TMP/TWOK Dry Dock Question

[Timo]

Regarding the need of multiple RCS systems, we don't really know how they steer at impulse. Mere thrust vectoring won't be enough to reorient the ship, not with the impulse nozzles situated the way they are. Does a TMP style ship fire RCS jets every time she wants to go to 123 mark 45 at 1/4 impulse?

It could well be that the ship has futuristic gyroscopes (probably some sort of gravity manipulation) for adjusting the attitude under impulse thrust, and a separate system that allows for fine movements and translations when the impulse drive is shut down.

In theory, a ship might do with just the futuro-gyros if those are tuned finely enough - but the ship then couldn't do translations, like "two meters to port, Mr Sulu, ease her into the docking tube", without using the impulse engines. And probably not even with impulse engines. But in TOS, they might have relied on tugs to bring their big starships to port. By TMP, they would have introduced "bow thruster" style independent docking abilities by adding Newtonian thrust.

Timo Saloniemi

 

[Search4]

Hi guys,

I actually own the drydock model... so i'm a bit proprietary about this question. The Christie's auction and all.

I can't comment on the RCS thrusters and such... obviously that's not a model think. But let me point out the model was modified for Generations and there's a new "office" complex in the front. That office was several decks tall, and clearly could house a permanent crew. So i'd argue the original version had minimal crew quarters, and they shuttled over from Scotty's office, and the new one is more self contained.

But I am enjoying the discussion!

 

[Data Holmes]

Hi guys,

I actually own the drydock model... so i'm a bit proprietary about this question. The Christie's auction and all.

I can't comment on the RCS thrusters and such... obviously that's not a model think. But let me point out the model was modified for Generations and there's a new "office" complex in the front. That office was several decks tall, and clearly could house a permanent crew. So i'd argue the original version had minimal crew quarters, and they shuttled over from Scotty's office, and the new one is more self contained.

But I am enjoying the discussion!

Any chance you could get up some some pics of the model?

 

[Tallguy]

Boy Search4, you just made a whole bunch of new best friends! Do you intend to keep it Generations-ized, or do you have any hopes of restoring it back to TMP?

 

[GodThingFormerly]

Regarding the need of multiple RCS systems, we don't really know how they steer at impulse. Mere thrust vectoring won't be enough to reorient the ship, not with the impulse nozzles situated the way they are.

I object to that rather arbitrary conclusion. If nothing else, has anybody ever measured the half-cone angle described by the impulse engine bells and the aft caps of the warp nacelles (along with, I suppose, the secondary hull) for an initial approximation of just how far the impulse thrust can be deflected without it intersecting any part of the starship's exterior?

Does a TMP style ship fire RCS jets every time she wants to go to 123 mark 45 at 1/4 impulse?

It could well be that the ship has futuristic gyroscopes (probably some sort of gravity manipulation) for adjusting the attitude under impulse thrust, and a separate system that allows for fine movements and translations when the impulse drive is shut down.

Do we really need to invoke gravity manipulation technology for starship guidance and control? Onboard momentum wheels and control moment gyroscopes (undoubtedly spinning on superconducting non-contact bearings) should be able to provide sufficient torque required for all of the roll, pitch and yaw maneuvers we saw in TOS/TMP without expending a single gram of impulse and RCS reaction mass. Not only that, the primary drawback of such devices in current spacecraft - saturation - would be rendered virtually moot care of the tractor beam. Once the flywheels approach their upper angular velocity limits the Enterprise could simply couple itself to a large asteroid and rapidly dump momentum, again, without wasting precious reaction mass or searching for a planet with a sufficiently strong exterior geomagnetic field to deploy magnetic torquers.

In theory, a ship might do with just the futuro-gyros if those are tuned finely enough - but the ship then couldn't do translations, like "two meters to port, Mr Sulu, ease her into the docking tube", without using the impulse engines.

I don't understand. MWs and CMGs can only affect spacecraft orientation, not translation.

But in TOS, they might have relied on tugs to bring their big starships to port. By TMP, they would have introduced "bow thruster" style independent docking abilities by adding Newtonian thrust.

It would have been a rather inexcusable oversight on the part of Starfleet to necessitate the presence of tugs for hard docking TOS-era starships, considering that every real-world manned space vehicle since Vostok 1 was equipped with some form of RCS.

TGT

 

[Pengy]

In one episode where the impulse engines were off line and the ship in danger of crashing, Kirk said "Fire ventral verniers." I think it was Court Martial, though I'm not sure. Anyway, verniers was the 1960s term for RCS.

 

[aridas sofia]

"Verniers" doesn't appear in any episode of TOS that I can recall.

TGT -- wouldn't a "tractor beam" be a form of gravity manipulation?

Also, you write...

Do we really need to invoke gravity manipulation technology for starship guidance and control?

