Impulse Drive: What do we know? (Non-canon speculation)

[Timo]

the Impulse engines wouldn't be considered and emergency system.

Makes no sense. If it's possible to treat any system as an "emergency" one, then main sublight drive and main weapons definitely should be treated as such.

There's the old question "Why don't they make entire aircraft out of the indestructible black box material?", and the usual answer is "Applying that on a large scale is expensive or heavy or power-hungry". But impulse deflectors would be a much smaller application than main shields, more comparable to a flight recorder than to a wing or a tail, and could probably easily be made more reliable in forcefield form than in solid matter form. In contrast, building a second set of impulse engines for braking, or a third and fourth for going left and right and fifth and sixth for going up and down, is downright weight-prohibitive; creating a mechanically swiveling engine assembly (or, if you are going to flip the entire ship, then making everything else important swivel in compensation), likewise.

The forcefields in the warp core never hiccup. So there's no good reason why the forcefields deflecting impulse thrust ought to hiccup, either. We've never seen them do so, after all.

Timo Saloniemi

 

[Saquist]

Makes no sense. If it's possible to treat any system as an "emergency" one, then main sublight drive and main weapons definitely should be treated as such.

Impulse engines are a "main system" or Primary system. They are used regularly and require frequent maintenance.
All emergency systems are only used in case of emergency. That's the definition of an emergency system. I've seen and studied building drafting plans for fire precautions.

Emergency doors are only used in case of emergencies. (that's why they set off alarms)
Emergency Fire Extinguishers are only used in case of emergencies. (that's why you have to break the glass)
Emergency lighting is only used in case of emergencies
Emergency fire escapes are only used in case of emergencies.
Emergency Rations are only used in case of emergencies.
Emergency First Aid kits are used only in case of emergencies.
Emergency Eye wash stations are used only in case of emergencies.



The reason why they are designated as such is because the government insist that these items be readily available safety precautions. If you are large enough a company they inspect this equipment. They must be checked every 3 to 6 months because they operate on batteries, or are limited in someway not meant for normal use, thus they are only in reasonable supply for short durations. If they are under use then they would need regular maintenance and regular resupply.

Impulse engines and warp engines are primary systems regularly used and frequently maintained and supplied.

But impulse deflectors would be a much smaller application than main shields, more comparable to a flight recorder than to a wing or a tail, and could probably easily be made more reliable in forcefield form than in solid matter form. In contrast, building a second set of impulse engines for braking, or a third and fourth for going left and right and fifth and sixth for going up and down, is downright weight-prohibitive; creating a mechanically swiveling engine assembly (or, if you are going to flip the entire ship, then making everything else important swivel in compensation), likewise.

And yet the distribution of the RCS implies that such a philosophy was part of any ships design in the Federation wouldn't it?

The forcefields in the warp core never hiccup. So there's no good reason why the forcefields deflecting impulse thrust ought to hiccup, either. We've never seen them do so, after all.

The warp core doesn't have force fields...that's never been said. That's magnetic constrictors. Only the Antimatter have fields of any kind.

 

[blssdwlf]

^^^
You've got way too much free time. Especially given that it doesn't really change anything.

Heh, Trek Tech

 

[RedShirt]

What makes you think thrust reverser forcefields would be lost when power is lost? We know for a fact that when the ship "loses all power" (i.e. drive, weapons, something they call "life support", and most of internal lighting but not all), the forcefields that keep her alive and prevent spontaneous combustion are still up and running.

For all we know, some if not most forcefields are by their very nature permanent, akin to permanent magnets. It would take power to shut them down in that case.

The only fields that would be imperative to keep operating in the event of primary & secondary power would be those containing the antimatter in their pods. It would be foolish to believe that the pods were not designed with their own internal battery back-up to keep the field running for a reasonable amount of time allowing the crew to concentrate on restoring main power. Any competent engineer would also include independently powered containment monitoring & pod ejection systems, should should these fields start to degrade before main power is restored.

