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Starport Capacity: Construction/Repair

RainOfSteel wrote:

"What is the construction and repair capacity of canon starports? (I'm thinking CT/T20 here, but any info would be helpful.)"


Mr. Steel,

Hold on to your vacc suit helmet 'cause you're not going to like the answer. Q: What's the construction and repair capacity of canon starports? A: No one knows.

For years, Our Olde Hobby had been pinning everything on the C&R rates found in CT's 'Trillion Credit Squadron' (TCS). There C&R rates were determined by starport rating and world population, but not tech level oddly enough. However, the C&R rates (and the tax rates) found in TCS were recently declared of no use for modeling OTU-3I C&R rates (and taxes) by Mr. Miller. He pointed that TCS is a wargame and not an accurate model of the 3I.

The recently released GT:Starports ( Added 28 NOV 03: Typo and Brain Cramp Alert! See note below!) has C&R rates, but I've read of errata issues regarding them on the TML; i.e. 1000 years to build a Tigress-class battleship.


Sincerely,
Larsen

Note - I meant to type GT:Spaceships not GT:Starports. Too much turkey apparently.
 
Hello Chris,
As Mr Larson points out, there aren't an awful lot of things one can go by regards to building ships. In the original rules from TRILLION CREDIT SQUADRON, they gave build time estimates for hulls larger than the ones listed in book 2 of Classic Traveller. As it chances to be, TRILLION CREDIT SQUADRON can be found again in the reprints by FAR FUTURE ENTERPRISES at http://www.farfuture.net/ (which reprint book it can be found in I don't recall unfortunately - but they run about $30 per reprint book containing around 8+ classic traveller booklets)

As for GURPS STARSHIPS - the rules contained therein permit ships to be built at an unbelievably fast rate. I'm not sure which threads Mr Larsen is speaking of when he references the time to build a Tigress Dreadnaught, so I will leave it for him to expand upon his statement ;)

GURPS STARPORTS however, has a different approach to ship building that might be of interest to you. Specifically, that one "starship building module" (takes up 6 dtons of space etc) can build 1 dton per year. The build rates for hulls can be based on that set up alone. However. You just knew there was going to be a however didn't you? ;)

if a ship is say, 800,000 dtons displacement, and you had a build time of 2 years - the starport itself would need some 400,000 dtons worth of starship building modules in order to complete it in 2 years. When starports discussed the number of shipbuilding modules a normal starport might have, I seriously doubt 400,000 dton's worth of capacity were mentioned.

In the example given in STARPORTS, it listed a type B starport with the capacity to handle some 15,000 dtons worth of shipbuilding capacity. If I recall correctly, that starport was a pop 8 world on a main route and with an X-boat route (besides being a subsector capital.

If we assume that this were a class A starport instead of a Class B starport, we'd find that it would take 800,000/15,000 years to build, or 53 years.

Oddly enough? Of all the rules available in the GURPS TRAVELLER universe, the starports rules are the one I'd trust the most (I've already pointed out on TML as well as on the JTAS discussion boards, that the rules from GURPS STARSHIPS are obscenely fast! A destroyer class ship can be built in 19 days if I recall correctly (or was that 19 weeks?).

Just as an aside? In reading Tom Clancy's book on aircraft carriers - it takes roughly 5 years to build such a beastie from the laying down of the keel to the launch and acceptance by the navy. In order to build an 800,000 dton ship in five years, it would take some 160,000 starship modules to create.

If it were my traveller universe? I'd state it simply as such:

All Dreadnaught and Major Carrier sized ships are built at Depot systems. They are the only systems with large amounts of ship building capacity available for the construction. All other cruiser hulls and such are built at both local shipyards at GTL 12 (TTL 15) or at the Depot system.

Keep in mind, one shipyard module can service 26 dtons of ships per year for maintenance purposes. A 200 ton trader will require the use of roughly 8 such Modules. Thus, according to GURPS STARPORT rules - not only does a shipyard have to be large enough to build ships - it must also have enough capacity to handle maintenance chores.

Another thought to consider is that GURPS STARSHIPS assumes that a ship building crew works only 1 shift a night. One might consider the concept that a shipyard's capacity is really THREE times normal if the shipyard is being worked round the clock.

I hope this has been helpful.
 
Hello Chris,
If you want a fast and dirty mechanism for estimating times for repairs as well as costs? I would suggest you take the price of the item being repaired, determine what percentage of the item needs to be replaced/repaired, and use this as a base cost. Then multiply the entirety of the item's repair cost by 1.25.

