Indentation on the underside of the secondary hull...

[Wingsley]

The indentation on the underside of the stern of the secondary hull of Constitution-class starships caught my eye and got me to thinking. What is it there for? Why didn't they just taper the underside of the hull to mirror the topside?

Then an idea hit me: the indentation could be there to provide this class of vessel with a means to "piggyback" a small, detatchable "mission module" for deep space deployment. (While there is no canonical evidence to support this use, there is also nothing explicity ruling it out, either.) Such a "mission module" could be anything. It could be a small cargo container, a storage tank, a laboratory, a planetfall basecamp capable of landing once it is "dropped" from orbit, a proto-space station, or even a small pre-"runabout" deep space scoutship.

I was wondering if anyone could check and see how many decks deep this indentation is, and also approximately how long it is. If a "mission module" could be attached there, it might be a little longer than the aft tip of the hangar deck, but not by much. It looks to my untrained eye to be an impressive volume.

I was also wondering if anyone's schematics left the door open for some kind of hatch or airlock or docking port anywhere in that area. Does anyone here have any drawings of that part of the ship?

 

[Vektor]

I suspect the existence of that feature owes itself more to simple aesthetics than any functional considerations. I've built several 3D models of the TOS Enterprise and I have noted more than once how bulky and ungraceful the secondary hull looks before that "cove" has been cut out of it.

Having said that, there's a whole collection of hatches and access panels down the bottom centerline of the secondary hull that were present on the original filming model but never clearly seen on camera, including a red-outlined rectangular hatch on the underside of the cove in the exact location you're talking about, so I suppose anything is possible.

 

[Wingsley]

How many decks deep is the "cove"?

How long is it?

 

[Forbin]

I think the in-universe explanation (or at least my personal one) is that the shape has something to do with the way the warp field flows around the ship. It's a "warp dynamics" feature.

 

[David cgc]

That makes the most sense, since every other starfleet ship with a saucer-and-engineering-hull configuration has a similar cutout. And while you might be able to attach something to fill the space on a Constitution, I wouldn't want to try on an Excelsior, Galaxy, or Intrepid.

 

[Kirkunit]

Vektor said:
Having said that, there's a whole collection of hatches and access panels down the bottom centerline of the secondary hull that were present on the original filming model but never clearly seen on camera, including a red-outlined rectangular hatch on the underside of the cove in the exact location you're talking about, so I suppose anything is possible.

From what I can tell, the Warp engine appears to be a horizontal structure within Engineering. It's possible that the engine is in-line with the red rectangle in the scallop you're describing. If the rectangle represents a hatch, the Warp engine or "Warp Core" or whatever could be ejected through this opening, in an emergency.

 

[aridas sofia]

Jefferies identified those things as hatches for fuel and cargo, so I guess that works.

I think the cutout is there, as Vektor notes, for aesthetic reasons. In particular, it gives the stern a very naval "transom" like the aft of a sailing ship. The curve of the underside of that secondary hull and this cutout all seem designed to hint at naval shapes. When you combine that with the "flying saucer" of the primary hull, and the "rockets" of the nacelles, you get a complete picture of a naval spaceship. Something that goes one better than the stereotypes of the science fiction of the time in supplanting dramatic curves and sweeps with something that looks functional.

 

[Captain Robert April]

I like Petri Bloomqvist's notion of that being a workbee docking bay.

 

[Waugh]

See any of the various cutout drawings to see how many decks. The warp core is not located anywhere near that section of the ship. Here's a shot for you to see the red detailing of the underside of the fan tail.

 

[ed629]

I forget where, but one tech explanation that I read which included a diagram. It basically said that the cutout was there to shape the warp field since the hulls themselves influenced the shape of the warpfield.

 

[Cary L. Brown]

One thing that's worth noting is that most REAL naval vessels have similar construction... the term "fantail" isn't a Trek creation, after all.

So part of the reason it's there (and part of why we all sort of visually "expect" it to be there) is that we're used to seeing similar construction in real-life aquatic vessels.

I suspect that was related to where Jeffries came up with the slice-away. If you look at his original sketches, it's not there... and when it got added to his first color sketch, it wasn't a cut-out at all, it was a line on the hull.

So most of this is keyed to our (learned or innate?) expectations about what a ship SHOULD look like.

 

[Kirkunit]

Waugh said:
See any of the various cutout drawings to see how many decks. The warp core is not located anywhere near that section of the ship. Here's a shot for you to see the red detailing of the underside of the fan tail.

I expect I've seen just about every cutout of every Enterprise ever made. And just because those artists chose to depict Engineering the way they did, doesn't mean they're right. The actual location and configuration of Engineering was never established in TOS, so anyone's guess is just that.

If you wanted to argue on-screen evidence, there appear to be windows on the upper walkway -- which would seem to locate Engineering in the upper decks of the secondary hull. (Even though, IIRC, there do not appear to be corresponding windows visible on the outer hull.)

 

[Captain Robert April]

If memory serves, that cutout accounts for about two standard deck heights.

 

[Wingsley]

Are you sure about that?

I've peeked at some cutaway drawings on the web, and it looks like at least three.

 

[Captain Robert April]

Lemme dig up my own findings on that...

Let's call it two and a half.

 

[Wingsley]

Any idea on the length of that indentation, from the tip of the Hangar Deck to the aft end of the ship's keel?

 

[Captain Robert April]

Looks like around 150 feet, give or take a few.