Quick Calc Help Req - Comparative Volume of Shipbuilding

[Illuminatus Primus]

I cannot find good data on the volume of the Imperial-class Star Destroyer, much less that of the Executor-class command battlecruiser. I wish to compare the volume of the Death Star I and Death Star II to the construction volume of an ISD and Executor. The dimensions of the latter two (although they are prolate, and not spheroid; so a sphere's volume taking their equatorial diameter into account is an estimation) are readily available in easily form to derive the volume. However, I can't find good data on the ISD (and nothing whatsoever on the Executor). Does anyone have the volumes? Or the actual proportions on hand? Also I'm obviously comparing the rate of construction as well.

[VT-16]

The only thing I know of, is the mass-ratio. The Executor-class is 100 times more massive than the Imperial-class. (ITW:OT, SW:CL)

[Murazor]

The main site gives a figure in the comparison of Federation and Imperial industry:

However, a lone ISD is still an impressive sight for primitive cultures, who are generally incapable of constructing a vessel on that scale (the Federation has never been able to build a starship longer than 700 metres). Its length is approximately 1600 metres, and its volume is approximately 9E7 m³. Contrast this with the Federation's front-line warship, the military-version GCS. Several hundred of these ships were deployed in their recent Dominion War, making them the apparent backbone of their fleet (their Defiant-class and Sovereign-class ships are few in number). The GCS is a mere 650 metres in length, and a mere 6.5E6 m³ in volume. Federation cultists invariably compare the length of the two ships when comparing their size, but volume defines mass, and the volume of an ISD is fourteen times as large as the volume of a GCS. A one-dimensional comparison of length is oversimplistic and unrealistic- a 10m sphere is 8 times larger than a 5m sphere, even though it is only twice as wide.

As far as construction times, I think that there was some talk of it taking less than a year in the best shipyards (Kuat, Fondor...), but it apparently takes several years when you only have mobile shipyards (I'm thinking about the model taken by the Yevetha from the Black Fleet that was just finishing their first new ISDs when the New Republic declared war).

[evillejedi]

If we define 25,000 Imperator I vessels at the time of ANH (if it is a latter estimate adjust accordingly for vessel type and time span) this would require a production rate of over 100 vessels a month from assorted shipyards if steady production began right at the end of the clone wars. (clarification, this is just a minimum reference point)

From more detailed model estimates the ISD volume is 9.3e7 so the above estimate is very accurate.

I will lookup the SSD volume later. (posted estimated reactor output multiple instead)

The construction time frame of the SSD ranges from a few months to much longer depending on the resources at hand. Large yards like Fondor, CEC? or KDY can easily output single constructions on the order of 1e9 m^3 or more a month. Probably without much or any impact to other facilities. Civilian space stations would also be in this scale (though may not have anywhere near the complexity or tolerances)

The DS I/II had construction rates/volume of millions of times greater than this (Even if the DSI construction took 20 years it is still around a million times more material per month)

[Ritterin Sophia]

IIRC the 25,000 quote was describing ISD-II's, not ISD-I's or all ISD's. Can anyone confirm that and what year that comment was made?

Also, there seems to be two conflicting numbers, extrapolating the number of ISD-I's from the number of ISD-II's made since ABY 0 gives a total number of ships that's hugely different from the 24 SD's per sector*, nevermind the ships in the oversectors.

*Assuming that each sector has 36 member worlds like the Chomell Sector that Senator Amidala represented, we'll be minimalistc and assume only a million member worlds, that gives us 27777.777777777777777777777777778 sectors.

[evillejedi]

I'd be interested in the clarification as well since it does produce a significant spread.

If it is an ISD II number then (making another assumption that ISD II's debut was around or right before ESB)

25000 ships over a 3 yr period = 8333/year
25000 ships over a 2 yr period = 12500/year
25000 ships over a 1 yr period

spread out over a 20 year period of continuous production (assuming ISD I production was ramped down as ISD II production ramped up) this would result in a spread of (of course the rate is free to vary ,but for this example)

166K,250K,500K

with 2 million member worlds (divide down for other estimates) this would come to the following with 24 ISDs per sector

288 worlds/sector ~6950 sectors
192 worlds/sector ~10400 sectors
96 worlds/sector ~20800 sectors

[Illuminatus Primus]

Alright, so we're looking at a relative volume of the DS2 being in the (low)billions of ISDs, and the DS1 in the (low) ten(s) of millions.

