?  Create warp force fields.  Want metals to be stronger?  Use warp magic.  All tightly tied together and quite innovative, but... Well, falls flat on its face for me.

In this instance, the government having better drives than civilians, it's not that big of a stretch.  IMO, it's not a stretch at all, more so in the context of the 40K universe. 

That's not the stretch.  Indeed, the principle of "technological diffusion" as discussed on the project is merely just this idea--the Adeptus Mechanicus controls the high technology, and through them the "government" through contract.  What sticks in the craw is the idea that they control the "super-dooper" sublight drive while everyone else has to deal with the crappy stuff, something that already happens with warp drive... except it doesn't.  Not quite.

Ultimately it's the same phenomenon as giving every race a new type of interstellar travel.  It smacks of slopping writing.

Does this count as a heretical double post?   

Yes, it did.  Please use the Modify button.

It would still need to generate power to work, so there must be something that gets used.

Ah, this is similar to the Traveller jump drive argument... Not that this is inherently a problem once we realise that we're stepping more into the realm of "fantasy."  (See the above, though.  If it's what is necessary then, again, we can revisit the concept.  It just strikes me as... a bit on the lame side.)

Yes, even nuclear/fission reactors use fuel, but the amount needed to generate power is significantly less than fossil fuels.  (Bad analogy I know). 

Hydrogen fuel.  And the reactors do use fuel, but at a much lower rate than the type needed to generate thrust...


Amusingly, going to reactionless thrusters leads us in the same place as the old Traveller!

Again, I'm not against it.  The "reaction" drives are in keeping with the original material, but not in the majority of the assumptions that have been made subsequently.  Thus, the balance of the 'fluff' is to make the universe a bit smaller and have the reduced transit time.

Kage

[JRaup]

I think ships should be able to reach a system's mainworld from the warp zone in weeks rather than years.

This is the determination that we had previously made as well.  I believe it was something like 6 weeks to the warp zone for the average ship, though quicker ships could obviously make it in less time.

Just to pose a little train of thought here, the 6 weeks for an "average ship," is that at "posted no wake cruising speeds?'  Or would that be at max velocity?  I got to thinking in this way from looking at how shipping lanes at ports are controlled.  If you take the warp jump point as the point of entry of a harbor/port, then certain restrictions are immediately in force.  Speeds are controlled, as are what lanes which vessels can be in.  You could even take an air traffic control approach, with a central CnC center directs all incoming and outgoing traffic from a system, assigning them their routes and speeds.  Now this doesn't do a dang thing to solve the root issue at hand, but it could help put that 6 week figure into a deeper context.

Note that the Gothic War, involving hundreds of ships fighting over a whole sector, involving what seems like a very large number of battles, was resolved in something like 15 years.

I think that one of the reasons that GW might have taken a step back from this approach is because they realised their wars are going to take a rather long time to prosecute.  There's no "running in to save the day" for the Space Marines when everyone can see them coming for a year.

If you reduce the warp zone too much, though, you lose the admittedly small buffer zone that transit time represents.  So, in short, buggered if you do, buggered if you don't.

I'm not so sure about this.  I liken warp travel to the "Golden Age of Sail."  In that era, most captains would stick to well charted routes, even if it took forever to get from point A to point B.  An adventurous captain could go where "here there be monsters" and make the journey in less time.  Or, to further the comparison a bit, storms can be a significant factor.  In sailing, you can do a number of things when faced with a storm.  You can go around it, adding time to your journey (often a significant portion of time).  You can skirt it, reducing the time added, but running some risks of catastrophe.  You can go right through it.  This is the really dangerous one, as the results can be unpredictable.  You may get a favorable wind and current and save time.  You could run into a head wind and lose time.  You could end up wrecked or lost.  So, transliterating this over to 40K (and probably poorly), you have the stable, known warp routes.  You have the not so stable, but usable routes.  Then you have the option to pioneer a route, even if for just one trip. Usual warp issues still apply.

To add one more layer of complexity, what if a similar concept to the in system routes applied to the warp ones as well?  That is to say, that some routes are "military only," and others are for specific types of vessels?  This could greatly effect transit times depending on what form of vessel you're talking about. 

In my opinion, the BFG history articles are more credible sources in regards to the time and scale of space travel, compared to, say, Black Libary novels who briefly mention travel times as a plot device. 

And an article which expressly talks about the "average" journey?  Bugger... I cannot find it in the documents that I have to hand, but it's a pull-out box on the right hand page at the top of WD139/140.

I know, I know.   I'm just throwing that out for completeness.  Whatever we do we'll going to be invalidating some 'fluff.'  If it were just me I would select the longer transit time.  Why?  Because it suits my sense of "scale" of the 40k universe.  Since, however, this is obviously not an individual project I'm more than willing to bend. 

(It's strange to note, though, that GW has spent much of its time "compressing" the size of the universe by making it quicker to reach the warp zone, but also seems to have partially "uncompressed" it by making warp travel longer... Guess it gives them more time to talk about daemons scratching on the hull and inside the minds of psykers, or some such.)

Well, to my mind there's scale and there's scale.  I don't think I'm suggesting you can cross the Imperium from one side to the other in a matter of days, or even weeks.  It would be months, and more likely a year minimum to my interpretation.  Those time frames of course would indicate "ideal" voyages, unhindered.  So the chances of that actually happening should be rather slim. 

Yeah, but it's also been one of those aspects that has never been "definitively" stated anywhere.  IIRC, even the old WD articles were more "suggestions" and "guidelines" than this is it sort of things.

It was mentioned as the "average warp trip," so... take that as you will.  It's from the same couple of articles that "defined" warp travel time, which is equally contentious given the figures that GW come out with.

I think I'm coming in line with more of this in my head, conceptually.  See my above responses for more detail.

No, what I'm aiming for is a "happy medium" of sorts.  I think that we can reconcile it all, fluff wise and mechanics wise, to have a logical flow to it, and have it work not only from a "pure science" perspective (even if making some huge presumptions), but from an actual game play perspective. 

Consistency in producing a "framework of interpretation" is something that I prefer, yes.  That and the longer transit time would certainly give CELS a bit more of a reason to have his cryostasis units in the Venturer! 

Oh, I can conceive of several reasons for the Venture to have cryostasis units.  And only a few of them have to do with travel!

And can I just point out that there's a bit of inconsistency in your argument?  Sure, it's a small thing, but it kind of made me chuckle.  You're arguing for strict Newtonian "real physics" with the sublight drives, and against "super-science," but are perfectly willing to accept "warp drives" as envisioned in 40K fluff?  Wouldn't that qualify as "super-science?"

That's not an inconsistency by a recognition of the parameters of the 40k universe and the lens through which one observes it.    There's a difference, for example, between realising the context of the warp and the means by which the fictional characters interface with it, and then using that as an argument for pulling whatever argument that you want out of the 'ole derriere. 