As for thrust vectoring fields... why would you not expect a system that has to redirect tons (kilo? mega?) of force from exhaust reactants to require main power to stay online? Batteries - no matter their energy density - are only going to do so much.
However, considering that the impulse engines are a primary and/or secondary power source, the point is moot. The real concern of failure falls to the field generator & emitters... which means you better have a back-up plan if you expect to stop again if you ever get going.

If it's possible to treat any system as an "emergency" one, then main sublight drive and main weapons definitely should be treated as such.

Wow, glad I've never worked on anything you've designed; it's really difficult to maintain priorities when anything or everything is an "emergency" system.
I'd imagine that on spacecraft keeping the air breathable would be #1 with having power to the radios so you can call for help hot on its tail (in the Trekverse I'd probably add allowing navigation shielding to operate for a few hours so that cosmic radiation doesn't fry the crew). Propulsion & weapons don't mean squat if your crew is dead.

Any field patching up a hull breach should only get minor consideration since the affected area should have been immediately evacuated and hatches to that section sealed just in case there is a power failure. Never bet your life on a magic field during an emergency or battle situation when there is a door (or even, hopefully, a 1-man shelter) not too far away.

There's the old question "Why don't they make entire aircraft out of the indestructible black box material?", and the usual answer is "Applying that on a large scale is expensive or heavy or power-hungry". But impulse deflectors would be a much smaller application than main shields, more comparable to a flight recorder than to a wing or a tail, and could probably easily be made more reliable in forcefield form than in solid matter form. In contrast, building a second set of impulse engines for braking, or a third and fourth for going left and right and fifth and sixth for going up and down, is downright weight-prohibitive; creating a mechanically swiveling engine assembly (or, if you are going to flip the entire ship, then making everything else important swivel in compensation), likewise.

Leaving aside the notion that there's such a thing as "indestructible black boxes", how do you justify magic fields being better at mundane things over physical constructions or system? Either energy is nearly free in the Trekverse - rendering weight & mass restrictions pointless (thus allowing you the luxury of as many redundancies as you want) - or it's not... at which point I would always want a "non-powered" fail-safe option to fall back on.

And if you're worried about multiple impulse engines being too cumbersome, then one obvious solution is to have a central fusion generator complex with the reaction products routed via plumbing to accelerator & exhaust assembles fore & aft. The RCS can change the orientation of the vessel in 3 dimensions allowing the ship to go "forwards" & "backwards" as necessary (if we're following Newtonian applications, anyway).

The forcefields in the warp core never hiccup. So there's no good reason why the forcefields deflecting impulse thrust ought to hiccup, either. We've never seen them do so, after all.

Modern particle accelerators don't require any magic fields to operate (other than magnets) so why would a warp core?
Hell, the only times I can personally recall seeing a forcefield around a reactor was once on the Defiant and once on the Enterprise-E... and the latter failed in the first volley of enemy fire. Sounds like a helluva hiccup to me.

 

[Timo]

The only fields that would be imperative to keep operating in the event of primary & secondary power would be those containing the antimatter in their pods.

Still doesn't make any sense. Why should one arbitrarily choose not to give similar permanence to the impulse drive?

Getting the hell out of Dodge is typically a life-or-death matter. It's plausible that warp drive is too complicated to be made idiotproof and failureproof, but that's only more reason to make impulse drive immune to any damage short of the Last Trump. There is no philosophical-doctrinal reason to diss the impulse drive in this respect - the only possible obstacle to making the impulse drive less than indefinitely resilient is technological.

Which takes us right back to the basic nature of forcefields. These are 100% safe and sound when they keep warp cores frop blowing up. Why should they be less than 100% safe in other applications?

...Whether the warp core keeps working thanks to "magical" or "realistic" fields is immaterial here. If a field exists that is 100% safe for keeping antimatter from interacting with matter, that same field can be used for diverting the impulse exhaust by definition.

how do you justify magic fields being better at mundane things over physical constructions or system?

Why would this require any justification? There is no a priori reason to think that forcefields would be weaker or less stable than solid matter, or that they would require power to exist. Matter is a forcefield of its own kind already, consisting of insignificant bits of dirt being held together by electromagnetic attraction and nuclear repulsion without any need for an outside power source.