Quite frankly, who gives a shit what Pelleaon has to say? He's senile, we know the Moff's militaries were only somewhat part of the full Imperial Navy (on some level they were colonial auxiliaries, with their own officers, commissions, and academies), and he doesn't even get the number of worlds in the Empire right (51 million is a lower limit figure). This is of course disregarding the fact that large fractions of Imperial war might at any time during the height of the Empire were sequestered where he would not hear of their composition or magnitude. The Executor, worth approximately 100 ISDs in volume, was built in a couple months; the Death Star II was built at the rate of hundreds of millions of ISDs per month.

Anyway, I was hoping for more exacting figures so we could post the relative volumes with error bars and such.

[Surlethe]

The volume of an ISD hull is approximately 4.46e7 m^3. This takes into account neither the protrusion of the reactor bulb nor the superstructure, so it should be treated as an absolute lower limit. I'm working on calculating the volume of the superstructure to arrive at an approximate result for the volume of the ship.

[Surlethe]

The superstructure of an ISD is more than 9.57e6 m^3, which gives a lower estimate of 5.42e7 m^3 for the ship. In calculating the superstructure, I ignored the smallest of the significant structures -- a heuristic estimate of its volume gives perhaps 3e5 m^3 -- and the neck of the bridge. All of these calculations also ignored the reactor bulb, the trench notches, and the hangar, heuristically assuming that these will "cancel out". Calculating the bridge neck and including substantial overlap with the rest of the superstructure, we arive at an upper estimate of 5.56e7 m^3.

N.B.: these estimates are not upper and lower limits because the calculations do not control for the volume of the hangar (should the hangar be considered internal or external volume?), the trench notches, and the reactor bulb protrusion. The approximation method also does not take into account the side trenches themselves; this should be an insignificant error.

We can be pretty confident, though, that the volume of an ISD is approximately 5.5e7 m^3.

[Illuminatus Primus]

How did MW get the 9e7 cubic meter figure on the website?

[Surlethe]

How did MW get the 9e7 cubic meter figure on the website?

I do not know. You can get 9e7 m^3 by approximating an IsD as a 1600 m by 800 m by 70 m box, but for all I know it could be from a source I haven't read.

[evillejedi]

The 9e7 ISD estimate I am getting is from a relatively accurate 3D model of the vessel (based on fractal sponges excellent rendition, but a lot less polys) that takes into account almost all features of the vessel.

for a 17.2 KM ex I get 19.3e9 m^3 or 215x the volume of an ISD

and for a 19 km Ex with some scaling tweaks I get around 30e9 m^3 or 333x the volume, this would be calculating the bulk features (>100m) of the super structure, fantail and docking bay. The depth of the vessel may be off so if you specify the height and width you want calculated I will rescale it.

The actual volume calculation is performed by the volume measure function in 3ds Max

[Surlethe]

I'm not sure why these results differ by 60%. I'll scan and post the calcs; they made use of the blueprints in the Essential Guide, by way of Curtis Saxton.

[evillejedi]

I'll validate some of the specific scalings to that reference, I believe fractal sponges version was based off of the model shots on SWTC so there is some perspective and angle correction that may have been done that probably exaggerate some proportions.

http://fractalsponge.net/ISD/gallery/index.html

[Surlethe]

Just eyeballing, it seems like on the models you linked the superstructure is higher and the trench is wider than the blueprints. That's a subjective impression, though.

[evillejedi]

I think the vessel is a little deeper as well, the aft distance between the engine nozzles and the wedge is very minimal in the essential guide.

I am going to be building a massing model from the major details from the essential guide image to see how much of a difference it makes.

[Illuminatus Primus]

Why don't we compare the Devestator model photos on SWTC instead? Its more important to get a realistic model than see the difference between two potentially inaccurate apocryphal images.

Eville, thanks for the Executor model at 19 km.

[Surlethe]

Why don't we compare the Devestator model photos on SWTC instead? Its more important to get a realistic model than see the difference between two potentially inaccurate apocryphal images.