I guess it was the insistence on maintaining the dichitomy between sublight and warp travel.  Just struck me as a bit off.  And I whole heartedly agree that people should not just be pulling rationales out of the ether.  There has to be a logical progression with things, and it has to make sense in the context at hand.  Now, we just need to agree on what defines the context.   

I don't think you need a lot of hand waving to make it work.  There just has to be a valid back story to it. 

On the technological standpoint there is more of a problem, in my mind at least.  Again, it's not one that I'm unwilling to go beyond, I just find that the more you do this then the more "fantasy" that your universe gets, which is fine if that's what you want, but... Ah well.

I think it's unavoidable honestly.  There is already so much "fantasy" at work that it is part and parcel of the issue.  This is more like the old DnD arguments over "low fantasy" vs. "high fantasy."  It's all in where you draw the line.  I've always tended to allow the whole range myself.  Why limit oneself unnecessarily?  In that vein, as I see things, the Imperial hierarchy is the "high fantasy," along with the Cardinal and Eden worlds.  You then have the middle of the road stuff in the Hive worlds, most of the Agri-worlds, some of the Knight worlds, etc.  Then you have the "low fantasy" with the feudal worlds, many of the death worlds, and whatever xenos you care to create.  This is wonderfully usable for any sort of campaign.  But, and back to the issue at hand, it's when you try to go to a different world that things get murky.

It's one of the reasons that I normally hit a wall when dealing with Philip S's technology interpretations.  Need a Thunderhawk to be aerodynamic?  Create warp force fields.  Want metals to be stronger?  Use warp magic.  All tightly tied together and quite innovative, but... Well, falls flat on its face for me.

See, this would be too much for me.  The warp does not need to prevalent in everything.  It's too easy a way out with out really establishing things.  Why does this work?  Magic.  You can achieve the same results, such as why a T-Hawk can soar through the sky, without resorting to a cliche.

In this instance, the government having better drives than civilians, it's not that big of a stretch.  IMO, it's not a stretch at all, more so in the context of the 40K universe. 

That's not the stretch.  Indeed, the principle of "technological diffusion" as discussed on the project is merely just this idea--the Adeptus Mechanicus controls the high technology, and through them the "government" through contract.  What sticks in the craw is the idea that they control the "super-dooper" sublight drive while everyone else has to deal with the crappy stuff, something that already happens with warp drive... except it doesn't.  Not quite.

Ultimately it's the same phenomenon as giving every race a new type of interstellar travel.  It smacks of slopping writing.

Not sure I follow that last bit in the first paragraph.  Can you exapand upon that a bit more for me?
And I would agree that just giving each race a "new" type of interstellar travel is weak writing.  Unless an author intends to really muck with the universe, say by stating that there are different "warps," then it's just a kludge to get get around details they don't have and can't be bothered with. 

Does this count as a heretical double post?   

Yes, it did.  Please use the Modify button.

I didn't notice I could add quotes from other posts to the one I was writing through a button.  Really wish more boards had this feature...

It would still need to generate power to work, so there must be something that gets used.

Ah, this is similar to the Traveller jump drive argument... Not that this is inherently a problem once we realise that we're stepping more into the realm of "fantasy."  (See the above, though.  If it's what is necessary then, again, we can revisit the concept.  It just strikes me as... a bit on the lame side.)

Yes, even nuclear/fission reactors use fuel, but the amount needed to generate power is significantly less than fossil fuels.  (Bad analogy I know). 

Hydrogen fuel.  And the reactors do use fuel, but at a much lower rate than the type needed to generate thrust...

Hydrogen fusion engines.  Nice.  So, in theory a ship could "refuel" just by moving (trace gasses and pockets), or by skimming a gas giant? 

Amusingly, going to reactionless thrusters leads us in the same place as the old Traveller!

Again, I'm not against it.  The "reaction" drives are in keeping with the original material, but not in the majority of the assumptions that have been made subsequently.  Thus, the balance of the 'fluff' is to make the universe a bit smaller and have the reduced transit time.

Kage

Is going the Traveller route so bad?     I'd have to dig out my old maps, but IIRC, if you wanted to go from one end of Traveller's Imperium to the other, even at Jump 6, it would still take you around two years of travel time, and that covered less space than the 40K Imperium.  That was just the Imperium, not including the Terran Federation or Zhodani space. 

I guess it all depends on what you want the limiting factor to be.  Currently in 40K it's just time.  That's it.  I'm rather unsatisfied with that, as it comes across as just arbitrary, with no real reason other than "it sounds good." 

[CELS]

This is the fudge that I mentioned elsewhere.  I do not find it particularly pleasing since it buys into the inconsistency rather than sorting it out, which if we recall was one of the little goals that we had with the project.

Well, it's been so long since we discussed this, so I'm probably forgetting something critical, but... it seems to me that the reason we suggested reactionless drives with a minimal fuel expenditure was because the conventional thrusters described in GURPS weren't effective enough. But... since reactionless drives are effectively magical by virtue of being so fantastically advanced, why is it a bad idea to create magical fusion drives that are far more powerful than what seems possible?

I think that one of the reasons that GW might have taken a step back from this approach is because they realised their wars are going to take a rather long time to prosecute.  There's no "running in to save the day" for the Space Marines when everyone can see them coming for a year.

Actually, while the first argument is probably spot on (I mean, how would they be able to resolve any of their worldwide campaigns otherwise?) the second argument is less valid. There's no running in to save the day when enemies are able to make quick surprise attacks either.

And an article which expressly talks about the "average" journey?  Bugger... I cannot find it in the documents that I have to hand, but it's a pull-out box on the right hand page at the top of WD139/140.

I remember that article as well.

Just to pose a little train of thought here, the 6 weeks for an "average ship," is that at "posted no wake cruising speeds?'  Or would that be at max velocity?  I got to thinking in this way from looking at how shipping lanes at ports are controlled.  If you take the warp jump point as the point of entry of a harbor/port, then certain restrictions are immediately in force.  Speeds are controlled, as are what lanes which vessels can be in.  You could even take an air traffic control approach, with a central CnC center directs all incoming and outgoing traffic from a system, assigning them their routes and speeds.  Now this doesn't do a dang thing to solve the root issue at hand, but it could help put that 6 week figure into a deeper context.

I've definitely taken the air traffic control approach in heavily populated colonies. As I see it, this is one of the important reasons why important Imperial systems have monitor stations and listening posts. They serve also to guide and control the traffic within the system. And on top of that, there are minefields and various other security systems to keep incoming ships within certain routes.

To add one more layer of complexity, what if a similar concept to the in system routes applied to the warp ones as well?  That is to say, that some routes are "military only," and others are for specific types of vessels?  This could greatly effect transit times depending on what form of vessel you're talking about. 

A very interesting and original idea. One question though - how could you possible control who uses the military warp routes?

