SLN, and MAlign playing catch up with Manticoran superiority

penny wrote:Doh! Just a few clicks upstream kzt said that David said that the LD's tractor's had the range of PDLCs. What, 100,000 km?

If a wedge does interfere with a spider drive's operation then g-torps would go haywire before they reach attack range. If not explode. So, there can't be interference, lest it is with a much more powerful wedge. But I certainly won't rule it out. Thanks for the responses. I was pulling my hair out.

tlb wrote:Yes, a tractor beam might well have the range of a PDLC, but that does not mean that the spider drive needs to reach out that far to work. Even though the beam is very strong (compared to normal tractor beams), it still must attenuate some with distance. So why reach the full theoretical distance when the Alpha wall is right at hand? The beam does not need to reach out more than a few kilometers in order to pull the ship ahead and I hope the LD would not get within 100 kilometers of a warship with an active wedge.

penny wrote:You mean 100,000 kilometers?

Seems like rather extraneous information from the author if it has no significance. It begs the question of just how far the beam does extend before breaching hyperspace. And exactly how is the maximum range ever reached if before the maximum range is reached hyperspace is breached. Does the LD have an idle/neutral gear where the LD's tractors do not breach hyperspace? It would seem logical that the LDs tractors could be utilized as, well, normal tractor beams for towing / grabbing objects in n-space.

Something else, IINM, there are several tractor beams grabbing hold of the alpha wall. Are each of those beams grabbing hold of the same area on the wall?

It also seems intuitive, in an emergency that any ship's tractor beam can interfere with an LDs tractor's operation.

As I understand it, KZT was talking about the range where a tractor beam could do damage and not the range for spider drive operation. I am not using the 100,000 km range, since I see no reason for the drive beams to reach out that far.

I expect the spider drive beams are dedicated to movement, because it would mess with the flow if you tried to divert one to tow an object. The ship is big enough to have general purpose beams. An ordinary general purpose beam is not going to interfere with anything, because it is not strong enough to interact with the Alpha wall. The only problem would be if the towed object gets hit with a drive beam.

The way I visualize the drive process, it looks like an 8 man racing boat (not that the number of beams is limited to 8) with the beams being the oars. On command the beams point forward (but off to the sides) and each grabs its own piece of water (Alpha wall) and pulls the boat forward; then releases and prepares to repeat. Neutral or idle just means that the beams are turned off, or at least have their power turned down to not grab the wall.

The beams are repetitively, not continuously, grabbing the wall at a place further ahead each time. The drive beam heads could actually be fixed at a forward angle, but then the ship would have to switch bow for stern in order to decelerate.

Jonathan_S wrote:My personal and uninformed guess on this is that RFC won't want to deal with this. And seems to me the easiest way to avoid doing so would seem to be to claim that the bending is restricted to the no larger than the size of a wedge, and a spider drive has no greater reach than the span of a wedge, and so the issue is moot because you'd get a (destructive) wedge to spur interaction before you'd have to worry about the spur's anchor point bending out from under it.

markusschaber wrote:My personal idea on this is that the bending happens strictly within the wedge, between the two bands. The 3d space (or maybe even 4d space-time) are bent to implement the acceleration/deceleration. And the bending of the alpha wall is just a side effect, unintended, but also unavoidable (or not worth the additional effort of avoiding it).

Theemile wrote:Wedges can be a single band (civilian wedges usually are).

Sorry for my unclear expression. I meant space between the upper and lower band of the wedge, the place where the ship resides within (in the center at max acceleration, and with some degree of freedom at lower accelerations).

As I understood, military drives have "double-layer" bands (two bands very close to each other) for each the upper and lower band, while civilian drives have only a single layer for each band.

penny wrote:It would seem logical that the LDs tractors could be utilized as, well, normal tractor beams for towing / grabbing objects in n-space.

Something else, IINM, there are several tractor beams grabbing hold of the alpha wall. Are each of those beams grabbing hold of the same area on the wall?

Only if their power can be dialed down - something that isn't necessary for their functionality as a drive system. It's said
"no one in his right mind had ever imagined tractors or pressers that powerful" [MoH] -- powerful enough they'd tear apart anything they tried to grab at their normal drive power. (But only at "sufficiently short range" -- when compared to actual weapons).

