Escape Velocity Problem Returns in T5!

[rancke]

Overall, the Imperium overall hasn't expanded much since Arbellatra's time - in fact, it's probably gotten smaller, losing a few systems in the Marches and about three-quarters of worlds within 50 parsecs of Sol.

A few systems more or less doesn't make any real difference and a shortening of the communications lines in one direction doesn't help in the other directions. For practical purposes the Imperium is exactly the same size as back in Arbellatra's time. Which means its communication pressures are exactly the same seriousness that prompted Arbellatra to set up a "pony express" style system in the first place. Now, a pony express system is significantly more expensive than an ordinary courier system, and it's only advantage is that it wrings a few hours advantage out of every link. The whole system makes no sense unless the difference between an average of 3.8 persecs per week and 3.9 persecs per week (or whatever the figures would be -- certainly somewhere in the upper ranges of between 3 and 4 parsecs per week) would actually be important.

It follows that a system that average 2.6 parsecs per week is not doing anything to alliviate any of those pressures. Furthermore, as I've pointed out before, by the Classic Era, at least, it is being outperformed by civilian J4 traffic -- that is to say, the same traffic that wasn't good enough back when the X-boats were first concieved.

Conclusion: Something else is taking up the slack, and I submit that in navy couriers we have the perfect 'something else'.

I'd say that advanced information is valuable, but long-haul information is not as valuable as you might think, because of the structure of the Imperium.

Trying to have it both ways. Either it's valuable enough for a small handful of the High & Mighty to try to maintain a monopoly (in which case it's valuable enough for a large number on Nearly As High & Mighty to invest in breaking such a monopoly) or it's not.

The feudal structure of the Imperium means that actual implementation of the Emperor's decrees is left to local leaders, typically at the subsector level. This in turn means that it is usually more important to know what the subsector officials are actually doing than to hear the Emperor's decree first.

Important for who? It's important for the local leaders to get their orders from the Emperor fast and it's also important for the Emperor (and his ministers) to get reports from his faroff servants fast. Arbellatra thought so. I see no reason to suppose that Strephon wouldn't think the same.

Not quite. What I'm saying is that advance information from far away isn't valuable enough, in the ordinary course of things, to warrant upgrading the existing X-boat system or to support widespread commercial services at J-5 or J-6.

And I say that it would be be worth it to the Imperial bureaucracy if there hadn't been an alternative that rendered the X-boats irrelevant.

But this is a case where the government has set up a separate postal service - the IISS Communications Branch is the postal service of the Third Imperium. That it is slower than Naval couriers isn't the Navy's problem - if the Emperor feels a need to speed up the mail, he certainly has the budget and authority to do so. ;-)

Precisely my point. That the Emperor has not felt the need to speed up the X-boats (and, indeed, has allowed them to deteriorate to the parlous state they're in by the Classic Era) shows that there is a speedier alternative: The IN's speedy couriers.

So I conclude that routine governmental traffic is the responsibility of the IISS by virtue of the Imperial decree that set it up. To my knowledge, that hasn't been rescinded or countermanded.

I mentioned that the original dispatch quite possibly (even likely) still go by X-boat. But I think copies go by Navy courier. There's no reason why not, since the couriers will be flying either way, carrying navy dispatches between fleet headquaqrters and sector headquarters and between sector headquarters and the Admiralty on Capital.

Of course, the Navy will handle emergency dispatches when necessary for the good of the Imperium.

Of course. Just as it will carry routine dispatches for the good of the Imperium.

I thought it was a fun exchange, so I'm glad you did.

It was silly of me to respond in kind because (IMO) an admiral would never say any such thing in the first place. One, because he wouldn't be short of couriers to pass along dispatches from subsector capital to sector capital (where they can be forwarded to Capital), and, two, because he's duty bound to obey orders from the duke.

Correct. And if carrying government dispatches is a 400-year-old traditional task of the IISS, then the Duke wouldn't think of going to the Admiral except in a real emergency. So a lot of this comes down to your preference for your game versus mine versus what's been published about the OTU.

It seems to me that it comes down to the X-boats indisputably not functioning as canon claims they do, and me thinking an explanation for that would be nice while you don't see any discrepancy that needs to be accounted for.

I submit that published OTU canon says that the X-boat network is used for the routine work of government and commercial communications.

And I submit that canon also say that the X-boats are the fastest available means of communication, which is quite obviously no longer the case by the Classic Era.

"The xboat service was established to provide for the fastest possible transmission of information for official, commercial, and private purposes." [BoJTAS2:13]​

And it must be said that such a pony express type setup would be faster than anything ordinary commercial traffic or even ordinary J4 couriers could match. By days per link for commercial traffic and half days per link for couriers.

I doubt that there are many military commanders who feel that they have far too many resources to accomplish the tasks they've been charged with. So regardless of how many couriers the Admiral has, he is probably loathe to lose any, unless he absolutely has to.

But since he has to send reports to Sector HQ, he absolutely has to. Just how often is a matter of conjecture (personally I favor a daily courier) but it's definitely going to be often enough to beat any service restricted to J4, even if it had been optimized, which, as we both agree, the X-boats are very far from being.


Hans

 

[Drakon]

Do you have any reason why you have that impression? I don't have any canon support myself, but I've never even considered the possibility that the sector admiral wouldn't be co-located with the sector duke.

