Information I'd love to know

penny wrote:But you touched on something I was going to ask. Without a sail I didn't think a ship could enter hyper. So, what can one do with an SD that cannot be repaired by a repair ship?

A ship can lose sails while in hyper and survive? How is that? A ship on the seas losing its sails in treacherous waves is toast.

Sails are needed in a gravity wave and when going through a wormhole. It was not that long ago that I was corrected in one of these threads when I thought the ship had to be under sails to make a hyperspace transition (sails are ONLY required on a transition if entering or leaving a gravity wave).

Note that HMS Wayfarer lost sails, wedge and hyper-generator during the fight in the Selker Rift (but still was in better shape than the Peep ship PNS Achmed) from Honor Among Enemies:

Chapter 41 wrote:"Thank you," Harrington said simply, then looked him straight in the eye. "Our vector's carrying us lengthwise down the rift, Captain, but we're angling towards the Silesian side. My best guess is that we've got about nine days before we drift into the Sachsen Wave and break up. That, of course, assumes the Selker Shear doesn't get us first. As I see it, our only real chance is to use the pinnaces to mount a sensor watch and hope one of your people comes looking for you so we can get a com message to them. If they get here in time," she drew a deep breath, "I will surrender myself and my people to you. For now, however, what's left of this ship is still a Queen's ship, and I am in command."

tlb wrote:

penny wrote:But you touched on something I was going to ask. Without a sail I didn't think a ship could enter hyper. So, what can one do with an SD that cannot be repaired by a repair ship?

A ship can lose sails while in hyper and survive? How is that? A ship on the seas losing its sails in treacherous waves is toast.

Sails are needed in a gravity wave and when going through a wormhole. It was not that long ago that I was corrected in one of these threads when I thought the ship had to be under sails to make a hyperspace transition (sails are ONLY required on a transition if entering or leaving a gravity wave).

Note that HMS Wayfarer lost sails, wedge and hyper-generator during the fight in the Selker Rift (but still was in better shape than the Peep ship PNS Achmed) from Honor Among Enemies:

Chapter 41 wrote:"Thank you," Harrington said simply, then looked him straight in the eye. "Our vector's carrying us lengthwise down the rift, Captain, but we're angling towards the Silesian side. My best guess is that we've got about nine days before we drift into the Sachsen Wave and break up. That, of course, assumes the Selker Shear doesn't get us first. As I see it, our only real chance is to use the pinnaces to mount a sensor watch and hope one of your people comes looking for you so we can get a com message to them. If they get here in time," she drew a deep breath, "I will surrender myself and my people to you. For now, however, what's left of this ship is still a Queen's ship, and I am in command."

My badd. You are correct. We just went over that.

But how can a ship be towed into hyper from n-space without sails? Let me explain. Picture a pickup truck towing a car with an attached chain. There is going to come a point when that chain is going to jerk.

When a ship is towed, the ship under power is going to accelerate very quickly. I can't see a tractor beam holding on for dear life.

penny wrote:But how can a ship be towed into hyper from n-space without sails? Let me explain. Picture a pickup truck towing a car with an attached chain. There is going to come a point when that chain is going to jerk.

When a ship is towed, the ship under power is going to accelerate very quickly. I can't see a tractor beam holding on for dear life.

On the previous page of this thread, I thought the tow would only work if the acceleration was kept so low that the ship in tow was not damaged. Note that a ship can tune the acceleration under either wedge or sails to be any value from zero to the maximum dictated by the compensator. Otherwise a ship would continue accelerating past the maximum velocity set by particle shielding, which would be a bad thing.

But effectively that means a massive ship cannot be towed, since the compensator field from the working ship will not extend far enough. That is why a repair ship that can do just about anything that a shipyard can do is needed.

penny wrote:No, I really did mean 'if it cannot be towed through hyper.' I simply wasn't aware it'd take so long!

Well you'd be towing it lightyears -- while not even going at the speed of light - so years to the closest star.

A warship's rad shielding is good for up to 0.8c in normal space -- but a disabled one might not have rad shielding and I don't know how much the towing vessel 'plowing the road' would help with that. So the tow velocity might be far lower that than.

penny wrote:Reason being, I thought repair ships are as limited in what they can do as doctors contemplating Regen. If the heart is dead, the engine (nodes, rings) then I thought she is totaled and headed for the breakers. But towing an SD? How many ships can simultaneously tow a warship? Only one, lest wedge fratricide? Yet we never hear of a ship being scuttled, have we?

