This does look a lot like the Ent-D, even though they are really opposites. D had a vanishingly small secondary hull, the polar opposite of this. But both are explorers with lots of real estate.
Some thoughts about the Star Wars connection later.
In a way, Planet of the Titans WAS filmed. You see, Ken Adam was also part of another long running franchise of a certain British Secret Agent. And in 1979, Ken Adams idea of the future was in fact released--it was called Moonraker.
The thing is, it is a bit more trek-like than folks give it credit for being. Forget the colorful jumpsuits of Drax's men, and imagine Shatner in the cool grey on white uniform striding down the tubes (with some of the consoles softened up a bit) and you have starfleet command.
Compare Drax's station and the Office complex/upside-down Regula One. The solar panels on one and the listening outpost that V'ger absorbs/"de-rezzes" on the other. Busy designs both compared to the smooth Mushroom Spacedock, which owes much to Bespins cloud city.
I see more similarities. Heck they even had a true parabolic dish on the bottom. So I would call it a lost years era station--pre TMP. You may remember the drawings of tubes in much of that section in the Art of Star Trek.
Here are some thoughts on the McQuarrie-prise design. We saw from the Ariel shuttlecarrier that the design allows for nacelles to push a much larger hull than usual. Starfleet Saucers slice through subspace, where Klingon ships are more about piercing it. Here, you have both approaches in combination. Now, with Ariel, the secondary hull is more fluted where McQuarrie uses straight lines and is much larger judging by the grounded saucer. This seems to indicate a change in propulsion. In the TOS-TMP era, warp-dynamics involve a certain amount of streamlining for both higher speed and efficency. We see this exaggerated in Excelsior, with the ENT-D being quite fluid indeed, and also with nacelles getting smaller in relation to the bulk of the hull.
So in the Planet of the Titans universe, I would submit that certain breakthroughs might have come early--that an old slaver tech ship was found--or better still keeping with McQuarrie, an old ship from a galaxy far far away is found, and hyperspace is reached. In this universe, Praxis happens much earlier, in the Lost years post TOS pre TMP, and the linear warp drive path isn't explored fully. With the Fed's number one threat out of the way, the Galaxy class concept gets pushed ahead of schedule. Warp research stagnates, and simpler nacelles that aren't TMP fast are made. These nacelles are robust, contain their own back up reactors.
Warp fields don't have to hug the hull of the ship as well, and size is increased with new reactor designs (hypermatter). Thus Excelsior never happens and fluid designs are not pushed for. A big warp bubble using Ariel philosophy is as good as it gets since a second FTL approach is in hand. Ariel is warp only so is fluted since warp is all there is. Warp speeds are higher--the field more effecient, and cross galaxy travel is still in the future as per the Enterprise evolution.
They are designed to operate for very long periods of time, should the back-engineered hyperdrive fail. That is only used to jump between galactic spiral arms, to cross a galactic disk, with exploration done at warp flybys with the ship no longer out of sight of the universe, as it were. There are two designs, one with a wide secondary hull, and one with a triangular hull that isn't as large--the two study models that exist in the TNG prime universe as warp-only designs (Unification, Wolf 359, etc.)
Now the largest of the two designs is itself a tug. A saucer with a rounded edge is used for standard exploration, and Ken Adams very detailed saucer hull is an actual landing starbase type to be seeded across the galaxy, with newly found iconian doorways left behind. The shuttle have wings now, since repulsor lift adds to anti-gravity and higher in atmo speeds are desired without having to have a bubble shield around the shuttlecraft. Here, the moonbase look is on purpose as are the telescoping designs that make the saucer very busy. No Veridian III type ditching here.
Now, in terms of triangular hulls, we see that in the Klingon D-10 from FASA--and an upside down version of that on the cover of Shane Johnsons book BLUEPRINTING THE SCIENCE FICTION UNIVERSES. In fact, you could say that linear warp came from D-7 Graph units. I have heard it said that some of the cooling tech is in the klingon wedge hulls with coils only in the rump nacelles. Maybe wedge hulls have cooling at the edges, klingon style, allowing for small nacelles to do big jobs. In Ariel, it is just an add on to standard linear nacelles with self contained cooling, chillers, etc. for back ups now. In McQuarrier, the jet nose is a true bussard intake, prechiller.
As far the more narrow hulled McQuarrie-prise we saw entering the asteroid base (shown as a Tholian base in Enterprise), take a look at what this artist has done--and his take on the study models
http://s149.photobucket.com/albums/s71/pauly1972_photos/Apollo%20Class%20USS%20Gage/
http://www.ex-astris-scientia.org/articles/wolf359-other.htm#titans
http://www.ex-astris-scientia.org/schematics/phase21.jpg
Larger Version
http://www.ex-astris-scientia.org/schematics/phase22.jpg
http://www.ex-astris-scientia.org/articles/wolf359.htm
Of course, Apollo here is the Jetsons class version of the Ent-D
http://s112.photobucket.com/albums/n167/aridas_sofia/trek/?action=view¤t=JetsonsEnterprise.jpg
or a Nebula version of the Ambassador-- http://shipschematics.net/startrek/images/federation/tacticalcruiser_apollo.jpg
--or this:
http://memory-alpha.org/wiki/Apollo_class
Imagine if the bridge had filled Shepperton Studios in the mid to late 70's.Old BSG size and bigger!
I think it would have been similar to TMP but with the rounded egg chairs of Mike Minor, IIRC.
If Shepperton had been used, it probably would have held the interior of the Titan pyramid type structure.
Misc designs
http://trekbbs.com/showthread.php?t=126655
Older FJ designs
http://federationreference.prophpbb.com/post9941.html#p9941
