Evolution of a Starport

[Scarecrow]

Yes, Mr Bolton of this parish did one a while back...

http://www.traveller3d.com/sizechart/index.htm

Enjoy,

Crow

 

[ravells]

Oh that is amazing! It's so rare when you get exactly what you ask for on the web!!!

Thanks Crow!

Ravs

 

[Scarecrow]

Heh! Thank Andrew!

For some volumes... I've been working on a dTon volumes project on and off for a few years in which I build 1:1 scale block models of famous Sci-Fi starships and fighters and calculate their volume as accurately as possible and convert into dTons.
This is what I have to date:

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">SHIP_________________dTons (13.5 cubic Metres)

X-Wing Fighter_______2.7
TIE Fighter__________1.74
B-Wing_______________4.19
A-Wing_______________2.15
Y-Wing_______________3.34
Jedi Interceptor_____0.45
Star Fury____________14.2
Colonial Viper_______1.34
Millenium Falcon_____63.96 (depending on which length you accept as canon)
Slave1_______________32.01
Rebel Transport______1324.1
Enterprise A_________18661
Enterprise D_________433352.2
Federation Starbase__219.76 mil
Star Destroyer_______5.1 mil
DeathStar II_________1265.8 Billion
Tydirium Shuttle_____44
Hindenburg___________18,212.69
Cloud City___________22,690.5 mil
Borg Cube____________2.1 mil

</pre>[/QUOTE]1 DTon = 13.5 M cu
1 Billion = 1,000,000,000,000
1 Trillion = 1,000,000,000,000,000,000

Traveller ships it seems, really aren't that big

Crow

 

[ravells]

So this is quite interesting. The nearest traveller equivalent of a 747 on Andrew's site is a 600dt subsidised liner. The largest aircraft today (the An-225, so the web says) is 10m or so longer than a 747 (so still within the 600dt range). In fact the web also says that the An-225's take-off weight is about 6 t which fits quite nicely.

So using the 747 as a 600dt yardstick and going back to my question above about the dtonnage of the pictured craft, and guesstimating by eye:

Hindenberg: 2500 dt? (more volumetric shape)
Supertanker: 5000 dt?
Battle Star G: 6500 dt?

These sizes mean that the types of starship that normally put down at a Starport (merchants, shuttles and liners) are of similar dimensions to aeroplanes at a modern airport.

I wonder through whether there is a case for having behemoth non-starships for intra-system cargo transport that actually use the downport. I suppose (engineering considerations permitting)it would depend on the economics of lots of trips ferrying the cargo to orbit as opposed to one trip for the ship to land planetside.

Ravs

 

[Scarecrow]

The Hindenburg is actually just over 18,000 dTons

it's 245m long and using plans of it, I modelled it 1:1 scale (bearing in mind it was a close volumetric approximation and not an exact replica down to every last rivet) and it produced a volume of: 245,871.39 cubic Metres.

/13.5 = 18,212.69 dTons

The Supertanker looks to be over twice that and as a totally wild stab in the dark, I'd guess that the Galactica would in the 100,000 dTon range.

Note that you can't take Traveller ships' dTonnage as strictly accurate either. I'm pretty sure Andrew's got his lengths correct according to canon, yet note that the 200dTon Empress Marava is about a 3rd of the size of the 200 dTon Beowulf above it!!!

Crow

 

[Liam Devlin]

Ravs:

given the Hindenburg's displacement at 18Ktons,

and the largest, best known freighter of the 3rd Imperium (MT-era) is the Imperial-class Bulk freighter came in at 20Kton J3/1G, you've got a decent amount of leeway.

The Imperial-class 20kton was built primarily in USL configuration, although PSL & SL versions of the hull are noted to have been retrofitted later.

Tukera-Lines LIC, & her subsidiaries also had a 10kton Bulk freighter (J-1 & J-2/1G)models, as well as their Hercules-class 5kton J1/1G bulk freighter, SL hull.

The 10kton is mentioned several times, but was never statted out (MT-COACC), but was Streamlined (SL) hulled for planetary landings and was a favorite surplus transport vessel of Mercenary outfits of the rebellion era.

