Rules Only: The Advantages of Low Tech Starships

[Spinward Flow]

Usually when people like my teenaged self headed towards the Starship Construction rules in LBB5, the immediate imperative was to angle for TL=15.
After all, it was "the best" ... so why settle for anything less?
And given the way the construction system was structured ... there were NO advantages to be had in angling for any starship designs below TL=15 (or at least, none that were obvious enough to register).

Power plants required more tonnage, costing more MCr to purchase (and maintain) as well as more crew required to staff the (larger) engineering section.
Armor required more tonnage with lower limits on maximum armor factor.
Turret weapon factors lost +DM.
Bay weapons lost weapon factors.
Spinal weapons required more tonnage and in a lot of cases more EP (a triple whammy of tonnage, increased power plant+fuel and crew requirements).
Computer models available (and thus maximum hull code) were limited by tech levels.
Fuel purification plants required more tonnage and cost more.

For most Adventure Class Ships (ACS), all of those factors conspired to create a mentality of "TL=F or Bust" when it came to custom designing starships to have fun with.



So I have a somewhat vested interest (both as a Player and as a Referee) in seeking some way(s) that allow "low tech" starships in the TL=9-12 range (when power plants are 3 tons per EP in LBB5.80) to have what might be considered "hidden advantages" that aren't immediately obvious at first glance from a purely Munchkin Gamer perspective.

First and foremost would be ... COST.

LBB4, p43 contains this Note on Prices and Tech Levels

In General, prices will tend to drop by 5-15% at each tech level after the level of introduction of an item, with examples of the Item sold at the regular base price generally incorporating improvements or representing deluxe models.

Now, as a generic rule of thumb, I would further define that price drop as being:

• -5% per tech level drop down on Non-industrial worlds.
• -10% per tech level drop down on worlds which are neither Industrial nor Non-industrial.
• -15% per tech level drop down on Industrial worlds.

With such a rules interpretation/extension in place, the cost benefits of building low tech starships at high tech shipyards becomes readily apparent.

If a TL=9 starship becomes 15*(15-9)=90% cheaper to purchase at a TL=15 Industrial starport type A shipyard ... suddenly Glisten/Glisten, Mora/Mora and Trin/Trin's Veil become THE de-facto go-to shipyards of the Spinward Marches for construction of TL=9 starships used throughout the Spinward Marches in the 1105 era of CT.

By contrast, the same TL=9 starship built at TL=13 Lunion/Lunion or Strouden/Lunion would instead cost 15*(13-9)=60% cheaper to purchase.



Of course, the problem with such a ruling is that it runs afoul of the "but what about TL=9 built at TL=16 Industrial shipyards?" problem. Because of where the linear scaling is set, it's possible to wind up with a 7 tech levels differential which results in a 105% cheaper cost to purchase ... in other words the shipyard would wind up paying the buyer to take the ship from them because a TL=9 design is so "worthless" to construct at TL=16.
Instead of paying MCr100 for a MCr100 base price starship, the shipyard pays you MCr5 to take possession of the low tech starship.

So there are some scaling limit problems when tech levels aren't merely limited to the TL=9-15 range (which CT pretty explicitly was).
But we're better than that now.



The other big advantage of owning a low tech starship would be (ironically) ... ease of maintenance.

In LBB1-3, and in LBB2 in particular, tech levels operated on a "you must be this high to buy this toy" basis, where the only hurdle was acquisition. Little to nothing was ever mentioned or implied about the Logistics Tail of trying to maintain and service high tech equipment ... including items (like starships) that easily exceeded the local tech level. I personally view this as an oversight in rules design for CT so as to simplify things enough to fit into the LBB format without padding out the word count too much. However, it also creates edge case oddities where if all you need is a type A/B starport to maintain your starship(s), regardless of tech level, you can wind up with places like Vilis/Vilis/Spinward Marches being "perfectly fine" with performing annual overhaul maintenance on ACS TL=15 starships with little to no notice.