Being afraid of forcefields is no different from arguing that ships should never be made of artificial iron because natural wood is less likely to fail, solely because it's more familiar and was already used by great-granddad.

I'd imagine that on spacecraft...

Imagine again - it pays off, in terms of making for more interesting drama. For example, gravity control is much more important than breathing air, because lack of former kills you in a millisecond (unless the ship around you stops doing its usual body-pulping accelerations) while lack of latter allows you to live for minutes. And if something goes wrong for outside reasons (the ship's internal problems are probably well anticipated and taken care of), having working engines to evade those outside reasons will keep you alive while merely fighting off the symptoms (such as loss of gravity, oxygen or heat) will get you dead.

All that said, I'm not a great believer in thrust reversers in impulse engines. These engines don't seem to behave much like rockets under any circumstances: we don't witness propulsive jets, we don't see much if any correlation between the status or direction of motion and the degree to which an impulse "exhaust" glows, and we don't observe a starship at impulse following the rocket equation when it comes to carrying and expending propellant. Also, no impulse engine ever seems to be placed anywhere near the thrust axis of a starship (save perhaps for the TOS/TMP ship), yet starships don't start spinning madly when impulse drive is engaged.

OTOH, we do know very well that Trek technology has made Newton obsolete and that every action doesn't come with equal and opposite reaction any more. The role of an exhaust jet in impulse propulsion may well be negligible or nonexistent, in which case reversing the jet is a waste of time.

Timo Saloniemi

 

[Santaman]

The so called impulse exhaust probably isn't the exaust of the drive itself but to get rid of the residue coming out of the fusion reactors powering the drive, some ships go without it like the Nebula..

 

[Saquist]

Wow, glad I've never worked on anything you've designed; it's really difficult to maintain priorities when anything or everything is an "emergency" system.

Timo,
You should really listen. (I don't say this often) But I can honestly and truthfully say in my profession, you have no idea what you're talking about. If you can't listen to me, then listen to him. Listen to somebody.

It's not as though I don't know what you mean or what you're trying to express but the reality is SO much different than your perception right now. Mildly, I suggest you do some study on the National Fire Protection codes or Acts in your region.

 

[Timo]

It's a semantics issue, really. You keep saying "emergency systems" but I'm discussing the concept of systems that are needed in an emergency. Apparently, the technical terminology on the issue is such that "emergency systems" are something else than the machinery I'm talking about...

Impulse engines are needed in an emergency. Thrust manipulation for them is needed in an emergency. Perhaps this is achieved by systems that sit dormant 99% of the time and thus meet the criteria of "emergency systems", perhaps not. Doesn't change the fact that impulse thrust manipulation ought to be completely reliable and that there's no plausible reason for it not to be. Everything else about the ship ought to fail earlier if the designers have their heads bolted on right.

Timo Saloniemi

 

[Saquist]

It's a semantics issue, really. You keep saying "emergency systems" but I'm discussing the concept of systems that are needed in an emergency. Apparently, the technical terminology on the issue is such that "emergency systems" are something else than the machinery I'm talking about...

Impulse engines are needed in an emergency. Thrust manipulation for them is needed in an emergency. Perhaps this is achieved by systems that sit dormant 99% of the time and thus meet the criteria of "emergency systems", perhaps not. Doesn't change the fact that impulse thrust manipulation ought to be completely reliable and that there's no plausible reason for it not to be. Everything else about the ship ought to fail earlier if the designers have their heads bolted on right.

Timo Saloniemi

Trust me Timo, I know exactly what you're saying.
I could have gone into Emergency Procedures and Programing too.

Impulse engines being needed in an Emergency is situational and vague. It's just as vague as any system on the ship being necessary in any particular emergency.

Isn't the point mute? We already have a situation where Enterprise was clearly using her best speed to get away from Reliant, it's shields were disabled and yet we still see Enterprise backing away like we've seen Defiant, and one other Enterprise do on Numerous occasions. Isn't this theory already defeated?

