Excelsior Technical Manual: Grand Finale


Vice Admiral
Hi there, some of you fellow old-timers will remember me from when I was a frequent board visitor, with my last appearance now being more than five years ago. To others, nice to meet you. I'm the guy with the unhealthy Excelsior obsession that wanted to write a tech manual for her. After years of on-again/off-again work, I am resolved to finally finish my attempted Excelsior Technical Manual.
For Excelsior, I'm operating from a few assumptions:
  • I'm treating the U.S.S. Excelsior and her sisters as "real" vehicles that have been represented by physical and digital miniatures over the years, with the "real thing" being a hybrid.
  • Excelsior's official length is indeed 467 meters as established by the original production diagrams (even though there is strong evidence that it should probably be 622 meters found here.)
  • Alpha and Beta canon will be respected as much as possible, so long as I don't have differing opinions that require extreme mental gymnastics.
I've written two sections, one of a more historic nature and the other of a more technical nature. I've previously posted sections of the text here, but after my last attempt decided to create a site to host them.

If you haven't seen my site before, check out Starfleet Heritage and History Command, and more specifically the Excelsior Memorial Museum page which has links to the historic and technical posts. The latter are somewhat incomplete and newly posted. All pages will likely be updated throughout the process. As opportunities arise, I am using this project to express personal opinions on various Trek Tech subjects.

The entire thing is being updated to be written from a "current" 2402 perspective, including related events from Star Trek: Picard, so be wary of spoilers if you haven't checked out that series and plan to. If this project proves enjoyable (and I have any strength left) I plan to publish a few other similar technical history articles

Hope you'll join me for the ride and wish me luck. :rommie:
Thanks for the support! I forgot to mention the main point of all this, which is to have fun. It's easy to get stuck in the weeds.

Now a bit of discussion. One thing I wanted to mention was how this aligns in my own head canon for how Starfleet ships were developed and built. In my timeline, Excelsior is the first major class to not use hull pressure compartments in her construction.

What are these? Some of you may remember this diagram from the TOS turbolift alcove and elsewhere:


I believe it was @Shaw who originally suggested that these should correspond to major bulkheads in the ship's assembly rather than decks, with decks built within them. This is also how I'm operating. I surmise that hull pressure compartments have been a central factor to starship construction all the way back to NX-01, before forcefields were so prevalent and reliable. The compartments are built individually, likely on a planetary surface or inside some kind of stationary hangar facility, then brought to dry dock and assembled into the ship's final form, with a second layer of hull added afterward. Wherever two compartments meet you have a double thick bulkhead that is just as thick as the outer hull.

Here's a preview of what my incomplete TOS and refit Enterprise cross sections look like:



As you can probably see, I reverse engineered the refit compartments from the TOS, presupposing that the compartments from the TOS ship were redesigned and rebuilt to create the refit ship's shape. This would make such rebuilds of a vessel theoretically much simpler (and plausible) if that vessel was stripped down to her compartments, the compartments rebuilt and then reassembled into a similar but new shape.

Here's similar previews of my Miranda and Constellation:



You can see that these two would share many of the same hull pressure compartments, while also having quite a few unique ones. It's important to note that hull pressure compartments are not slices through the ship, but rather spheres, discs, rings and "donuts" that fit into the overall shape.

However, we know from the TNG technical manual that the Galaxy class and presumably other ships of the modern era instead have a lattice of rooms and compartments suspended within the ship, which seems to preclude the idea of hull pressure compartments. I'm conceptualizing Excelsior as the "missing link" of sorts. The ship's major components - saucer, dorsal, engineering hull - are each one large pressure compartments with decks and compartments suspended within a la TNG. I imagine the Ambassador class to likely be the first major ship design built in the full "monocoque" manner.

Why does all this matter? Well, to my thinking Excelsior's design was just new enough that it was still easily adaptable, explaining in part why the Constitution class was phased out in its favor. I'm presently in the process of reworking my deck placement on the 467 meter Excelsior and will share that for comparison soon.
I've gone back and realigned the decks on my latest drawing. This revised set of originally featured the 622 meter length and decks spaced accordingly (from the previous thread.) Despite this, these drawings are far more accurate than the outline and other drawings I had used previously.


I've ended up with one more deck than in my technical writeup! However, given the age of the technical writeup and the less accurate drawing that originated with, I shouldn't be surprised. I already expected to have to go back to the technical writeup with revisions so this isn't much of a problem.

