Spider drive ships and impeller drives and alpha nodes

tlb wrote:I agree there are many possibilities for the extraction. What you say would work, but the one I favor is that they transitioned to hyperspace and traveled to a meeting place where the freighters picked them up.

Actually, no, this is quite important. If they didn't transition to hyperspace because they couldn't because they don't have hypergenerators and the ability to project Warshawski sails, that tells us something.

Though hypergenerators aren't difficult to have. Yachts have them. It's their ability to return home on their own that is in question.

tlb wrote:I agree there are many possibilities for the extraction. What you say would work, but the one I favor is that they transitioned to hyperspace and traveled to a meeting place where the freighters picked them up.

ThinksMarkedly wrote:Actually, no, this is quite important. If they didn't transition to hyperspace because they couldn't because they don't have hypergenerators and the ability to project Warshawski sails, that tells us something.

Though hypergenerators aren't difficult to have. Yachts have them. It's their ability to return home on their own that is in question.

If a hyper-generator is needed to make a transition, then you are completely wrong, see Storm from the Shadows:

Chapter 51 wrote:Absolutely nothing seemed to happen for the next two or three minutes, but appearances were deceiving, and Topolev waited patiently, watching his own displays, as Task Force One of the Mesan Alignment Navy translated ever so slowly and gradually back into normal-space.
This maneuver had been tested against the Mesa System's sensor arrays by crews using the early Ghost-class ships even before the first of the Shark-class prototypes had ever been laid down, and Task Force One had practiced it over a hundred times once the mission had been okayed.

ThinksMarkedly wrote:

tlb wrote:The Ghost class scouts were delivered by freighter, but it is generally assumed that they flew away under their own power (even if it was just to a meeting somewhere with another freighter). We do not have a description of how that worked at Grayson, since there is not a wormhole to serve as a fake destination.

Actually, the Ghost's extraction need not have been stealthy. Only the insertion had to be. For leaving, they could simply go to an RV point in the outer system and await a freighter come to pick them up. The freighter's translation would be noticed, but that's not a problem so long as they're gone before the reaction force can come in.

That is, they need to be further out in light-hours than the time it takes (in minutes) to load on the freighter. If they can load minimally for translation in 2 hours, then they need to be 5 light-days out.

There is no "up" translation signal. No one sees you jump into hyper from normal space, only the downward translation gives off a signal (you are dissipating so much energy with the down translation.)- they will just see your drive signal disappear. David answered this several years ago the first time this topic came up.

That and he confirmed that the Ghosts DO have hyper drives, the freighters were just for covert insertion close to the system so they didn't have to do a complex entrance maneuver like the Sharks did, and they left under their own drives, not requiring a ex-fil by freighters.

tlb wrote:If a hyper-generator is needed to make a transition, then you are completely wrong, see Storm from the Shadows:

Chapter 51 wrote:Absolutely nothing seemed to happen for the next two or three minutes, but appearances were deceiving, and Topolev waited patiently, watching his own displays, as Task Force One of the Mesan Alignment Navy translated ever so slowly and gradually back into normal-space.
This maneuver had been tested against the Mesa System's sensor arrays by crews using the early Ghost-class ships even before the first of the Shark-class prototypes had ever been laid down, and Task Force One had practiced it over a hundred times once the mission had been okayed.

Oh, right. They do have hypergenerators because of this practice. It wasn't used during the insertion, which is why it wasn't on my mind.

Theemile wrote:There is no "up" translation signal. No one sees you jump into hyper from normal space, only the downward translation gives off a signal (you are dissipating so much energy with the down translation.)- they will just see your drive signal disappear.

Well I suspect that there might well be a signal in the Alpha bands from transitioning up into them from normal space — but you’re right that there’s no signal of the departure in normal space; so the Ghost’s departure wouldn’t have been noticed.

Though I’m not sure why you’d have to be dissipating more energy going down; the Alpha wall bleeds off 92% of your velocity in either direction. (Though in practice ships tend to be moving much faster when starting a downward transition)

Mycall4me wrote:Interstellar travel in hyper in the Honorverse depends on the hyper generator the impeller drive and for grav waves alpha nodes. The spider drive is none of those things.

As far as I remember, the first hyper capable ships had just a hyper generator, and used traditional thrust engines to accelerate, impellers came later. After Adrienne Warshavski had invented the grav sensors, this allowed "safe" hyper travel as ships could avoid the dangerous grav waves, and even more later, the warshavski sails have been invented (with the alpha nodes), allwoing to actually exploit the grav waves for fast and energy efficient "sailing", and worm holes.

So, in theory, a hyper should be enough, if the spider drive can work against "higher" walls.

The other point is that the traditional spindle-shape with two impeller rings is required to produce traditional impellers. It might be possible to produce warshavski sails for grav wave and wormhole travel with (possibly modified) alpha nodes in a different, non-traditional setup.

Jonathan_S wrote:

Theemile wrote:There is no "up" translation signal. No one sees you jump into hyper from normal space, only the downward translation gives off a signal (you are dissipating so much energy with the down translation.)- they will just see your drive signal disappear.

