UC Warship crew complements?

[Juumanistra]

Pre nuke power aircraft carriers might help on this one. Large tanks were on board that took up a large part of the lower decks of the ship that serviced both the ship and her air wing. I'd guess 10% of the total volume of a ship would be devoted to fuel if not more.

Even on a ship like the Enterprise-D there are large tanks for fuel on those fancy cross sections that also span a few decks so a Gundam warship should be no different.

Propellant is not the same thing as fuel in spacecraft that're governed by the Standard Model. "Fuel" is the stuff that is used by a shipboard power source to generate heat and/or electricity. That heat or electricity is then used to provide energy -- via a working fluid for heat -- to the propellant, which is energized and throttled out the tailpipe to provide motive force for the vessel. Allocations of usable internal volume for fuel are going to be nominal, given the volume efficiency of even modern nuclear systems. Allocations of usable internal volume for propellant, however, are going to consume almost of of the space. This is because the best propellants tend to be the lightest, but their lightness also makes them not terribly dense. (See, e.g., hydrogen.) Now, of course, there're ways to ramp up density via both conventional physics and handwavium, but even the invocation of metastable metallic hydrogen only gets you so far. As said above, a volume ratio of 1:3 is probably being generous, and should be considered a floor.

...and it occurs to me that, as I write this, that BFK also tackled it. Not going to let that stop me from being verbose, though!

Don't forget it is said that ships (in particular the white base) are highly automated so the crew complement is probably smaller than you'd think. Most of the crew probably goes to MS maintenance.

This is the type of dim-bulbed handwaving that I hate about Gundam's world-building. As, you know, the hero's ship is highly automated! While those knuckle-dragging mooks aboard the hundreds of other ships built by the Federation working by gaslight and manually training their ship's turrets. (Because the Federation's evil, you see. Or the mooks are faceless fodder to die at the hands of the Zeeks.) Either way, sucks to be them! As they weren't awesome enough to happen to fall in with the hero and therefore get a berth on the Cool Ship.

I'll just say the Pegasus's day is coming and be done with the topic for now, lest I get to ranting about systems density and utilization rates.

Well, that's a good number. Diesel-electric submarine usually also carries good amount of batteries to operate the electric motor once it submerge. That's almost 10% on med sized one (calculated by watching the diagram). Large vessel that has 200m length probably need some 5%, Salamis was powered by fusion reactor anyway giving it 24x7 independent power source. However, charging those MP cannons might be too much without having to charge it first. Like Star Trek's Enterprise, the power source cannot keep up with Shield, Warp drive and Weapon active all at once. On red alert and once they began to fire those phasers, the ship drains power from battery. So battery is a must.

No. Just...no. You build your ship's power source around your peak power consumption. This means that whatever you're using for a power source has to cope with all possible demands during combat. For a space-going warship in the UC continuity, this means having to produce output sufficient to provide for full broadsides, power for all relevant combat systems, and the ability to accelerate up to a certain redline point. If you don't do that, you're failing at even the most basic elements of defense procurement, which is always build the vehicle or vessel to the needs of the mission. Just because the ship designers in Star Trek are idiots doesn't mean we have to be too.

They may not be powered by mini fusion reactor but I doubt they could be bigger than the one on today's nuke powered submarine. Which seems small compared to the submarine's length or size.

A proper warship does not just have one fusion reactor. A singular point of failure like that is frankly unacceptable. You're likely looking at two primary fusion power reactors, to provide for redundancy and keep the wear-and-tear on each individual reactor down by allowing them to run at less-than-full-tilt most of the time. These probably won't be Minovsky piles: Given the setting's relative scarcity of He-3, it'd make sense for the primary power reactor to use something else other than precious He-3 for its primary power needs. (This also provides a nice upside in which standard cruising does not produce Minovsky radioactive waste.) Probably a D-T primary burn loop, given the abundance of deuterium and the relative ease with which that fusion operation can be undertaken. Even if the reaction produces issues with neutron damage.

Then you're probably looking at another pair of auxiliary power sources, to provide redundancy and assist in load balancing. I'd assume these would be small, gas-cooled fission reactors. You're also probably looking at a fifth reactor that's a dedicated Minovsky fusion pile, whose operations process is optimized for fast cylce-ups and thermal efficiency at breeding Minovsky particles. It's basically a generator that is cycled up with a kick-start and needs to produce the most Minovsky particles with the lowest amount of waste heat per He-3 atom input.

And I think I'll close my clinic on power system design here, before even getting into the question of whether the engines have their own dedicated fusion pile(s). Because that means deciding what the engines on these ships even is, and that's another massive world-building project unto itself.

[Tangerine]

But then again, we're not talking the best possible scenario for UC space warship. The battery function does based on the animation. Even the best of MS used charged e-pac or e-cap to fire those beam gun or rifles. Their ultra compact fusion reactor may or may not be enough to power those beam weaponry requirement, some said it's already packed like a bullet and the reactor only need to jolt them in order to fire the said beam. If even MS powered by nuke can't maintain their relatively one small weaponry (compared to Salamis') without having to rely on 'batteries'. I doubt those Salamis' much bigger mega particles cannon can be sustained solely by their reactors alone without having to rely on batteries. Unless we're talking about some very inefficient and expensive way to bolt up reactors just to make them 100% able to use those MPC all the time continuously.

It's better to make numerous number of the same ship with lesser generator and stock them with batteries. They charged it everytime and still can be used on combat situation where usually the MPCs are only used continuously for a brief period of time. Once it stopped it automatically charged as there are surplus electricity. There's no different in MPCs performance at all. It's highly efficient, economical and make good sense. Further more, doesn't it said somewhere that the produced heat is the main problem why a ship need to stop firing their MPCs? So they aren't mean to be fired continuously for a long period of time anyway. Old folks always says, why bother with bigger engines just to satisfy good stats on the report.