Which brings to mind the question of why anyone would assume that the drydock yards on TL=10 Vilis will have an "unlimited" supply of parts and spares to refurbish a TL=15 starship that needs to have annual overhaul maintenance done on it?

I mean ... logically ... TL=10 Vilis would have an industrial supply base capable of manufacturing parts and spares of TL=10 locally, but presumably not of TL=15 (otherwise they would be a TL=15 world society). And as anyone who has ever worked in aerospace maintenance can attest to ... if you don't have the spare parts to replace (mission critical) stuff, that machine is going to be grounded until you do. You can't just "wish" the requisite parts and spares into existence ... and they aren't a result of Cargo Cult worship practices. High tech items have to be manufactured SOMEWHERE ... and if that somewhere "isn't local" then it will need to be transported (in this case, either the part comes to the ship or the ship goes to the part).

Which is a long winded way of saying that high tech starships ought to be "tethered" to a required for high tech level worlds capable of building/maintaining starships of that technology level.

In other words ... a TL=13 starship ought to require annual overhaul maintenance at TL=13+ worlds with a type A or B starport ... not just "any old A/B starport will do" kind of thing.

And as soon as you introduce that "high tech starships require high tech maintenance" logistics tail requirement, suddenly EVERYTHING changes in terms of being able to operate on the fringes of civilization in the low tech backwater regions.

If you can't maintain something, then it's only useful until it breaks ... creating a "burner" style of disposable consumption and usage.
Instead of buying a starship to use for 40 years, you buy it and only use it for 1-2 years until it stars falling apart and then you sell (used) and buy a new one.



By contrast, if you have a high tech shipyard build a low tech starship at a significant discount ... that low tech starship can be maintained at an increasingly wide variety of ports of call. So a TL=9 starship built in a TL=15 shipyard will have a significant cost reduction to the construction cost for purchase (and consequently, bank financing! ) while also being low tech enough to easily maintain throughout a wide swath of locations. That low(er) tech barrier to maintenance then makes it possible for the low(er) tech starships to find niche roles and markets along the fringes and backwater worlds that would be uneconomical for higher tech starships to ply their trade in, simply because the logistical tail "tethering" them back to their high tech shipyards of origin gets to be "too long" for practicality (spend more time ferrying to and fro long distance each year just to keep up with maintenance).



Put those two factors together ... cheaper to buy, easier to maintain ... and suddenly it makes a whole lot of sense for commercial shipping to angle for low tech starships (TL=9-11) as being the best investments, rather than always angling for the highest of the high tech available in every single instance.



Thoughts?

 

[Condottiere]

You leverage overall costs of ownership, and for freighters rate of return on investment, which may not always line up with the artificial charts laid out in the rulebooks.

 

[willtron3030]

As to the TL9 craft in a TL16 shipyard, I think the best solution is not using a linear scale for the cost reduction, but an exponential scale. Instead of
$COST_{adj} = COST_{base} × (1 - (k × (TL_{yard} - TL_{ship})$

consider
$COST_{adj} = COST_{base} × (1 - k)^{TL_{yard} - TL_{ship}}$

where k is the cost reduction per tech level difference by world type.

So, a TL9 craft built in a TL16 yard would get a discount of 68% on industrial worlds, 30% on non-industrial, and 52% on all others.

In situations where a yard is providing services to craft of a higher TL, where that is permitted, reverse the constant for In/Ni worlds, and the same exponential formula works to compute the extra cost.

 

[whartung]

Which brings to mind the question of why anyone would assume that the drydock yards on TL=10 Vilis will have an "unlimited" supply of parts and spares to refurbish a TL=15 starship that needs to have annual overhaul maintenance done on it?

Doesn't need an unlimited supply of parts, just enough for MY ship!

There's all sorts of little issues going on here.

Things should be cheaper at higher TLs, to a point.

