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Warp Nacelle Question

Dnoth

Fleet Captain
Fleet Captain
Hello everyone, I write fanfiction here on the board.

A question popped in my head: Do nacelles work together or independently? (i.e. Could a ship go to warp with only one operational nacelle?)

Thanks for your time, guys!
 
A little of both. In one particular Enterprise episode (can't remember which one), they went to warp with one nacelle damaged and non functioning, but they were severely limited as to how fast they could go.
 
Depends on who you ask.

If you look at the speculations of Jesco von Puttkamer in "The Making of Star Trek: The Motion Picture" and Roddenberry's own creative restrictions from TNG, it would seem that even numbers of nacelles work together to create a warp. There are many customers of FJ's 1975 Tech Manual who were less than thrilled by the later of these pronouncements.

For me, I like the symmetry of paired nacelles, and if more than two made a difference, I would think Kirk's Enterprise would've had more. And if only one made for a simpler and more practical design, I would expect Archer's Enterprise (or the same-era Intrepid) to have only one.
 
Yeah, Roddenberry believed that you needed paired nacelles to generate a warp field; having only one nacelle would be equivalent to building a helicopter without a tail rotor to counter the torque from the main rotor. Such a helicopter would spin around instead of flying.

It's since been shown somewhat consistently that this doesn't seem to be a necessity. Ships can function on only one nacelle, but at much less speed and efficiency. Much like how some modern aircraft can function on one engine, to a degree.

sunshine1.gif
 
I'd say that we can chalk it all up to warp field symmetry. I think the NX's 'symmetric field governor' may have been a minor attempt at explain why ships have two nacelles rather than one or three, though what exactly I don't know and I don't think it was ever said. Perhaps it is somehow advantageous for a ship's warp field to be wider than it is tall, thus dual, wide spaced warp nacelles are the standard on most ships.

In my mind, the nacelles are only the last piece in the complex puzzle of what makes a warp-capable ship 'fast' including mass, power, structural integrity, etc. Time and again on TOS we saw the original Enterprise threatening to tear herself apart when too much power was applied to the engines ("That Which Survives" comes to mind in particular) so a third warp nacelle might have been impractical at least in that case because the ship just didn't have a good enough structural integrity system.
 
I love the symmetery of the hero ship design in TREK.

Whether it's NX-01, NCC-1701, -A, -B, -C, -D, or -E, or Sisko's Defiant, or even Janeway's Voyager, it looks great and there's enough cumulative precedent in the TREK universe that this is the best and most practical way to build a Federation starship.

In high school, back in the '80's, I would take FJ's Saladin/Hermes schematics and redraw them with a second nacelle and a hangar bay extending back from the bridge. If Ptolemy can have two nacelles hanging down (we saw that Reliant did), then why can't a starscout?

That's just me.
 
There's enough on and off screen evidence to support the idea that starships can and do function with one nacelle. But clearly they function better in pairs, and do interact with one another in that configuration.

As I recall, there was some conjecture before The Motion Picture that the nacelles functioned by pulling the fabric of space/time through the nacelle and out the back, functioning much like a jet engine in that regard (I believe that's how FJ viewed it). With that being the case one nacelle would work just fine. In fact, if that were the case you'd want to keep two nacelles far enough apart so that they wouldn't interfere with one another.
 
My original thoughts were that it was a function of redundancy. It'd be harder to disable warp functions when there are two nacelles.

One example of a ship with one nacelle was a Saladin-class, granted it was never seen on screen. It was, however, in Star Trek Technical Manual by Franz Joseph.

At any rate, it seems the consensus is: one will work, but two is better.

Thanks for your input everybody.
 
Glad to help. ;) Andrew Probert had some interesting ideas, and actually created several of the infamous "Roddenberry Rules." Specifically, he created the rule that nacelles are supposed to have line of sight between each other, because Probert felt they needed to "see" each other and that energy passed between them, through the warp grills.