A few things to note here:
  • I've retained 9 ft saucer decks and 12 ft engineering decks as Andrew Probert used for the refit
  • The bridge dome is going to be a snug fit for a bridge and observation lounge as expected
  • The saucer superstructure and saucer edge windows all line up pretty well to these decks
  • The saucer undercut isn't any more problematic than it is on the TOS or refit Enterprise
  • The neck's deck nine is more like a half deck and will be comprised of hull latching machinery
  • "Generations" lines about deflector control being on deck fifteen really don't line up, but I don't care; I imagine that deck 15 was probably the deck that Kirk had to crawl down from to get to deflector control rather than where deflector control actually was
As I was alluding to previously, there's no hull pressure compartments. However, there WILL be lines to delineate between the saucer/neck, neck/engineering hull, and engineering hull/"humpback" as these are built separately and then assembled. I consider modularity to be another important key to the class's longevity.

If you were wondering, I do plan to flesh this out fully into an MSD in addition to the black and line "master blueprints" and deck plans. The plans are meant to resemble the diagram that Scotty was examining in "Star Trek VI" when he discovered the missing uniforms. See here for what I did with the Excelsior II class MSD.
I'm here with a minor update. I've updated my deck alignments along with a few other features. I've adjusted the deck spacing at the top of the neck to better fit the ship overall.

Please forgive the artifacts from previous iterations of this drawing. :)

"TSFS"/"TVH" intermix chamber:

"TUC" intermix chamber:

The idea here is that when originally built the Excelsior had a TMP-style "swirl" intermix chamber that ran all the way from the deflection crystals to the "humpback" where the power transfer conduits run to the nacelles. The "humpback" contained a secondary reactor that was essentially a secondary antimatter reactor, re-energizing the plasma for the transwarp drive engines. After the transwarp experiment "failed" (even though Starfleet didn't admit to it as such) the new warp scale was discovered and the modern (TNG-era) warp core was invented, as seen in the second version. It's this version of the ship that became so long-lasting, and would not have the secondary reactor in the "humpback" which would be mostly empty now. I've yet to figure out what, exactly, will go in place of the upper part of the saucer where the old intermix chamber was and I'm open to any suggestions. I didn't want to continue the warp core into the saucer in case of saucer separation, but have previously considered a "hybrid" design that would be TNG-style but cease to operate after saucer separation. Speaking of, I'm toying with the idea that the Excelsior class was the first major starship class that could theoretically reconnect after separation, though I also think this probably didn't work in practice until perhaps many iterations later. I attribute the unusual "half-deck" of latching mechanism in the neck to this attempt. This could explain how Riker had practiced saucer separation and reconnection prior to "Encounter at Farpoint" on the Hood. Also by my reckoning, Excelsior is also the first design to use modern warp coils like those seen in the TNG era, with previous designs being different, likely more like the asymmetrical coils of the NX-01 than anything afterward.

How and why did I arrive at this warp core arrangement? It's a bit of a journey but I feel obligated to explain. In TSFS we get a brief flash of the Excelsior's intermix chamber when Scotty is "turning in" for the one and only time. As best I can discern, after years of viewing and reviewing all the films, I believe this is the only glimpse we've ever gotten of any Excelsior warp core. However, we did see the Enterprise-A's warp core in TUC, which was very clearly a redress and reuse of the TNG sets. It's my conclusion that had those sets not been redressed for use on TNG, it would have looked more or less the same as it had in TMP/TWOK/TSFS in those films. (I'm ignoring the "engine room" set from TFF.) So, if we take evidence onscreen literally, you can conclude that the Excelsior project somehow brought about the modern TNG warp core. If you don't take it literally, you could "pretend" that the TMP intermix chamber never changed... but for me, that's boring. Dissenting opinions are always welcome.

Another question I asked myself in this is, what WOULD an Excelsior class engine room have looked like had we seen one in TNG/DS9/VGR? We notably saw the engine room of the Hathaway and Pegasus on TNG, and in each case they were not reuses of the standard TNG engine room. I would imagine an Excelsior-class engine room would have likely followed this pattern, or reused the TNG engine room itself. It's also interesting to note that they 80-year-old Hathaway seemed to also feature a TNG-style (thought not identical) warp core, which could have always been refit later but by its very existence I think lends credence to the idea that the Excelsior might have been the first to feature this core design. I did question the relative short stature of the TNG warp core but it's only a few decks "shorter" than the Enterprise-D's and no one has ever really established that this style of warp core's power is contingent on its size.