Stepping back from there, the Tukera Lines 'Long' Liner at 3ktons (CT-MT fame) J4/1G, that followed the X-boat routes (USL hulled, orbital docking only), and their 1kton J3/1G Long-liner enlarged version of the trusty 400dt 'Subbie' airframe.

& Lest I forgett, the TransImperiallines, LIC's 2kton Frontier Far Trader, 2ktons J2/2G.

From these sources ravs, looks like the biggest landing commercial vessel is 10Ktons, as the others are primarily unsuitable for planetside landings, and will have to rely on Lighters/ shuttles to ferry the freight dirtside.

Orbital & Dirtside:
+10Ktons--Medium Imperial Bulk freighter
+5Ktons--Hercules-class Bulk freighter
+2Ktons--TransImperiallines Frontier Far Trader
+1Ktons--Tukera-Lines "Long-Liner"

Orbital Only:
+20Kton--Large Bulk Imperial-class freighter
+3Ktons--Tukera Lines "Liner"


helpfully yours,

 

[ravells]

The Hindenburg is actually just over 18,000 dTons

Blimey!

Just working off rough dimensions of a 747 fuselage then, length: 70m, cabin width: 6m, fuselage height: 10m = 4,200 / 13.5 = 311 dtons.
(not including the dtonnage for the wings).

Thinking about it because dtonnage is a measure of volume, the increase of dtonnage would rise geometrically if the length, bredth and height increased arithmetically.

I think for the purposes of guaguing scale on the starport I'm better off forgetting dtonnage and just using Andrew's pictures as a guide.

Thanks again, Crow!

Ravs

:Edit: I'm going to have to stop saying 'dtons' and just say 'tons' (it confused the hell out of me at first as I thought it was the si index of x10 tons, until I found out that the d stood for displacement)

:Edit: Thanks Liam, but see above, I'm not sure how useful (in terms of scaling the starport) tons are as a measurement.

Crow, as you have the software there, if it's not too much trouble could you make varying cigar shapes (generic hull) of 25m, 50m, 100m, 200m length and tell me what the tonage would be (or just the volume), and again if not too much trouble the same for a generic saucer shape? Crow - no need, I've found a volume calculator on the web Here

Cheers

Ravs

 

[Hemdian]

Just a thought: As berthing capacity increases you'll need to upsize the port's generator, and not just for the larger general facilities. Berthed ships will want to power down their power plants prior to maintenance. So these ships will want to switch to an external electrical power supply for housekeeping needs for the duration. In fact it may even be considered a safety issue to not run a berthed ship's power planet unnecessarily.

Regards PLST

 

[Andrew Boulton]

The FF&S2 spreadsheet give dimensions based on tonnage and configuration.

http://www.traveller3d.com/downloads/FFS2XL97.xls

 

[Valarian]

Originally posted by Hemdian:
Just a thought: As berthing capacity increases you'll need to upsize the port's generator, and not just for the larger general facilities. Berthed ships will want to power down their power plants prior to maintenance. So these ships will want to switch to an external electrical power supply for housekeeping needs for the duration. In fact it may even be considered a safety issue to not run a berthed ship's power planet unnecessarily.

Regards PLST

Wouldn't it take too long to start up when you want to leave? I don't think nuclear power plants in naval vessels now are shut down completely even when in dock. May be one of the ex-naval guys on the boards could enlighten us.

 

[Andrew Boulton]

A cold start takes about an hour, according to MT.

 

[ravells]

Originally posted by Andrew Boulton:
The FF&S2 spreadsheet give dimensions based on tonnage and configuration.

http://www.traveller3d.com/downloads/FFS2XL97.xls

Thanks Andrew - looks far too complicated for my simple brain, though! I'm just going to do an excel spreadsheet with the basic dimensions to input for different shapes.

Quick question: Am I right in thinking that dtonnage is a measure not just of all the 'empty bits' within a ship but the entire space bounded by the fabric of the hull?