Example: Item takes up 24 spaces in a ship (drive damage, stateroom damage, and maybe some cargo hold damage).

Drive damage is such that it sustained 75% damage, two staterooms suffered total damage, and the hold suffered minor damage.

say that the drive costs 20 MCr. 75% of that is 15 MCr. Total to repair the drive would be 18.75 Mcr. Say the two staterooms cost .5 MCr apiece, for a total of 1 MCr value. Final cost to repair those staterooms is 1.25 MCr. Cargo capacity doesn't cost anything, but you recall that hulls themselves cost .1 MCr per dton. If you estimate that the cargo lost 4 dton's worth of cargo due to battle damage, you could estimate the hull repairs as being .1 x 4 x 1.25. This would bring the repair bill to .5 MCr. Total expenses of repair would be 20.5 MCr.

Mind you, that kind of battle damage would be rather extensive!!!

But for other aspects where the damage is relatively light, I'd peg it lightly...
 
I suspected there were some conflicts out there. :cool:

Thanks, everyone, for the info about GURPS. I don't own those (money issues, and the one I really want, Far Trader, is out of print), but it's interesting to hear what they're doing. CT and T20 definitely don't mention anything at all.

There was another thread where someone mentioned making players throw dice to check for available slots at the local starport when requesting annual maintenence. The thought really got me going, and I was wondering what the existing data was or if anyone had created their own house rules for it.

Let's see, quick and dirty:

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Pop Multiplier
----- ------
0-4: 100
5-6: 1000
7-8: 10000
9-A: 100000</pre>[/QUOTE]Multiplier * (TL + Mod) = dTon Size Limit.

Mods:
Add -5 for Type C Starport
Add +1 for Type A Starport
Add +1 for Scout Base
Add +2 for Waystation
Add +3 for Naval Base
Add +4 for Navy & Scout
Add +5 for Navy & Waystation
Add +1 per Jump Route Terminus
Add +50 for Depot *
Add +20 per Shipyard **
Add +1 for Subsector Capital
Add +2 for Sector Capital
Add +3 for Domain Capital
Add +10 for Capital or Vland ***

* The Depot/Shipyard bonuses do not stack (IMTU, Depots have various Shipyards available).
**The Shipyards of MTU.
Construction only happens at A ports (of course).
***Or other special/famous systems as determined by the GM.

A Starports Build & Repair & do Annual Maint.
B Starports Repair & do Annual Maint.
C Starports Minor Repairs.

Slots: The number of ships that can be Built/Repaired/Maintained at a time.

Slots = Pop + TL + Mods + Extra Starport Mod

Extra Starport Mod
A = x5
B = x2
C = -5

Minimum of two Slots.

Ok, yes, I really did just make all that up out of thin air. Heh, I'll have to think about it for a while.
 
Didn't Admiral Atrabella have to wait several years for new battleships to be built before she could throwback the zhodani in the 2nd frontier war. This gives about 5 years building time for a large multi-100ktn battleship.

I would scale smaller ships construction times accordingly.

Cheers
Richard
 
Arbellatra probably did have to wait. Exactly how long is open to debate. If we go by Supplement 9, a Tigress Class builds in 41 months in quantity. That's 3yrs 5months, which is only one more month than the 300 kdTon smaller Plankwell or Kokirrak, though they are around three times more expensive.

But it's exactly what I note here, that a Tigress takes only 1 more month to build than a Plankwell despite being so much bigger. I don't put much faith in these build-time numbers because of this.

Then there are the other systems after CT.
 
RainOfSteel wrote:

"Arbellatra probably did have to wait. Exactly how long is open to debate."


Mr. Steel,

Yes, she did have to wait IF we choose to believe the story in GT:Behind the Claw. That publication was the first to say explicitly that Arbellatra needed to build the heavy hitters for her "Goin' To The Core Tour" fleet. Given the fact that she'd just fought the 2nd Frontier War and negotiated a 'land for peace' deal with the Outworlds Coalition, I'd guess she had most of her fleet on hand already.

Certain aspects of GT:BtC are problematic. The story about Arbellatra is one. BtC's history of the 5th Frontier War; which is utterly incompatible with the war history presented in CT's SMC, is another. Of course, without these canonical gaffes, we Travellers would have far less to grouse about! ;)

"If we go by Supplement 9, a Tigress Class builds in 41 months in quantity. That's 3yrs 5months, which is only one more month than the 300 kdTon smaller Plankwell or Kokirrak, though they are around three times more expensive."