Oh, I can conceive of several reasons for the Venture to have cryostasis units.  And only a few of them have to do with travel!

Then head on over to the Venturer forum, you big tease!

Hydrogen fusion engines.  Nice.  So, in theory a ship could "refuel" just by moving (trace gasses and pockets), or by skimming a gas giant?

Definitely. The Venturer has this ability, for example. However, it seems very likely that the raw material would have to be processed. Not all ships would have this ability and, indeed, it's one of those things that makes the Venturer special. So it's not just plain H2, as I see it.

[Dragon Lord]

Please note that in the warp ships do not use their sublight drives but, rather, utilise the Geller Field as "warp sails," for want of a better term.  At least, that is the justification that Anargo uses and, I feel, the one that we're going to stick with.

I didn't intend to suggest that they did, I was merely acknowledging that whatever the warp drives of a ship do they deal with a realm in which the laws of physics as we know them quite simply do not exist and as such they can pretty much do whatever they like within our background interpretations of the warp and warp travel.

As far as whether there is a difference between ships with engines that require trained Adeptus Mechanicus personnel to maintain and those that do not, I don't find that a huge problem.  That I can remember most Imperial starships, and certainly all military ones are described as having Mechanicus personnel on board, so one of their tasks being to maintain the engines (the maintainence of which would for the most part be beyond other Imperial personnel) I don't think is particularly problematic.

With that said, if this is the only way to solve the issue then, yes, I'm willing to go forwards with it.  I would, however, rather not go down the route whereby the military has the reactionless thruster fudge-drive and the poor schleps only get a reaction-based drive.  That's one of the reasons why, in the RPG statistics for the Venturer, I selected the fusion drive as the "current" 40k version, and the "fusion torch" (limited "superscience" drive) as the one from the past--that they each had a strength and a weakness in comparison to each other.

As far as making the jump to superscience and reactionless drives goes we can go down that route if necessary, but it is not particularly in keeping with the background and I know we generally prefer not to invoke superscience unless there is a good background reason.  In addition though I may have said what I did about Mechanicus maintainence of starship engines I don't think that non-mechanicus maintained vessels should have to make do with an entirely different and inferior class of propulsion system, just one of the same class that is not quite as good/powerful.


Another point that I wanted to add to my original post but did not have time is that the numbers that Kage and I have put out from opposite ends of the problem (Kage from the side of what a ship with a certain engine can achieve and myself from what it needs to do things in a certain period of time) both assume that the ship is going from point A to point B in an essentially uniform space with no external forces present.
This is of course somewhat incorrect as the influence of gravity will be everywhere in a star system.  Gravity is not an entirely negative influence either, it is possible to use gravitational swing-bys of worlds to gain speed, though there is not evidence of Imperial vessels employing this method extensively they could well use just the destination/departure world's gravitational field in this way, giving them a bit of starting momentum or allowing them to stop on reaching their destination.  Another point is that relatively recently there has been some research suggesting that in our solar system there are gravitational 'tubes' set up by the influence of the various planets that could make travel around the solar system somewhat easier, these if they exist here would of course also exist in other star systems and perhaps Imperial vessels make use of them.  This probably wouldn't help us vastly but it would provide a bit of assistance.


Another point that cannot be entirely dismissed when considering starship propulsion is the location of the jump point.  I fairly arbitrarily chose the distance of Uranus, since this is not right on the edge of the solar system but is a fair distance out and older background at least certainly seems to suggest that the jump lay near the edge of the system.  However a lot of the systems that have been created in the Anargo sector if I remember correctly do not show the same sort of orbital spread as the Sol system, and indeed there is no reason to assume that they should do, as such the 'edge' might well be somewhat further in than the orbit of Uranus in most systems and thus the jump point somewhat further in.
I have another thought regarding Lagrangian points, but that is quite technical and I don't have time to go through it properly now.

[Kage2020]

Just to pose a little train of thought here, the 6 weeks for an "average ship," is that at "posted no wake cruising speeds?'  Or would that be at max velocity? 

"No wake?"  Not sure that I follow you there since the term as applied doesn't really make sense to me, so obviously I'm missing something.  My gut response was, "Erm, what wake?  While the "Age of Sail" is an obvious point of inspiration to the 40k interstellar travel imagery, there really isn't any water in space..."

As for "maximum velocity..."  The travel times that I posted were at "maximum velocity," although the time would not be significantly affected if they decided they wanted to slow down.  Otherwise, fuel - and c - is the only real limit to the "maximum velocity" of a reaction-based ship.

And, just while it is in my mind, I would rather go for a multiplier of the efficiency of the engines - a standard constant applied to the amount of delta-v that can be generated to the fusion drives, or perhaps a variable that depends on "tech level" - than replace with reactionless thrusters.  Why?  Dang it, there are only a few reasons and I know how pathetic they are.  First, because it gives me the illusion that we're still dealing with a sci-fi universe not matter how flaccid it might be getting, and secondly because the idea of ships taking an entire day of acceleration (or deceleration) just suits my sense of "lumbering behemoth" ships.  Having a ship come barrelling out of the warp at 500 mps and realising that they should have slowed down before entering the warp because know they're not going to be able to slow down in time... It evokes for me that Age of Sail imagery, but grand sweeping arcs of broadsides, ships forced by environmental factors to change their tactics... the tactics and strategy of engagement when you have to take relative velocities in hand.

Erm, but there we go.

I got to thinking in this way from looking at how shipping lanes at ports are controlled.  If you take the warp jump point as the point of entry of a harbor/port, then certain restrictions are immediately in force.  Speeds are controlled, as are what lanes which vessels can be in.

The only problem is that you have a warp zone, which is a three dimensional sphere (maybe) that wraps around the system at a given distance from the star.  The singular jump point, which arises out of the concept of the stable warp route (not a bad idea!), only becomes feasible for calculated warp jumps or those jumps in which the security of the product is of paramount importance (thus the "safe" route). Indeed, we have explored the idea of "armouring" the jump point, which is to say have some form of armed emplacements ("star fort" or "fleet") at the jump point.  Unfortunately, "realistically" it's just such an easy thing to get around.  A ship coming through at, say, 300 mps is going to barrel by any defenders if they could even predict the point in space that they would emerge from (this is random even for a stable warp route)...

More logically, or at least a more coherent argument, would be to put "port authorities" around the place of interest, or the "mainworld."  This also means that the only real "slow down" that you need to do is matching velocities between the origin and destination systems (i.e. so you can slow down before reaching the world).  This makes a tad more sense when it comes down to fuel economy... And certainly makes piracy a bit more of a viable concept (though with the sweets come sorrows).

You could even take an air traffic control approach, with a central CnC center directs all incoming and outgoing traffic from a system, assigning them their routes and speeds.

