Robert Maynard
Volunteer Moderator
Are we sure that it's 2m x 1m (x 1m)?It still fits in a cannister 2x1m in game.Something has to give.
Cargo size and shape
- Thread starter Soron Silin
- Start date
Technically, it could be under incredibly high pressure to the point where it solidifies under normal operating temperatures. Under high pressures, hydrogen can be denser than water; the only potential issue is that the pressure required is quite literally astronomical - it only occurs naturally at the heart of gas giants and synthesising it on Earth generally requires heavy-duty diamond pressure chambers.
I was thinking more along the lines of the volumetric dimensions itself not being the limiting factor for most modules. This would make the shape far less important because even if it were rather irregular or elongated, it would still be big enough for a module of that mass.
Not when the limiting factor is only mass and essentially never volume.
Even the densest of ED ships would bob like a cork in water, and some of the least dense configurations of larger ships might be even lighter than air.
Compared to the density of the ship, ~700kg/m^3 is very high.
This has come up several times before, and I still don't find it at all likely that "hydrogen fuel" is pure hydrogen.
The densest hydrogen storage mechanisms we currently know of that wouldn't require any special handling, cooling, or safety measures could cram significantly more hydrogen into a canister than if you used liquid hydrogen, and would actually weigh just about one metric ton for 1.5 cubic meters.
Yay, this debate again!
I think we're mostly in agreement that the optional slots at least need to have the same form factor across ships, since you can freely move modules between ships. It also seems intuitively obvious that each module size is double the volume of the next size down. Beyond that, debates about the internal geometry of ships tends to founder on the fact that we don't have any firm data that sets the baseline size of a module. If you assume they are just large enough to hold their equivalent volume in cargo canisters, the larger ships wind up being mostly empty space. But if you size them according to what would fill the larger ships, or to match the size of the externally visible doors, they wind up being much too large for the smaller ships.
Also, you can use subtargets to see the modeled location of modules inside a ship, and the optional modules are always distributed around the bulk of the ship, usually off the centerline.
I think we're mostly in agreement that the optional slots at least need to have the same form factor across ships, since you can freely move modules between ships. It also seems intuitively obvious that each module size is double the volume of the next size down. Beyond that, debates about the internal geometry of ships tends to founder on the fact that we don't have any firm data that sets the baseline size of a module. If you assume they are just large enough to hold their equivalent volume in cargo canisters, the larger ships wind up being mostly empty space. But if you size them according to what would fill the larger ships, or to match the size of the externally visible doors, they wind up being much too large for the smaller ships.
While tempting, I don't think this is logically consistent. For instance, in ships with both a size-5 and size-6 internal slot, you can put the fighter bay in either one. That implies that the (fixed-location) space above the fighter launch door, is not the actual fighter bay optional module. And that's a good thing, because if it were, that would imply that the size-5 and up optional modules have a spectacularly poor packing density, given that there is room for hundreds of cargo canisters in that space. Silly as it seems, I think the most likely conclusion is that the space above the fighter bay door is just empty space, and the fighter bay modules contain the stuff needed to assemble new fighters, and are housed elsewhere in the ship.
Also, you can use subtargets to see the modeled location of modules inside a ship, and the optional modules are always distributed around the bulk of the ship, usually off the centerline.
Last time this came up I think we decided that hydrogen fuel is the only obviously problematic commodity. Ammunition - which seems to take up neither mass nor volume - is far less realistic.
Pallets do exist - you can see them scattered around stations, and occasionally in wreckage signals. And the picture and description of cargo racks in the outfitting screen suggest that ship cargo racks are similar, and that our ships include automated cargo handling gear. Who knows, maybe cargo gets loaded/unloaded by the pallet load "off camera" when we're in the market screen. But given the size of the cargo hatch, it seems like cargo only ever enters or leaves in single canisters.
Robert Maynard
Volunteer Moderator
Good point - I had assumed (dangerous, I know) that the hydrogen would be transported as a liquid.
Regarding ship densities, I found this:
Robert Maynard
Volunteer Moderator
If cargo is not stored in canisters inside the ship, where are the canisters stored inside the ship (as a ship can discharge its cargo 1t at a time in flight)?
Not necessarily... Maybe they can compress it further with sci-fi tech.. especially if they already can do it in a high energy physics lab.
You can't simply use mass as the determining factor for module space though, as different modules have different masses. For example, a class 5A prismatic shield clocks in at 40 tonnes, while a 7D shield generator clocks in at 16 tonnes. If mass was the determining factor then we should be able to fit a class 7D shield generator in a class 5 slot and have capacity to spare. This is even without getting into engineering mods that affect mass even further, or the massless modules like fuel scoops.