It's an interesting idea, but difficult to evaluate since some designs clearly violate this premise (such as the Intrepid and Defiant), and others like the TOS Enterprise do not have exterior warp grills. So personally, I tend to ignore this rule myself.

sunshine1.gif
 
I'd see the nacelles as the exact analogy to seagoing vessels' propellers.

They translate the power generated by the engines into motion. If the ship has just one, there is some torque involved, and this has to be cancelled; also, a single propeller is vulnerable to combat damage. But single propellers are cheap, which is the important point. You might want to build your attrition units (like Saladin destroyers) in this configuration.

If the ship has two propellers, it can use differential thrust for better maneuverability. It also has some redundancy, if one propeller is knocked out - but a two-prop ship that has lost one prop is worse off than a ship that was designed for single-prop ops from the beginning (Cf. the trouble NX-01 had when one nacelle was knocked out, limiting speed to warp 1.4). Also, two props can channel more power into motion. This is the favored configuration for cruisers in naval history - why not in Starfleet as well?

Three props, of course, can channel even more power, which is why this configuration is favored by battleships of old. Four is usually overkill, because there are conflicts of space then...

Also, a single large propeller is sometimes favored because it can be made quiet more easily than multiple, smaller, faster-turning props. Perhaps the Hermes scouts and their ilk favor single nacelles for this reason?

Timo Saloniemi
 
Here's my own take on things... we should not be talking about NACELLES at all here... the real issue is "coil sets."

Also... note that this is specific to LINEAR warp nacelles (what's been seen, canonically, since TMP, but which is arguably NOT the configuration of the pre-TMP warp systems).

For instance, consider the 1701-D. It has two nacelles, but it has FOUR coil sets... two nacelles, each of which has a top and a bottom row of coils.

Now, a single coil set creates forward movement by enveloping the ship in a subspace field, and by creating additional "nested" subspace field bubbles. Each coil creates a bubble, and the then next aftmost coil creates a bubble... and since the coils are arranged linearly, the compression of the subspace fields aftwards is much greater than that of the same fields forwards of the nacelle's axis. This creates a "warped" subspace field bubble... the bubble wants to go to it's lowest-energy state (where it would be perfectly symmetrical) but it's being forcibly created as a non-symmetrical bubble.. and that attempt to "equalize" is what gives the COIL SET some forward momemtum.

The thing to consider here is that each coil set can then, by definition (if you accept my explanation, obviously!) only provide a simple linear "straight ahead" (or, arguably, "straight behind" if you reverse the sequence of coil activation) "thrust vector." (Yeah, it's not really thrust, per-se, but you get the idea.)

So, fine... with one coil set you can go forward or back. But you CAN'T TURN!

So, let's say that you then have a system to put the sets of coils slightly out of sync with each other. Say you have a single nacelle with two sets of coils (sticking with the 1701-D example). You could slow the top coil set relative to the bottom coil set, very slightly, and as a result you could steer upwards. Or increase the sequencing speed of the top coil set relative to the bottom coil set, and steer downwards. But you can't turn left or right, and you can't roll.

Carrying this forward... with TWO nacelles (and thus four coil sets), you get the ability to steer up, down, left, or right, simply by adjusting the timing of the various coil sets.

You can also roll by adjusting the left nacelle to pitch up or down, and the right nacelle to pitch in the opposite direction.

And it makes sense that the further apart the coil sets are, the more effective your ability to steer in that axis would be. Thus, sticking with the 1701-D example, the ship should be able to turn left and right while at warp very efficiently (since the nacelles are spaced far apart) but would be a bit more sluggish in pitching up or down. It will also be able to roll, roll reasonably effectively... more so than it can pitch, but less than it can yaw.

Make sense?

So why keep two coil sets in a single nacelle? Well, in the case of the Stargazer, we see that some ships don't do that. But it seems to me that you're going to get the highest EFFICIENCY OF OPERATION when pairs of coils are closely coupled (meaning that they're adjacent, that the fields are able to merge very easily without much wasted energy, etc). In other words, the Stargazer might be very MANEUVERABLE at warp, but might not be particularly EFFICIENT at warp.

The two-nacelle approach works nicely, because it's balanced... you have one direction where you're very manueverable, but you are still pretty efficient.