As things get older, they get cheaper and more expensive at the same time. There's a point of "peak cheapness" when we talk not just purchase price, but costs over the lifetime of the product. That's manifest a lot by infrastructure as parts get rare, expertise fades, etc. Ye Olde "we need more COBOL programmers" syndrome.

I knew a guy restoring a 50's Chevy. But he put a modern motor into it. Why? I dunno, really. Cost? Expertise? More reliable? Modern V8 with EFI, solid state ignition, and a management computer vs carbs and jets and coils? The car didn't care. Obviously it affected the "collectability" of the car, but he wanted a driver, not a garage queen.

Show up at a TL-15 port and it may cost more to get your TL-9 ship serviced. "Normally, we'd put Frank on it. He was a wiz at those. But, uh, he died."

I don't see any reason you couldn't put a TL-15 Power Plant or M-Drive in to a TL-9 Hull. Maybe not a J-Drive (who know about that lanthanum grid and all that and it's compatibility). Might need to update some of the engine controllers and consoles and such.

Of course, why would you? In HG there's no real TL benefit with M-Drive (not past 9), but there is for the Power Plant. A creaky Free Trader could gain 4 tons getting TL-15 power plant (not necessarily useful for cargo, but might make a nice ships locker, or cram a couple extra low berths in there -- they won't care.)

TL-9 Parts may be available at a TL-15 shipyard, but they had to be shipped in.

Pomade Vendor: I can get the part from Bristol. It'll take two weeks, here's your pomade.
Ulysses Everett McGill: Two weeks? That don't do me no good.
Pomade Vendor: Nearest Ford auto man's Bristol.

Of course, this is complicated, perhaps, by the fact that there are "new" "old" parts being made. They're making something on those TL-10 worlds. But, it's one things to have them made, it's another to have them stocked and available when you need them.

Also, I don't think there's any reason why a TL-12 starport can't install a TL-13 drive from someplace else. This is that classic "knowledge transfer" conundrum (i.e. "Why isn't everyone TL-15", save for TimeRovers backwater where they like to churn their own butter). It may be one thing to manufacture such a drive, but installing it should be a mostly rote "mechanical" process. Also, if you can ship in a TL-13 drive, you can probably ship in a TL-13 mechanic to install it. And it's fair to make an exception for Jump drives since I consider them integral to the ship. A power plant is a power plant. But a Jump drive is a drive and a hull.

So, anyway.

There should be a spectrum of parts availability. Eventually costs bottom out. I can't imagine buying a "new" TL-9 ship at 90% off. But within 2 TLs I think it works ok.

 

[HanleyTucks]

Interesting thoughts. The simple rule that a TL-x ship can only be serviced at a TL-x or greater world changes a lot.

However, a TL-15 place can't necessarily build a TL-9 ship. Even today NASA can't build Saturn V, for a bunch of reasons both technical, human resources, bureaucratic and political. And that's barely one level of tech difference, if that

To think too of things like valves, which only a couple of places in the world make now.

On the other hand you have places like rural Africa, Asia and South America who really have no use for modern microchipped cars and mostly just want slow trucks built in the 1950s, and a few motorbikes.

So perhaps they won't often manufacture the lower tech ones, but will certainly maintain them and keep them going decades longer than anyone expected.

However, the modern world doesn't give the best examples, because everything is so close. If the better shipyards are months of travel away, that TL-9 world is more likely to just build their own ships.

 

[Spinward Flow]

I think the best solution is not using a linear scale for the cost reduction, but an exponential scale.

It's certainly a functional solution that takes care of the "too much discount at too much tech level differential" problem ... but it does so at the cost of complexity to compute. The first time I looked at that formula you provided, my first impression was "CT would never use that formula" owing to how CT went out of its way to simplify formulas to the maximum extent possible, with a strong preference for simple calculation arithmetic (plus, minus, multiply, divide) that could be run on the simple calculators of the late 70s/early 80s.