Odd, isn't it? IIRC, S:9 has the Plankwell-class built in a modular fashion, unlike most major IN combatants. That means any quoted Plankwell build time is even more useless because the construction method employed is different than the norm.

"But it's exactly what I note here, that a Tigress takes only 1 more month to build than a Plankwell despite being so much bigger. I don't put much faith in these build-time numbers because of this."

Spot on. Sadly, according to a few posts on the TML, GT:Spaceship's build rates seem to be suffering from MegaTraveller Syndrome - we'll need the errata to make sense of them. :(

"Then there are the other systems after CT."

Sure 'nuff. Anyone know of a MT build rate? A TNE build rate? T4? T20? Anyone? Bueller?


Sincerely,
Larsen
 
Now I know I'm not the most knowlegable on this topic, but according to my copy of High Guard,
Quote:
"Construction Times: Ships of 5,000 tons or less can be completed in 36 months
or less by any competent shipyard. Ships over 5,000 tons require from 24 to 60
months to complete, based on conditions, volume of orders, and the degree of haste
desired by the ordering government."

Maybe this will shed some more 'pleasent' light on the subject.
 
Granpafishy wrote:

'... according to my copy of High Guard,
Quote: "Construction Times: Ships of 5,000 tons or less can be completed in 36 months or less by any competent shipyard."


Mr. Fishy,

Sure thing. That's in my copy of HG2 also. So, ~36 months for 5K dTons? How much for just 100dTons? 1000? 2500? Still 36 months for a Suleiman? A Beowulf? A Kinunir?Also, what is meant by the term 'competent'?

"Ships over 5,000 tons require from 24 to 60
months to complete, based on conditions, volume of orders, and the degree of haste desired by the ordering government."

So, 5001 dTons takes ~24 months but 500,000 dTons will 'only' take 60 months? Less than triple the time for a two orders of magnitude increase in displacement?

And that's depending on conditions, volume of orders, degree of haste, and so on. Just what does 'conditions' mean? Which 'conditions' apply? How about 'volume of orders' too? How much 'haste' can a government apply?

At Electric Boat, once we sealed up the hull you could only fit so many workers into that space at any one time. After a certain point, we all got into each other's way and the amount of work done actually decreased.

"Maybe this will shed some more 'pleasent' light on the subject."

Maybe it will. Who knows? I'll stick with our first answer to Mr. Steel's question; We don't know.


Sincerely,
Larsen
 
Fair enough, but with everything that has been said so far, these figures hold fairly consistent. Besides, there has to be some work for the referee now doesn't there.
 
You can also derive shib-building rates per module from the rules in the TNE World Tamer's Handbook. However, this requires you to derive a value for determining shipyard capacity in terms of number of modules employed.

Fundamentally, a small starship *COULD* be built in a week if there were sufficient resources to do it. However, building times shoudl vary by all of the following factors:

1: In berth is faster than outside a berth
2: berth size sufficient for hull plus chunk movement
3: availability of preconfigured modules of various types
4: available workforce: numbers and skill...
5: work ethic of managment (1 shift per day vs 3 per day)
6: Bolt-on vs Keel-Out modes of construction
7: ability to get resources to the berth
8: distance of berth from machining facility *
9: amount of customization from familiar design **
10: skill of architecht
11: needs of the government(s) for the berth space.
12: other resource scheduling issues

* it is not, of need, a major factor, unless the plans are untried.... in which case, fitting and/or fabrication errors are compounded by the distance.
** if the design is a variant of a familiar design, this may actually increase construction time, due to crew doing things per the standard plans, rather than the current ones! But in general, the more familiar the process, the less time lost to figuring out the build sequence and logistics.

Take for example, the "Victory Ships" of WWII. A standard design, which, at first, took nearly 2 months, but very soon became a 3 week (or less, in some cases) build due to familiarity, fully engaged logistics support, and round-thew clock construction, with no competing use for the slipways.

Now, a Traveller 100 Td scout is a smaller craft, but definitely an order or two more complex. But, with the increased automation, and higer-level "Starting points" in the overall construction tree... it probably could be cranked out in a few weeks, assuming a definite need, supply support in place, and with the orders of the government (or sufficient cash).

I myself use TCS rates, as maximum throughput rates. Nominal rates are about 1/2 that.
 