That extreme power is also why I don't think a regular tractor would interfere with them (assuming the ships were close enough for those ranges to overlap). The spider nodes' spurs might well blow out the regular tractor's emitter -- but they're just so much more powerful that the tractor that I can't see it impacting them noticeably.

And adding the ability to dial back the spider nodes' power output, or for that matter to control their spread to zone objects for towing, would likely drive up the size and complexity of each of those nodes (assuming it such controls were even compatible with a design optimized around operating at previously unimagined power for a tractor-like emitter). There's just no reason to put that complication (and possibly even fragility) into your drive when you've plenty of room to stick normal tractors on the LDs.


The text isn't explicit about where they grab the Alpha Wall, though the requirement for trilateral (or more) symmetry indicates that each skeg's nodes much be grabbing off to their side - so you need the three radially symmetric pulls to control the sideways and turning motions so you've full control over its maneuvers. But the text just doesn't say anything about whether the entire row of nodes on a given skeg is aimed converging at a single point, is generating parallel beams to grab a line of spots, or diverging so each grab point is further apart than the physical projectors are. (though my bet would be one of the later two possibilities)

But what does seem clear is that they they pull on a very short cycle. My interpretation is that they're adjusting their grab point(s) each time to compensate for the ship's movement. But the actual text just says the "dozens of beams" are "pulling in micro-spaced bursts" [MoH]


Nothing about any of this seems to require that the gravity spurs the nodes create reach any great distance. The Alpha Wall is everywhere, and you're only pulling for a micro-burst, so changing angle between the node and the anchor point doesn't seem like it'd be a problem (a longer beam would have less angular change per second as the ship moved - but if, as I believe, the node is adjusting its grab point every micro-burst that wouldn't matter). So I'm on the side of them likely having no more reach that a wedge would -- no more than 500 km from the ship.

Jonathan_S wrote:Nothing about any of this seems to require that the gravity spurs the nodes create reach any great distance. The Alpha Wall is everywhere, and you're only pulling for a micro-burst, so changing angle between the node and the anchor point doesn't seem like it'd be a problem (a longer beam would have less angular change per second as the ship moved - but if, as I believe, the node is adjusting its grab point every micro-burst that wouldn't matter). So I'm on the side of them likely having no more reach that a wedge would -- no more than 500 km from the ship.

I suppose it depends on whether the beam can be focused for a particular distance. I certainly agree that they do not need to reach out more than 500 km, but frankly I do not see a need to reach even 5 km for the drive to work.

On thinking about it more, I think my analogy to an 8 man racing boat is wrong, in that I believe it might be too jerky if all the beams pull at the same time. If you number the beams from 1 to N on each of the three keels, then perhaps only the three same numbered beams pull at the same time - so the vector is straight ahead and the time between beam firing is correspondingly shorter, making the effect much smoother.

tlb wrote:

Jonathan_S wrote:Nothing about any of this seems to require that the gravity spurs the nodes create reach any great distance. The Alpha Wall is everywhere, and you're only pulling for a micro-burst, so changing angle between the node and the anchor point doesn't seem like it'd be a problem (a longer beam would have less angular change per second as the ship moved - but if, as I believe, the node is adjusting its grab point every micro-burst that wouldn't matter). So I'm on the side of them likely having no more reach that a wedge would -- no more than 500 km from the ship.

I suppose it depends on whether the beam can be focused for a particular distance. I certainly agree that they do not need to reach out more than 500 km, but frankly I do not see a need to reach even 5 km for the drive to work.

On thinking about it more, I think my analogy to an 8 man racing boat is wrong, in that I believe it might be too jerky if all the beams pull at the same time. If you number the beams from 1 to N on each of the three keels, then perhaps only the three same numbered beams pull at the same time - so the vector is straight ahead and the time between beam firing is correspondingly shorter, making the effect much smoother.

That probably depends on something else we don't know -- the total force that each node's gravity spur can produce.