Last but not least, here is the drawing from TUC that I'm seeking to emulate with my drawings:

More to come!
Good writing! I just read through your historical section of the museum. You have a great command of that authoritatively historical patter that good history books have. I can't tell which parts are alpha canon, beta, or just out of your own head. It all sounds 'real,' and as far as I'm concerned this is now the definitive history of the class.

Qapla'! :klingon:
My head canon has the warp core in the hump, plus deuterium, you could blow it and nacelles and all off in one go.

That might allow it to function independently.

The secondary hull's deep fantail makes me think it could accommodate a drop-ship--- making its side view more like Oberth's.

The flat top a staging area...

Another vision of Excelsior
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Good writing! I just read through your historical section of the museum. You have a great command of that authoritatively historical patter that good history books have. I can't tell which parts are alpha canon, beta, or just out of your own head. It all sounds 'real,' and as far as I'm concerned this is now the definitive history of the class.

Qapla'! :klingon:

Thanks very much for the kind words! I've... probably read too many history books. :rommie:

My head canon has the warp core in the hump, plus deuterium, you could blow it and nacelles and all off in one go.

That might allow it to function independently.

The secondary hull's deep fantail makes me think it could accommodate a drop-ship--- making its side view more like Oberth's.

The flat top a staging area...

All valid points. I did think of including the intermix chamber in the "humpback" and a while ago did a number of studies of different intermix chamber configurations. Forgive the earlier versions of the drawing.





Ultimately I carried on with more detailed versions of some of them:



This is the TMP version that would have been the design prior to TUC:

This is the TNG version that I ultimately locked onto:

For me, the placement of the deflection crystal(s) is the most telling element as to the placement of the warp core, since we know that the TMP Enterprise's intermix chamber was intended to be topped with this crystal, and that seems to be a logical conclusion during this era.

Truthfully, I am still rather conflicted as to whether the TMP version should be the design for the entire class's lineage or whether the TNG upgrade narrative makes sense. Despite everything I said earlier, I don't think it's that much of a stretch to squint and pretend the Enterprise-A still had the TMP-style intermix chamber. The upgrade just happens to fit better with what was seen and makes for a better narrative. In either case, there's going to be some kind of warp core in the neck and it doesn't hold me up in defining the decks and other spaces.

I do also generally agree with your idea about the aft undercut having the potential for some kind of unseen cargo attachment; the two rectangular recesses on the undercut could be some kind of mounting points:

I consider the flat top to be cargo bay access; the section between the neck and hump could open up with cargo bay doors and in theory you could fly a ship through Shuttlebay Two and up through the cargo bays.
A minor update, I've begun rearranging hull spaces while also doing a study on the individual decks.

First, here's the latest version of the cutaway:

Next, here's an exercise I found helpful before in visualizing the decks:

A few things to note:
  • You can see already that a lot of the space of the saucer decks is not full head height, and will be filled with various support systems.
  • Deck One is just a rough placeholder and will require more attention to try to make things fit.
  • Deck Two doesn't have very much head height space; the circular main section under the bridge and the long "spar" behind that (which I will depict as being the subspace antenna with a Jefferies tube underneath for service)
  • I've already realized while posting this that part of Deck Three is cut off and will be fixing that.
  • I expect Deck Four and Deck Eight to have the primary hull escape pods hidden behind blow-away panels.
  • The neck and saucer not being aligned will require some minor creativity to depict the saucer and neck sections in the same space. The full version of the deck plans will likely not look like the above and resemble the Franz Joseph deck/page placements for efficiency and ease of viewing.
  • The SD-103 type shuttles docked in the main bay have been scaled up around 50% from the size they are depicted on the model as necessitated by the 467 meter size
More to come!
I didn't expect to have much more time to work on this today, but somehow ended up with it. Not complaining. :rommie:

I'm beginning to explore compartment and turboshaft spacing, beginning with the large Deck 07 and Deck 08, which are the two main decks that extend fully to the saucer edge:


I'm beginning to reconsider doing these in black and white and instead do them in color, but either way the color is helpful for evaluation. Yellow indicates turboshafts and turbolifts, with the darker yellow indicating a passthrough to below. There will be a 3/4 ring that connects each turboshaft "spar" to the central vertical turboshaft that I haven't drawn in yet. To evoke the spirit of the overhead turboshaft diagram from TMP-TSFS, the plan is to have corridors at cardinal points, with turboshafts halfway in between. This shouldn't misalign with any hull features (such as the landing feet on the ventral saucer) and should provide decent quick access for anyone to most compartments.