Mostly it is based on the fact that Kaasu, the Sector Capital, does not have a naval base. Can you have a fleet headquarters without having a naval base? Obviously you believe you can, and that the situation is more analogous to the Pentagon versus Norfolk, but I am not so sure. The bulk of the naval assests would be at Depot, so it seems logical headquarters would be there as well.

Again, a courier doesn't need a base to be stationed at. It can be stationed anywhere (though in some places logistical support will cost more than in other places).

While true, I was thinking more about the communications link between Depot, Sector Fleet Headquarters and our own local fleet commands.

 

[Drakon]

The logical place for an admiral is wherever the center of his comm net is.
IF the subsector "duke" has authority over the admiral, then yes, there's a good reason for both the admiral and the fleet courier net to routinely include it. Otherwise, no, there's no reason at all for a non-naval base subector capital to have the numbered nor reserve fleet's Admirals present, nor a routine dispatch run.

I can think of one reason, intelligence.

Corridor has the Vargr to Coreward to deal with, the whole reason why there are so many numbered fleets in Corridor is to protect the Imperium's Coreward flank from invasion. Indeed, during the Rebellion era, after all the Corridor fleets get stripped, the Vargr do invade and sever the link between Deneb and Vland.

Keeping the Sector archduke and subsector dukes informed of the Vargr is one reason why you would have comm links established.

One in 6 jumps runs into the 8th day. You need to allow for targeting errors (which are, per MT, TNE, and T4, not that uncommon) on top of the longer lobe. 8 ships is going to be cutting it tight several times a month.
9 allows for reasonably robust schedules that are only disrupted by the roughly 1 in 400 jumps that have more severe issues. (Outside CT and T5, it's nigh impossible to misjump more than a thousand AU unless you actually ignore maintenance and reasonably safe operations, but it's not uncommon to have minor mishaps. T5, it's remarkably easy to wind up stopped short.)

So a 10 ship squadron for one run would be ideal, and provide enough redundancy to handle most contingencies.

 

[rancke]

Only if the Subsector duke has ANY AUTHORITY at all.

Which he has. "Interstellar government starts at the subsector level".

The subsector duke is, in many ways, analogous to a provincial governor in a historical European empire. He's the direct representative of the Emperor (King), his duchy (province) is an administrative subdivision of the larger empire that funds the navy. It would be much stranger (though not, I admit, completely out of the question) if he didn't have authority at least equivalent to that of a historical royal governor.

The logical place for an admiral is wherever the center of his comm net is.

And the logical place for the center of his comm net is where he is, so that doesn't help us.


Hans

 

[rancke]

Mostly it is based on the fact that Kaasu, the Sector Capital, does not have a naval base. Can you have a fleet headquarters without having a naval base? Obviously you believe you can, and that the situation is more analogous to the Pentagon versus Norfolk...

Or London versus Portsmouth. Or, going historical, the various provincial capitals and the admirals stationed in those provinces.

...but I am not so sure. The bulk of the naval assests would be at Depot, so it seems logical headquarters would be there as well.

Why would the bulk of the naval assets be at Depot?


Hans

 

[Drakon]

Or London versus Portsmouth. Or, going historical, the various provincial capitals and the admirals stationed in those provinces.

Exactly.

Communication time is a bit problematic in the Imperium's case.

Why would the bulk of the naval assets be at Depot?

Basically that is the gist I got from reading Rebellion Sourcebook.

"depots typically encompasses entire star systems..." pp33 Rebellion Handbook

it makes them sound pretty big.

I probably should clarify; I think Depot has the largest consentration of naval assets in the sector. That I think the bulk of the fleet would be deployed, mostly along the border. Spacers belong on ships and ship belong in space. But of the remaining assets, Depot would probably have the most. After all, isn't Depot where the Plankwells were mothballed?

Are Reserve fleets co located with their numbered fleet counterparts?

 

[rancke]

Communication time is a bit problematic in the Imperium's case.

Hence the existence of provinces (i.e. duchies) with dukes in charge.

Basically that is the gist I got from reading Rebellion Sourcebook.

"depots typically encompasses entire star systems..." pp33 Rebellion Handbook

it makes them sound pretty big.

Depot/Corridor has a population in the thousands. That makes it sound pretty small. And I wonder just how many mothballed ships are stored in Corridor's depot, so temptingly close to those acquisitive Vargr neighbors.

I probably should clarify; I think Depot has the largest consentration of naval assets in the sector. That I think the bulk of the fleet would be deployed, mostly along the border. Spacers belong on ships and ship belong in space. But of the remaining assets, Depot would probably have the most. After all, isn't Depot where the Plankwells were mothballed?

Mothballed ships are only potentially part of the standing fleets. I don't think they're counted as part of any specifc fleet's complement until they are reactivated and assigned.


Hans

 

[rancke]

It occurs to me that some capitals may lack an Imperial naval base because for historical reasons they make extensive use of the planetary navy's facilities. There'd be an Imperial not-quite-a-full-base too, of course.


Hans

 

[Drakon]

Depot/Corridor has a population in the thousands. That makes it sound pretty small. And I wonder just how many mothballed ships are stored in Corridor's depot, so temptingly close to those acquisitive Vargr neighbors.

I am curious about the mothball fleet' constiuency as well, for different reasons.

Actually I curious about constiuencies of the fleets assigned to the subsector as well. Who is the expert on the Imperial Navy?

