Why place warp cores away from nacelles?

[Crazy Eddie]

And the energy being pumped into the plasma could indeed be something truly exotic - not electricity, nor compression waves, but something that only dilithium can produce when bombarded with the more conventional energies of m/am annihilation.

How about electrically charged gravitons and anti-gravitons?

 

[Crazy Eddie]

What I've never understood is how they can run fusion reactors without having 70% or more of the ship's mass be devoted to fuel.

Fusion reactors don't require that much fuel. In a given volume of the reactor only about 2% of the atoms in the reactor vessel are actually being fused; the rest are being heated by the energy released by those fusion reactions, either transferring heat to whatever's collecting the energy or waiting their turn to be fused with other atoms. Without venting the plasma propulsively, the Enterprise' fusion reactors could probably run for several years from a fuel tank the size of a swimming pool.

 

[Crazy Eddie]

Of all the engine components, the main reactor would need to be the most accessible if something went wonky. How'd you like to be the poor shlub who has to crawl all the way up those damn pylons to cut off the power flow or the ship is gonna blow up in five minutes....and it takes twenty minutes to crawl up that pylon?

It is my firm belief that if the reactor cores were located in places that were less accessible to desperate tooth-gnashing technicians, the occurrence of "The ship will explode in five minutes" plot devices would miraculously cease. Simply having the warp core in an accessible place leads the temptation to have the Great God of Angst engineer some incomprehensible situation that involves a bunch of engineers frantically banging on the warp core with hammers trying to keep it from blowing up.

Of course, the in-universe solution is simple enough: at the first sign of trouble, the reactor scrams automatically. Most of these "The warp core's gonna blow!" scenarios pretty much hang on a totally contrived failure of dozens of backup systems and safety mechanisms that are supposed to prevent exactly this sort of thing from happening; I mean what's the point of being able to eject the warp core if the ejection system fails 99% of the time anyway? As for maintenance... if you need to access it that badly, just hop on a transporter and beam there with a specially fortified sight-to-sight system.

Of course, none of this is going to prevent plot contrivance scenarios from happening. The nacelle transporter breaks down for some reason, or they can't jettison the nacelle for some reason, etc etc. Basically, anything that can go wrong with a centralized warp core can go wrong with an external reactor.

You also don't want your main power source in a location that's just begging to be shot off by some smartass Klingon who's a really good marksman with a disruptor cannon.

How about some smartass augment with a phaser lock?

Same problem, really. Anything that can go wrong with a warp core can go wrong with a nacelle reactor. In this case, though, Kahn has to hit BOTH of the nacelles in order to deprive the Enterprise of offensive power. Otherwise, the ship can still function somewhat on its one good engine, enough to limp out of the battlefield by transferring drive plasma from the good engine to the dead one.

As for the nacelles, it's not the power that makes them so dangerous, it's what they do with that power that requires them to be held out away from the main hull. In function, a M/AMRC is simpler than a fusion reactor, i.e., instead of having to induce a fusion reactor on some poor unsuspecting hydrogen atoms, which is pretty power intensive to begin with, with a matter/antimatter reaction, you just feed in protons and antiprotons from either end and they pretty much do the power generation all on their own, with the big trick being the containment part and channeling all that high energy plasma to the warp engines and wherever else it's needed.

Which are all good reasons to have the reactors in the nacelles. Their design is pretty simple... in fact, the warp cores on most ships really ARE small enough to fit inside the nacelles (the nacelle control room on the E-D could easily house an entire warp core). Their simplicity makes them less maintenance intensive than fusion reactors, and keeping them close to the drive coils simplifies the power transfer problem. The only thing this scheme would complicate is FUEL transfer; even if you can't store fuel in the nacelles (thus making them totally self-contained propulsion units not unlike a modern jet engine) pumping deuterium and anti-deuterium up to the reactors is bound to be simpler than pumping drive plasma and whatever it is they transfer. I doubt the EPS power taps would take up that much room, they could fit into the nacelles themselves.

The same logic applies to, say, aircraft propulsion; anything that goes wrong in a jet engine that would lead to catastrophic failure will happen way too quickly for your engineers to fix it in the nick of time, so your engine should simply shut down immediately until you can fix it later. If it fails so quickly that you can't shut it down, then you're already dead anyway.

 

[shipfisher]

That's more or less what the TNG manual suggests, Shipfisher.