 

[RedShirt]

It's a semantics issue, really. You keep saying "emergency systems" but I'm discussing the concept of systems that are needed in an emergency. Apparently, the technical terminology on the issue is such that "emergency systems" are something else than the machinery I'm talking about...

Impulse engines are needed in an emergency. Thrust manipulation for them is needed in an emergency. Perhaps this is achieved by systems that sit dormant 99% of the time and thus meet the criteria of "emergency systems", perhaps not. Doesn't change the fact that impulse thrust manipulation ought to be completely reliable and that there's no plausible reason for it not to be. Everything else about the ship ought to fail earlier if the designers have their heads bolted on right.

Timo Saloniemi

Oh, okay. I didn't realize starships were always in battle or on a collision course with something. My bad.

 

[Timo]

Well, it's the likeliest life-or-death emergency for a starship. Hiccups with air conditioning aren't immediately life-threatening: something as trivial as life support could wait for a week to be repaired, while the crew breathed the perfectly good air stored in their town-sized vessel and waited for the heat to dissipate or accumulate.

You don't worry about things like fire aboard an aircraft, either. Critical issues are staying airborne and landing safely; if there's a fire, the procedure is not to attack it with extinguishers, but to put the plane on nosedive, hit the ground, hope that you can walk away from that crash, and then walk away from it while the plane either burns (hopefully slowly, thanks to water mist systems or such) or is extinguished by "earthly" firefighting means. A bit counter-intuitive, but the people doing these things know what they are doing.

People building and flying starships might know a thing or two we don't, too.

Isn't the point mute? We already have a situation where Enterprise was clearly using her best speed to get away from Reliant, it's shields were disabled and yet we still see Enterprise backing away like we've seen Defiant, and one other Enterprise do on Numerous occasions. Isn't this theory already defeated?

More like confirmed: apparently, even if everything else fails, impulse reverse still works...

Or then doesn't. After all, the stern-first retreat is much slower than the nose-first part of it; perhaps the ship backs off on thrusters first and tries to turn so that the forward-only impulse engines can be engaged?

In any case, there either are forcefield thrust reversers in action there or then not. We really can't tell. All we know is that some forcefields aboard that ship are working perfectly fine despite a) main power being down and b) the nebula messing with shields. Otherwise, the ship would have gone kaboom in an instant.

Timo Saloniemi

 

[Crazy Eddie]

I don't understand the context of "This".

See below.

You mean fail-secure.
RCS thruster won't have the accerlation or speed of impulse. It's just not the same. Sure you're able to move but that's back up. That's like trying to change orbit in the space shuttle with thruster.

That's exactly what I mean, and it's exactly what they DO.

If the space shuttle's OMS engine fails, standard procedure is to transfer OMS propellant and use the RCS thrusters for a deorbit burn. They hate to do this, because it takes forever and the orbital calculations are a pain in the ass, but the RCS system is the shuttle's only feasible backup system.

Basically, what I'm saying is space craft don't GENERALLY have that kind of fail-safe redundancy. They have dozens of different failure modes, all of which accomplish either survivability or some limited mission fulfillment in the event of a primary system failure. Abort modes are like this: if you're flying something that doesn't have engine-out capability, then the loss of an engine means a backup system kicks in that gets you the hell off that rocket as quickly as possible so you can at least survive to fly another day. If you DO have engine-out capability, then you have to burn the engines longer to compensate for the loss of a motor, and your ground control team is going to have to dance on a mathematical knife edge to make sure you hit your target orbit.

Enterprise may be a fictional space craft, but it IS a spacecraft, and it wouldn't be all that surprising if it operates under the same rules.

We don't actually know why shields don't work in the nebula.

They said it's all the static discharging gas.

Which has what to do with shields? For all we know the reason shields don't work is because phasers and photon torpedoes will instantly collapse them by triggering a static discharge. That would have virtually no effect on any other forcefield system.