Watson's Inquisitor/Draco makes some mention of this IIRC with regards to the Sol system although, once again, the "realism" of it is up for grabs.  Remember, "space is big.  Really big.  In fact, you wouldn't believe how mind bogglingly big space really is.  I mean, you thought a trip down to the local shops was a long way, but that's peanuts when compared to space..." (paraphrased, obviously!)

I'm not so sure about this.  I liken warp travel to the "Golden Age of Sail."  In that era, most captains would stick to well charted routes, even if it took forever to get from point A to point B.  An adventurous captain could go where "here there be monsters" and make the journey in less time.

When it comes down to the actual infrastructure, or even mechanics, of travel, I think that you'll find that our basic assumptions are very similar to the ones that you are arguing for, JRaup.  One of these is that the stable warp route and the calculated warp jump are by far the most common type of warp jump...

Then you have the option to pioneer a route, even if for just one trip. Usual warp issues still apply.

Incidentally, this is one part of the "story" of the Anargo sector that will be explored in the future, or the idea of creating a trans-Abyssal warp route through the "Heart of Anargo."  Erm, not directly relevant for the thread, but just replying with some musings and comments.

To add one more layer of complexity, what if a similar concept to the in system routes applied to the warp ones as well? 

Functionally the military has a number of tactical and strategic advantages when it comes to transit times, and with the warp it is the fact that they have a Navigator and are freed from the "shackles" of the stable warp route.

Well, to my mind there's scale and there's scale.  I don't think I'm suggesting you can cross the Imperium from one side to the other in a matter of days, or even weeks.  It would be months, and more likely a year minimum to my interpretation.  Those time frames of course would indicate "ideal" voyages, unhindered.  So the chances of that actually happening should be rather slim. 

Erm, I think that it is important to remember that most of the transit times that I originally mentioned were in an individual system.  We already have the information on warp transit time since that is fairly well fixed by the 'fluff,' even though some latitude has been introduced by recent publications.  We've even come up with a solution for that, though to be honest the application of it seems a bit... more tenuous at this stage.

I guess it was the insistence on maintaining the dichitomy between sublight and warp travel.

Even when one understands the contextual nature, I don't even believe that there is a dichotomy being created between sublight and warp travel.  Both have a certain burden of imagery that we are trying to construct into a framework of interpretation rather than have the "speed of the plot" approaches that abound in the literature.

There has to be a logical progression with things, and it has to make sense in the context at hand.  Now, we just need to agree on what defines the context.   

With regards to warp travel, there's previous discussion and even an article of how the "Layered Warp" and the concepts of relative depth in the warp refine warp travel.  It did make its way to an article format, but unfortunately as you can see the new version has yet to make its way to the Explore (WiP) site, and only the old version exists at the moment for reference.

As to sublight propulsion.  That's up for grabs once more, although I think keeping reaction-based thrusters and just multiplying the delta-v by some reasonable factor would work while paralleling the imagery.

I think it's unavoidable honestly.

To an extent that is true.

See, this would be too much for me.  The warp does not need to prevalent in everything.  It's too easy a way out with out really establishing things.  Why does this work?  Magic.  You can achieve the same results, such as why a T-Hawk can soar through the sky, without resorting to a cliche.

Just offering a reason that I would be reticent to go down some routes and for those determinations to be able to inform us about the "reality" of the 40k universe.

Not sure I follow that last bit in the first paragraph.

The sloppy writing bit (excepting the typographic "slopping")?

And I would agree that just giving each race a "new" type of interstellar travel is weak writing.  Unless an author intends to really muck with the universe, say by stating that there are different "warps," then it's just a kludge to get get around details they don't have and can't be bothered with. 

Indeed.  And how many "star drives" do we have in the 40k universe?

I didn't notice I could add quotes from other posts to the one I was writing through a button.  Really wish more boards had this feature...

The only board that I believe doesn't have an Edit/Modify button that I'm aware of is the FFG one... Even then it has a time-sensitive edit button.

Hydrogen fusion engines.  Nice.  So, in theory a ship could "refuel" just by moving (trace gasses and pockets), or by skimming a gas giant? 

That's the general idea, yes, although one doubts that a rampscoop is going to be desperately effective moving at the velocities the ships are going to be.

Is going the Traveller route so bad?     I'd have to dig out my old maps, but IIRC, if you wanted to go from one end of Traveller's Imperium to the other, even at Jump 6, it would still take you around two years of travel time, and that covered less space than the 40K Imperium.  That was just the Imperium, not including the Terran Federation or Zhodani space. 

Again, we're conflating the discussion about sublight and supralight travel, here, or at least potentially so.  I cannot remember the exact figure, but I believe it is meant to take around 40 years to cross the Imperium. 

But... since reactionless drives are effectively magical by virtue of being so fantastically advanced, why is it a bad idea to create magical fusion drives that are far more powerful than what seems possible?

Seems that I have independently come to that conclusion as well.  This allows some scaling to exist between the various types of drive without recourse to breaking too many laws of physics.

Actually, while the first argument is probably spot on (I mean, how would they be able to resolve any of their worldwide campaigns otherwise?) the second argument is less valid. There's no running in to save the day when enemies are able to make quick surprise attacks either.

The second is merely more cynical than the former, with the former argument seemingly being one that you're more comfortable with.  Just sayin'.  Nothing bad meant by that.

A very interesting and original idea. One question though - how could you possible control who uses the military warp routes?

Or the civilian ones, to be fair.  Even the concept of system defense ala minefields is problematic.  But that is a discussion for another thread.

In addition though I may have said what I did about Mechanicus maintainence of starship engines I don't think that non-mechanicus maintained vessels should have to make do with an entirely different and inferior class of propulsion system, just one of the same class that is not quite as good/powerful.

As above, a generic multiplier of the "fuel efficiency" solves the problem nicely.  We already have a TL-based differentiation, so I don't see the need to exacerbate this by having "plasma drives" restricted to the Imperial authorities while everyone else is using... say, ion drives.

Kage from the side of what a ship with a certain engine can achieve and myself from what it needs to do things in a certain period of time) both assume that the ship is going from point A to point B in an essentially uniform space with no external forces present.

Indeed.  The figures also didn't change because of the decreasing mass of the ship either.  I'm an archaeologist, not a physicist and really didn't want to break out the differential equations!

Another point that cannot be entirely dismissed when considering starship propulsion is the location of the jump point. 

As above, our current working hypothesis is that the jump point is at:

D (AU) = sqrt. [M (Sol) / P]

where P is the probability of "catastrophic warp drive failure" and was arbitrarily determined to be 0.003.  For Terra, as in the above calculations, this puts the warp zone at 18.26 AU from Sol, or about 17.26 AU from Terra... on average, since it is simplifying it to circular orbits.  Thus, the distance to the warp zone is dependent upon the "mass shadow" of the central star.  There will be smaller ones for planets, but most will be fairly negligible.