Then you've forgotten some key points from On Basilisk Station
While Sirius was 'only' purportedly waiting for a repair ship to come out from Haven with spare drive tuners for her ostensibly malfunctioning alpha rings, during the battle HMS Fearless lost at least one Alpha node (Alpha Two) - and her impeller rings both fully failed right after the battle (and had to be jerry rigged to limp back to Basilisk). Afterwards repair ships popped over from Manticore to patch her drive up enough she could go through the wormhole under her own power.

Repair ships can rebuild an entire drive -- they'll just take longer doing so than a full repair yard would be. It's just a matter of time and money. Now they probably can't fix a ship that's got major structural issues - but dead nodes while large and requiring very precise calibration and tuning are, conveniently, exposed on the outside of the hull where you can get at them. There's not even any armor in your way.

penny wrote:But you touched on something I was going to ask. Without a sail I didn't think a ship could enter hyper. So, what can one do with an SD that cannot be repaired by a repair ship?

A ship can lose sails while in hyper and survive? How is that? A ship on the seas losing its sails in treacherous waves is toast.

I know this has been covered fairly recently; but to reiterate.
When entering hyper there are two relivant scenarios:
1) The system exists within a rift, so there's no grav wave on the other side of the hyper wall. Sails would be ineffective because they'd have nothing to grab.
2) The system exists within a grav wave, if you don't rig sails before entering hyper the grav wave will tear you to pieces.

But in situation 1 even the early hyper scouts -- which predate the invention of sails, heck predate the invention of the impeller drive, were able to enter hyper. They used fusion engines!

And the text discussion ships maneuvering under wedge immediately before, or immediately after, entering hyper -- no indication that even ships which can form sails switch to them before entering hyper (except in situation 2)

In fact here's a couple of bits of text-ev I hadn't dug up for the last discussion

In Enemy Hands wrote:With her forward alpha nodes gone, Prince Adrian had lost her Warshawski sails . . . and Adler lay squarely in the heart of a hyper-space gravity wave, where only sails would permit a ship to maneuver. That single, devastating salvo from Katana had doomed his ship, and McKeon knew it.

Ashes of Victory wrote:Diamato remembered the unending succession of disasters, the helplessness with which he had watched other battleships being clawed down, blown apart by those incredible LACs' impossible grasers or-possibly even worse-fired into just until they lost an alpha node or two. With even one alpha node down, it was impossible to generate a Warshawski sail, and Hancock lay directly in the path of a grav wave. Which meant no one without Warshawski sails could maneuver in hyper at all . . . and that, in turn, meant there would be no escape from the vengefully pursuing Manty superdreadnoughts of the system's inner picket.

If sails were required to enter hyper at all then it wouldn't matter whether those systems lay within a grav wave of not - losing an alpha node would trap any ship in any system. But it doesn't.

Now as for losing a sail in hyper. Well, you'd only have them rigged while in a grav wave -- and the vast majority of hyper is rifts, between waves, such as the Selker rift where Wayfarer and her LACs (which don't have sails at all) saved the liner Artemis fought the Peep raiding squadron.
But you normally need two sails to use a grav wave -- here's what the text says about the hyperspace convoy ambush I mentioned earlier

Short Victorious War wrote:"Ma'am," he spoke softly, as if to a child, "we out-mass those ships seven to one, and they have to close to energy range. They know what that means as well as we do. So they'll do the only thing they can. They'll open their broadsides to bring every beam they can to bear, and they'll go for our forward alpha nodes. If they take out even one, our own foresail will go down, and this deep into a grav wave—"
He didn't have to complete the sentence. With no forward sail to balance her after sail, it was impossible for any starship to maneuver in a grav wave. They would be trapped on the same vector, at the same velocity. They couldn't even drop out of hyper, because they couldn't control their translation attitude until and unless they could make repairs, and even the tiniest patch of turbulence would tear them apart. Which meant the loss of a single sail would cost Reichman at least two ships, because any ship which lost a sail would have to be towed clear of the wave on a consort's tractors.

So a ship can survive (with good luck and prompt help) losing one of her sails while in a grav wave. But the loss of both would be basically instantly fatal.

penny wrote:An aside: Jonathan, I've been needing to thank you for all of the additional information you include in many of your posts. Dunno how you feel Bout it, but it was one of your posts that made the lightbulb come on in my head in the ? thread. It was your posts that led to me realizing that the two theories had been solved. Good conversation fuels discovery. Kudos 2 U!


PS

Trying to repair the engine of an SD, even if she was back home in the yard dogs hands I thought would be as difficult as Theemile's tag line says RFC said ...