As to the population figures, I've always assumed the numbers were permenent residents. Not the possibly 10,000s of transient personel. 1,000 people live on Depot, probably retired navy veterans inhabiting that string of beachfront huts on those tropical islands

Weyland is the same way. A class B starport, capable of building starships and a Navy base, with a population of 300. :>

Mothballed ships are only potentially part of the standing fleets. I don't think they're counted as part of any specifc fleet's complement until they are reactivated and assigned.
Hans

Agreed they are not active, but they are still naval assets that can be reactivated, or salvaged, and brought to bear.

 

[rancke]

Actually I curious about constiuencies of the fleets assigned to the subsector as well.

According to Rebellion Sourcebook, regular fleets generally have from 8-10 squadrons of 6-8 main ships (auxiliaries are pretty much ignored). The ratio of BatRons to CruRons in the FFW countermix is roughly 1:3, which may or may not mean much (they could be subject to selection bias).

As to the population figures, I've always assumed the numbers were permenent residents.

That's one of the perennial discussions. Some canonical UWPs have been explained by transients not being included. Some have been explained by transients being included. Look here for a thread with a list of UWPs expressly composed of transients and a discussion of the ramifications. Note that the naval depot in the Solomani Rim is explicitly stated to be composed entirely of transients.

The definition doesn't speak of transients and residents but about 'inhabitants'. Which may rule out short-term transients, but would, IMO, include long-term transients. As for the economic footprint (IMO the most salient factor, since the trade rules are all based on the population number being all there are), a transient that will be replaced by another transient when he leaves is as good as a resident.

Not the possibly 10,000s of transient personel. 1,000 people live on Depot, probably retired navy veterans inhabiting that string of beachfront huts on those tropical islands

See, that's the problem with that explanation. If transients didn't count, the population should be 0, not 1000, since security is so tight. The last thing the navy would want is a local population with a claim to own the system...

I shall studiously avoid any reference to the 'unknown indigenous population' that is said to constitute 18% of the population of Depot/Corridor. o:


Hans

 

[Drakon]

According to Rebellion Sourcebook, regular fleets generally have from 8-10 squadrons of 6-8 main ships (auxiliaries are pretty much ignored). The ratio of BatRons to CruRons in the FFW countermix is roughly 1:3, which may or may not mean much (they could be subject to selection bias).

So, Tigress and Atlantics for the front line squadrons and Plankwells and ???? for the reserve fleets?

That's one of the perennial discussions. Some canonical UWPs have been explained by transients not being included. Some have been explained by transients being included. Look here for a thread with a list of UWPs expressly composed of transients and a discussion of the ramifications. Note that the naval depot in the Solomani Rim is explicitly stated to be composed entirely of transients.

The definition doesn't speak of transients and residents but about 'inhabitants'. Which may rule out short-term transients, but would, IMO, include long-term transients. As for the economic footprint (IMO the most salient factor, since the trade rules are all based on the population number being all there are), a transient that will be replaced by another transient when he leaves is as good as a resident.

Not sure it matters if we are talking about naval bases. Economically the military does not create wealth, it eats resources and destroys the wealth of the enemy. Theoretically, the economical extensions for any military base should be negative.

What is that? No, of course not, no way I would take that bet.

See, that's the problem with that explanation. If transients didn't count, the population should be 0, not 1000, since security is so tight. The last thing the navy would want is a local population with a claim to own the system...

Its 1,000 people in an entire solar system. I doubt there is much danger of them taking on the Imperial Navy successfully.

Again it is very easy to see 1,000 old naval and marine vets, decide they rather retire on a tropical beach on Depot rather than truck back to their home system. Have you seen those beaches?

 

[rancke]

So, Tigress and Atlantics for the front line squadrons and Plankwells and ???? for the reserve fleets?

Non-obsolete ships for the regular squadrons, obsolescent ships for the reserve squadrons, obsolete ships for mothballing. The Tigresses are still being replaced (if you accept GT material), Atlantics are being phased out, and as far as I can tell the Plankwells are still regular fleet material. 'Reserve' is used for several different concepts, and I think the 'strategic reserve in Corridor Sector' refers to the Corridor Response Fleet rather than the mothballed ships in Corrridor.

Not sure it matters if we are talking about naval bases. Economically the military does not create wealth, it eats resources and destroys the wealth of the enemy. Theoretically, the economical extensions for any military base should be negative.

Negative for whom? Usually a military base means an influx of money from the government for the local civilian economy. But that's besides the point. Depots may be an exception to the general rule, but the general rule is that passengers and cargo are calculated based on the population figure rather than on any hypothetical supernumerary transient population.

Its 1,000 people in an entire solar system. I doubt there is much danger of them taking on the Imperial Navy successfully.

'Not much danger' is not 'no danger'. Local residents evidently have a lot of rights in the Imperium judging from the number of tiny populations the Imperium apparently accept as sovereign. Note that I'm not saying that it makes sense; IMO the vast majority of low populations would be transients to a man. But that's what current canon shows.

Again it is very easy to see 1,000 old naval and marine vets, decide they rather retire on a tropical beach on Depot rather than truck back to their home system. Have you seen those beaches?

The description on the wiki is "marginally habitable (cold) with occasional liquid water due to geothermal effects". Not much tropical beach to be found there apparently. Though I admit that I have no idea how canonical that is.

The type 5 government is odd too. A naval base would have a captive government and nothing but. And as for the type of captive government, I can't think of any more rigid autocracy than a military post. A constitutional autocracy (Imperial Code of Military Justice ), but an extremely inflexible chain of government.