We have been told that the torpedoes, RDs, and their derivatives have too short a hull to mount sufficient nodes for high acceleration. But we don't know if that's just because the cycling time of the "micro-burst' pulls is too long with that few nodes or if to get acceleration you need several/many trios at a time pulling.



Still, even if the drive needs some greater multiple of 3 at a time to get the acceleration they might be able to split them into two, three, or more groups as have each group pull as a whole to somewhat smooth the pulls out.

(As an example if they could split them into 3 groups then, say,
trios 1, 4, 7, 10, 13 all pull, then
trios 2, 5, 8, 11, 14 pull, then
trios 3, 6, 9, 12, 15 pull, and
the cycle repeats)

Tlb’s analogy of oars is interesting. I think it was tlb. This text based version of the site makes it difficult to sort and distinguish posts on the small screen of a smart phone. But the analogy makes it easier to visualize in some respects, and harder in others.

If you have ever rowed, you know it is a concerted effort. I have questions the author will have to answer as far as maneuvering. I never quite understood how an impeller drive ship turns. Text describes a crab-like changing of direction which I suppose has to do with thrusters trying to overcome such enormous accelerations. How does a spider drive turn?

If tractors normally grab the wall from each side of the ship for forward propulsion, it would seem at least a third of the emitters are useless when turning. Which implies that all of the tractors are not needed for propulsion in the first place. Except perhaps for maximum acceleration.

With everyones input and after thinking about it, I also agree that the tractors don't reach out all that far before they create a hole into hyperspace. My reasoning becomes apparent if you visualize an eighteen wheeler at an intersection and how much room it needs to make a turn, likewise an LD would require too much space to operate. Turning might be impossible if caught too deeply in-system and it needs to extricate itself. It cannot afford to blow its horn for traffic to move. Its turning radius would be very impractical. And it can't use thrusters to reorient the ship as the hydrogen expulsion would be visible. But hey, I used to think the same thing about an SD. I suppose subs had a fairly long turning radius as well too. So, perhaps it is much ado about nothing.

Jonathan's post about operating the tractors in trios is interesting and would seem plausible and quite necessary given the circumstances.

I also wonder if an LD would have an advantage or disadvantage in stopping distance. Subs of yore needed to kill their forward movement quickly. Can an LD’s tractors bring it to a full stop very quickly? (In my head I am seeing the big wet navy warships roll out the huge anchors that suddenly grab the ocean bottom and jerk it to a stop. Is that just Hollywood?) I suppose deceleration would also be limited by the grav plates.

But I just can't figure out how a tractor can control at what range it pierces hyperspace. Especially if the tractor’s power is not variable. Like someone said, hyperspace is all around. As soon as the beam leaves the emitter a hole in n-space should be made mere meters from the emitter!; seemingly putting the skegs awfully close to the breach created into hyperspace. Which is the entire problem fueling my incredulity about opening this hole inside the hyper limit.

Dunno if an LD has shuttles aboard. But impeller drive ships can open gun ports in the sidewalls for firing point defense clusters and ports for allowing escape pods, etc. I don't suppose an LD has that worry, but a shuttle better be wary of running into those beams.

penny wrote:Tlb’s analogy of oars is interesting. I think it was tlb. This text based version of the site makes it difficult to sort and distinguish posts on the small screen of a smart phone. But the analogy makes it easier to visualize in some respects, and harder in others.

If you have ever rowed, you know it is a concerted effort. I have questions the author will have to answer as far as maneuvering. I never quite understood how an impeller drive ship turns. Text describes a crab-like changing of direction which I suppose has to do with thrusters trying to overcome such enormous accelerations. How does a spider drive turn?

If tractors normally grab the wall from each side of the ship for forward propulsion, it would seem at least a third of the emitters are useless when turning. Which implies that all of the tractors are not needed for propulsion in the first place. Except perhaps for maximum acceleration.

With everyones input and after thinking about it, I also agree that the tractors don't reach out all that far before they create a hole into hyperspace. My reasoning becomes apparent if you visualize an eighteen wheeler at an intersection and how much room it needs to make a turn, likewise an LD would require too much space to operate. Turning might be impossible if caught too deeply in-system and it needs to extricate itself. It cannot afford to blow its horn for traffic to move. Its turning radius would be very impractical. And it can't use thrusters to reorient the ship as the hydrogen expulsion would be visible. But hey, I used to think the same thing about an SD. I suppose subs had a fairly long turning radius as well too. So, perhaps it is much ado about nothing.