For reference, I did a lot of my ship design calculations on a credit card sized calculator with an 8 digit LCD display (which I took EVERYWHERE and pretended was an original series Star Trek communicator due to the "flip to open" protective cover included with it) that couldn't even compute square roots, let alone more complex exponential scale functions (which today we take for granted in our calculators.



So an exponential scale like that would not make a good fit for CT "feel" formula.

However, if the formula were written differently, it would work.

Cost_base / (1 + C * (TL_shipyard - TL_craft) ) = Cost_final
C = 0.05 (Non-industrial), 0.15 (Industrial), 0.1 (all others)
TL_shipyard is allowed to exceed TL_craft to be constructed.
TL_craft is not allowed to exceed TL_shipyard under normal circumstances, but may be permitted as a special exception for cutting edge research projects.



A TL=15 shipyard building a TL=9 starship on an Industrial world for a base cost MCr100 design yields the following:
MCr100 / (1+0.15*(15-9)) = MCr100 / (1+0.9) = MCr100 / 1.9 = MCr52.6315789

A TL=15 shipyard building a TL=9 starship on a world that is neither Industrial nor Non-Industrial for a base cost MCr100 design yields the following:
MCr100 / (1+0.10*(15-9)) = MCr100 / (1+0.6) = MCr100 / 1.6 = MCr62.5

A TL=15 shipyard building a TL=9 starship on a Non-industrial world for a base cost MCr100 design yields the following:
MCr100 / (1+0.05*(15-9)) = MCr100 / (1+0.3) = MCr100 / 1.3 = MCr76.9230769

THAT computation "feels" a lot more like a CT era type of formula which prevents a runaway discount from happening as cited in my OP. Among other things, it means that a -6 TL ship design is almost "half price" to build at a shipyard on an Industrialized world, rather than being "90% off" as a discount.



Such a modification to construction costs and purchase price (and therefore bank financing needed!) if applied more broadly has some rather interesting implications for Traveller macroeconomics of starships. For one thing, the "cost advantage" of purchasing "less than maximal tech level" designs becomes a serious consideration in choosing a ship class to build ... and where to have the construction done. In the Spinward Marches of 1105, the "best deals" for low tech starship construction to be had might very well happen to be at Glisten, Mora and Trin (as previously cited in my OP) ... but if the starship is TL=9 with a Jump-1 drive, the transit time to reach a subsector such as Regina using the Spinward Main could (and presumably would) be prohibitive and ultimately not all that cost effective (not to mention, potentially risky).

In other words, final purchase cost advantages might wind up getting a lower priority than having a closer shipyard (such as Efate/Regina) do the construction. Yes, the price might be slightly higher (MCr62.5 instead of MCr52.6315789), but delivery to begin service in the Regina subsector would happen so much faster (and less at risk of an intercept by pirates) from Efate than it would from Glisten, Mora or Trin due to the shorter distance to transit to reach the Regina subsector that the slightly higher purchase price would be worth the front end expense. After all, at Jump-1, you're looking at 31 jumps just to get from Mora/Mora to Regina/Regina ... which at 2 weeks per jump is 62 weeks (1 year, 2.5 months!). Transits from Glisten/Glisten to Regina/Regina would need 46 jumps ... which at 2 weeks per jump is 92 weeks (1 year, 10 months!).

This kind of logistical tail on deliveries is something that Megacorporations could afford to take advantage of relatively easily, thereby keeping "older" starship designs in continuous volume production at the most advantageous locations for attrition replacement in their transport fleets (so the logistics of needing to move across a sector to reach an area of operations is less of an issue) but which smaller operators may not be able to afford to gain access to. However, it is also the kind of pricing factor that means that the details of the map become relevant, simply because not every high tech/industrialized world is "conveniently located" nearby to a region of space you want your ship to be operating in.