I should have held on to my TNG tech manual. It would have made it easier to remember where I snatched that dilithium idea from.

I gave many trek books away years ago during a "divest myself of boyish things" phase while under the mistaken impression that growing older was always associated with growing up. My wife has assured me that I've managed to avoid the growing up part quite successfully so far.

-------------------------------------------------------
A favourite saying of my loving wife:
If a man speaks in the forest but no woman is there to hear it...IS HE STILL WRONG?

 

[Plecostomus]

Not going to quote but... the idea of the reactor scramming at the first sign of trouble... that's how it is in real life. Three Mile Island, most of the damage occurred due to decay heat after the reactor tripped. Chernobyl, they ran a damn foolish experiment in a realm of reactor-behavior they knew was prone to surges, the computer sent the shutdown signal dozens of times right up to the point of the explosion but the system was blocked from actually shutting down by the operators.

As for for the warp-core being simpler than a fusion-reactor, I don't think so. This is pure opinion and information based on the tech manual... but the warp core handles antimatter so it has additional layers of redundant protection... plus as designed look at the diagrams in the manual... we are not injecting a stream of frozen slush we are injecting a an ionized plasma/near-plasma stream into the core... The injectors are choked full of equipment to that effect.

Then you have the containment system that is absolutely critical-path, without that you die. And the heat-transfer system. And the dilithium crystal positioning system, and the interlock seals for the chamber, and the interlock seals for the PTC port...

A fusion reactor by contrast is a big torus or sphere wrapped with containment generators, a technobabble ignition system, a cooling system, and a plasma outlet. Thats why you see references to microfusion power plants in Trek Tech lit, because you can shrink that down to wee size as opposed to trying to shrink a warp core down to size.

 

[kent]

Well, generally speaking, to get from one point or another you kind of have to move by some way.

But copper wires don't move when they allow electricity to get from one point to another. Even the electrons within don't really move: they just sort of wiggle around, kicking the next one, so that electricity is transmitted. Plasma could be analogous to that. After all, as you say:

"we're venting drive plasma"

which is something people only yell in emergencies. It doesn't occur normally - drive plasma doesn't escape from the ship unless something goes wrong, so there's no need to constantly get more of it, either.

And there are references to "second stage plasma accelerators" we just don't know WHERE.

Indeed. But acceleration need not involve movement from A to B: the plasma could be made hotter, or more conductive to warp energies, by accelerating it into even more frantic wiggling-in-place.

FWIW, the "superchargers" that are blatantly visible on the hulls of the Enterprise or Akira class ships don't seem to be at the midpoints of the likely conduits, but relatively close to the warp reactor. Their role thus might not be one of doing more of the same as the reactor does, after the effects of the reactor have died down a bit due to distance - but of doing something extraordinary to the plasma that doesn't happen at all on starships that lack the "plasma accelerators". That's sort of what a turbocharger does in a combustion engine, too: it doesn't directly help move the pistons with greater force, it helps modify the incoming fuel-air mixture with extra air.

Timo Saloniemi

And yes there are plasma injectors in each warp nacelle, suggesting the warp plasma conduits "move", probably via magnetic constrictors, to the nacelles where they are injected into the nacelles.

And you'll notice that in every scene involving engineering on TNG or the TNG movies, involving the Sovereign and Galaxy class', the conduits always appear to be "pumping" the warp plasma into the nacelles or into the EPS grid. In older ships, the warp nacelles were turned off, but in more modern capable ships, they are always on and glowing blue for hot standby. The plasma isn't a conductive force, it's the fuel for the nacelles themselves. The episode in which Troi sensed someone committed suicide in the nacelle control room is pretty good evidence as it shows a plasma injector literally injecting the warp nacelle with the plasma. Hence whenever a nacelle gets hit it vents plasma. Even the refit constitution had plasma vents on the aft edges of the warp pylon, the Galaxy had them on the dorsal aft nacelle (those two recessed areas on the back of the nacelle.), and the sovereign class has them on the pylons again.

And while yes there is no direct evidence there are those superchargers or what have you on the transfer conduits, it seems a logical conclusion given how long hey are that they'd be moved to that location. It would excite the plasma even further giving it more of a gravitational flux to access subspace. The Akira class "superchargers" aren't really said to be that at all actually. On the NX-01 yes. But on the Akira they could be something COMPLETELY different, like a fuel dump port, or consumable supply hatch.