By necessity, Deck 07 has "overpasses" that allow access to the outer saucer rim beyond the ventral undercut. Cabins will alternate facing outward or inward depending on turboshaft placement, and I think generally feel accurate, without forcing anyone to walk too much. (If I wanted exercise I think I'd jog the continuous corridor on one of these decks!) At each location where the outer saucer rim has windows, there will be a two-deck recreation area/dining room combination for the crew that are open to the outer corridors. I should mention that these decks will mostly be crew quarters, too.

With this, I should be able to start fleshing out the decks above and below. More to come!
Continuing down the rabbit hole of general deck layouts...










Decks 02 and 03 are largely uninhabitable and will have life support and similar equipment. Deck 02 is quite small and will likely only have a few bridge-adjacent offices, with much of the remaining uninhabitable space dedicated to the dorsal sensor array and related systems. Deck 03 will feature standby bridge officer quarters (as seen in TUC) and the main science labs. Deck 05 features the dorsal escape pods surrounding the habitable area.

I realized that Deck 08 had too many turboshafts on it and decided to simplify. As a result, Deck 07 has ended up being (for now) the main turboshaft deck for the saucer, with shafts extending up from the four branches to the decks above and below. You can see the placeholder for the dorsal phaser banks on Deck 03. I've added general reserved space for the impulse engineering spaces and added the two large deuterium tanks on Decks 05 - 07. I've also added the auxiliary deflector to Deck 08. The auxiliary deflector is purposefully three small deflectors, to suggest the three round windows on the front of the TOS Enterprise may have fulfilled this role for that ship. The remaining saucer decks need to be drawn and I'll need to add the landing feet next, as well as begin to flesh out just what the impulse engineering spaces look like.

More to come!
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@BK613 Thanks! And I definitely won't be holding on to symmetry as I go further in. This is just to get started.

For whatever reason, Starfleet seems to favor putting random things on the starboard sides of their ships, which, personally, I find an amusing call back to the TOS Enterprise only being totally finished on that side. :rommie:
I thought I'd take a break from the decks, now that the saucer decks are roughed in, to share a preview of the external drawings and how I intend to present them. Hopefully you can see the resemblance to Scotty's engineering diagram.



I don't think I can take an award for most accurate plans, but I feel confident that these are right up there. I need to fill in lots of details, but got these about as far along as I need them to do the decks. The fore and aft views are honestly my favorite and help me remember why I have always been so fond of this ship.

More to come!
Sorry if I missed this somewhere, but are these drawings going up on a website in real time, or just here for now?

All good, I plan to post the finished drawings along with the writeups on my site:
Starfleet Heritage and History Command - Excelsior Memorial Museum

The neck could store a lot of deuterium..the ridges like layered design padlocks

A very interesting idea! Those darn ridges are very mysterious. While I do plan to include a secondary deuterium tank and the ship's backup fusion reactors in the neck, my general thought is the neck ridges (and the ones on the "humpback") are some kind of intercoolers, and that the Excelsior ran very "hot" during its transwarp trials. These intercoolers probably kept the newer drive exceptionally cool, too.
Apologies on the lack of updates, it's been a busy few days. After this forced break, I decided to revisit the deck layouts and alignments more using my external schematics; something just felt off about how the decks were all lining up.

The secondary hull width, open volume and deflector alcove both need some re-evaluation, and the bridge is just a placeholder. The fantail shuttlebay (aka Shuttlebay One) will also likely change shape, as the one above was modeled on one of the more recent model kit concepts for that area.

Once I get these aligned the way I want them, I plan to save this as a separate file from my external layouts and apply the general corridor/turbolift layouts I was working on above to the existing decks, as well as explore the others. I'm increasingly of a mind to present the decks in the format above, though static rather than animated. I think it's helpful to see where on the ship a particular deck aligns.

More to come!