The bright side is that this puts a number of the planets outside of the warp zone and, as above, makes a whole lot of other things increasingly possible.  Like piracy, for one.

I have another thought regarding Lagrangian points, but that is quite technical and I don't have time to go through it properly now.

LaGrange points are the weakness in GW's science.  I am discounting them here as influencing the warp zone by fiat, although they have always offered a way out of the contentious 'fluff' and a return to the older premise of a "warp gate" (as a natural phenomenon). 

If people would really like to go down the route of these incredible "short cuts" to the warp zone, I wouldn't be averse to that, but the universe would once again massively shrink when, for example, people can just pop out of the warp at just under 400,000 km away...

In fact, it would probably be a strategic nightmare, which is why I would tend to not use LaGrange points as a way of bypassing the Warp Zone.

Kage

[JRaup]

Just to pose a little train of thought here, the 6 weeks for an "average ship," is that at "posted no wake cruising speeds?'  Or would that be at max velocity? 

"No wake?"  Not sure that I follow you there since the term as applied doesn't really make sense to me, so obviously I'm missing something.  My gut response was, "Erm, what wake?  While the "Age of Sail" is an obvious point of inspiration to the 40k interstellar travel imagery, there really isn't any water in space..."

Yeah, it's a boating thing.  When in a marina, there are signs posted with a  max speed and a "no wake" warning.  You're not supposed to be going fast enough to produce a wake behind you (for a variety of reasons).  As I was working with that whole harbor/port/marina theme, it just seemed natural.  And while there is no water in space (nor does it care if you scream), there are at least trace gasses, which could produce a wake like effect.  Not saying it should happen, just that it could happen.

As for "maximum velocity..."  The travel times that I posted were at "maximum velocity," although the time would not be significantly affected if they decided they wanted to slow down.  Otherwise, fuel - and c - is the only real limit to the "maximum velocity" of a reaction-based ship.

And, just while it is in my mind, I would rather go for a multiplier of the efficiency of the engines - a standard constant applied to the amount of delta-v that can be generated to the fusion drives, or perhaps a variable that depends on "tech level" - than replace with reactionless thrusters.  Why?  Dang it, there are only a few reasons and I know how pathetic they are.  First, because it gives me the illusion that we're still dealing with a sci-fi universe not matter how flaccid it might be getting, and secondly because the idea of ships taking an entire day of acceleration (or deceleration) just suits my sense of "lumbering behemoth" ships.  Having a ship come barrelling out of the warp at 500 mps and realising that they should have slowed down before entering the warp because know they're not going to be able to slow down in time... It evokes for me that Age of Sail imagery, but grand sweeping arcs of broadsides, ships forced by environmental factors to change their tactics... the tactics and strategy of engagement when you have to take relative velocities in hand.

Erm, but there we go.

I don't have a disagreement with the whole speed up-slow down concept.  If anything I support it!  See, I don't think it would matter if you have reaction or reactionless drives for this.  Even a reactionless drive wouldn't be able to stop on a dime as it were.  And as I see it, the type of drive wouldn't change the combat environmentals all that much either.  You'd still have to account for the movement of the target, your movement, distortions, etc. 

The concept of an efficiency coefficient could work for all of us.  The key to that I think would be in defining how many "old" drives there are compared to "new" drives.  What's the most common drive type, and how prevalent is it?  How rapidly do "new" drives get out into the universe?

I got to thinking in this way from looking at how shipping lanes at ports are controlled.  If you take the warp jump point as the point of entry of a harbor/port, then certain restrictions are immediately in force.  Speeds are controlled, as are what lanes which vessels can be in.

The only problem is that you have a warp zone, which is a three dimensional sphere (maybe) that wraps around the system at a given distance from the star.  The singular jump point, which arises out of the concept of the stable warp route (not a bad idea!), only becomes feasible for calculated warp jumps or those jumps in which the security of the product is of paramount importance (thus the "safe" route). Indeed, we have explored the idea of "armouring" the jump point, which is to say have some form of armed emplacements ("star fort" or "fleet") at the jump point.  Unfortunately, "realistically" it's just such an easy thing to get around.  A ship coming through at, say, 300 mps is going to barrel by any defenders if they could even predict the point in space that they would emerge from (this is random even for a stable warp route)...

Well, yes, you could just blow past the defensive positions, but would it really be a good idea? 
"Ha!  We blew past those chumps at Io!  Never saw us coming."
"Hey boss, what's that in front of us?"
"What?  Oh crap!  That's Saturn!"
*SMACK*

I'm not sure I like the Babylon-5 route with warp gates and the like, though I could see how it would fit in with the existing fluff actually.  But I would be more in line with the idea of an area, rather than a singular fixed point, which is conducive for ships entering/exiting from the warp.  Not the globe concept as given, but more of a window on that globe.  Of course there would be exceptions to this, but those should remain exceptions, and not become rules, as happens all too often.  In my thoughts, yes, a ship could just enter and exit the warp anywhere outside the system shadow, but the energy and safety factors would generally be prohibitive. 

More logically, or at least a more coherent argument, would be to put "port authorities" around the place of interest, or the "mainworld."  This also means that the only real "slow down" that you need to do is matching velocities between the origin and destination systems (i.e. so you can slow down before reaching the world).  This makes a tad more sense when it comes down to fuel economy... And certainly makes piracy a bit more of a viable concept (though with the sweets come sorrows).

I agree with this as well.  Though I would venture that piracy should still be mainly prevalent in the lesser developed systems.  You really shouldn't see a pirate raid in a Cardinal system for example.  Unless you have one very suicidal pirate captain.

You could even take an air traffic control approach, with a central CnC center directs all incoming and outgoing traffic from a system, assigning them their routes and speeds.

Watson's Inquisitor/Draco makes some mention of this IIRC with regards to the Sol system although, once again, the "realism" of it is up for grabs.  Remember, "space is big.  Really big.  In fact, you wouldn't believe how mind bogglingly big space really is.  I mean, you thought a trip down to the local shops was a long way, but that's peanuts when compared to space..." (paraphrased, obviously!)

I think there must be something for CnC in system.  Now, how far into a system before it takes control is another matter.  But there has to be some sort of port control, or you couldn't have the volume of traffic needed for trade and military matters.  You shouldn't just be able to say "hey that landing bay looks good, use that one."  Otherwise you turn local space into a giant parking lot free for all.  You'd have ships racing for the best "spots," jams as several ships try to get to the one that just opened, etc.  I'd be like a mall parking lot a Christmas.  The situation would demand a solution, and that solution is a CnC type set up to manage the traffic.

And now for a selection of fine Vogon poetry...

I'm not so sure about this.  I liken warp travel to the "Golden Age of Sail."  In that era, most captains would stick to well charted routes, even if it took forever to get from point A to point B.  An adventurous captain could go where "here there be monsters" and make the journey in less time.