Additionally, this kind of tech level discount factor also encourages "commercial" grade starships to use tech levels below the maximum available in order to get a discount on price point. So even though a world has TL=15, for example, there may be an economic preference to build commercial starships to a TL=13 standard so as to realize cost savings through use of "less than cutting edge" technology in their construction (which would be easier/cheaper to fabricate). This would then amount to a kind of backdoor way for CT to encourage the common commercial vs experimental prototype range of upper end tech level detail seen in later editions, such as TNE and MgT.

It would also mean that type A starports for Industrial worlds would very much be the shipyard construction hubs for their local region of space.

 

[Spinward Flow]

I don't think there's any reason why a TL-12 starport can't install a TL-13 drive from someplace else.

Theoretically, no.
Practically, yes ... there is a problem.
In your example, the local tech level is "insufficient" to match or exceed the tech level of the drive to be installed.

CAN they put it into the hull?
Well, with enough hammers, they can drive that nail into where it is supposed to go.

Are they QUALIFIED to do an up to spec job of it?
Not necessarily ... the tech level of the local personnel is lower than the tech level of the engineering they are dealing with, so you can't assume that the work gets done "correctly" like it should have been done by a higher tech level shipyard.

Interesting thoughts. The simple rule that a TL-x ship can only be serviced at a TL-x or greater world changes a lot.

It does.
It makes MAPS quite relevant in ways they wouldn't have been before.
It adds a kind of "terrain" factor to clusters of stars that wouldn't have been relevant without the understanding.

A place like the Vilis Trace around Vilis/Vilis/Spinward Marches suddenly has a supportable tech level limit of 10, absent the capacity to reach the Lanth and/or Sword Worlds subsectors.

In the Five Sisters/Spinward Marches subsector, Karin and Iderati both have a tech level of 12, but the rest of the subsector features lower tech levels than 12, which could be an important factor in the rimward half of the subsector to be mindful of.

As far as I'm concerned, from both a Player and a Referee perspective, needing to be mindful of the limitations of support for your high technology "stuff" in order to keep it maintained and operational adds an important dimension to the setting and locations such that you aren't just automatically going to want the "best high tech everything" in every situation by default. If you can't support and maintain that high tech using local sources, that high tech is going to have a much shorter lifespan of use than it might have in other regions of Charted Space.

So yes, all the "best stuff" is maximum tech ... but you don't always want to be "tied down" with maximum tech if you need a logistics tail that stretches across the sector to keep it in working order. Long supply lines are vulnerable to being disrupted and all that, so in some ways it makes sense to "match" the tech levels of your "stuff" to whatever the local star systems are capable of supporting locally.

 

[Grav_Moped]

Spinward Marches of 1105, the "best deals" for low tech starship construction to be had might very well happen to be at Glisten, Mora and Trin (as previously cited in my OP) ... but if the starship is TL=9 with a Jump-1 drive, the transit time to reach a subsector such as Regina using the Spinward Main could (and presumably would) be prohibitive and ultimately not all that cost effective (not to mention, potentially risky).

The other side of that is that if you get your J-1 ship built at TL-15 at Glisten, getting it out to the boonies where it can exploit its TL advantage and then back again for its annual service is going to mean spending a decent chunk of time on sub-optimal trading routes. That has its own costs.

It also means there's going to be a lot of excess low-Jn shipping capacity near the high-tech hubs.

 

[infojunky]

Points to consider, the Median Tech Level is 12. Starports will general have parts to support that. Book2 drives are standard drives using common assemblies that are useful across a broad swath of drives. Thus the commercial engine of the imperium is supplied.

Now custom ships built to the lasted tech live in a different universe large crews and expensive supply trains and the like are how they operate. Note most of the Navy falls into this category.

 

[Grav_Moped]

Points to consider, the Median Tech Level is 12. Starports will general have parts to support that. Book2 drives are standard drives using common assemblies that are useful across a broad swath of drives. Thus the commercial engine of the imperium is supplied.

Now custom ships built to the lasted tech live in a different universe large crews and expensive supply trains and the like are how they operate. Note most of the Navy falls into this category.