Anyway, a feudal technocracy is not my idea of how a retirement village would be governed.

EDIT: Here's my explanation for the population of 1000-1999 listed for Depot/Corridor. I don't claim it is a good explanation, but it's the best I can do:

Everybody in the system are transients, but only the ones actually living on the world are counted, because that's how the Scout Census rolls; they only count people living on the mainworld. Tens of thousands other people work elsewhere in the system (either no single place have more people than the "mainworld" or the place where the Port Admiral's HQ is located is counted as the mainworld despite its deficiency in population. Apparently no one are allowed to live on the world unless absolutely essential to the running of the HQ (For security reasons?). No dependents' housing, no rercreational facilities, and especially no retirement villages . As for the government type... well, you see, the Scout commander who did the latest survey was a moron.

I'm sorry; best I can do. (Actually, it's the best I'm allowed to do; give me leave to revise the UWP and I'd be able to do much better. :devil


Hans

 

[Drakon]

Non-obsolete ships for the regular squadrons, obsolescent ships for the reserve squadrons, obsolete ships for mothballing. The Tigresses are still being replaced (if you accept GT material), Atlantics are being fazed out, and as far as I can tell the Plankwells are still regular fleet material. 'Reserve' is used for several different concepts, and I think the 'strategic reserve in Corridor Sector' refers to the Corridor Response Fleet rather than the mothballed ships in Corrridor.

I am still trying to figure out which ship are in and out of service in 1105. You wouldn't have a list, would you?

'Not much danger' is not 'no danger'. Local residents evidently have a lot of rights in the Imperium judging from the number of tiny populations the Imperium apparently accept as sovereign. Note that I'm not saying that it makes sense; IMO the vast majority of low populations would be transients to a man. But that's what current canon shows.

I still feel that if its a great big sprawling complex. It's 1,000 people over 8 worlds. And if they are vets, that makes their loyalty to the imperium and the navy less of a problem.

The description on the wiki is "marginally habitable (cold) with occasional liquid water due to geothermal effects". Not much tropical beach to be found there apparently. Though I admit that I have no idea how canonical that is.

Travellermap is canonical, right? I note that there are differences between information there and travellerwiki. Reconciling differences in all the material has got to be a full time job.

The type 5 government is odd too. A naval base would have a captive government and nothing but. And as for the type of captive government, I can't think of any more rigid autocracy than a military post. A constitutional autocracy (Imperial Code of Military Justice ), but an extremely inflexible chain of government.

Anyway, a feudal technocracy is not my idea of how a retirement village would be governed.[/quote] I heard of a planet where the main form of entertainment was juggling geese. Live goslings, they were juggled. Different strokes for different folks.

Everybody in the system are transients, but only the ones actually living on the world are counted, because that's how the Scout Census rolls; they only count people living on the mainworld. Tens of thousands other people work elsewhere in the system (either no single place have more people than the "mainworld" or the place where the Port Admiral's HQ is located is counted as the mainworld despite its deficiency in population. Apparently no one are allowed to live on the world unless absolutely essential to the running of the HQ (For security reasons?). No dependents' housing, no rercreational facilities, and especially no retirement villages . As for the government type... well, you see, the Scout commander who did the latest survey was a moron.

Part of the fun for me is to figure out the story behind the various odd references. I know its all imaginary, but part of the fun is trying to rationalize some of the odd data.

As for changing the UWP, that will have to wait until we revise Pocket Empires or get a terraforming suppliment for T5

 

[aramis]

I am still trying to figure out which ship are in and out of service in 1105. You wouldn't have a list, would you?

Everything in Sup 9 is in service prior to the 5FW. Since it doesn't list a specific date, but says "The dates for the information in this book range from the year 1000 to 1107," it's probably 1107.

 

[rancke]

Everything in Sup 9 is in service prior to the 5FW.

True, but some of them are in "second line assignments", whatever that may mean exactly, and others are getting there. There are only a handful of AHLs left in the IN even as second line.


Hans

 

[Drakon]

Everything in Sup 9 is in service prior to the 5FW. Since it doesn't list a specific date, but says "The dates for the information in this book range from the year 1000 to 1107," it's probably 1107.

One reason for my focus on the Plankwells is that these were "rotated to the strategic reserve in Corridor Sector." by 1102.

It is also one of few big ships that I have a miniature of. And the idea of a Rebellion Era relic battleship being pressed back into service after the sector fleets have abandoned Corridor to the Vargr, might make an interesting adventure. Even if it is a bit cliche.

 

[djwildstar]

For practical purposes the Imperium is exactly the same size as back in Arbellatra's time. Which means its communication pressures are exactly the same seriousness that prompted Arbellatra to set up a "pony express" style system in the first place.

My point exactly: The Imperium is the same size circa 1100 as it was 500 years ago; therefore, a communications system that was fast enough in Arbellatra's time is STILL fast enough in Strephon's time.

Now, a pony express system is significantly more expensive than an ordinary courier system, and it's only advantage is that it wrings a few hours advantage out of every link.The whole system makes no sense unless the difference between an average of 3.8 persecs per week and 3.9 persecs per week [...] would actually be important.

I don't follow this logic. Just a few messages ago, you said:

Whatever extra expense a groundside message center would entail would still be pocket change compared to even one X-boat.

So which is it: does the cost of the groundside message center required for the "pony express" style message passing so insignificant that it is "pocket change" by comparison to the cost of only one X-boat, or is it so significant compared to the overall cost of the system that it mandates the design of the system be as efficient as possible?