When it comes down to the actual infrastructure, or even mechanics, of travel, I think that you'll find that our basic assumptions are very similar to the ones that you are arguing for, JRaup.  One of these is that the stable warp route and the calculated warp jump are by far the most common type of warp jump...

Yeah, I see this as well.  We're arguing granny smith apples vs. golden delicious IMO.  But the synthesis of these discussions should prove..."fruitful"...

Then you have the option to pioneer a route, even if for just one trip. Usual warp issues still apply.

Incidentally, this is one part of the "story" of the Anargo sector that will be explored in the future, or the idea of creating a trans-Abyssal warp route through the "Heart of Anargo."  Erm, not directly relevant for the thread, but just replying with some musings and comments.

Cool.  The concept I think does apply, if only tangentially.  I think this kind of goes to the heart of a lot of what we're discussing, even if it has strayed a bit..

To add one more layer of complexity, what if a similar concept to the in system routes applied to the warp ones as well? 

Functionally the military has a number of tactical and strategic advantages when it comes to transit times, and with the warp it is the fact that they have a Navigator and are freed from the "shackles" of the stable warp route.

Let me refine the idea bit more.  I would totally agree with you about the use of a Navigator when it comes to tactical applications.  Being able to go "off the beaten path" is a huge tactical and strategic advantage.  However, when it comes to logistics, stability is better.  One also has to consider how many navigators are there in the Imperium.  I don't imagine that there are enough to man every IN warship, and troop ship, and supply vessel out there.  So, I would postulate that while the main war fleets have navigators, the supply vessels don't.  That leaves them with using the known and stable routes.  As Napoleon said, an army only moves as fast its supply trains (well close enough), I would think that there would be dedicated routes for these vessels between major supply points. 

Well, to my mind there's scale and there's scale.  I don't think I'm suggesting you can cross the Imperium from one side to the other in a matter of days, or even weeks.  It would be months, and more likely a year minimum to my interpretation.  Those time frames of course would indicate "ideal" voyages, unhindered.  So the chances of that actually happening should be rather slim. 

Erm, I think that it is important to remember that most of the transit times that I originally mentioned were in an individual system.  We already have the information on warp transit time since that is fairly well fixed by the 'fluff,' even though some latitude has been introduced by recent publications.  We've even come up with a solution for that, though to be honest the application of it seems a bit... more tenuous at this stage.

I haven't come across that yet (warp times).  But I'll keep reading.  I probably won't agree with the conclusion, but that's neither here nor there.    

I guess it was the insistence on maintaining the dichitomy between sublight and warp travel.

Even when one understands the contextual nature, I don't even believe that there is a dichotomy being created between sublight and warp travel.  Both have a certain burden of imagery that we are trying to construct into a framework of interpretation rather than have the "speed of the plot" approaches that abound in the literature.

OK, so I'm looking for a "grand unified theory" type structure here.  I do realize that it may not be possible, but my mind insists on trying.   

I think I'm out of step with you in part because I'm not just looking at the "science" aspect.  Yes, that is an important factor, and goes a long way to establishing a solid back story.  But I also see a need to make whatever gets put down "practical."  Not is a strict "can this work" science sense, but in a larger "can the Imperium work like this" sense.  It's one of the reasons I get hung up about travel times.  I look at the economic, political, communication, and military aspects, and say to myself "this just can't work."  Not and have any sense of cohesion to the Imperium at least.  With my readings on the 40K verse, I get the sense that there is some level of central authority, but then I look at various fluff pieces and such, and don't see how that can be with all the various "restrictions." 

I suppose a lot depends on how you see the Imperium.  Is it a centrally controlled Empire, like the Victorian era ones, or is it more decentralized, with the Emperor and Terra being just another principality, like the Holy Roman Empire or the Ottoman Empire.  No, there is no supposition here, it does all depend on how you perceive the Imperium.  I guess the real problem here is that GW has taken elements from all of the potential examples, and just bolted them together.  There's no real cohesion to the concept, which leads to all sorts of semi-contradictions and gaps in the logic.

There has to be a logical progression with things, and it has to make sense in the context at hand.  Now, we just need to agree on what defines the context.   

With regards to warp travel, there's previous discussion and even an article of how the "Layered Warp" and the concepts of relative depth in the warp refine warp travel.  It did make its way to an article format, but unfortunately as you can see the new version has yet to make its way to the Explore (WiP) site, and only the old version exists at the moment for reference.

Cool.  I'll read up on that later.  Hopefully it will better ground me in what everyone else's thought processes are.

As to sublight propulsion.  That's up for grabs once more, although I think keeping reaction-based thrusters and just multiplying the delta-v by some reasonable factor would work while paralleling the imagery.

As I said above, this could work, as long as the end result is satisfactory.  Really, the mechanical/science specifics are somewhat irrelevant to me, as long as they have a logical "natural" flow to the fluff of it. 

I think it's unavoidable honestly.

To an extent that is true.

See, this would be too much for me.  The warp does not need to prevalent in everything.  It's too easy a way out with out really establishing things.  Why does this work?  Magic.  You can achieve the same results, such as why a T-Hawk can soar through the sky, without resorting to a cliche.

Just offering a reason that I would be reticent to go down some routes and for those determinations to be able to inform us about the "reality" of the 40k universe.

Oh I do agree.  I think we just draw the line a different points. 

Not sure I follow that last bit in the first paragraph.

The sloppy writing bit (excepting the typographic "slopping")?

And I would agree that just giving each race a "new" type of interstellar travel is weak writing.  Unless an author intends to really muck with the universe, say by stating that there are different "warps," then it's just a kludge to get get around details they don't have and can't be bothered with. 

Indeed.  And how many "star drives" do we have in the 40k universe?

Too many honestly.  I think a fundamental mistake was made early on, and it's juts been compounded over the years.  There really shouldn't be that many different drives.  The mistake I think was in confusing terminology for technology.  It should matter if you call a bolt shirley, it's still a bolt.  But what happened IMO, is that shirley stopped being a bolt, and became something else.  This misconception just became the norm, in part because the materials to make the various drives diverged so much.  It really shouldn't matter if all the basics are the same what a drive is made of, it still does exactly the same things as all the others. 

I didn't notice I could add quotes from other posts to the one I was writing through a button.  Really wish more boards had this feature...

The only board that I believe doesn't have an Edit/Modify button that I'm aware of is the FFG one... Even then it has a time-sensitive edit button.

I'm most familiar with PhP boards, none of the ones I'm on have this neat feature. 

Hydrogen fusion engines.  Nice.  So, in theory a ship could "refuel" just by moving (trace gasses and pockets), or by skimming a gas giant? 

That's the general idea, yes, although one doubts that a rampscoop is going to be desperately effective moving at the velocities the ships are going to be.

I did say "in theory."     IIRC, even in Traveller, ramscoops were not a good way to refuel a ship.  It was more of a "we don't have any choice" kind of thing. 