I suspect that has more to do with the phaser reaction with the hull. When the Enterprise got struck in the openning volly there was no explosive decompression. The phaser seemed to melt and disapate on the hull. On the other side of the hull there was flame or plasma. This seemed to be a brief effect as the phaser didn't concentrate in a certain area but rather traveled down the PTC on the Stardrive.

It was a rather different story in the torpedo bay, where the phaser beam is clearly shown slicing a wide deep gash in the side of the ship. No explosive decompression here either.

Additionally, the phaser strike in engineering is meant to be interpreted as a hull bridge, with the initial pyros being mounted on the wall above and to the right of the drive shaft. The door comes down at this point, and STAYS down throughout the movie, for precisely this reason.

The forcefields in the warp core never hiccup. So there's no good reason why the forcefields deflecting impulse thrust ought to hiccup, either. We've never seen them do so, after all.

The warp core doesn't have force fields...that's never been said.

Defiant's core does.

 

[Crazy Eddie]

Doesn't change the fact that impulse thrust manipulation ought to be completely reliable and that there's no plausible reason for it not to be.

There IS one reason: because even if it's only 95% reliable under less-than-ideal circumstances, that extra 5% may come at a systems/engineering cost that for outweighs the possibility of included emergency systems like RCS thrusters and the "emergency thruster" features that appear on both the TMP refit and the Galaxy Class.

Suffice to say, like the OMS failure on the shuttle, it's something that rarely (virtually never) happens. RCS thrusters can be--and probably are--designed to operate as a maneuvering supplement in the event that the thrust vector field becomes inoperable.

As for the original question of this sub-thread, if you insist that the vectoring forcefields MUST have been operable in the mutara nebula, you could just as easily make the case that RCS thrusters could have achieved the same results in the event of a "rudder failure" and that both ships were equally effected to the point that we wouldn't have noticed the difference.

 

[Timo]

True enough. So the forcefield thrust reversers may or may not exist, in terms of canon: there's no real argument for or against.

Some sort of thrust reversing is evident in the sense that the ships fly as if there was a rocket flame coming from their arse - forward, forward-with-turning, and sometimes reverse. Whether this thrust really involves a "flame" is unclear, but "Relics" shows that a ship using impulse engines on reverse leaves "scorch marks" in the direction into which the ship is being pulled while the engines are fighting against the pull. Might be signs of impulse exhaust hitting the doorways of the Dyson sphere, or might be signs of the impulse subspace field twisting the texture of said doorways.

Timo Saloniemi

 

[Saquist]

That's exactly what I mean, and it's exactly what they DO.

If the space shuttle's OMS engine fails, standard procedure is to transfer OMS propellant and use the RCS thrusters for a deorbit burn. They hate to do this, because it takes forever and the orbital calculations are a pain in the ass, but the RCS system is the shuttle's only feasible backup system.

Then that is a fail secure system. Or Propulsion backup system.

Problem is thrusters are not going to get you comparable speeds. (trek)

Basically, what I'm saying is space craft don't GENERALLY have that kind of fail-safe redundancy.

Fail-secure.
The Space Shuttle has 1,621 "Criticality 1R" items. which means no single failure would result in catastrophic failure. Part of them are the O-Rings which are a redundant features, the triple redundant Avionics, Tripple redundant Main Engines, Yaw and Pitch Thruster are more than Tripple Redundant. These are not Critical 1 items.

On the Enteprise the power systems were triple redundant. NCC-1701 had Main Power, Auxillary Power and Battery Power, the Enterprise D could easily reroute phaser power. Voyager had a secondary phaser coil.

Which has what to do with shields? For all we know the reason shields don't work is because phasers and photon torpedoes will instantly collapse them by triggering a static discharge. That would have virtually no effect on any other forcefield system.

I only know what they tell me.
I also have no reason to doubt it. It's cut and dry cause an effect.

It was a rather different story in the torpedo bay, where the phaser beam is clearly shown slicing a wide deep gash in the side of the ship. No explosive decompression here either.

Additionally, the phaser strike in engineering is meant to be interpreted as a hull bridge, with the initial pyros being mounted on the wall above and to the right of the drive shaft. The door comes down at this point, and STAYS down throughout the movie, for precisely this reason.