Hey Chris?
For what it is worth, I will end up having to go through that painful process myself. ;)

Some thoughts I've been thinking are thus:

1) Assembly lines are faster than workers in free form.

2) Shipbuld rates during World War II were based on getting the most out the fastest. Some of the ships that were built in a matter of weeks ended up being shoddily built *because* of the fast construction times.

3) as things progress, construction as an art should also have benefitted - and thus be faster

4) as things progress and become more complex, construction should slow down. (don't you just love #'s 3 and 4?)

After digging up the information off the net, here are some facts.

Volume of a Sphere is: 4/3 x Pi x R^3.
Surface area of a sphere is 4 x Pi x R^2

If we use the formula that 500 cubic feet = 1 dton...


100,000 dton ship will have a radius of 228.54 feet (rounded to nearest 100ths)

Surface area will be 656,342.9 square feet.

200,000 dton ship will have a radius of 287.94 feet and a surface area of 1,041,879.42 square feet.

The questions you'd have to ask yourself are these:

How long does it take to build the HULL itself?
How long does it take to build the "internals"?

Example: say we are building the 100,000 dton ship. It takes X amount of time to build the hull itself (based on square feet of surface). It will take 1.6 (roughly) times longer to build the hull for the 200,000 dton hull as it took to build the 100,000 dton hull assuming you use the *same* work crew.

Lets say it takes Y amount of time to build the internal modules for that 100,000 dton ship. It will take 2Y units of Time to build that 200,000 dton ship's internal modules.

All this presupposes that you use the *same* work crew.

But remember ONE thing if nothing else
file_23.gif

The change in radius between the smaller ship and larger ship was only approximately 50 feet!

So, you've doubled the volume and increased the surface area by 1.6 times. The change in dimension however from the first ship to the larger ship was only 26%.

Just some interesting thoughts/observations using hard numbers ;)
 
and rememer, very few ships are spheres....

and, for construction speed purposes, more surface area is better.

I see several modes of shipbuilding:

keel out: the keel is laid, then working outward from the keel, systems are added as they are encountered.

Block by block: differnt blocks of the ship are constructed in a "main-spar - out method", then those spars are connected to the keel.

Shell In: Build the keel and the shellm, then feed things into it. Not a terribly likely mode for anything over a few hundred tons. Airliners are built this way, in sections.
 
Why oh why do we insist on thinking of starships being built like ocean going ships?

Keel first? How very two dimensional... must resist temptation to use quotes from cheesey Sci-Fi movies...

Submarines have to be your starting model, and modern subs are just about built from the inside out because once the pressure hull is in place it becomes several orders of magnitude greater to work on anything major.
 
Originally posted by Sigg Oddra:
Why oh why do we insist on thinking of starships being built like ocean going ships?

Keel first? How very two dimensional... must resist temptation to use quotes from cheesey Sci-Fi movies...

Submarines have to be your starting model, and modern subs are just about built from the inside out because once the hull is in place it becomes several orders of magnitude greater to work on anything major.
Being close to both a port that can build ships (Bremerton) and an plane manufacturing plant (Boeing in Everett), it is a simple method. Planes, ships, & subs are all built in sections, with the keel or back bone of each piece being the first to be laid down, because everything is built off of it. When all the section are finished, they bring the pieces together and the internals are then connected. Thats how you can have so many people working on one craft, is because they are not getting in each others way.
 
Planes, ships, & subs are all built in sections, with the keel or back bone of each piece
The keel refers to a spinal support that runs the length of the ship. Once upon a time this was laid down first and then the rest of the ship built upon it. Modern construction methods, as used in the aviation industry and ship building use a modular construction method as you say, in sub building this is taken to the extreme so that the decks are constructed and then the modular hull sections are connected around them, thus providing much more three dimensional integrity.
Technically a sub should be able to roll 360 degrees on its long axis and remain intact, I don't think there's many ships could mirror the feat.

I have always thought that Traveller space vessels should be constructed in a similar manner to subs and planes so that they can survive the three dimensional stresses (inertial dampers etc not withstanding) that multi G, high agility maneuvering would place on a several kton ship.
 
I also think that any large Traveller ship will be build in modules that will then be assembled. The modules could even be built in different star systems and then transported in ships to the final assembly shipyard.

There's an adventure seed for you: find the pirates who hijacked the main bridge module for the latest Imperial dreadnought as it was being transferred to Depot for assembly.
 
