Where are the Jefferies Tubes?

[Kamen Rider Blade]

I got to thinking about the Structural Layout / Cross Section of each deck of your typical Federation StarFleet StarShip.

Then it occured to me, where the eff are the Jefferies Tubes located.

Which lead me down the rabbit hole in google which lead me to this classic Ex-Astris Scientia Article about Jefferies tubes.

But then I got to thinking, it doesn't make sense that the Jefferies tube would be in between decks, we've never seen crawl spaces between decks for servicing. I could be wrong, or my memory isn't clear after countless years of Star Trek.

I've always remembered each Jefferies Tube to be on the same decks as listed in the plans.

But then this little diagram from Ex-Astris Scientia reminded me.

But their location doesn't make sense, and many times we see access to Jefferies tube, the tube is located at a height that is in the middle of the deck with access hatches located there.

This allows you to service Mechanical, Electrical, Plumbing & Piping to the Left/Right/Above/Below you.
Does that location for Horizontally placed Jefferies Tube make sense IYO?

Are there any improvements you want to implement on the Jefferies Tube for Engineering / Repair staff?

In my head cannon for bugeting of the Deck Volume Cross Section Height was at 4.0 meters.
This is what I thought the break down for each section would be:

The Floor / Ceiling covering section being 3x 0.12 meter thick chunks
- This would allow for a nice strong armored floor along with whatever covering needed
- The Drop Ceiling would also have nice armored panels as well to protect the MEP (Mechanical, Electrical, Plumbing/Piping volume.
- The Inner Ceiling would protect the Support Area / Structural member of each deck

What do you think of that Deck Cross Section Height budget allocation for each Deck layout?
Is that a reasonable height?

 

[blssdwlf]

The original Jefferies tube that angles up into the machinery seemed to make sense as it allowed you to get to an unusual volume of the ship. But with the ones that go thru the middle of the decks it just seems weird. Why not just make those a narrow corridor?

 

[Kamen Rider Blade]

Why not just make those a narrow corridor?

Less room for bulky machinery?

 

[Deks]

Its possible the Jeffries tubes are usually used by antigrave maintenance drones and DOT's. They are certainly big enough for those.
Humanoids can obviously use them as well, but weren't necessarily intended for such an extensive use.

 

[Kamen Rider Blade]

Humanoids can obviously use them as well, but weren't necessarily intended for such an extensive use.

How many scenes have we had in Star Trek that involve a Jefferies Tube?

I'm pretty sure we lost count.

 

[Deks]

How many scenes have we had in Star Trek that involve a Jefferies Tube?

I'm pretty sure we lost count.

Well, just because we had many jeffries tube scenes still doesn't mean they were intended to be used as extensively by the ship's crew.
To me, it makes more sense those would be mostly used in emergencies and by automated drones which conduct maintenance, repair and upgrades... or by some engineering crew to fix problems that automation could not?

 

[blssdwlf]

Less room for bulky machinery?

I dunno - just looking at your illustration of the vertical ? spaces it'd make more sense to just open them up as a corridor. As for bulky machinery they could be fully accessible on the walls, etc. I can see tunnels in specific situations but not in areas where there are already corridors around them. But that's just my IMHO.

 

[trekshark]

Isn't there a tube above ten forward in Power Play?

 

[publiusr]

I thought they went up into the pylons

 

[Locutus of Bored]

Isn't there a tube above ten forward in Power Play?

Yeah. It looked to me to be between decks just inside of the inward sweep of the Ten Forward windows and directly behind where the outer saucer rim sensor pallet strip is, perhaps providing access to it for maintenance and swapping out parts.

 

[DEWLine]

That's actually a good placement for that Jeffries tube, given the sensor pallet arrays.

 

[aridas sofia]

I thought they went up into the pylons

I think that was the intention. Jefferies refers to it as an “Engineering Power Shaft” in an early drawing, and it first appears in Charlie X. There wouldn’t have been much reason for it to be angled if it wasn’t meant to infer it climbing up into the prominent angled pylons seen on the ship model.. Of course, a “real” Jefferies tube would then extend a hundred or more feet to the nacelle. What we are then seeing is someone climbing into the very beginning of it where it opens into a… corridor?

There is that problem, that the tube is situated in a corridor when it would make much more sense for it to be in Main Engineering. Maybe that means that in the very beginning, when the set for the Jefferies tube was built, Main Engineering was thought to be in the saucer. Thus the curved corridor outside it.

 

[yotsuya]

The TOS Jefferies tubes have no clear placement. They are angled like the pylons, but there is no clear indication they lead to the pylons. They do link to important engineering items, but their use was kind of general implying that similar tubes could be in various places to access various things.

In Star Trek V, it is a full height mechanical area behind a regular crew area. It is in the secondary hull so the one we see is on a deck with a much higher ceiling than would be the case in the saucer.

In TNG there is also no clear placement most of the time. But in TNG, the Enterprise was designed with plenty of space for these to crisscross ship.

And keep in mind that we are dealing with ships with complex curved hulls. There is plenty of space for a lot of these in the areas that have too little head room for a regular deck. These areas exist in nearly all ship designs.

 

[aridas sofia]

Like I said, the angle makes it look like the original intention was that it led to the nacelle. Original intention. The rest is post-original intention. If there had been a crawlway specifically described as leading from a corridor up a pylon, how would it have looked any different from what we saw in TOS?

 

[Transaction Declined]

Did they ever show the far end of the angled access way in any episode of TOS?

 

[David cgc]

Did they ever show the far end of the angled access way in any episode of TOS?

No, I don’t think that that was depicted until ENT, where we saw it lead into a TFF-style full-sized utility corridor.

 

[Transaction Declined]

I never watched ENT, sadly. Nacelle access aside, I imagine that these tubes aboard the original NCC-1701 would also provide a way for crew members to reach those three viewports on each pylon. However I really cannot think of a reason for their location beyond providing Mk1 Eyeball backup for hard docking with other spacecraft and platforms in the event the photic sonar/LiDAR malfunctions.

 

[DEWLine]

Eyeball backup works as a reason for those viewports for me.

 

[Richard Baker]

Eyeball backup works as a reason for those viewports for me.

The battle in the Mutara Nebula would have been very different if people just looked out the windows...

 

[F. King Daniel]

Yeah. It looked to me to be between decks just inside of the inward sweep of the Ten Forward windows and directly behind where the outer saucer rim sensor pallet strip is, perhaps providing access to it for maintenance and swapping out parts.

Hilarious since Ten-Forward doesn't fit into the saucer rim to begin with!

Still not as bad as the Delta Flyer sprouting an entire rear cabin AND THEN somehow a Jeffries Tube as well