It follows that a system that average 2.6 parsecs per week is not doing anything to alliviate any of those pressures.

I don't follow this, either. If we agree that the size of the Imperium is the same size as it was in Arbellatra's time, and if we agree that X-boat system was sufficient to alleviate those communications pressures at that time, why do we disagree that the same system, making the same average speed, is acceptable circa 1100?

Furthermore, by the Classic Era, at least, it is being outperformed by civilian J4 traffic -- that is to say, the same traffic that wasn't good enough back when the X-boats were first conceived.

I see two issues with this:

1) Civilian J-4 traffic does not seem to operate "pony express" style, at least from available canon description. For example, the Tukera Long Liners seems to operate on the same "merchants turn" as most other OTU commercial shipping, with roughly 2 weeks between jumps. If they operate over the same routes as the X-boats, they will therefore average about 1.3 parsecs per week. If other commercial J-4 traffic deviates from X-boat lanes on routes optimized for J-4 performance (which is likely), then it will make closer to 2 parsecs per week average. Operating on a "merchants turn", it would take J-6 ships that made maximum jumps 85% of the time or more to exceed the speed of the X-boat system.

2) I don't have any canonical information on the existence (or lack) of J-4 commercial shipping in the mid-600's. I believe the widely-accepted assumption is that J-4 was the cutting edge of Imperial technology when Arbellatra created the X-boat system. So in Arbellatra's time, there were no competing J-4 commercial traffic. Also, you seem to contradict yourself later in the same post, when you state that the X-boat system was an advance over commercial transport when it was created.

To beat the performance of the X-boat system on a consistent, long-haul basis, you would need to set up a similar network with dedicated courier ships and message centers that allows for "pony express" style message hand-offs. With some assumptions (6-hour hand-off and 80% navigational efficiency), I compute realistic performance figures for these networks at 3.1 parsecs per year for J-4, 3.9 for J-5, and 4.6 for J-6.

A little fiddling with the formulas also shows that the canonical X-boat network is operating at about 67.5% navigational efficiency. So the gap between the theoretic performance of a J-4 X-boat network (roughly 3.1 parsecs per week) and the canonical network (2.6 parsecs per week) is not that great, and is due to inefficient location of the X-boat stations. The model also shows that it is basically not feasible for a J-4 network to reach the 3.8 to 3.9 parsec per week speeds.

Using the same model, an Imperium-wide J-6 courier network would cost about three times what the current X-boat network costs due to ship and crew costs alone. If such a network operated with the same navigational efficiency and hand-off time of the X-boat network, its overall speed would be about 3.9 parsecs per week. This is a 50% improvement in speed for a 300+% increase in costs - little wonder that the Imperium doesn't believe it to be cost-effective. This leads me to suspect that it is unlikely that anyone has a courier network comparable to the X-boat network in extent and superior to it in speed.

Applying this model to the Navy courier network, I estimate that they accept a larger hand-off time, which reduces the number of ships required to service each link. Assuming the Navy has better navigational efficiency, their network probably averages 4.3 parsecs per week. Modeling the ImperialLines network as a single Jump-6 ship operating over a well-planned point-to-point route, I compute 4.6 parsecs per week. These numbers compare well to the figures in Rebellion Sourcebook, which give 4.64 for a Type TJ, 4.33 for the Naval couriers, and 2.55 for the X-boat system.

That the Emperor has not felt the need to speed up the X-boats (and, indeed, has allowed them to deteriorate to the parlous state they're in by the Classic Era) shows that there is a speedier alternative.

I'm confused: what do you mean about the X-boat network deteriorating? Do you have any evidence for that assertion?

It seems to me that it comes down to the X-boats indisputably not functioning as canon claims they do, and me thinking an explanation for that would be nice while you don't see any discrepancy that needs to be accounted for.

I think the part I don't understand is where you claim that the X-boats cannot or do not function as canon claims that they do.

I submit that canon also say that the X-boats are the fastest available means of communication, which is quite obviously no longer the case by the Classic Era.

"The xboat service was established to provide for the fastest possible transmission of information for official, commercial, and private purposes." [BoJTAS2:13]​

No, it does not.

Your quote shows that the xboat service was intended to be the fastest possible when it was created. It does not provide any information on the success or failure of the xboat system to meet that goal, or about its present status.

And it must be said that such a pony express type setup would be faster than anything ordinary commercial traffic or even ordinary J4 couriers could match. By days per link for commercial traffic and half days per link for couriers.

Yes. The quote you give therefore also supports the concept that J-4 was the best available Jump technology when Arbellatra set up the X-boat system in the mid-600's. At that time, most commercial shipping would have been in J-1 and J-2 vessels, with the occasional J-3 ship. I expect that J-4 technology was restricted to military vessels, even if it was not actually classified; the X-boat system may well have been the first civilian use of it. Therefore, before the X-boat system, routine communication between the Imperial core and the frontier traveled at rates well under a parsec/week - my model puts it at about 0.65 parsecs per week for commercial shipping, and roughly 2.2 parsecs per week for dedicated J-3 couriers on an optimized route.

In addition to employing the fastest available ships in the mid-600s, the X-boat message routing system allows for "pony express" style relays, getting inbound messages sorted and placed on outgoing ships in a matter of hours instead of days (this in turn required standard equipment and protocols across the entire network). As a result, the X-boat system speeds message traffic by a factor of 4 - from about 0.65 parsec/week to to 2.6 parsec/week - four times the speed of ordinary mail, and more than twice as fast as a civilian courier.