Is going the Traveller route so bad?     I'd have to dig out my old maps, but IIRC, if you wanted to go from one end of Traveller's Imperium to the other, even at Jump 6, it would still take you around two years of travel time, and that covered less space than the 40K Imperium.  That was just the Imperium, not including the Terran Federation or Zhodani space. 

Again, we're conflating the discussion about sublight and supralight travel, here, or at least potentially so.  I cannot remember the exact figure, but I believe it is meant to take around 40 years to cross the Imperium. 

Like I sort of said above, I think this all goes hand in hand.  I think things have to work as a whole, and not just as individual aspects.  It all has to fit together, or it just kind of falls apart once you take a step back and look at things.  Like the 40 year cross-Imperial transit time.  It may sound good, and have legitimate rationales, but to my mind, it just doesn't work on the whole.  Too many other things become suspect as a result.

EDIT: Quick question, which Venture thread should I bring up my ideas for why it has the cryostasis equipment?  Abilities or aesthetic?

[CELS]

EDIT: Quick question, which Venture thread should I bring up my ideas for why it has the cryostasis equipment?  Abilities or aesthetic?

Abilities or RPG statistics, please. It's only been discussed in the RPG-thread so far.

Sorry for not replying to other parts of the discussion. This thread is branching out, growing quotes like fungus in my bathroom wall, and I'm having difficulties keeping up and keeping track of what's actually being said.

[Dragon Lord]

As above, our current working hypothesis is that the jump point is at:
D (AU) = sqrt. [M (Sol) / P]...

Fair enough, that of course can be altered to shuffle the jump point further in system if desired, increasing the probability of catastrophic warp entry failure to 1% would bring it in to 10AU and of course the use of M(sol) is fairly arbitrary.

LaGrange points are the weakness in GW's science.  I am discounting them here as influencing the warp zone by fiat, although they have always offered a way out of the contentious 'fluff' and a return to the older premise of a "warp gate" (as a natural phenomenon).....

Just to outline some of the mechanics of Lagrange points there are 5 points in a system of two large bodies, e.g. the Sun and the Earth, L1 and L2 lie about 1.5million km inside and outside the Earth's orbit on the Earth-Sun line, L3 is on the opposite side of the Sun (so 2 AU away) and L4 and L5 lie on the Earth's orbit 60 degrees ahead and behind the Earth (and thus are 1 AU away).
So if we allowed the use of Lagrange points as 'warp gates' the closest one could exit the warp to Earth would be 1.5million km.  Also L1,2&3 are unstable, objects placed there will tend to fall towards the Sun or the Earth, whereas L4 and L5 are stable, objects placed there tend to remain there.  As such if we said that only the stable Lagrange points could be used, which seems potentially reasonable, the closest one could appear is 1AU away.  The use of Lagrange points does I suppose also bring up the issue that it would then be in some cases more efficient to 'Lagrange point hop' using the warp to get around a system, which is not something that is ever discussed in the background.  One could argue that it is because unlike the system edge Lagrange points must be carefully gravitationally mapped before they can be used safely and this is only ever done for the main world usually but it is perhaps not the ideal solution.  Then again one could also say that only the L4 and L5 points of gas giants are deep enough to use as warp gates, making it likely that only one would ever be used as there is no advantage to using others, and not all systems have one gas giant let alone more than 1.  This would also place the closest jump point several AU outside the inner system and mean any travel between major inhabited worlds in the system would have to be via realspace.

I do agree that an efficiency modifier is probably the best option for getting the intra-system travel times to something more reasonable, I just thought I would lay out the Lagrange point option fully so that people can see what it would involve.

Also quick question Kage what is the unit 'mps' that you are using, is it miles per second?

[Kage2020]

And while there is no water in space (nor does it care if you scream), there are at least trace gasses, which could produce a wake like effect.  Not saying it should happen, just that it could happen.

I have my doubts that given the average density of interstellar gases are going to create a significant "wake" effect, since they're - what? - 1 atom per cubic centimeter? 

See, I don't think it would matter if you have reaction or reactionless drives for this.  Even a reactionless drive wouldn't be able to stop on a dime as it were.  And as I see it, the type of drive wouldn't change the combat environmentals all that much either.  You'd still have to account for the movement of the target, your movement, distortions, etc. 

Reaction-based and reactionless thrusters have a completely different "feel" when applied in a sci-fi universe, though.  Or at least completely different in my experience, since it relies upon use rather than merely the passage of time.

The concept of an efficiency coefficient could work for all of us.  The key to that I think would be in defining how many "old" drives there are compared to "new" drives.  What's the most common drive type, and how prevalent is it?  How rapidly do "new" drives get out into the universe?

The answer to that question depends primarily on who gets the most advanced drives and, in this case, the point at which the "STC" for fusion torch drives becomes available (which has about the same delta-v, but an increased acceleration).  Or perhaps even antimatter drives, which I believe have been mentioned with regards to G/DAoT ships, but which I also felt were more appropriate for "military" vessels.

The "efficiency" of the drive therefore depends on the "tech level," which defines the overall "mps" (or how much delta-v) the drive system can generate with a given amount of fuel.  This requires the in-universe answering of the question as to what level of technology does the Adeptus Mechanicus allow the Imperium at large to access.  Our previous answer is that it was Low Martian, or TL 10.  But what about the Imperial military?  Do they allow them access to Common Martian?

Well, yes, you could just blow past the defensive positions, but would it really be a good idea? 
"Ha!  We blew past those chumps at Io!  Never saw us coming."
"Hey boss, what's that in front of us?"
"What?  Oh crap!  That's Saturn!"
*SMACK*

Assuming that the "jump point" is that close to Saturn.  It is unlikely that this would be the case.  Furthermore, you can always jump to another point along the warp zone.

I'm not sure I like the Babylon-5 route with warp gates and the like, though I could see how it would fit in with the existing fluff actually.  But I would be more in line with the idea of an area, rather than a singular fixed point, which is conducive for ships entering/exiting from the warp.  Not the globe concept as given, but more of a window on that globe.

As above, one can argue that this is the "probability wake" of a drive exiting the warp from the stable warp route.  Even so, it is suggested to be an incredibly large volume of space on the order of 8 billion-odd (or more) cubic kilometers.  That's not really a practical volume to defend, mine or whatever. 

In my thoughts, yes, a ship could just enter and exit the warp anywhere outside the system shadow, but the energy and safety factors would generally be prohibitive. 

Mirrored here by fuel and, of course, whatever game mechanics that you use to control warp travel.  Hopefully Rogue Trader will introduce those to the 40k universe.  (I have my doubts that they will, or at least they will be what many of the people interested in those rules would like to see... )

I think there must be something for CnC in system.  Now, how far into a system before it takes control is another matter.