Jonathan's post about operating the tractors in trios is interesting and would seem plausible and quite necessary given the circumstances.

I also wonder if an LD would have an advantage or disadvantage in stopping distance. Subs of yore needed to kill their forward movement quickly. Can an LD’s tractors bring it to a full stop very quickly? (In my head I am seeing the big wet navy warships roll out the huge anchors that suddenly grab the ocean bottom and jerk it to a stop. Is that just Hollywood?) I suppose deceleration would also be limited by the grav plates.

But I just can't figure out how a tractor can control at what range it pierces hyperspace. Especially if the tractor’s power is not variable. Like someone said, hyperspace is all around. As soon as the beam leaves the emitter a hole in n-space should be made mere meters from the emitter!; seemingly putting the skegs awfully close to the breach created into hyperspace. Which is the entire problem fueling my incredulity about opening this hole inside the hyper limit.

Dunno if an LD has shuttles aboard. But impeller drive ships can open gun ports in the sidewalls for firing point defense clusters and ports for allowing escape pods, etc. I don't suppose an LD has that worry, but a shuttle better be wary of running into those beams.

An LD would still be accel/decel limited by the force exerted on it's crew through the grav plates. So - no stopping advantage

penny wrote:Tlb’s analogy of oars is interesting. I think it was tlb. This text based version of the site makes it difficult to sort and distinguish posts on the small screen of a smart phone. But the analogy makes it easier to visualize in some respects, and harder in others.

If you have ever rowed, you know it is a concerted effort. I have questions the author will have to answer as far as maneuvering. I never quite understood how an impeller drive ship turns. Text describes a crab-like changing of direction which I suppose has to do with thrusters trying to overcome such enormous accelerations. How does a spider drive turn?

If tractors normally grab the wall from each side of the ship for forward propulsion, it would seem at least a third of the emitters are useless when turning. Which implies that all of the tractors are not needed for propulsion in the first place. Except perhaps for maximum acceleration.

I have never tried to use my phone to browse this website, I always travel with a laptop (and often a tablet) (note the cursor is transparent again). I just tried looking with the tablet and I think that would be doable, but I still prefer using a mouse.

The three keels are absolutely essential, just as a three legged stool is the simplest stable seat. But for turning, all three can be involved by varying the power (or the cycle time) on each of the keels; because that changes the vector.

As for a boat bay, just have it in the rear; since the drive beams are not pointed that way.

My guess for turning with a wedge drive is that the inclined planes get closer on one side to turn to the side. To turn both sideways and up or down, perhaps the ship has to rotate to change into a pure sideways turn?

tlb wrote:As for a boat bay, just have it in the rear; since the drive beams are not pointed that way.

I'd guess that bow would be more likely that the rear. The Sharks are definitely pod layers I think the LDs are known to be too, so their rear is presumably where the pod doors are.

Though I don't think a bay on one of its (three) broadsides would be all that much trouble for the shuttles. A shuttle launching straight out would have to pitch up (or down) over 60 degrees to be on a path for running into a drive beam. That's actually more maneuvering freedom that a shuttle launched from a conventional impeller ship; where more mild pitch angles than that would run you into the wedge -- an equally fatal navigational mistake.

We speculated on smaller hyper capable ships in-between Ghosts and LDs. An LD is a fairly large vessel, the size of a fort. Is it possible to bolt the smallest hyper capable ship on to an LD for an emergency getaway? The captain -- and in the MAN a captain might be in short supply -- does not have to go down with the ship. For the GA the smallest hyper capable ship would be a frigate, right? How much larger than a LAC is a frigate? Is it feasible for the LD to carry a hyper capable spider drive ship? Of course, as long as it does not eat into its weaponry. Internal or external.

And if so, how would that affect acceleration?

A Ghost-class ship can certainly be carried by an LD. It just won't have hyper capabilities.