 

[kent]

Which are all good reasons to have the reactors in the nacelles. Their design is pretty simple... in fact, the warp cores on most ships really ARE small enough to fit inside the nacelles (the nacelle control room on the E-D could easily house an entire warp core). Their simplicity makes them less maintenance intensive than fusion reactors, and keeping them close to the drive coils simplifies the power transfer problem. The only thing this scheme would complicate is FUEL transfer; even if you can't store fuel in the nacelles (thus making them totally self-contained propulsion units not unlike a modern jet engine) pumping deuterium and anti-deuterium up to the reactors is bound to be simpler than pumping drive plasma and whatever it is they transfer. I doubt the EPS power taps would take up that much room, they could fit into the nacelles themselves.

The same logic applies to, say, aircraft propulsion; anything that goes wrong in a jet engine that would lead to catastrophic failure will happen way too quickly for your engineers to fix it in the nick of time, so your engine should simply shut down immediately until you can fix it later. If it fails so quickly that you can't shut it down, then you're already dead anyway.[/quote]



The nacelle control room on the Enterprise-E, and the Enterprise-D respectively, are actually IN the nacelles themselves. The warp core of the Enterprise-E is 12 decks high, and the Enterprise-D is 10 decks high. That would occupy a significant portion of each nacelle, even if split in half. So in addition to cores, you have to include the off axis field controllers, the warp coils themself, plasma injectors, bussard collectors, hydrogen storage and trasnfer technologies, plasma vents, magnetic field emitters FOR the bussard collectors. It just wouldn't be feesible to also include a warp core as well. yes they can be tiny but the TINIEST that the Federation has built in the 24th century was 4 decks high on the Defiant. That's still a big portion.

It makes more sense to have a warp core in the secondary hull with direct access to the antimatter pods and dueterium tankage. you can stop fuel from reaching the core without having to worry about the fuel also travelling all the way to each nacelle. The nacelle emits so much energy itself that it would also probably endanger the reactor in it. It's not a plane, it's not some jet, it emits a HUGE amount of energy and has a HUGE amount of components to it. And it's generally agreed upon that the taller the warp core, the more efficient it is unless you can work your way around that IE the swirl intermix of the Intrepid and the looping of matter and antimatter to simulate a larger warp core IE the Defiant.

And if there is some huge problem, it is possible to shut down the warp core or contain the problem, it's beend one quite a few times. Especially on Voyager. It didn't matter that the warp core was in the secondary hull. And if the problem was too great, they ejected the core where it had the chance to "cool" down in space, rather than just saying, FUCK it, let's just exlpode and all die. If it were in the nacelle you'd eject not only you're entire nacelle but the core as well, screwing you in so many ways. only starbases can really create a warp coil, it's not something you can replicate.

 

[Crazy Eddie]

The nacelle control room on the Enterprise-E, and the Enterprise-D respectively, are actually IN the nacelles themselves. The warp core of the Enterprise-E is 12 decks high, and the Enterprise-D is 10 decks high. That would occupy a significant portion of each nacelle, even if split in half.

There's never been an in-universe explanation for why the core MUST be twelve decks high. Actually, it seems to be a consequence of the distance between the deuterium tanks and the anti-deuterium tanks; most of the core is actually one enormous fuel injector.

Whereas the Defiant's warp core is four decks high and COULD easily fit into the existing nacelle control room of the E-D. That would more than suffice for a galaxy class if you're going to have TWO of them driving your ship.

And if there is some huge problem, it is possible to shut down the warp core or contain the problem, it's beend one quite a few times.

Then safety is not an issue. AT ALL.

 

[Captain Robert April]

As for for the warp-core being simpler than a fusion-reactor, I don't think so. This is pure opinion and information based on the tech manual... but the warp core handles antimatter so it has additional layers of redundant protection... plus as designed look at the diagrams in the manual... we are not injecting a stream of frozen slush we are injecting a an ionized plasma/near-plasma stream into the core... The injectors are choked full of equipment to that effect.

Then you have the containment system that is absolutely critical-path, without that you die. And the heat-transfer system. And the dilithium crystal positioning system, and the interlock seals for the chamber, and the interlock seals for the PTC port...