...and I'd answer "absolutely not". But isn't this a bit like asking whether we need to invoke diesel motors for nautical propulsion, when sails will do? If the gravity manipulation has already been adopted by the conceptualizers of this fictional universe as having been installed on that ship for other purposes, then it begs an answer why it wouldn't be used for other purposes. Not that it absolutely wouldn't -- sailing vessels today have engines and yet use their sails. But there is a reason for the anachronism. I'd think there would be a similar reason for having to use RCS when inside people are walking around in one gee comfort courtesy gravity manipulation and space is being warped all to hell every time they want to get to the next story.

 

[Timo]

I object to that rather arbitrary conclusion. If nothing else, has anybody ever measured the half-cone angle described by the impulse engine bells and the aft caps of the warp nacelles (along with, I suppose, the secondary hull) for an initial approximation of just how far the impulse thrust can be deflected without it intersecting any part of the starship's exterior?

It wouldn't be so much a matter of where the impulse engines can direct their thrust, but of how they can have enough of a momentum arm wrt the center of mass to effect practicable changes in orientation. If the ship is of homogeneous density, the engines are rather poorly positioned right next to the center of mass. If nearly all the mass is in the warp coils, then things might look a bit brighter, but only for yaw where vectoring is relatively unobstructed.

Assuming that impulse engines are a rocket-type drive, of course. If they produce thrust via other means, we could just as well say that the RCS system of the ship is a miniature impulse drive that is equally free of the need to eject propellant. Two somewhat separate systems, for coarse and fine propulsion, would seem to be called for (even if both are actually built into the aft end of the saucer).

Do we really need to invoke gravity manipulation technology for starship guidance and control?

I'd go with aridas' answer to that: they have the technology, so they might just as well use it. For one thing, it reduces the consumables aboard; for another, it could be stealthier, at least as far as the sensors of primitive adversaries go. Even the fact that it pollutes less might be considered.

I don't understand. MWs and CMGs can only affect spacecraft orientation, not translation.

I thought that's what I was saying. For translations, you'd either need rocket-type RCS systems pointed whichever way, or then the sort of gravity manipulation system that can direct "pure thrust" wherever you need without requiring exhaust jets (similar to the "field drive" interpretation of impulse engines). You couldn't do intricate docking maneuvers if you only had gyros, or the sort of gravity manipulation system that merely does the work of gyros.

It would have been a rather inexcusable oversight on the part of Starfleet to necessitate the presence of tugs for hard docking TOS-era starships

Oh, I don't think so. It could be a perfectly acceptable tradeoff. It's not as if aircraft carriers today would be built with the ability to dock themselves with bow thrusters, even though tiny frigates can certainly do that.

It might well be that rocket-type RCS systems that are practicable enough for large starships were only developed in the late 2260s and implemented on the Enterprise more to see whether they would work than out of any operational necessity. "Nice to have" features have seldom been part of military thinking, although there's always a first time for everything, and the TMP refit would be an excellent time to do some promotional experimentation.

Timo Saloniemi

 

[aridas sofia]

It might well be that rocket-type RCS systems that are practicable enough for large starships were only developed in the late 2260s and implemented on the Enterprise more to see whether they would work than out of any operational necessity. "Nice to have" features have seldom been part of military thinking, although there's always a first time for everything, and the TMP refit would be an excellent time to do some promotional experimentation.

I can't imagine that people that developed an ability to warp space would need to wait 200 years to develop a practicable RCS thruster for a 180,000 ton ship.

 

[Data Holmes]

I think this is all a little to heavy to be thinking about when i had a few drinks. lol


The idea that the RCS be a small form of Impulse drive is an interesting approach. I'm surprised no one has thought of it before.

 

[Search4]

Hello,

I'm glad to post a picture or two, if there's demand - believe me, the movie version (all prettied up and lit) is more attractive.

The model in TMP had three "rows" of lights on the side, the Generations version had two. SO - i'm going to fix it up (one of these days...grrr...) but restoring it to original isn't possible without restoring it back to something that does not exist.

 

[Timo]

I can't imagine that people that developed an ability to warp space would need to wait 200 years to develop a practicable RCS thruster for a 180,000 ton ship.

But nobody is in any hurry to develop bow thrusters for supercarriers and supertankers today. Tugboats exist, and they are practicable, so why bother with independent precision maneuvering capabilities for something that only needs to precision-maneuver in the vicinity of well-established ports?

I mean, the only time Kirk ever needed to precision-maneuver in TOS would have been to dock with that Masao class space station in the redone "The Ultimate Computer". And probably he never docked, instead parking some distance away and using transporters as with K-7. Starships (with capital S) might not be designed for snuggling up to other space structures, even though some other Starfleet vessels such as replenishment or boarding-assault ships might have this design requirement.

Timo Saloniemi

 

[Vance]

Except, Timo, that we also see Constitution class ships tethered on more than one occasion (granted, only in newer works). I think we have to treat the RCS system on the 'old girl' the same way we handle the phaser banks, photon launchers, and gangway hatch.