@Kirby: I disagree. If propellant used 2/3 space available of the UC ship then we should know since logically speaking the ship's shape should be very very different than already being portrayed on tv since they need to store them somewhere either on the inside along the length axis, distributed like a fish bone or in a bulk near the engine room. The shape should be really-really different. The way Salamis shaped is like regular naval warships and not like Apollo rockets. But funnily that sort of explains why the ship blow up easily the moment the bridge or anywhere around the hull, got attacked and penetrated by any kind of weapons.

[Brave Fencer Kirby]

Given the setting's relative scarcity of He-3, it'd make sense for the primary power reactor to use something else other than precious He-3 for its primary power needs.

I'm not sure that that's actually much of an issue. We never hear anyone talking about He-3 shortages or the need for more He-3 efficient technology, anyway. It would be an interesting worldbuilding point if such was the case, but I don't recall anything from either the animation itself or the supplemental materials that suggests that it is.

I doubt those Salamis' much bigger mega particles cannon can be sustained solely by their reactors alone without having to rely on batteries.

Actually, that's explicitly the case. The difference between a mega particle cannon and a beam rifle is that the former syphons its Minovsky particles (and the power needed to fuse them into mega particles) directly from a reactor, which gives it effectively unlimited ammo, while a beam rifle needs a pre-charged e-cap to function, limiting the number of times it can fire to the capacity of its e-cap.

I disagree. If propellant used 2/3 space available of the UC ship then we should know since logically speaking the ship's shape should be very very different

Why? Propellant is almost always a fluid; it will conform to whatever shape tank you pump it into. The shape of the ship is determined by its function; UC warships look more like conventional naval warships than Apollo rockets because they're single-stage multi-use orbital warships, whereas the Saturn V is a single-use, multi-stage Earth-to-moon cargo haulers.

[Juumanistra]

I'm not sure that that's actually much of an issue. We never hear anyone talking about He-3 shortages or the need for more He-3 efficient technology, anyway. It would be an interesting worldbuilding point if such was the case, but I don't recall anything from either the animation itself or the supplemental materials that suggests that it is.

The operative term was relative scarcity. It's not truly scarce, in the way that oil was in the West during the Arab Oil Embargoes of 1973 and 1979. Rather, it is scarce relative to its competitor fusion fuels, e.g. D-T and D-D, due to the costs of importing it en masse from the Outer Solar System or cracking many megatonnes of lunar regolith. But the necessity of using non-Minovsky-cycle reactors really is a function of world-building things we don't know of, such as the robustness of the gas giant convoy system and Earthside demand for He-3 beyond military applications, as well as how that relates to the product pipeline. (E.g. does a ship come in from Jupiter carrying 100,000tn of He-3 and have enough not only for existing orders but also ample reserves for market upswings, or does the same ship come into space-harbor with only enough product for some of the existing orders on its multiyear waiting list for He-3?)

[Tangerine]

Actually, that's explicitly the case. The difference between a mega particle cannon and a beam rifle is that the former syphons its Minovsky particles (and the power needed to fuse them into mega particles) directly from a reactor, which gives it effectively unlimited ammo, while a beam rifle needs a pre-charged e-cap to function, limiting the number of times it can fire to the capacity of its e-cap.

Now, that's new. Thanks for the info.

Why? Propellant is almost always a fluid; it will conform to whatever shape tank you pump it into. The shape of the ship is determined by its function; UC warships look more like conventional naval warships than Apollo rockets because they're single-stage multi-use orbital warships, whereas the Saturn V is a single-use, multi-stage Earth-to-moon cargo haulers.

Well if 2/3 is propellant then the other 1/3 is everything else. If we assume the scape available is 200x15x10 then 30,000m^3. 1/3 of it is 10,000m^3 of space spread alongside the giant propellant tank like a jacket. Not to mention MS facility and weapon rooms. May still sounds a lot until we factor-in things like corridors to connect them. Two major way left/right from "front" to "rear-end". At least 3x2m in height and width. That means (3x2x200m of length) x 2 left/right side = around 2,400m^3 just for connecting them. and I don't even want to calculate the minimum space needed to store 4 MS inside.

[Brave Fencer Kirby]

That has to do with size rather than shape, though. It's certainly reasonable to argue that the Salamis isn't large enough for its stated mission (a pocket MS carrier capable of independent deployment across the Earth Sphere), but that's different from saying that it isn't the right shape for that.

[Zinegata]

I'm not sure that that's actually much of an issue. We never hear anyone talking about He-3 shortages or the need for more He-3 efficient technology, anyway. It would be an interesting worldbuilding point if such was the case, but I don't recall anything from either the animation itself or the supplemental materials that suggests that it is.

He-3 is scarce enough that during the One Year War both sides agreed not to attack each other's HE-3 shipments.

Actually, that's explicitly the case. The difference between a mega particle cannon and a beam rifle is that the former syphons its Minovsky particles (and the power needed to fuse them into mega particles) directly from a reactor, which gives it effectively unlimited ammo, while a beam rifle needs a pre-charged e-cap to function, limiting the number of times it can fire to the capacity of its e-cap.

Yep, although discussing this topic on another forum, we came up with an interesting possibility that maybe the e-cap stores only megaparticles and no energy. This is why having an e-Cap isn't enough to be able to fire a beam rifle - your Mobile Suit still needs to provide the energy to actually accelerate those mega-particles into Mobile Suit-killing velocities.