And the one-nacelled approach would be much different... basically, you'd have four sets of coils inside of one housing. This is the approach you'd take for a ship that needed to be very efficient but didn't really need much in the way of FTL maneuverability. It could go like a bat outa hell in a straight line... just don't ask it to turn on a dime!

Anyway, that's been my theory for years now... it's consistent with everything we've ever seen on-screen, has no disproof (I don't take magazine articles to be "canon"), and makes good scientific sense (within the fictional "science" we have to work with here, I mean).

Now, there may be other ways to distort a subspace field and allow steering besides using sets of coils as I describe above. For instance, the original-series nacelles may not have been "linear" at all... I've always assumed that the white sphere at the aft end was a bubble-generator,and that the inside of the nacelle had at least one similar device internal to the structure, in-line... with those creating the forward/aft momentum, and probably with a couple of offset smaller bubbles in there as well to provide lateral adjustments.

Now, that means that, within an "old style" nacelle, you might have two (originally) or three (tos-series-version) "fore/aft" bubbles, and a pair of smaller "up/down" bubbles in each nacelle, and you'd steer left/right by adjusting the nacelles (similar to above). In a one-nacelle version, you'd just have four little bubbles (up/down and left/right) inside a single nacelle housing. The "little" bubble generators would be so much smaller than they would barely impact the construction of a nacelle at all.

So... that's my view of how these things work. Attack! :D
 
^^Makes sense to me...at least the TNG model; less so, however, with the TOS explanation.

LCARS 24, while I thank you for contributing, the article doesn't seem to go into detail as to why operating with one nacelle will tear a ship apart.

Plus, in the opening of that paragraph, the author says "Most vessels use two warp nacelles." Wouldn't every ship have to according to the article?

...actually, the author says, "the operation of a single warp nacelle can literally tear a ship apart." (as you quoted) ...not that it would.
 
As most people are posting I think it's like ship with two screws today.. They "can" run on one but not very well.. As seen in ENT. Also, in VOY's "Year Of Hell" they make a point of saying one of the nacelles is a "lost cause"
 
Unicron said:
Glad to help. ;) Andrew Probert had some interesting ideas, and actually created several of the infamous "Roddenberry Rules." Specifically, he created the rule that nacelles are supposed to have line of sight between each other, because Probert felt they needed to "see" each other and that energy passed between them, through the warp grills.

It's an interesting idea, but difficult to evaluate since some designs clearly violate this premise (such as the Intrepid and Defiant), and others like the TOS Enterprise do not have exterior warp grills. So personally, I tend to ignore this rule myself.

I just browsed into your 'Warp Nacelle' response and wanted to comment on it.

First, Gene created his own "Roddenberry Rules", not I. In one of them, he stated that "warp engines operate in tandom and that they were codependent,... no single or triple engines". I'm the one who (in an attempt to establish a bit of design continuity) ruled that nacelles should 'see' each other. As you correctly observed subsequent designs do violate this rule, but I had no hand nor control of those violations,... my successor(s) did. True, the TOS Enterprise nacelles do not have warp 'grills', as we've come to know them, but they do, by their inboard recessed detailing, infer a codependency.

I hope this helps clerify things a bit.
 
Hi Andrew! Good work on the Ambassador. Maybe we can get back to this design when you're done:

IdealE.jpg


:)

OT, I seem to recall conversations with you from many years ago where you mentioned an "in universe" explanation that the new nacelles on the TMP ship worked in a different way than the old ones, necessitating pairs in line of sight, and that was why you now saw an "intermix chamber" in TMP but not on the old ship, and why there was a plan to show some SFX between the two.
 
Aridas Sofia, that conversation must have been a long time back, but if I said it, that was my thinking at the time... I just don't remember it. Yes, there was a visual effect planned to be seen interacting between the two nacelles of the TMP Enterprise. When Trumbull took over the SFX,... that idea was lost.

And after the Ambassador, I'm moving straight to the vertical Warbird, but we can talk about that aforementioned project too.
 
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