They're THERE, but we're just not seeing them for whatever reason.

But, however it's done, the RCS system seems too basic and fundamental to not have installed. Certainly you would want an internal maneuvering system for working within docks and fine-detail movement.

 

[ahkyahnan]

I'm glad to post a picture or two, if there's demand.

Well, I would never 'demand' it, but I would be very interested in seeing your pictures. Looking forward to them.

Mark

 

[Tallguy]

Hello,

I'm glad to post a picture or two, if there's demand - believe me, the movie version (all prettied up and lit) is more attractive.

Yes, yes! Please!

 

[Basill]

Hello,

I'm glad to post a picture or two, if there's demand - believe me, the movie version (all prettied up and lit) is more attractive.

Yes, yes! Please!

Indeed, it would be a reference treasure.

 

[Timo]

Except, Timo, that we also see Constitution class ships tethered on more than one occasion

Where?

AFAIK, the ship class isn't seen outside TOS/TAS at all, except for the "repeat performances" in DS9 "Trials and Tribble-ations" and ENT "In a Mirror, Darkly" where she most certainly doesn't do any self-tethering.

The only example of a tethered Constitution I know of would be from TOS-R "Ultimate Computer", with the bow of the Lexington apparently attached to that station. But that could have been done by the station's tugs and tractors.

And while rocket-type RCS might sound "fundamental", many a "fundamental" thing is omitted from today's vehicles and gadgets because it isn't required operationally. Say, most main battle tanks don't have rear view mirrors - a technology that certainly exists, but is difficult to implement on that specific type of vehicle, and serves no practical purpose there anyway.

Really, if we want to consider the Constitution class groundbreaking (like fanfic and novels do, and like the Mirror Archer and Trip thought, even if it's never canonically stated), we might just as well give her a different set of onboard systems from her predecessors. Say, it was a big step forward, not backward, when steam-powered warships lost their rigging...

Timo Saloniemi

 

[Vance]

I explicitly said 'newer works', such as TOS-R and Enterprise... that's pretty weak of you to parse that way.

And, realize what you're arguing. That the RCS 'thruster' system is 'old and obsolete' by the time of 2260, but come 2270, it's right back in plain view on all the ships and remains so through the 2300's. That's a rather silly argument to make, don't you think?

And, you're also trying to talk about the RCS as if it were a ship's main drive. Obviously, it's not, and no one here is making that claim. It functions a sole purpose, the very finite control of the ship through docks and other similar situations. We see them used for that purpose in most of the movies, and on some occasions in the 'new gen' shows.

It's irrational to assume a very circuitous logic about how viable RCS systems are, and that they would have been dropped for a couple of generations, just because the 'grey lady' didn't have them explicitly marked on her hull.

 

[Tallguy]

Well that's the issue isn't it? You're justifying the existence of RCS in TOS by pointing to work that was done AFTER TOS by folk not involved with TOS. They could have given the Enterprise variable pitch warp pylons like Voyager. Doesn't mean that the TOS gang ever thought that the E had them then. Maybe (aside from budget concerns) they never docked at a station because the TOS team said "it's not like a ship that big can maneuver that close to another ship / station". Or maybe "we have tugs for that." Or more likely "Oh, wait until you see the outfit we come up with for HER. Whooooo!"

That was one of the big crits of the NX (no, this isn't Enterprise bashing, really) was that because they incorporated so much TMP / TNG stuff the tech now seems to go "backward" and you wind up with discussions like this. (I don't think the NX should have looked more like TOS but it should have looked a LOT less like TMP.)

It is the kind of thing that I wonder if the gang thought of it and discounted it, or if it just never crossed their minds. (Kind of like I wonder if any of the writing staff knew that an orbit doesn't collapse the moment you lose power.)

 

[Vance]

But, we also know that they came up with Photon Torpedoes in the middle of the first season, because they were screwing up with Phasers. It just happened that we never saw a situation in TOS where RCS would come up. There was no drydock scenes, etc. If there was such a scene for TOS, they probably would have been written in ('maneuvering thrusters!')

Unlike all the other aspects of the Trek franchise, TOS was very much a 'work in progress' in nearly every aspect. Nothing was nailed down, and tech and details would change as the show progressed. It's hard for me to be religious in adherence to what we're presented with when I know all of what was going on with the show.

It's not like there weren't OTHER aspects of the Enterprise expressly mentioned that we never see, such as escape pods, aft phasers, broadsides, etc. An RCS system could, for the sake of franchise consistency, just be handled the same way.

But think about what we're really arguing here, a grand total of six clusters mounted four on the hull and two in the nacelles. Really, if it weren't for the big yellow markings for them on the uprated Enterprise, would they be that noticeable?

In this case, I just figure that it's easier to accept that they're THERE, along with the phaser banks, torpedo launcher, and gangway, than invent entire reams of treknobabble to explain why they aren't.