I was going that route before I discovered the EG blueprints on the SWTC. Measuring angles and scaling from the photographs is far more time-consuming and error-prone because the photos are all taken at angles.

Just how apocryphal are the blueprints, anyway? I'm not up-to-date on EU and supplementary materials canon aside from the ICS.

[evillejedi]

based on this image

http://theforce.net/swtc/Pix/chron/isdventral1.jpg

and this image

http://theforce.net/swtc/Pix/Xbarbican/ ... r21isd.jpg

I get a dagger volume of 7.3 e7 m^3 with the bay and notches modeled with a 1600m exact length. No other surface details were added at this point and no engine volume is added in either. I only built for inset geometry such as the notches, lateral trench and bays. No super structure is included at this time.

my accuracy is probably +/- 3 m for any dimension in most cases (the image scales roughly to 1 pixel = 2 m and with blurring I placed the guides as close as possible)

The two images were combined by ratioing the ventral view width to the aft width and then scaling the total height ( I then compared the lateral images elsewhere on SWTC to establish a lateral trench height based on simply lining up elements like the notches and bays)

depending on the length of the vessel (1600m exact or something larger like 1629m) I can scale to figure out the deviation

In comparison to the model based on fractal sponges this is slightly wider and deeper in the hull so the other model probably underestimates by a bit

I could continue modeling the superstructure, but that seems to be close as well (though the superstructure I previously built is more in line with an ISD II vessel than a I)

the Essential guide schematic is radically different than the ventral view above, the points of the hull and the notches are 100's of meters different as shown below
http://warlords.swrebellion.com/junk/egcompare.jpg

[Surlethe]

God damn it. Looks like the EG blueprints are really inaccurate.

[Illuminatus Primus]

That's fucking pathetic. Could the WEG and EG people really not be arsed to go examine the models to make their blueprints? Is this really what EU loonies wank to? Jesus. What's the point of being an official author if you cannot be arsed to use the Skywalker Ranch resources? Saxton must have been the very first prick who was like, hey, can we look at your guys' models before we draw them in our book? kthnx

[fractalsponge1]

I can't really add much to the technical discussion, but I might be able to add some information to the scaling for the ISD.

There are no accurate blueprints of either ISD subtype in existence, unless the ILM model shop made internal blueprints to help construct the Avenger model in TESB. As far as I'm aware none have ever been published. Eyeballing from model photographs is as good as it gets. The EGVV plans are, well, shit, as I found to my great dismay while modeling. I have never seen a sketch or drawing of either subtype that is consistent to the studio model in all major features, so it is best to use movie and studio model references as far as possible.

My model was based on the detail features of the Avenger, with some embellishment/modification here and there, references depending. I think I got it fairly close by v2, by comparison with my references, with one important difference: the hull length is slightly off. Devastator and Avenger actually have rather different hull proportions. The best references I had available at the time I made the hull was of the Devastator studio model, so the proportions are scaled off that. In the much larger Avenger model, the hull is proportionally longer (perhaps as much as 10%), which may explain why my brim trench looks a bit thicker in comparison.

There is a model being built by a friend of mine that is attempting to do a detail-for-detail 3d reproduction of Avenger. I am helping him with interpreting the references, and the resulting proportions are, as far as I can tell, the most accurate available, but it won't be finished for a long, long time.

If anyone needs references for ISD proportions, I have access to a decent amount, just pm me.

[Illuminatus Primus]

So how accurate do you think the 9e7 cubic meter estimate is?

[fractalsponge1]

I'd say for an Avenger-proportion hull (finer than that of Devastator for a fixed length), 9e7 is reasonable, though I would say from my initial, very rough estimates that might be a bit lower, perhaps by 10%, but that depends on the volume estimates of the superstructure, which is tricky, and evillejedi's estimates are probably right on the mark. The Devastator hull at 1600m would be a fair bit more voluminous though.

[Illuminatus Primus]

Do you think they have different lengths? That's not unreasonable, and I'd run with a proportional estimate; rather than trying to fix the length at 1600 m. Afterall, the Block IIIA Arleigh Burke-class DDG is longer than the earlier classes.