Well I suspect that there might well be a signal in the Alpha bands from transitioning up into them from normal space — but you’re right that there’s no signal of the departure in normal space; so the Ghost’s departure wouldn’t have been noticed.

As far as I remember, the ship needs to put energy in when "climbing up" in the hyper bands, and this energy is released back when the ship lowers down (or back to normal space).

Jonathan_S wrote:Though I’m not sure why you’d have to be dissipating more energy going down; the Alpha wall bleeds off 92% of your velocity in either direction. (Though in practice ships tend to be moving much faster when starting a downward transition)

As far as I understood, the velocity energy lost adds to the hyper footprint - I have fading memories of hyper footprints being stronger when the ships are faster, which is usually frowned upon due to the bad side effects to the passengers.

(Btw, is there any textev whether treecats have similar problems on hyper travel? )

Well, one of the primary reasons I started this thread (it may not have been clear) was looking for potential downsides inherant in spider drive ships due to the triple skeg hull form requirement.

So after going through the orientation of the decks part of the thread of the deck being perpendicular to the accelleration, it struck me that there is a possibly significant problem bc of that orientation requirement.

It was pointed out somewhere, in the books, or here, that the triple skeg allowed for three (six?) missile broadsides. Good, right? Well if the decks are "stacked" like a skyscraper layed on it's side, that would HAVE to mean that the missile tubes COULDN'T be arranged on a single deck (or more as in a SD) but have to have each tube correspond into the "stack" of decks. MAYBE they could fit two per deck if the "floor" and "ceilings" were far enough apart, but I would think that that would be unlikely and pose additional problems on any one deck anyways.

And THAT would mean that tube loading and servicing requirements would have all KINDS of gyrations to go through. And while I'm thinking about it missile stowage could be problematic as well, especially as it pertrains to needing acess to the "stack" of tubes.

Correct me if I'm wrong, but that seems to me to be another significant inherent design complication to overcome in designing a spider drive warship.

Which is all good as far as I can see. As far as I'm concerned ANYTHING that detracts from a spider drive warship's efficiency, or effectiveness is a GOOD thing.

markusschaber wrote:The other point is that the traditional spindle-shape with two impeller rings is required to produce traditional impellers. It might be possible to produce warshavski sails for grav wave and wormhole travel with (possibly modified) alpha nodes in a different, non-traditional setup.

You do need a double-ring of impellers for the way impellers are used by starships -- but (as a bit of side tangent) we do see other impeller powered craft or devices that work just fine with a single ring of impeller nodes. (Though I'm not sure if they're technically considered Beta nodes, or if they'd have some other designation.
But they definitely seem to lack the sail capability that distinguishes an Alpha node).

Those would include shuttles, pinnaces, missiles, drones, and forts. All can form an impeller wedge; but none are shown or described to have more than a single impeller ring. (Well, okay, technically MDMs have 3 impeller rings; all bunched near the tail of the missile. But only one is used at a time)


Still that aside doesn't affect your point that we don't know if you used Alpha nodes onto to create sails if you'd have the same hull shape limitations.

markusschaber wrote:

Jonathan_S wrote:Though I’m not sure why you’d have to be dissipating more energy going down; the Alpha wall bleeds off 92% of your velocity in either direction. (Though in practice ships tend to be moving much faster when starting a downward transition)

As far as I understood, the velocity energy lost adds to the hyper footprint - I have fading memories of hyper footprints being stronger when the ships are faster, which is usually frowned upon due to the bad side effects to the passengers.

(Btw, is there any textev whether treecats have similar problems on hyper travel? )

Yes faster moving ships seem to produce a larger signal; that's what I was alluding to when I mentioned that in practice downward transitions were usually begun from higher velocities than upward ones.

I knew "crash translation" were rougher on people (and systems) but this got me to look again to see how they were defined (I couldn't recall if they were simply any transition beginning from high velocity; or if they were somehow related to how quickly you were moving down through the hyper bands. But HAE seems to indicate that it is the former)

Honor Among Enemies - Ch. 10 wrote:A ship bled over ninety percent of its velocity as it broke each hyper-space wall in a downward translation, which could be a handy tactical maneuver. But crash translations were rough on personnel and systems, and merchant skippers preferred the gentler, safer stress of a low velocity translation. It not only allowed their crews to avoid the violent nausea crash translations induced but also reduced alpha node wear by a measurable percentage

(emphasis added)

Though when later discussing impact of damage to Artemis's hyper generator Fuchien says "my downward translation rate's been cut by something like eighty percent". Does that mean she needs to have a velocity that's 80% lower before transitioning; or are we back to possibility different rates of crossing between bands?

And it talks later about how Artemis was able to cautiously translate down to the Alpha bands without using impellers "possible for such a slow transition". But I don't think she'd have had the time since separating from Wayfarer (given that her impellers were down for most of that to hide while the Peeps followed Wayfarer and the decoy pretending to be Artemis) that I don't think her velocity could be much less than it was when it was earlier said that she couldn't survive a "crash translation" at that speed. So is a "crash" translation both velocity and rate of moving between bands? I'm confused.

The first big quote seems quite clear; but then doesn't seem to perfectly align with the later Artemis scenes...