A fusion reactor by contrast is a big torus or sphere wrapped with containment generators, a technobabble ignition system, a cooling system, and a plasma outlet. Thats why you see references to microfusion power plants in Trek Tech lit, because you can shrink that down to wee size as opposed to trying to shrink a warp core down to size.

Note that I said "simpler in function", not simpler overall. A fusion reactor has to induce the reaction, whereas with an antimatter reactor, it's a subatomic version of "boy meets girl, boy kisses girl, boy and girl mutually annihilate". The complexity is all part of safely containing simple physics and being around to tell the tale and make use of the progeny of those horny little protons and antiprotons, namely, the high energy plasma.

 

[Plecostomus]

As for for the warp-core being simpler than a fusion-reactor, I don't think so. This is pure opinion and information based on the tech manual... but the warp core handles antimatter so it has additional layers of redundant protection... plus as designed look at the diagrams in the manual... we are not injecting a stream of frozen slush we are injecting a an ionized plasma/near-plasma stream into the core... The injectors are choked full of equipment to that effect.

Then you have the containment system that is absolutely critical-path, without that you die. And the heat-transfer system. And the dilithium crystal positioning system, and the interlock seals for the chamber, and the interlock seals for the PTC port...

A fusion reactor by contrast is a big torus or sphere wrapped with containment generators, a technobabble ignition system, a cooling system, and a plasma outlet. Thats why you see references to microfusion power plants in Trek Tech lit, because you can shrink that down to wee size as opposed to trying to shrink a warp core down to size.

Note that I said "simpler in function", not simpler overall. A fusion reactor has to induce the reaction, whereas with an antimatter reactor, it's a subatomic version of "boy meets girl, boy kisses girl, boy and girl mutually annihilate". The complexity is all part of safely containing simple physics and being around to tell the tale and make use of the progeny of those horny little protons and antiprotons, namely, the high energy plasma.

I disagree, a fusion reaction doesn't require a magic crystal to regulate the reacton... fusion is controlled by the rate of fuel fed and the rate at which the reaction is induced. Matter-antimatter reactors require the regulation of the crystal, positioning of the crystal, feed of two separate fuel streams (one of which will fuck your shit up if it leaks) and the resultant gamma-ray release. I forget were I read it but a matter-antimatter reactor burning anti-hydrogen and deuterium would actually release more neutrons and gamma than a fission reactor.

I'll have to go looking for that source. I have a bit of nuclear-tecnobabble in my past and on the surface I tend to agree with that assumption... annihilation releases gamma... and there would be a spare neutron for every proton and electron annihilated... *shrug*

In the end it's all pretend at this stage so do as you wish with the designs for your ships and engines in your reality. It's neither right nor wrong.


Personally, I wouldn't mind a micro-fusion reactor powering my iPod because at worst it would incinerate my arm and possibly my torso when the containment fails. Warp-core powered iPod would weigh twice as much and destroy the entire metro and the block above me because of the antimatter contained within.

 

[kent]

The nacelle control room on the Enterprise-E, and the Enterprise-D respectively, are actually IN the nacelles themselves. The warp core of the Enterprise-E is 12 decks high, and the Enterprise-D is 10 decks high. That would occupy a significant portion of each nacelle, even if split in half.

There's never been an in-universe explanation for why the core MUST be twelve decks high. Actually, it seems to be a consequence of the distance between the deuterium tanks and the anti-deuterium tanks; most of the core is actually one enormous fuel injector.

Whereas the Defiant's warp core is four decks high and COULD easily fit into the existing nacelle control room of the E-D. That would more than suffice for a galaxy class if you're going to have TWO of them driving your ship.

And if there is some huge problem, it is possible to shut down the warp core or contain the problem, it's beend one quite a few times.

Then safety is not an issue. AT ALL.

I agree safety is not an issue much at all.

And I also agree that there is no direct on screen evidence that the higher the warp core the more efficient the reaction and power generation. But to me, with taller warp cores almost always equaling more efficient and powerful ships, it makes sense. A couple notable exceptions: the Defiant. but like i said they could loop the ma/ama around a few times to simulate a taller warp core. And the Intrepid class. Then again that warp core uses a swirl intermix, making all 6 decks a reactor. And it's not always the relation of distance from the dueterium tankage to antimatter tankage...on the Sovereign class the antimatter tankage is a few decks above where the warp core stops, and the same is true for the intrepid class. Their MSD's show it. So why didn't the warp cores stop where the antimatter pods/tankage were?