Originally posted by Sigg Oddra:
Why oh why do we insist on thinking of starships being built like ocean going ships?

Keel first? How very two dimensional... must resist temptation to use quotes from cheesey Sci-Fi movies...

Submarines have to be your starting model, and modern subs are just about built from the inside out because once the pressure hull is in place it becomes several orders of magnitude greater to work on anything major.
Not 2-d, when the keel is running down the spinal mount... rather than being the bottom of the displacement hull of a modern craft. (And, in modern airliners, there really is no keel equivalent.)

But, for anything which is going to subject itself for high-multiple-g accellerations (modern airliners seldom exceed 2G loading in operation, and 3G loading in certain take-off and landing maneuvers), some centralized mass linking structure is a necessity.

In MT, the rules seem to assume this is the shell. TNE assumes a shell and spine (minimum armour and minimum spine). CT implies a spine.

The keel of a naval craft is also sometimes refered to as the spine and/or backbone, sometimes just back (As in, "The mine broke her back, and she foundered then and there."). Some (very few, actually, btu they do exist) ships have separate spines and keels, and subs use a shell-integrity model.

Now, apllying the term keel to a spacecraft, it refers to the main structural integrity member, rather than the "Bottom of the hull", and is more properly a spine, but the two terms have been used nigh interchangeably on the TML for well over a decade now.

And note that I said "keel out" rather than "keel up".

(Boy, am I in pedanatic mode right now... apologies for tone...)

We have many different ship building rulesets (CT/B2, CT/B5, MT, TNE/BL, TNE/FF&S, T4/QSDS, T4/SSDS, T4/FF&S2, GT, T20. Plus, for the further afield, 2300 Starship Architecht's Manual (from Star Cruiser), Star Hero, CORPS VDS, Space Opera, Space Master (in two editions), Alternity GM's and Starships books, Starfire, and Star Frontiers Knight Hawks; all of these have been used at some point for traveller games of one sort or another, and have ship design sequences. One friend of mine still uses 1st ed starfire for his ship design system. He assumes a small ship universe (8-250 spaces, roughly 10 Td per space based upon his notes...)

Now, lets assume a 50 year lifespan. (We know this to be low... but in the long run, a fair assumption due to non-wear losses.) This means that we need to replace the tonnage every 50 years. We'll assume a 6 months-imperial time frame; we'll assume an A port provides all the ships it encounters (in the core, this is way wrong, but in the marches, it may be providing far more than it encounters month to month. We'll also assume 1 month per year down time for self-maintenance (actually only 2 weeks for maintenance bays, to make math easier...). 13 months per year. 4 weeks per month.

Step one: tonnage replacement, is two times 6-month capacity... or 1 % per 6 months of the overall tonnage.
so monthly capacity is 1/6% per month.
Plus, the entire tonnage requires maintenance, at 2 weeks per year; assuming perfect distibution, and no construction bays used, that's 25 units, each of 2 weeks and 4% of serviced tonnage. We'll assume that this is actually 1 week, plus queuing time so tonnage for maintenance yards is halved, to make required service ammount 2% per 2 weeks, or 4 % per month. So we need a yard which can build/maintain 4_1/6% of it's serviced fleet per month.

step two: serviced tonnage from WTN. WTN is in credits... there are tonnage values based upon median cargo sizes.
Let us assume, however, that those figures are accurate. Now we need to turn those tonnages into tonnages of ships...

let's assume J2, 1G, 10% overhead above that (bridge and staterooms, 200+ tons). 23% for Jump, 4% for PP (2% for the PP, 2% for the fuel), 3% for the maneuver drive. That gives us 40% overhead. So cargo tonnage * 10/6, 1_2/3. Lets assume that this needs to be adjusted further to account for non-merchant craft, to a nice round number... say 2x or 3x (depending on YOUR TU's millitancy, maybe as much as x5).

So take the median monthly trade volume for the A port's WTN, and multiply by 2 for a laizze faire TU, 3 for a more normal one, 5 for a paranoid one. Let's assume x3 (or, roughly 1/2 of all tonnage is NON merchants.)

Step three: How much tonnage capacity: roughly 25/6% of the shipping tonnage! Round up to 5% on the frontier. In the core, you may as well halve this, or even less.

step four: integrate it:
3x the trade volume and 1/20th the tonnage: 15% of the monthly tade volume in tonnage per month on the frontier.

half that in the core. Or even less.
 
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