I.e. a solid metal cube of 14m.5^3 would be 1 dton and not 0 dtons.

Ravs

 

[Valarian]

I thought dTonnage was the volume of liquid hydrogen the body would displace if immersed.

 

[ravells]

If that's the case, then I don't understand how 1 m^3 of any material can displace any more or less than 1 m^3 of any liquid - unless you're floating the material on the liquid in an environment with gravity, so the density of the material and the strength of gravity will become relevant factors.

I had understood a dton to be the volume occupied by one ton of liquid hydrogen (presumably measured at 1 gravity).

...but then that would not explain why it's called a displacement ton.

ravs

 

[Andrew Boulton]

Originally posted by ravs:
Thanks Andrew - looks far too complicated for my simple brain, though!

It is a bit of a sledgehammer to crack a nut, but you only need the Hull section.

A dton is the volume displaced by 1 ton of liquid hydrogen.

 

[Icosahedron]

Originally posted by ravs:
I had understood a dton to be the volume occupied by one ton of liquid hydrogen (presumably measured at 1 gravity).

...but then that would not explain why it's called a displacement ton.

This is correct. When a ship of a certain volume is completely submerged in liquid hydrogen it will diplace a certain mass of lHyd. You are measuring the number of tons of Lhyd the ship displaces, hence the name.

 

[kaladorn]

Depends what sources he used. Recall that Traders and Gunboats had some deckplans which are... seriously broken. I'm sure not all deckplans have been correctly drawn to scale so using them in size comparisons is dubious...

 

[GypsyComet]

Originally posted by Scarecrow:
Note that you can't take Traveller ships' dTonnage as strictly accurate either. I'm pretty sure Andrew's got his lengths correct according to canon, yet note that the 200dTon Empress Marava is about a 3rd of the size of the 200 dTon Beowulf above it!!!

Crow

The Marava and Beowulf are both notoriously inaccurate. The Sulieman, Animal, March Harrier, and Sommerset are fairly close to stated displacements.

 

[GypsyComet]

Originally posted by Liam Devlin:

Orbital & Dirtside:
+10Ktons--Medium Imperial Bulk freighter
+5Ktons--Hercules-class Bulk freighter
+2Ktons--TransImperiallines Frontier Far Trader
+1Ktons--Tukera-Lines "Long-Liner"

Orbital Only:
+20Kton--Large Bulk Imperial-class freighter
+3Ktons--Tukera Lines "Liner"


helpfully yours,

The Imperiallines TI/TJ can land, but has to fold up its wings to do so. Most of the habitable space is high in the hull, so water landings are also done where available. Specific landing conditions will also determine if it needs to de-dock its Shuttle, which sits in an indentation in the two bottom decks. No official deckplans and only three artwork appearances (from which my deckplans were derived).

According to the published deckplans (DGP Traveller's Digest, very early), the Tukera Long Liner needs either a special cradle or water landing areas, as its down wings *don't* fold up. As a Tukera design, it is likely to only call on ports equipped for it, so the cradles will normally not be an issue.

 

[Liam Devlin]

Gypsy Comet wrote:

The Imperiallines TI/TJ can land, but has to fold up its wings to do so. Most of the habitable space is high in the hull, so water landings are also done where available. Specific landing conditions will also determine if it needs to de-dock its Shuttle, which sits in an indentation in the two bottom decks. No official deckplans and only three artwork appearances (from which my deckplans were derived).

Which were well done btw, might I add. x10! And true, the TI/TJ was designed for frontier landings, the MT-Rebellion Sourcebook illus. pp.84-85, give us the conclusion waterborne 'soft' landings are preferred. MT-Imperial Encyclopedia illus. page 51 gave us an 'in-space' flight picture of the whole vessel (albeit by a diff artist).

According to the published deckplans (DGP Traveller's Digest, very early), the Tukera Long Liner needs either a special cradle or water landing areas, as its down wings *don't* fold up. As a Tukera design, it is likely to only call on ports equipped for it, so the cradles will normally not be an issue.

Kewlness. I had not known that GC. Thanx!