At some point after the X-boat network was deployed, J-5 technology was developed. It would have first been a military secret. Even after it was no longer a secret, use of these drives in civilian ships would have been restricted - perhaps by law, and certainly by the lack of availability for drives and maintenance. The same would be true of J-6 drives. In fact, I'm not aware of a canonical J-6 ship that isn't either a Navy ship or directly under the control of the Emperor (except for the J-6 Tukera liners mentioned in JTAS 2-4), so it may be that even circa 1100, J-6 technology is still restricted or rare.

 

[rancke]

My point exactly: The Imperium is the same size circa 1100 as it was 500 years ago; therefore, a communications system that was fast enough in Arbellatra's time is STILL fast enough in Strephon's time.

But the current X-boat system is not fast enough for Arbelatra's time. Given an optimized use of J4 links, a courier system could achieve speeds close to 4 parsecs per week even with ordinary couriers.

So which is it: does the cost of the groundside message center required for the "pony express" style message passing so insignificant that it is "pocket change" by comparison to the cost of only one X-boat, or is it so significant compared to the overall cost of the system that it mandates the design of the system be as efficient as possible?

It's not the groundside message center that makes the pony express (potentially) a tiny bit faster than ordinary couriers. It's having a boat standing by to jump out as soon as the messages it is carrying have been transferred, saving you the time it would take an ordinary courier to refuel (Exactly why couriers employed pony express style are inferior to X-boats is a bit of a puzzle, really). And the high cost is based on having multiple X-boats and on the tenders needed to collect and refuel X-boats, not on the message center.

I don't follow this, either. If we agree that the size of the Imperium is the same size as it was in Arbellatra's time, and if we agree that X-boat system was sufficient to alleviate those communications pressures at that time, why do we disagree that the same system, making the same average speed, is acceptable circa 1100?

Because the canonical speed of the X-boats in 1100 is not the fastest achievable with J4. I conclude that the speed of the X-boats would have been higher in Arbellatra's days as otherwise they would have been irrelevant back then too, being inferior to J4 couriers rationally employed.

1) Civilian J-4 traffic does not seem to operate "pony express" style, at least from available canon description.

No, of course not. They need to spend days at each stop. But the information they carry don't need to spend the same time before it moves on. The issue of Capital News that one ship carries into port (or rather, a copy of it) can leave on the next outgoing ship. Besides, the ship it came in on is as likely as not to be going back the way it came.

For example, the Tukera Long Liners seems to operate on the same "merchants turn" as most other OTU commercial shipping, with roughly 2 weeks between jumps.

Let's not get into that discussion. Fortunately it's moot, since, as I said, information doesn't have to wait for the ship to finish its business.

If they operate over the same routes as the X-boats, they will therefore average about 1.3 parsecs per week.

The main passenger routes, by which I mean routes between high-population worlds, will average something in the upper reaches of the 3 to 4 parsec per week range, depending on how frequently passenger liners depart.

If other commercial J-4 traffic deviates from X-boat lanes on routes optimized for J-4 performance (which is likely), then it will make closer to 2 parsecs per week average.

Commercial J4 traffic will parallel X-boat lanes optimized for J4 information traffic. I've never said otherwise. I just don't think that the amount of cargo that is conveyed by J4 freighter would amount to enough to be called a major trade route. J4 passenger liners that are a little more expensive than J2 and J3 liners I see as perfectly reasonable. As I said in connection with J6 liners, some people are willing to pay extra to get there faster. So information piggy-backing on J4 passenger liners will make somewhat (but not a lot) less than 4 parsecs per week.

2) I don't have any canonical information on the existence (or lack) of J-4 commercial shipping in the mid-600's. I believe the widely-accepted assumption is that J-4 was the cutting edge of Imperial technology when Arbellatra created the X-boat system.

I believe the widely-accepted knowledge is that J4 technology was over 300 years old by the time of the Civil War, so I take it for granted that it was in civilian use by then.

So in Arbellatra's time, there were no competing J-4 commercial traffic. Also, you seem to contradict yourself later in the same post, when you state that the X-boat system was an advance over commercial transport when it was created.

That's because I take it for granted that the original X-boat network was optimized for the fastest possible information transfer. Whereas one glance at the current X-boat routes makes it abundantly clear that this is not the case in 1100.

To beat the performance of the X-boat system on a consistent, long-haul basis, you would need to set up a similar network with dedicated courier ships and message centers that allows for "pony express" style message hand-offs. With some assumptions (6-hour hand-off and 80% navigational efficiency), I compute realistic performance figures for these networks at 3.1 parsecs per year for J-4, 3.9 for J-5, and 4.6 for J-6. A little fiddling with the formulas also shows that the canonical X-boat network is operating at about 67.5% navigational efficiency. So the gap between the theoretic performance of a J-4 X-boat network (roughly 3.1 parsecs per week) and the canonical network (2.6 parsecs per week) is not that great, and is due to inefficient location of the X-boat stations. The model also shows that it is basically not feasible for a J-4 network to reach the 3.8 to 3.9 parsec per week speeds.