RFC said "refitting a Beowulfan SD to Manticoran standards would be just as difficult as refitting a standard SLN SD to those standards. In other words, it would be cheaper and faster to build new ships."

You're very welcome. I enjoy how much your posts have me going back and digging up text-ev to try and support my thoughts (even when they don't agree with your). And sometimes I get surprised and find things I'd forgotten or overlooked - which is a great way to keep the series fresh in my mind.

As for refitting the Beowulfian SDs - the nodes aren't the problem. Okay, they'd need new nodes to retrofit in bow or stern walls, or FTL transmitters. But that's the easy stuff.
Even the compensator they'd need to keep up with a Manticoran SD(P) is comparatively easy.

The real problem is that they can't carry or fire modern missiles or CMs, don't have enough CM launchers, have no way to mount Keyhole or Keyhole II platforms, don't mount enough PDLC. The different and larger launch tubes for the MDMs and Mk-31 CMs/Vipers would require massive amounts of cutting through armor, gutting out all the magazines and rebuilding them. Adding Keyhole would require new very high bandwidth data lines be run and the belt armor reshaped to make mounting recesses for them. And all that for a ship that's still smaller and less combat capable than a new SD(P).
That's what would take longer and cost more than a new build -- not replacing, or even upgrading, the impeller nodes.

tlb wrote:But effectively that means a massive ship cannot be towed, since the compensator field from the working ship will not extend far enough. That is why a repair ship that can do just about anything that a shipyard can do is needed.

I forgot to mention, more importantly the hyperspace generator field might not cover the towed ship either; so it will NOT make the transition with the towing ship.

So the extremely large carrier cargo ship would be needed, if it could be built. Better to build more repair ships, which are more generally useful; such as when used to rebuild infrastructure after the Yawata Strike.

Edit: and again while I was drafting this someone, tlb this time, partially preempted my point. Ah well, can't be bothered to edit the rest of this

penny wrote:But how can a ship be towed into hyper from n-space without sails? Let me explain. Picture a pickup truck towing a car with an attached chain. There is going to come a point when that chain is going to jerk.

When a ship is towed, the ship under power is going to accelerate very quickly. I can't see a tractor beam holding on for dear life.

Actually I don't think you could enter hyper at all while actively under tow. (Fortunately you don't need to be)

If you're using the towing ship's hyper generator to get both ships into hyper I think you'd have to drop wedges to get close enough. Even maxed out a hyper generator can only reach several km from the hull -- when the Yu was playing that game in HotQ his ships' "generators were powerful enough to extend their translation fields over six kilometers beyond their own hulls if he redlined them". But a wedge or sail reaches over 100 km from the hull - so unless you're towing something small enough to safely tuck inside your wedge you'd need to drop wedge to get it close enough to jump it into hyper.

And if the towed ship still has a functional hyper generator then I'd expect the act of translating into hyper to break the tow -- and the two ships aren't going to be perfectly synchronized.

Still, while it's somewhat safer to enter hyper while accelerating it isn't required. You can coast, drop the tractor, translate into hyper, and then resume tractoring the towed ship again. It's space, nothing dramatic happens when you shut down the wedge or drop the tractor -- the ship(s) just keep on the same vector ballistically -- it's not like a trailer which goes out of control if the it comes off the tow hitch.

(Also the towing ship doesn't have to accelerate hard. Likely when towing it'd be starting at a snails pace and only very slowly building up speed -- specifically to avoid overstressing the tractor or throwing things around in the towed ship. Though if the towed ship still has power and functional grav plates then it can safely handle much higher acceleration than if it's a totally dead hulk like the Masadan LACs apparently were)

Jonathan_S wrote:Edit: and again while I was drafting this someone, tlb this time, partially preempted my point. Ah well, can't be bothered to edit the rest of this

penny wrote:But how can a ship be towed into hyper from n-space without sails? Let me explain. Picture a pickup truck towing a car with an attached chain. There is going to come a point when that chain is going to jerk.

When a ship is towed, the ship under power is going to accelerate very quickly. I can't see a tractor beam holding on for dear life.

Actually I don't think you could enter hyper at all while actively under tow. (Fortunately you don't need to be)

If you're using the towing ship's hyper generator to get both ships into hyper I think you'd have to drop wedges to get close enough. Even maxed out a hyper generator can only reach several km from the hull -- when the Yu was playing that game in HotQ his ships' "generators were powerful enough to extend their translation fields over six kilometers beyond their own hulls if he redlined them". But a wedge or sail reaches over 100 km from the hull - so unless you're towing something small enough to safely tuck inside your wedge you'd need to drop wedge to get it close enough to jump it into hyper.