Indeed.  To be honest, for massively developed systems like hiveworlds or worlds on major shipping routes...?  I do believe that there is an arbitrarily established perimeter at which ships do begin to get "funneled," but that truly is going to vary from world to world.  For example for the Terran system I would imagine that it lies at least at Jupiter...

So... interesting argument, and well taken with the caveat that it truly depends on the world and strategic choices in question.  We can make more of this in our descriptions of the individual worlds, or perhaps someone can even work up a guideline based upon the star type and world type as to what this might be.

Yeah, I see this as well.  We're arguing granny smith apples vs. golden delicious IMO.  But the synthesis of these discussions should prove..."fruitful"...

*kaboom-tisch...*

Cool.  The concept I think does apply, if only tangentially.  I think this kind of goes to the heart of a lot of what we're discussing, even if it has strayed a bit..

Yep, even though it wasn't specific I feel that this thread was designed to discuss sublight drives.  We all are fairly familiar with the operation and "rules" that govern the warp drive.

However, when it comes to logistics, stability is better.

An accepted truism at Anargo.

One also has to consider how many navigators are there in the Imperium.

Anargo considers them to be very rare, rather than what is in essence a "servitor" class, one for every ship.  Indeed, we argue that the short-distance "calculated warp jump" is by far the most common type of jump, and thus is moderated by the system of major, minor, and feeder trade routes - stable warp routes - that criss-cross the subsectors, and which also exist between the subsectors themselves.

In short, we've been there, done that, and have the T-shirt.  Indeed, one of the things that we've been waiting for is to get sufficient numbers of the worlds finalised so that we can begin to build up this skein of systems using a defined series of trade guidelines (modified to 40k), rather than just pulling them out of our bottoms.

I haven't come across that yet (warp times).  But I'll keep reading.  I probably won't agree with the conclusion, but that's neither here nor there.     

WD139/140 for the originals.  There are some potential ones here that we might be using, but their application isn't quite yet... solid.  Thus I'm biased towards the originals, even if I think that the ones here have greater potential in the long run.

I think I'm out of step with you in part because I'm not just looking at the "science" aspect.  Yes, that is an important factor, and goes a long way to establishing a solid back story.  But I also see a need to make whatever gets put down "practical."  Not is a strict "can this work" science sense, but in a larger "can the Imperium work like this" sense.  It's one of the reasons I get hung up about travel times.  I look at the economic, political, communication, and military aspects, and say to myself "this just can't work."

I do not think that are approaches are mutually exclusive, except where I use the "reality" (as much as possible and with full realisation that we're dealing with a fictional universe) to expose the holes in the Imperium.  We have to accept that it has existed for ten millennia, even if the majority realise that it is through designer fiat, so being aware of the glitches and perhaps even exploiting them in continuing narrative is, for me, acceptable.  Similarly, it's part of the reason that I'm not particularly inspired by the parochial and thematic approach of Dark Heresy--I don't want to have earlier and later medieval Europe shoved down my throat, but would rather see it as a progressive system wherein it will fail or grow stronger by making given choices.

Erm, but there we go.

Suffice to say, though, that the Imperium isn't going to break because it takes 10 months for a ship to get from the warp zone to a mainworld, especially given the standard argument with regards to the efficiency of the Adeptus Administratum.  (Just out of interest, we argue that the Adeptus Administratum is actually rather efficient, but also recognise that they're dealing with a shed-load of information exchange--that's one helluva bandwidth.)

With my readings on the 40K verse, I get the sense that there is some level of central authority, but then I look at various fluff pieces and such, and don't see how that can be with all the various "restrictions." 

This is assumed, yes, but it is far more diffuse than most people seem to recognise.  In this it seems very much like feudalism coupled with true 'empire.' 

However, my bias or socio-cultural framework is more influenced by late Republic/early Imperial Rome than later medieval Europe, even if some feudal aspects are throw into the mix.

Cool.  I'll read up on that later.  Hopefully it will better ground me in what everyone else's thought processes are.

Please remember that it needs to be modified given the more recent discussions, with that article being written well over 5 or more years ago to offer a "narrative" to the warp...

As I said above, this could work, as long as the end result is satisfactory.  Really, the mechanical/science specifics are somewhat irrelevant to me, as long as they have a logical "natural" flow to the fluff of it.

As an "explorationist-simulationist," reality negotiates with the context of the universe.  I'm fine with people getting "reasonable" travel times between the warp zone and the mainworld, but it should inform subsequent materials.  Having a slower trip making the journey in half the time as a faster ship would make very little sense unless there was a reason for that (such as the faster ship having almost no fuel left).

In short, there should be consequences for choice and action.

I'm most familiar with PhP boards, none of the ones I'm on have this neat feature. 

*whispers*

This is a PHP and MySQL board.  Wheres you meant phpBB?  We haven't used that software for some time so I'm not really that familiar with it and its limitations any more.

Like I sort of said above, I think this all goes hand in hand.  I think things have to work as a whole, and not just as individual aspects.  It all has to fit together, or it just kind of falls apart once you take a step back and look at things.  Like the 40 year cross-Imperial transit time.  It may sound good, and have legitimate rationales, but to my mind, it just doesn't work on the whole.  Too many other things become suspect as a result.

Not quite sure why the 40 year period doesn't work since it really just defines regions of political effectiveness and influence on a much smaller level.  But then again the idea of centralisation and the Imperium has been questionable since the start, even if like the 'fluff' on the anthropogenic nature of the Chaos Gods it has been there for quite some time.

Fair enough, that of course can be altered to shuffle the jump point further in system if desired, increasing the probability of catastrophic warp entry failure to 1% would bring it in to 10AU and of course the use of M(sol) is fairly arbitrary.

Of course, but it was a distant that people originally felt comfortable.  Far enough out there without requiring that they travel beyond, say, 49 AU for Pluto.  Suddenly that ten months is going to take 25...

With that said, there are going to be problems.  Those peskily heavy M-type stars are going to have a warp zone that is much, much further away... 

The use of Lagrange points does I suppose also bring up the issue that it would then be in some cases more efficient to 'Lagrange point hop' using the warp to get around a system, which is not something that is ever discussed in the background.

Aaargggh!  I'm getting flashes of the computer game, I-War (which was incidentally a game that I absolutely loved, but there we go).  Again, the overall implications are such that the appearance of a "warp gate" in the inner system should be one that is a rarity, just like it was in the older 'fluff' (IIRC), rather than something that is overtly moderated by the LaGrange points...

I do agree that an efficiency modifier is probably the best option for getting the intra-system travel times to something more reasonable, I just thought I would lay out the Lagrange point option fully so that people can see what it would involve.

Thanks for taking the time to do so.  We had already discarded them as a possibility, but I'm always willing to explore new ideas.

Also quick question Kage what is the unit 'mps' that you are using, is it miles per second?

Yes.


So is 42 days really how quick people want a "quick ship" getting the 17.26 AU to the warp zone?

Kage