I concur. That's the point of "standard" LBB2 drives -- they can be commodities, and are sufficiently value-dense (MCr/Td) to be worth shipping long distances. And the low-tech ones aren't obsolete in the way that old tech is here-and-now, because it's easy to keep building the old stuff and Vilani aren't big on revising their standards once they've been established.

Some examples here are VW making Buses in Brazil and Beetles in Mexico long after the corporation had shifted to newer platforms at home and for export, and LML and Bajaj continuing legacy production of old-style Vespa scooters (which they'd licensed from Piaggio for in-country manufacture) after Piaggio moved on to modern designs for the Vespa marque. Here, they're partly nostalgia and partly because the tooling had been amortized long ago. In the OTU, it's because it's still cutting-edge in some places and they need backward compatibility.

HG navy has smaller engineering crews (for large ships -- except it adds a layer of management/leadership on top).

 

[Grav_Moped]

Also, one of the central conceits of Traveller is that while high tech is often better, low tech solutions still work. "Shotguns in space!" and all that.

One thing HG could have brought to the table, and didn't quite (and I'm not sure T5 entirely fixes it) is that low tech could be good enough for non-combat purposes, while adding the high-power-draw and volume-costly components needed by combatant vessels requires high tech power supplies. For example, having maneuver drives require "___ EP" per ton of drive rather than per G, so that higher acceleration requires disproportionately more power.

 

[willtron3030]

with a strong preference for simple calculation arithmetic (plus, minus, multiply, divide) that could be run on the simple calculators of the late 70s/early 80

I had simplified it to the exponential from my four-function "brute force" solution. (eg, on an Industrial world, it would be (cost * 0.85) at one-TL diff, (cost * 0.85 * 0.85) for two-TL diff, etc.).

Interesting thoughts. The simple rule that a TL-x ship can only be serviced at a TL-x or greater world changes a lot.

However, a TL-15 place can't necessarily build a TL-9 ship. Even today NASA can't build Saturn V, for a bunch of reasons both technical, human resources, bureaucratic and political. And that's barely one level of tech difference, if that

To think too of things like valves, which only a couple of places in the world make now.

On the other hand you have places like rural Africa, Asia and South America who really have no use for modern microchipped cars and mostly just want slow trucks built in the 1950s, and a few motorbikes.

So perhaps they won't often manufacture the lower tech ones, but will certainly maintain them and keep them going decades longer than anyone expected.

However, the modern world doesn't give the best examples, because everything is so close. If the better shipyards are months of travel away, that TL-9 world is more likely to just build their own ships.

There was a research trend in research in the 90s called "intermediate technologies". The term described using high tech to design and optimize plans for devices that could be mass produced in an industrial society and exported, or built individually with simpler tools. Either way, the product could be maintained or repaired in the lower tech, non-industrial area / developing economy, and it still benefits from the design and optimization.

I could imagine a High-TL world building creating lower-TL designs for colonies and colonies mining operations in other systems, so the consumers have a better chance at achieving self-sufficiency sooner. Obviously not a Vilani strategy, but still.

 

[Spinward Flow]

The other side of that is that if you get your J-1 ship built at TL-15 at Glisten, getting it out to the boonies where it can exploit its TL advantage and then back again for its annual service is going to mean spending a decent chunk of time on sub-optimal trading routes. That has its own costs.

If the J1 ship is TL=15, then it's going to have to return to Glisten (or Rhylanor or Mora or Trin in this example) for annual overhaul maintenance, since those are the only TL=15 shipyards in the Spinward Marches sector.

If the J1 ship is TL=9, then any ol' starport A or B with TL=9+ will do and a return trip to Glisten for annual overhaul maintenance is not only unnecessary but also potentially counterproductive in terms of availability on route elsewhere in the sector. This is where the low tech advantage of having a wider array of logistical support locations comes to bear on the bottom line in the accounting department.