I disagree with your analysis. All you need to do to achieve it is to bypass worlds that would reduce the average jump length. If an important world is two parsecs away, you send off two couriers, one for the world and one for a whistlestop four parsecs away. Astrography will sometimes force a 3-parsec jump in the route, but the majority of jumps will by 4 parsecs

Using the same model, an Imperium-wide J-6 courier network would cost about three times what the current X-boat network costs due to ship and crew costs alone.

a) I doubt that. Perhaps if the couriers were expected to maintain 4 times a day service, but across long distance one courier per week doing 4 parsecs beats 4 X-boats per day doing 2 or 3 or 4 parsecs. b) Whatever it costs, the IN would already be paying for it.

Continued next post​

 

[rancke]

Continued from previous post

If such a network operated with the same navigational efficiency and hand-off time of the X-boat network, its overall speed would be about 3.9 parsecs per week. This is a 50% improvement in speed for a 300+% increase in costs - little wonder that the Imperium doesn't believe it to be cost-effective.

You keep ignoring the description of the X-boat network that claims that they provide "the fastest possible facsimile information transfer between worlds" (emphasis mine). Not the fastest cost-effective, not the optimum speed, but the fastest possible. Which, allowing for a bit of hyperbole[*], is 3.9 parsecs per week, not 2.6.

[*] The fastest possible is slightly over 4 parsecs per week, but that would be really expensive with deep space relay stations and multiple couriers per jump. (If you send off two couriers simultaneously, the average time for the information to arrive goes down by an average of 5-6 hours; by using more couries you can get that down to around 8 hours saved per jump (on the average).​

This leads me to suspect that it is unlikely that anyone has a courier network comparable to the X-boat network in extent and superior to it in speed.

Navy couriers. Oh, they won't cover the Imperium as widely as the X-boats do, but sector and subsector capital to capital they will.

Applying this model to the Navy courier network, I estimate that they accept a larger hand-off time, which reduces the number of ships required to service each link.

Sure. Though few couriers per week (say, one per day) would probably be a greater source of savings.

Assuming the Navy has better navigational efficiency, their network probably averages 4.3 parsecs per week. Modeling the ImperialLines network as a single Jump-6 ship operating over a well-planned point-to-point route, I compute 4.6 parsecs per week. These numbers compare well to the figures in Rebellion Sourcebook, which give 4.64 for a Type TJ, 4.33 for the Naval couriers, and 2.55 for the X-boat system.

You got that from the speed of dissemination essay in MT, right? I consider that story highly implausible, but even if we accept them, the couriers still beat the X-boats. So the X-boats are not, as the essay claims, the fastest possible means of information transfer.

I'm confused: what do you mean about the X-boat network deteriorating? Do you have any evidence for that assertion?

The fact that in 630 they were designed to be the fastest means of information transfer and that in 1100 they're not. Plus the bizarre doglegs and weird contortions of the network.

I think the part I don't understand is where you claim that the X-boats cannot or do not function as canon claims that they do.

They're not the fastest possible means of information transfer in 1100. They're not even the fastest means of information transfer given the restriction of being only J4.

Your quote shows that the xboat service was intended to be the fastest possible when it was created. It does not provide any information on the success or failure of the xboat system to meet that goal, or about its present status.

True. I'm assuming that Arbellatra would have insisted on getting it done right. Unless you can demonstrate that it isn't possible to do any better than 2.6 parsecs per week, I will continued to assume that the X-boats did do better at first. Also, if they didn't get it right back at the start, the problems that Arbellatra were concerned about would still have been plaguing the Imperium in 700 and the X-boats would have been upgraded to J5 to ease those still unrelieved strains.

Yes. The quote you give therefore also supports the concept that J-4 was the best available Jump technology when Arbellatra set up the X-boat system in the mid-600's.

Was that ever in dispute? I believe it is an established fact that the Imperium reached J4 in 300 and J5 in 700.

At that time, most commercial shipping would have been in J-1 and J-2 vessels, with the occasional J-3 ship. I expect that J-4 technology was restricted to military vessels, even if it was not actually classified; the X-boat system may well have been the first civilian use of it.

400 years after it was invented?!? I don't believe it.

In addition to employing the fastest available ships in the mid-600s, the X-boat message routing system allows for "pony express" style relays, getting inbound messages sorted and placed on outgoing ships in a matter of hours instead of days (this in turn required standard equipment and protocols across the entire network). As a result, the X-boat system speeds message traffic by a factor of 4 - from about 0.65 parsec/week to to 2.6 parsec/week - four times the speed of ordinary mail, and more than twice as fast as a civilian courier.

The whole business of sorting messages is irrelevant. If it's a problem, you store the information in separate files beforehand. The X-boats may well be able to handle a greater amount of messages, but information can be prioritized.

At some point after the X-boat network was deployed, J-5 technology was developed. It would have first been a military secret. Even after it was no longer a secret, use of these drives in civilian ships would have been restricted - perhaps by law, and certainly by the lack of availability for drives and maintenance. The same would be true of J-6 drives.

What you say makes sense up until the point of the restrictions. There is no evidence that J6 is restricted by law or by availability in 1100 and the evidence of the ship construction rules that it isn't.

In fact, I'm not aware of a canonical J-6 ship that isn't either a Navy ship or directly under the control of the Emperor (except for the J-6 Tukera liners mentioned in JTAS 2-4), so it may be that even circa 1100, J-6 technology is still restricted or rare.