It may have penetrated but it was not an explosive decompression meaning if it was breached it was through integrity only.

Defiant's core does.

Which is it?
Internal Force field or External Force field.
Because chose the Defiant to represent the affirmative statement defers to Nemesis Enterprise where that external force-field failed quite easily.

 

[Crazy Eddie]

Then that is a fail secure system. Or Propulsion backup system.

Right. Space ships don't usually have fail-safe systems for engines, only fail-secure.

Problem is thrusters are not going to get you comparable speeds. (trek)

There are two sides to this, Saquist. On the one hand, it's a television show and thrusters can and will achieve this result if the writers want them to (or at least, the ship will be able to make due by switching to thrusters).

On the other hand, in the real world when talking about space ships, SPEED is irrelevant, all that matters is acceleration. If the impulse engines are still operable, then your forward acceleration doesn't change, and thus you're using manuevering thrusters to steer the ship instead of a more efficient thrust-vector system. That'll make the helm sluggish, to be sure, but the ship will still be relatively maneuverable. And if the impulse engines go out altogether, you simply transfer the fuel feeds to the emergency thrusters; you would perform an emergency engine burn for a longer duration and end up with the exact same velocity.

In either situation, a failure of a primary maneuvering system is hardly the end of the world (though it could be, for plot reasons, if you wanted it to).

On the Enteprise the power systems were triple redundant. NCC-1701 had Main Power, Auxillary Power and Battery Power, the Enterprise D could easily reroute phaser power. Voyager had a secondary phaser coil.

Then for manuevering systems; we have the main impulse deflection fields, the RCS thrusters, and emergency thrusters. Good old tripple redundancy.

Which is it?
Internal Force field or External Force field.
Because chose the Defiant to represent the affirmative statement defers to Nemesis Enterprise where that external force-field failed quite easily.

I don't believe it DID fail in Nemesis. In DS9 it is claimed that the purpose of the forcefield is to shield the engine room from the high temperatures and radiation from the core. some cores probably keep the forecefields on the inside, while high-powered/compact ones like Defiant's engine use an external field.

 

[Saquist]

Then that is a fail secure system. Or Propulsion backup system.

Right. Space ships don't usually have fail-safe systems for engines, only fail-secure.

I'm sure the engines have plenty of fail-safe systems such as the anti-matter containment fields but it's not relevant in this debate since we're talking about back-ups and redundancies.

There are two sides to this, Saquist. On the one hand, it's a television show and thrusters can and will achieve this result if the writers want them to (or at least, the ship will be able to make due by switching to thrusters).

In all realism even if thrusters are capable of propelling the ship hat speeds of 30,000 miles per second (unlikely) it will take 69,000 years to travel 4 light years. In trek Acceleration is everything and it's extremely unlikely that without subspace fields that the ship could expend it's fuel and reach this speed.

On the other hand, in the real world when talking about space ships, SPEED is irrelevant, all that matters is acceleration. If the impulse engines are still operable, then your forward acceleration doesn't change, and thus you're using manuevering thrusters to steer the ship instead of a more efficient thrust-vector system. That'll make the helm sluggish, to be sure, but the ship will still be relatively maneuverable. And if the impulse engines go out altogether, you simply transfer the fuel feeds to the emergency thrusters; you would perform an emergency engine burn for a longer duration and end up with the exact same velocity.

I'm not saying it's no possible but it is in-evident.
Warbird
Nebula
Steamrunner
Jem'Hadar Attackship
Defiant

Many others have no external indication of newtonian propulsion. The facts simply don't fit. (And I've never heard of Emergency thrusters)

I don't believe it DID fail in Nemesis. In DS9 it is claimed that the purpose of the forcefield is to shield the engine room from the high temperatures and radiation from the core. some cores probably keep the forecefields on the inside, while high-powered/compact ones like Defiant's engine use an external field.