It then becomes a bit of a Goldilocks Zone to balance out the "map" considerations of going farther away for construction at a cheaper price and then needing to pay for a longer transit to the cluster of stars of interest for routine operations. Additionally, there's a sort of push/pull on tech levels going on where you want both the highest tech level to build the lowest tech level you can easily sustain and maintain ... and that's where you get all kinds of situational edge cases dependent upon the MAP region you want to be working in. The "terrain" of the arrangement of stars and the tech levels/starports in those systems becomes context relevant to solving the problem of optimization.



Key takeaway being that the highest tech obtainable isn't always going to be the superior option simply by default.

Sure, TL=15 stuff is "nice to have" ... but if you want to maintain it you're going to be pretty firmly tethered to the few locations where TL=15 support is readily obtainable for sustaining your stuff. But if you're operating on the "fringes" of a polity where that kind of high tech is "hard to come by" locally, it should be the case that using lower tech stuff that can be supported more easily in the local region ought to be the wiser choice for sustainable operations.

So instead of being a "one size fits all" kind of situation (TL=15 is "best" everywhere, no matter what) ... instead you wind up with a context dependent situation that is different in different places contingent upon the details and specifics of the UWPs available in that region (and how long of a logistical tail to higher tech you're willing to put up with).



Your mileage may vary, of course.

 

[mike wightman]

LBB2 and LBB5 are different drive paradigms in several ways.
Under the rules of LBB2 any type A starport regardless of local TL can build any ship. Under LBB2 rules any A or B starport can perform annual maintenance regardless of local TL.

What is the TL of the Imperial Navy bases that maintain the fleet? Are they limited to the local world TL or are they all TL15...

 

[Condottiere]

Technically speaking, you probably could replicate lower technology levelled machinery, assuming it can be done with a three dee printer; one of the reasons that Adeptus Mechanicus tracks down templates.

At that point, it comes down to cost, depending on whether it's a one off, limited run, or continuing production.

Could also be produced by artisanal or craft orientated workshops.

 

[Spinward Flow]

What is the TL of the Imperial Navy bases that maintain the fleet? Are they limited to the local world TL or are they all TL15...

Given that the Imperial Navy features next to NO starships under TL=15, the naval bases are going to have to be local TL=15 outposts suitable for maintaining Imperial Navy starships.

The rest of the star system may be "limited" to lower tech levels (for instance, Denotam/Vilis/Spinward Marches is only TL=10, but it has a naval base) for civilian/common use, but the naval base offers TL=15 support for navy starships only (presumably subector, sector and imperial navies).

A naval base that is "limited" to the tech level of the star system it is in would be incredibly useless to the Imperial Navy in the Five Sisters (TL=12 max), Jewell (TL=12 max), Vilis (TL=10 max), Regina (TL=13 max), Lanth (TL=13 max), Lunion (TL=13 max) and Aramis (TL=11 max) subsectors of the Spinward Marches. Under those limitations, the rosters of fleet assets that could be supported in those subsectors would be horrifically substandard to the TL=15 Imperial Navy requiring entirely other ship classes than the standard (meaning added logistical and training complexity in administration).

Better to think of naval bases as being "TL=15 outposts" for navy starships.
However, this also means that in places like the Spinward Marches, almost all of the TL=15 logistics supplies kept in stock at the various naval bases throughout the sector are going to be sourced from (you guessed it) ... Glisten, Rhylanor, Mora and Trin ... as the only TL=15 worlds in the sector. That then means that in some very important ways, those four TL=15 worlds are somewhat critical to the supply chain needed by every single naval base throughout the entire sector (in an "all roads lead to Rome" kind of way for sourcing TL=15 components and supplies).

Kind of makes you wonder what the supply chains would have to look like between Glisten and Five Sisters, doesn't it?
I'm not talking about the XBoat route here for communications ... I'm talking about shipments of replacement materials and goods that are going to be needed by the kiloton to support routine operations in the Five Sisters under IN administration.



