Nurtz! I just done gone and crashed a probe into Mars! The drawing is scaled fine, but in my document, I list the scale as 1:10,000! Just how many cm are there in a m, anyway? Fortunately for all of us, I'm not a mechanical engineer. If the unit isn't Hz, I don't know what we're talking about!

That said, it should be 1:1,000. 0.1 cm on the drawing is equal to 1 m.
Regardless...
I've just had a big idea! I've said I was somewhat apathetic about this rev. I wasn't quite feeling it. What if I go the other way? What if I improve on the design by acknowledging the Union is so much worse than I've even assumed it to be! For example, without weird offsets, if they weren't running up the middle, where would I put the elevators? Answer: the Union doesn't have any! It's all switchbacking gantry stairs! The mechwarriors have to climb six stories if they want chow! They're not denied use of the crew heads, but no mechwarrior wants to get up in the middle of the night and have to climb six stories and then wait in line for a limited number of heads. Therefore, at some point, somebody started rigging up chemical toilets down by the emergency shower. Also, the mechwarriors wind up using the emergency shower as their only shower! Because of potential heavy metals, acids, and other contaminants, the emergency showers were never plumbed back into potable water recycling. At one time there were more heads on the accommodation deck, but they've been replaced by aux machinery over the years.
This goes back to the SLDF days. These ships were never designed for long term comfort. SLDF Mechwarriors DID complain about the upcoming plans. Senior officers slammed their fists on tables saying they could not accept this design. Civilian politicians responded by saying they could and would accept the design, or there'd be budget cuts the following year. The whole 'modern knights of the 31st c.' thing is in-universe propaganda. In reality, Mechwarriors are often treated like cattle by military planners.
Okay, those pillars are out! Also, I think the switchbacking gantry stairs on the upper mech deck will be outboard (on the -x axis), right off the cargo elevator (Mechwarriors sometimes hitch rides on that, if nothing else is going on). During battles, those stairs are precarious places to be. Also, don't be on them when the ship goes into zero-g Ops.
I understand your goal, which is using up all the bloated space of the Union using any listed lore and dimensions.
I think we're talking at cross-purposes. My goal is to come up with a Union class design. Your goal seems to be to ask whether we could make a better design or ship. We may be able to, but it's not a Union.
But, part of why you 'need' so much space is because of stuff like a giant running track for mechs, which you do not 'need', and which other mech carriers dont have.
It kind-of depends. I've shown that it's not much of a running track. There's barely enough room for 1 assault mech to walk abreast. You do need room for staging. Otherwise, you need to come up with a radical redesign (ex. put the engine up high, and then a bucket load of mechs down low, each with its own access doors, then you don't need internal staging).
If the description of the union didnt include such wasteful things as a ramp, youd get much more space.
Grrr... the ramp... If there's one thing I'm tempted to throw in the waste basket
despite being included in the fluff! But, my solution is to honor the spirit of the ramp by having two smaller ramps.
I understand blocking out open, wasted space for a ramp and running track because they are in the fluff, but I believe they are only in the fluff because the dimensions were so wrong the designers, like you yourself are doing, are finding ways to 'waste space' to match the incorrect dimensions.
Nope. I'm pretty happy with the mech decks. You need space for staging. How do the mechs get from their cubicles to the doors/drop chutes? You can't have a half dozen other mechs in their way.
Like when you look at your mech bay level, with the yellow shaded area housing the mech, the amount of space dedicated to the 8 mech bays is a small fraction of the space on that level.
Correct, but the geometry of mech bays limits the way they can be arranged. I showed that you can't move them in toward the center very much. One alternative is to give each cubicle access to a door (which is what the Leopard does). Another is to mess with orientation, but that'll only get you so much.
Also, are you are giving a lot more space to crew accommodations then the description mentions?
That was one of my initial problems. I showed in the first rev that a single accommodation deck is easily big enough to fit everyone, including the mechwarriors, all with access to properly plumbed heads. However, that's not in the fluff.
Are you doing bay personnel as fixed crew with listed accommodations, or as temp passengers housed elsewhere?
If you look at the mech bays in the latest rev, you'll see that I've put a little accommodation pod at the base of each gantry. It's a fully enclosed pod with double rack for a Mechwarrior and tech, 1 locker each and a small wash basin, plumbed with supply, but drains to waste. They are bay personnel with the associated consumables cost.
It feels like crew space is much larger and more comprehensive in your drawings versus fluff because you have so much space to add stuff, while also having vast tracts of empty space left over.
This is where the real challenge lies. Mechs are big, people aren't. Any ship big enough to carry even a few mechs will have oodles of room for people, and unlike mechs, people can sleep in double racks, literally stacked on top of each other. I'm pretty happy with how the mech decks turned out. The ship is pretty crowded for mechs, even though you and I disagree on the space required for staging. However, it's got lots of room for people. Yes, I have genuine empty spaces on the accommodation deck.
So while your deck layouts are cool, and try and fit the Union descriptions in, it doesnt mean they are efficiently using volume, nor does it mean you couldnt design a smaller volume if you went for efficiency.
Again, could we? Maybe, but it wouldn't be a Union.
But I ramble. My TL;DR is that you have 63k pixels on the 8 mech floor, with each mech assigned a 1600 pixel square, by total volume you can put 39 1600 pixel volumes on that single floor. So while you put in things like ramps and stuff, at the end of the day you still used a space that can hold potentially 39 mechs for only 8. We have different goals though, you are mapping a dropship that has the fluff listed volume. I only take umbrage to the 'it only barely fits' part of your statement, as I think it grossly understates the space being used, fluff or not.
Mechs aren't silly putty. You can't rearrange them so that they fill every available pixel. They're blocky, each one fixed in its design. Geometry limits the number you could put in. Each mech cubicle is 11m wide by 7m deep by 15 m high. You could rearrange them to fit a couple more on the deck (get rid of the workshop and magazine), but you can't fit 39, not by any stretch of the imagination. Another part where we seem to disagree is staging. You can't squeeze the mechs in like sardines. They have to have access to the drop chutes. This is a combat vessel. It has to get mechs ready to fight. One could imagine a cargo vessel, with no repair facilities, nor drop cocoons, nor anything, where mechs are genuinely lined up in close ranks and secured down, but this is a ship designed to drop into hot landing zones!
I'm back to my modern frigate/destroyer analogy. The aviation facilities consist of a hangar and flight deck. In the hangar, the helicopter has folded main and tail rotors. It's packed in very tightly. However, during those times, the flight deck is completely empty! So much so, that it winds up getting used for other things. That doesn't make it wasted space, though. During flying Ops, the helicopter is pushed out to the flight deck. Now, the hangar is empty. It's the same with this. The central walkway seems 'open,' but I'd argue that unless you redesign staging/egress from the ground up, it's very much needed space.
This goes further for the lower mech deck. It's very crowded with 4 drop chutes, landing gear hardware and so on.
It's the personnel decks that are giving me the most grief.