And if the towed ship still has a functional hyper generator then I'd expect the act of translating into hyper to break the tow -- and the two ships aren't going to be perfectly synchronized.

Still, while it's somewhat safer to enter hyper while accelerating it isn't required. You can coast, drop the tractor, translate into hyper, and then resume tractoring the towed ship again. It's space, nothing dramatic happens when you shut down the wedge or drop the tractor -- the ship(s) just keep on the same vector ballistically -- it's not like a trailer which goes out of control if the it comes off the tow hitch.

(Also the towing ship doesn't have to accelerate hard. Likely when towing it'd be starting at a snails pace and only very slowly building up speed -- specifically to avoid overstressing the tractor or throwing things around in the towed ship. Though if the towed ship still has power and functional grav plates then it can safely handle much higher acceleration than if it's a totally dead hulk like the Masadan LACs apparently were)

Thanks for that. It seems I was operating under another misconception. I always assumed that when entering hyper, even if not entering a grav wave, a ship has to accept a nominal acceleration. IOW, there is some acceleration even in hyper. As an analogy, on the open seas where currents are always moving. A river is probably a better analogy. I suppose hyper is analogous to "calm" seas and no minimal acceleration.

I'm having a hard time with there not being a nominal acceleration in hyper. I know that text says enemy forces meet in hyper to hide, plan, etc. But hyper has a velocity, though nowhere near the velocity of a grav wave, that is much faster than the would be velocity in n-space. That implies -- let's say for the sake of argument -- for every 1 km moved you actually move 100,000 km. Well, for every meter moved you actually travel 100,000 meters? On down to centimeters. That means ships would have to hold station perfectly to prevent any acceleration. I can't wrap my head around that. Thus, when entering hyper there simply has to be a nominal acceleration, at least until a relative velocity of zero is achieved. And if something is being towed, the beam should snap.

penny wrote:I'm having a hard time with there not being a nominal acceleration in hyper. I know that text says enemy forces meet in hyper to hide, plan, etc. But hyper has a velocity, though nowhere near the velocity of a grav wave, that is much faster than the would be velocity in n-space. That implies -- let's say for the sake of argument -- for every 1 km moved you actually move 100,000 km. Well, for every meter moved you actually travel 100,000 meters? On down to centimeters. That means ships would have to hold station perfectly to prevent any acceleration. I can't wrap my head around that. Thus, when entering hyper there simply has to be a nominal acceleration, at least until a relative velocity of zero is achieved. And if something is being towed, the beam should snap.

It's described more like the width of the galaxy is X% smaller each layer of hyper you go up.

So in the Alpha bands it isn't 4.246 LY from Earth to Proxima Centauri -- it's only 25 light-days. Distances between systems shrink by 62 times there.

But the text in the books makes the relative accelerations and distances between objects in hyper appear to behave normally. Within the Alpha bands if you move a meter you've moved a meter. At least relatively to everything else in the Alpha bands. If you accelerate at 9.8 m/s^2 for 1 seconds you'll have gone 4.9 meters and be moving at 9.8 m/s*. It's only when you translate back into normal space that you discover that you're 303-ism meters (62x further than that 4.9 meters) from where you'd entered hyper.

*Assuming you'd started with 0 velocity.

---
How fleets can still emerge more or less in formation is a point not addressed in RFC's physics. By the power of plot they do.
And similarly sensors of ships waiting in hyper somehow can't see other ships waiting across the solar system even if hyperlimit diameter / compression ratio yields a distance that's smaller than sensor range in hyperspace. <shrug>

penny wrote:I'm having a hard time with there not being a nominal acceleration in hyper. I know that text says enemy forces meet in hyper to hide, plan, etc. But hyper has a velocity, though nowhere near the velocity of a grav wave, that is much faster than the would be velocity in n-space. That implies -- let's say for the sake of argument -- for every 1 km moved you actually move 100,000 km. Well, for every meter moved you actually travel 100,000 meters? On down to centimeters. That means ships would have to hold station perfectly to prevent any acceleration. I can't wrap my head around that. Thus, when entering hyper there simply has to be a nominal acceleration, at least until a relative velocity of zero is achieved. And if something is being towed, the beam should snap.

If there's a nominal acceleration, then which direction is it?

If it's somehow like the currents in a river, wind flow for airplanes, or inclination for cars, travelling in the opposite direction would be slowed down instead of being accelerated.