Good question. I've been considering using GalCiv 2's ship builder to make some "screenshots" of my designs for my Aurora fics, but haven't gotten around to it yet.
If you're talking more about "I want to render something and am looking for scale suggestions", then I'd offer this:
The Space Shuttle is ~2040 tons (fully loaded, at takeoff -- the entire launch system, not just the orbiter). The solid rocket boosters account for about 60% of that, weighing in at roughly 590 tons each. The breakdown of that is 500 tons for the fuel, 90 tons for the empty tank itself.
The SRBs are 45.46m long and 3.71m in diameter. If we calculate them as a pure cylinder (overestimating the volume slightly because of the conical nose), we get a volume of 265.64 m
3. Figure that against the 590 metric tons weight, and you get an average density of 2.221 metric tons per cubic meter. Or, to be useful for our purposes, 0.45 cubic meters per ton.
So then (at least for fuel elements), 0.45 m
3 per ton would be a "realistic" value for fuel storage with modern-day tech, at least.
So a standard fuel storage (1 HS / 50 tons) would be 22.5 cubic meters, so maybe picture a cube about 2.85m on a side?
Of course, that's just fuel storage (and solid fuel at that, which is going to be extra-heavy). Other sections would be comparatively larger or smaller for the same amount of weight (cargo space would obviously be much larger volume for the same amount of space/ armor is probably a solid block of whatver). And it stands to reason that higher level techs could be much larger for the same amount of weight (or much smaller if miniturization is desired).
TLDR; it's sci-fi, just make that shit up.
As long as you're internally consistent.
EDIT: Also, for comparison, the largest commercial freighter on Earth (for now) is the Maersk E-class container ship.
Gross tonnage: 170,794 metric tonnes
Net tonnage (calculation of cargo space): 55,396 tonnes
Length: 397.71m
Beam: 56m
Depth (deck to keel): 30m
Given the shape of the E-class, and the fact that it's typically loaded way above the deck, you could envision a spacefaring cargo freighter to be of similar design, but with the hull simply doubled and "clamshelled" over the top of the ship.
So if we clamshelled an E-class to make a "space freighter", the result would be very blocky and the resulting vessel would be 397.71m x 56m x 60m = 1,336,305.6 m
3, and a vessel weight (not counting cargo) of 341,588 tons. For an average vehicle density of
3.912 cubic meters per ton.
If we do the same with a
Zumwalt-class destroyer (one of the boxiest, simplest hull designs I could think of, plus it's cutting-edge tech and a low crew complement), we get a ship that's 37,794 m
3 (no clamshelling, just calculated as a box) vs. 14,564 tons displacement weight =
2.595 cubic meters per ton. (real figure is probably considerably lower, because I realized that the superstructure is causing the imaginary volume cylinder to be far larger than it should be)
So, I'm being incredibly fast and loose with the math here, but if you want really, really ballpark numbers for the vessel designs as a whole, maybe start with 5 cubic meters per ton for commercial vessels, and maybe half that for naval vessels? This means your tankers and freighters and colony ships are going to dwarf your frigates and destroyers, but that's actually pretty accurate and true to the genre.
Taking the shuttle SRB example above, obviously component sizes are going to vary dramatically. Fuel stores will be very small and dense, engine will be pretty dense, crew sections and cargo will be light, electronics --especially sensors -- will be light. Weapons could run the gamut, depending on how you imagine them designed.
DOUBLE-EDIT: On further thinking, you'd have to tweak the values for ships with unusually large crew complements. The standard Crew Quarters section holds 250 people per 50 tons, or 5 people per ton. At the suggested military rate of 2.595 cubic meters per ton, that gives each person just slightly over 0.5 cubic meters. For reference, the Japanese "capsule hotels" are roughly 2m x 1m x 1.25m = 2.5 cubic meters. I think we can agree that the capsule hotel represents a lower threshold for what a crew would accept as livable quarters.
So for crew sections, maybe a rate of 12.5 cubic meters per ton for military (using the "capsule hotel" model), and maybe two or three times that for civilian (representing small cabins)?
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Topic: Aurora - The Dwarf Fortress of 4X Games (Read 2815232 times)