The issue with any of the alternative hydrogen storage chemicals, such as adsorption mats, water or ammonia, is that they are all more expensive under most circumstances than hydrogen. Hydrogen fuel in Elite is cheap, a similar price to even water which is pretty abundant, let alone the more exotic options. There's also the issue that it has to be obtainable from most main-sequence stars, which basically limits us to hydrogen, helium and trace amounts of things like lithium and oxygen. Whatever additives they put into the fuel to increase the hydrogen density can't even be stored and recycled, as an empty fuel tank has zero mass - the entire mass of the fuel has to be obtainable from scooping.
Maybe you're responding to someone else's post, but I think cargo stays in the canisters when brought aboard a ship. Just like the pallets in stations are just a bunch of canisters strapped together in a frame.
Either way, a ship large enough to carry fighters has plenty of volume to play with.
The very smallest ships would need careful consideration for all aspects of their layouts to make sense, but once you get to larger vessels, there is just so much volume that it would rarely be an issue.
Well, the Keelback doesn't. It's mostly empty fighter bay. But otherwise that's very much true.
For others interested in the "hydrogen fuel" discussion, here's a thread that summarizes the state of our thinking so far.
Bigger On The Inside
There is no liquid hydrogen commodity. There is 'hydrogen fuel'. The best way to put cheap hydrogen fuel into a can is to store it as a hydrocarbon (diesel) or perhaps a metal hydroxide. Even water has a higher volumetric density of hydrogen than pure liquid hydrogen. We've had this exact...
Mhh, I think the size is a mile off...
One canister can store between 11 and 13 imperial slaves. So a class 8 cargo rack should be able to store 256 * 12 => 3000+ slaves.
I'm not. I just find it exceptionally unlikely that any piece of equipment of any given class would need the same space as the same class of cargo rack.
There are plenty of potential reasons why a lighter class 7 module would still need to be slotted in a larger module slot than a heavier class 6 module, even if the modules don't fill all the volume available.
The cargo canister and their shape goes right back to the original Elite. I doubt much thought was put into it; they probably only wanted to make them distinctive and a reasonable size to be scooped. It's so traditional now that FDev are probably not going to change it any time soon, even if it makes no sense. I think we can all see that it doesn't stand up to scrutiny. The question is only where you draw the line.
Two of them fit in my cargo racks if their sizes are 1 x 0.4 x 0.4, with space for scaffolding around them. That's close enough to the right aspect ratio, but the cargo racks would have to double in size if they are 2m long, plus another 25% if they are 1m wide. It that across flats or across points? I couldn't find an authentic reference for that, only a comment on the Wiki. They must have a defined size -- they have a model after all.
If that box is 0.7m on it's longest side, then I can fit 8 people into half a class-1 bay. So it's not that far off.
Where does that 11-13 come from? I haven't bought or scooped any myself.
Two of them fit in my cargo racks if their sizes are 1 x 0.4 x 0.4, with space for scaffolding around them. That's close enough to the right aspect ratio, but the cargo racks would have to double in size if they are 2m long, plus another 25% if they are 1m wide. It that across flats or across points? I couldn't find an authentic reference for that, only a comment on the Wiki. They must have a defined size -- they have a model after all.
Here you go. This even looks about the right aspect ratio.One canister can store between 11 and 13 imperial slaves. So a class 8 cargo rack should be able to store 256 * 12 => 3000+ slaves.
Where does that 11-13 come from? I haven't bought or scooped any myself.
Hah! It's a funny thought, but even the Anaconda isn't that light. Still, if you filled a Conda with one standard atmosphere, it would contain about 124 T of air, vs a total hull mass of 400 T. (With the lightest possible set of modules, 480 T.) But I think we can safely assume that without modules, only a tiny portion of that volume would be pressurized.
(I am just taking the volume from the table posted above - although on another occasion I did confirm in Blender for a few ships that those volumes are roughly correct.)
Something tells me that they would be bigger than OP's assumption. We have to take into account room for human activity within the cargo rack, as well as the space for any equipment that may be a part of the module, such as the robotic arm of this guy's interpretation:
Source: https://www.youtube.com/watch?v=RfGfBX2gj2g
On a ship powered by a fusion reactor and equipped with powerful synthesis devices (that can make oxygen, SRV parts, and bullets out of rocks in seconds), you could probably make any compound from hydrogen on the fly.
Now if only the shield bubble was air tight!
Still, wouldn't take a very thick atmosphere for an exploration conda to become a dirigible.
From various descriptions (wiki's and all that). Both a metric or a shipping tonne can store about 12 imperial slaves. Provided they are not too fat.
Oh, and canisters are cylinders.
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Close enough; they're octahedral prisms.
In all truth, cargo racks are very likely more like this:
And semi-modular/stackable like
And semi-modular/stackable like