However, if you extend the thinking involved, it starts making a LOT of sense for the IISS to NOT be trying to update their fleet to TL=15 everything like the navy does. By keeping the IISS fleet "low tech" enough to sustain operations almost anywhere (TL=10+ is pretty ubiquitous by 1105) the IISS has a compelling reason NOT to modernize to higher tech levels like the IN does. So it's more of a "live off the land" survival strategy (for starship maintenance/sustainment) for the IISS so they don't have to go to the kinds of extreme expense the IN does in maintaining maximum TL=15 bases standard everywhere.

The IISS is more of a paramilitary than military service, so having an increased dependency on local sourcing of supplies and logistics makes a lot more sense for them, since local sourcing will wind up being cheaper in a lot of cases (don't need to ship stuff across entire sectors to support far flung outposts). So keeping the IISS low tech relative to the maximum of the Third Imperium becomes a logistical asset, rather than a liability (because the tech they are using is so out of date).

At the time the IISS was founded in 624, the highest tech level would have been 12 ... so a TL=9-10 standard for XBoats, Tenders and Scout/Couriers would make a lot of sense because TL=10 wouldn't have been cutting edge technology that was only sparsely available at the time. Instead, TL=10 would have been closer to being common commercial tech for the time, making sourcing easier.

So scout bases, unlike naval bases, have a lower tech level requirement for fleet maintenance and sustainment, meaning there are fewer locations where there is a scout base on a world with TL=9- that requires a logistics tail extending to another star system. When sourcing of components and supplies from other star systems is needed, the logistics tail will almost always be MUCH shorter and easier to manage for a TL=10 standard than it will be for a TL=15 standard like the IN needs to keep up with and maintain.

Scouts do not "require" technological superiority in quite the same way the combatants of their naval counterparts do.

And yes ... that kind of "low tech but still good enough" mentality is almost certainly why the XBoat Network has remained J4 for as long as it has. Higher jump numbers require higher technology logistics supply chains to support them ... which may not be readily accessible or economically sustainable in all areas, limiting the "reach" of any potential technology level upgrades.

Something to think about.

 

[Spinward Flow]

Technically speaking, you probably could replicate lower technology levelled machinery, assuming it can be done with a three dee printer; one of the reasons that Adeptus Mechanicus tracks down templates.

At that point, it comes down to cost, depending on whether it's a one off, limited run, or continuing production.

Could also be produced by artisanal or craft orientated workshops.

Once you get to TL=10 where Makertech goes mainstream commercial/industrial, it simply makes too much sense to have ALL of the components of a starship "on file" in the computer for data transfer to fabricators who can then make/manufacture the requisite part to computer defined specs. Higher tech levels simply require better tolerances/higher tech materials sciences to produce correctly using Makertech. That way, local industrialists and parts suppliers don't need to have ever seen (or heard of) the widget you need them to make for you, they just need the "instructions" for how to make the part that you specifically need and the whole thing is 3D print on demand.

 

[agorski]

Given that the Imperial Navy features next to NO starships under TL=15

Have you seen Sector Fleet? There's reserve fleets, and sector, subsector, and planetary navies that inherit older ships and operate at lower tech levels.

 

[Spinward Flow]

Have you seen Sector Fleet? There's reserve fleets, and sector, subsector, and planetary navies that inherit older ships and operate at lower tech levels.

None of those are Imperial Navy.

Yes, I'm well aware of Sector and Planetary navy services ... but they're "local" (for varying map sizes of "local") not IMPERIAL.

The naval base marker is for Imperial Navy bases, not for Sector and/or Planetary naval bases.
There has never been a question (as far as I know of) which naval bases belong to which service (imperial/sector/subsector/planetary) in places like the Spinward Marches maps from LBB S3. That's because ALL of the naval bases are Imperial Navy bases, rather than bases for subsidiary services.

 

[Condottiere]

The Imperium Navy probably has mobile space docks.