Neither am I, so I've been careful to include a caveat to that effect in those of my posts where I touch on civilian J6 ships. But I really don't see it myself. At the very least the megacorporations would pressure the Emperor to let them run J6 passenger liners between high-population worlds. And so would all those powerful multi-billionaires and government officials and corporate bigwigs who think their time is too valuable to waste by travelling by J3 and J4. And once the J6 drive is declassified, I see no reason why it should be restricted. Possibly it would still be on the 'don't sell to Aslans and Vargr' list, but not for Imperial citizens. OK, there's the Grand Conspiracy to Keep the Masses in the Dark, but I don't believe in it. I think it would be subverted by the Grand Conspiracy to get Important People to Capital without Wasting a Lot of Time and the Grand Conspiracy to get People their Breakfast News.


Hans

 

[djwildstar]

But the current X-boat system is not fast enough for Arbelatra's time.

Ah, here is our fundamental disconnect. I believe that the current X-boat system was fast enough for Arbellatra's time, and you don't.

Given an optimized use of J4 links, a courier system could achieve speeds close to 4 parsecs per week even with ordinary couriers.

I don't think the math supports that.

Here are my assumptions:
- An ordinary courier requires roughly 24 hours between Jumps to maneuver from the inbound jump point to a source of fuel, refuel, recalibrate drives, and possibly change crews or perform necessary maintenance that can only be done in realspace, and maneuver to the outbound jump point. I assume a "pony express" style handoff is required to reduce this figure below 24 hours.
- An optimized route involves 90% of jumps executed at J-4 directly towards the destination. The other 10% of jumps are allowed to deviate by a maximum of 1 parsec (which means that either the jump makes a dogleg that adds 1 parsec to the total distance, or that the jump is executed at J-3); larger deviations are not allowed. I believe this to be a fairly strict course plot, on the edge of what is do-able given Imperial astrography.

Here's my computation:
Jump = 4
Average Distance per Jump (AvgJump) = (90% x 4 parsec + 10% x 3 parsec) = 3.9 parsec
Navigational Efficiency = AvgJump / Jump = 97.5%
Handoff = 24 hours
Jumps Per Year (JumpsYear) = 365 / (7+Handoff/24) = 45.625

Average Distance = AvgJump * JumpsYear / 52 = 3.42 parsecs per week

So, a conventional J-4 courier on an optimized route can achieve about 3.4 parsecs per week. Even if the distance to be covered was a multiple of 4 parsecs, and there were fueling stops every 4 parsecs along the way, the conventional courier can barely exceed 3.5 parsecs per week.

It's not the groundside message center that makes the pony express (potentially) a tiny bit faster than ordinary couriers. It's having a boat standing by to jump out as soon as the messages it is carrying have been transferred, saving you the time it would take an ordinary courier to refuel (Exactly why couriers employed pony express style are inferior to X-boats is a bit of a puzzle, really). And the high cost is based on having multiple X-boats and on the tenders needed to collect and refuel X-boats, not on the message center.

Yes, you're right.

The main passenger routes, by which I mean routes between high-population worlds, will average something in the upper reaches of the 3 to 4 parsec per week range, depending on how frequently passenger liners depart.

I think the figures are in the upper 2 or just barely over 3 parsecs per week. Using 48 hours as an average time to find an outgoing ship headed to the correct destination, and the formulas above, I get a maximum of 3.04 parsecs per week using the 97.5% navigationally-efficient optimized route. However, I suspect that J-4 commercial shipping may be more willing to deviate from maximum drive utilization in favor of destinations that offer profitable trades. Plugging in 82.5% navigational efficiency, I get an average speed of 2.57 parsecs per week - very slightly slower than the X-boat network.

I suspect that finding an outbound connection within 48 hours is reasonable on busy trade links, but could become more problematic on other routes. If even one connection in 10 was missed, resulting in a 7-day delay, this would drop the average speed to 2.42 parsecs per week.

All you need to do to achieve it is to bypass worlds that would reduce the average jump length. If an important world is two parsecs away, you send off two couriers, one for the world and one for a whistlestop four parsecs away. Astrography will sometimes force a 3-parsec jump in the route, but the majority of jumps will by 4 parsecs

This approach can dramatically improve average message transmission times in the X-boat system, and is easy to implement in your own Traveller universe without changing the overall X-boat route map. It appears that this has not been done in the canon material, probably because of the difficulty of representing this routing on the traditional Traveller starmaps.

As a quick back-of-the-envelope estimate, I suggest that this would improve the navigational efficiency of the current network, and increase speeds from the canonical 2.5 to 2.6 parsecs per week to approximately 2.9 to 3.0 parsecs per week. An overhaul of the network map, relocating stations and links, would be required to increase the speed further.

Perhaps if the couriers were expected to maintain 4 times a day service, but across long distance one courier per week doing 4 parsecs beats 4 X-boats per day doing 2 or 3 or 4 parsecs.

A courier doing 4 parsecs beats X-boats doing 2, 3, or 4 parsecs over a short distance. Over longer distances, the delay in handing off messages adds up, and the "pony-express" style hand-off makes up for a lot of sins. Comparing a J-4 ship operating on an optimized route (the same 97.5% navigational efficiency described above) to the X-boat network (67.5% navigational efficiency, one ship every 6 hours), one ship per week on the optimized route would have an average delay of a half-week between receipt of a message dispatch of a ship on the next link in the route. Over the long haul, this exactly matches the speed of the X-boat network, making 2.6 parsecs per week. The courier would have to be faster, or significantly more frequent, to significantly exceed the speed of the x-boat network.