 

[JuanBolio]

I have no idea where they get the idea that M/AM reactions produce high-energy plasma. As far as I know you'll just get gamma rays and unusable particles like neutrinos. If you had a way to convert gamma rays into usable power (like electricity) that'd be cool, but the best way we know of is simply to utilize the heat generated.

 

[JNG]

I have no idea where they get the idea that M/AM reactions produce high-energy plasma. As far as I know you'll just get gamma rays and unusable particles like neutrinos.

Well, when there's more of the deuterium in there than there is of its antimatter counterpart, we can well imagine what happens to it. The 1:1 talk is a different story and is sometimes difficult to interpret. I think Wesley's test about this must have been some sort of trick question; maybe we didn't get the full story on it and there was accompanying info or something? The TNG Technical Manual says that the mix would always be 1:1 at warp 8 or above, though.

 

[JuanBolio]

Yes, you would get superheated deuterium if you had more matter than antimatter in your mix. Does that kind of plasma really convery more energy more efficiently than simple electricity?

 

[Ronald Held]

Maybe dilithium takes the annihilation gammas and neutrinos and converts them into more managable particles for the warp plasma?

 

[JuanBolio]

Maybe dilithium takes the annihilation gammas and neutrinos and converts them into more managable particles for the warp plasma?

The dilithium would either have to give up some of its own mass, or conjure matter out of nothingness. I'm sure dilithium converts pure M/AM reactions into usable energy somehow - but exactly how is a mystery. Such is the nature of unobtanium. *shrugs*

 

[Plecostomus]

Maybe dilithium takes the annihilation gammas and neutrinos and converts them into more managable particles for the warp plasma?

Yeah, the only real way for this to work is to have the "magic crystal" do something to the reaction.

 

[JNG]

^

That would certainly help me understand the dilithium-lined swirl chamber idea.

 

[Timo]

And yes there are plasma injectors in each warp nacelle, suggesting the warp plasma conduits "move", probably via magnetic constrictors, to the nacelles where they are injected into the nacelles.

How does that suggest movement? It just suggests that plasma has to be initially injected.

And you'll notice that in every scene involving engineering on TNG or the TNG movies, involving the Sovereign and Galaxy class', the conduits always appear to be "pumping" the warp plasma into the nacelles or into the EPS grid.

Naah. There's peristaltic movement of lights on the vertical warp cores, something that's supposed to reflect the pumping of reactants into the annihilation reactor according to the assorted Tech Manuals. But there's no good indication that stuff would be pumped outward from the reactor on the E-D design (the conduits don't have peristaltic lights), nor that the stuff being pumped would be plasma. It could just as well be energy within immobile plasma.

In older ships, the warp nacelles were turned off, but in more modern capable ships, they are always on and glowing blue for hot standby.

Seems so.

The plasma isn't a conductive force, it's the fuel for the nacelles themselves.

How could the nacelles "consume" plasma? It's supposedly matter: does it accumulate somewhere or what? There's no known return loop for it, and no known tailpipe. As said, plasma is only vented in emergencies, not in routine operations.

The episode in which Troi sensed someone committed suicide in the nacelle control room is pretty good evidence as it shows a plasma injector literally injecting the warp nacelle with the plasma.

There is no movement of plasma evident in that scene, though. Rather, the guy jumped into a stable pillar of glowing gas.

Timo Saloniemi

 

[Kemaiku]

I always assumed the "pumping" lights on the core and PTC's were simply a visual indicator for the internal activity of the conduits. That if the two were synchronous and going at a steady rate it was "normal" and as we see in several episodes of TNG the faster the ship goes, the faster the reaction the faster the lights flashed.

As for Dilithium one of the TNG diagrams shows that the crystal is porous to matter and antimatter but also deflects the gamma radiation into the plasma halo since conservation of momentum on particle collision would result in too scattered a gamma photon production, bending their paths into multiple coherent streams of intense radiation which "boosted plasma into the terrawatt range" as Geordi mentioned once.

As for the height of the core and its streams, maybe they need to work on the particle accelerator/LINAC concept of accelerating the streams to a minimum velocity necessary to produce the right reaction. And you have to admit the equivalent of two Berkley LINAC of about 3km down to even a 12 deck high core isn't bad.

Then again, TOS didn't even have a core at all so *shrugs*