I can only tell you what shown on screen.
What was shown had specific chronological purposes. What you suggest is much like the Star Wars fan fan claiming the domes on the Star Destroyer aren't shield generators when the necessary chronology of the storyboarding says they are. Once we entertain the lack of chronology in the visual we defeat the obvious director intent and the cause and effect for something purely conjectural. It's a self defeating interpretation.

 

[Mister_Atoz]

On the other hand, in the real world when talking about space ships, SPEED is irrelevant, all that matters is acceleration. If the impulse engines are still operable, then your forward acceleration doesn't change, and thus you're using manuevering thrusters to steer the ship instead of a more efficient thrust-vector system.

I don't mean to interrupt your debate, but I've never quite understood how "thrust vectoring" would serve to maneuver the ship as described in the TNG tech manual.

Assuming for a moment, that there are no shields or forcefield redirecting the thrust, if the impulse thrust is mechanically directed 45 degrees off the vessel's central axis, would't this thrust the vessel "diagonally" so to speak?...it wouldn't actually rotate the vessels heading right?


I guess what I'm asking is, could the impulse engines alone be used to rotate the vessel's heading without the use of maneuvering thrusters or forcefields?


Oh, and for the record, I hate the idea of force fields being used to direct thrust no matter how reliable, failsafe, or whatever, it just seems clunky and backward.

I tend to think of impulse engines as being a very advanced, but rather conventional newtonian engine, and not just a mini warp-drive as some people seem to be describing. The way I see it, starship use their "thrusters" to reverse, but if they are really in the need for some sub-light speed, they'll rotate 180 and use their impulse engines.

 

[Crazy Eddie]

In all realism even if thrusters are capable of propelling the ship hat speeds of 30,000 miles per second (unlikely) it will take 69,000 years to travel 4 light years. In trek Acceleration is everything and it's extremely unlikely that without subspace fields that the ship could expend it's fuel and reach this speed.

I fail to understand how or why that makes any difference.

Many others have no external indication of newtonian propulsion.

To be sure, the warbird has no "big glowy thing" to correspond to a traditional impulse engine. All the others, do, though, so I'm not sure what your point is.

And I've never heard of Emergency thrusters

Mentioned by the captain of the Saratoga in TVH and by LaForge in "Disaster." Also, there are visible features on the TMP Enterprise and the Galaxy class that are indicated in blueprints to be emergency thruster ports. On the Galaxy, they're built into the warp nacelles and the back of the spine of the drive section; on the Connie refit, they're below and to either side of the torpedo deck.

I can only tell you what shown on screen.

Maybe you should go ahead and do that, then, as the entire following paragraph is utterly confusing.

I mean, unless you're saying the Narada's disruptor blast directly slammed into the warp core, but that's not what I see, so what EXACTLY are you talking about?

 

[Crazy Eddie]

On the other hand, in the real world when talking about space ships, SPEED is irrelevant, all that matters is acceleration. If the impulse engines are still operable, then your forward acceleration doesn't change, and thus you're using manuevering thrusters to steer the ship instead of a more efficient thrust-vector system.

I don't mean to interrupt your debate, but I've never quite understood how "thrust vectoring" would serve to maneuver the ship as described in the TNG tech manual.

Assuming for a moment, that there are no shields or forcefield redirecting the thrust, if the impulse thrust is mechanically directed 45 degrees off the vessel's central axis, would't this thrust the vessel "diagonally" so to speak?...it wouldn't actually rotate the vessels heading right?

It depends on where the ship's center of gravity is. If you angle the engine exhaust so that the line of thrust is no longer directly through the ship's center of gravity, then the ship will turn about that center of gravity. It would be the exact same effect as if you suddenly attached a skyscraper to one side of the ship; it's no longer on balance, and will begin to rotate around a new common center of gravity.

I guess what I'm asking is, could the impulse engines alone be used to rotate the vessel's heading without the use of maneuvering thrusters or forcefields?

Depends on where the ship's center of gravity is, but probably. If, for example, the center of gravity is ten or so meters behind the impulse engine (between the front ends of the warp nacelles) then the ship could perform a yawing turn to starboard by twisting its exhaust jets a few degrees to port.