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Pearls of Weber

A collection of posts by David Weber containing background information for his stories, collected and generously made available Joe Buckley.

Climax to the Battle of Manticore

Why did Genevieve Chin not manage to tanslate into hyper-space in time to avoid 8th Fleet's massive bombardment?

Okay, this is a complicated one.

There are basically three factors involved in what happened to Genevieve Chin.

One, which I don't believe I've specifically discussed, unless I touched on it in my post on Apollo command and control questions, is that she was beyond the Havenites' estimate of maximum Apollo FTL control distance. While she recognized that the number of missiles coming at her were going to hurt, she anticipated that they would be beyond Apollo's reach and that her electronic warfare and missile defense capabilities would be far more effective than they proved.

Secondly, Chin didn't believe that every unit she was looking at was Apollo capable. The Havenites had never seen more than a handful of Apollo-capable units, and she'd just killed some of them. Her initial estimate, which I regret that I didn't give you the course of the book, was that perhaps half of the ship she was looking at were Apollo-capable. That's one reason she was thinking in terms of "bluffs" before she realized how wrong she was.

Thirdly, and sort of trumping all of the other factors (although this gets into some information that has never made it into the books, partly as a conscious decision on my part), she didn't have time, especially after she realized what was coming at her.

I've deliberately not given the actual cycle times on hyper generators in the books. This is partly because I've been reserving the right to change them, if I really have to. However, in order to help you understand what Chin's actual options were, it's probably time for me to at least explain exactly how the timing on hyper translations/hyper generators work.

Basically, just as a ship's mass/dimensions affect its acceleration rate, they also affect the speed with which it can make hyper translations. That is, a smaller, "handier" ship can cycle its hyper generator much more rapidly than a great big hairy superdreadnought, and military-grade hyper generators can cycle faster than civilian-grade hyper generators.

There are four basic levels of readiness for a hyper generator:

(1) Powered Down. This one, I think, is probably fairly self-explanatory.

(2) Routine Readiness. In this stage of readiness, the generator's basic readiness checks have been completed, there's a minimal power load on it, but its capacitors are not fully charged, and various safety interlocks are still closed to prevent… unfortunate accidents.

(3) Stand-By Readiness. In this stage of readiness, the capacitors are fully charged, the interlocks have been disengaged, and the engineer is ready to press the "go" button. However, even after the button is pressed, there is a minimum cycle time while the generator spins its field up to translation capability.

[ David seemed to have trouble counting the day he composed this, so I'll take the liberty of including the fourth readiness state for him:

(4) Sustaining. Running and in hyperspace. -Ed ]

It takes longer to go from Powered Down to Routine than from Routine to Stand-By. Basically, without getting into the detailed numbers (which scale with the tonnage of the ship, from a minimum cycle time of 30 seconds for even a dispatch boat), an 8,000,000-ton superdreadnought requires 4 minutes to go from Stand-By to actual translation. That is, the absolute minimum time for that ship to translate into hyper would be 240 seconds. To go from Powered Down to Translation, the same ship would require 32 minutes.

So Genevieve Chin required an absolute minimum of 4 minutes from the time that she issued the order to hyper out before her ships could obey it. That time figure, of course, does not include the time required for the captains of her ships to receive the order, transmit it to their engineers, and for the engineers to give whatever orders they'd have to give before the "go" button could be punched. The reason that I say in the book that she'd waited "two minutes too long" is that she realizes what's happening when the missiles are only about two minutes out. If she'd realized when they were still four minutes out, she might actually have gotten away into hyper before the missiles arrived, since her generators were at Stand-By readiness. As it was, it was physically impossible for her to dodge out of normal-space into hyper-space.

In my original draft, I'd touched on these constraints, but not in great detail. When I did my edit, I realized that what I'd written would actually have been more confusing to readers who didn't already know what I knew when I wrote it than it would have been simply to leave that entire aspect of the battle untouched. So in the great "squeeze the word count down" effort, I eliminated those passages. They saved me a few dozen words, and it seemed to me that the scene read smoothly without them. And, to be honest, I've been running a little gun shy over the entire "infodump" issue, and I made a conscious decision in this book to reduce them as much as I could.

In retrospect, I think I ought to have gone ahead and infodumped you, anyway. For those of you who are really into the nuts and bolts of the Honorverse, it wouldn't have been a problem in the first place. For those of you aren't into the nuts and bolts, it would have been another section you could have just skimmed through, but it would have made Admiral Chin's dilemma much clearer.

Now, while I'm on the subject of how hyper generators work, I should probably add that the generator's cycle time is only a factor in translations into hyper, at least under normal circumstances. This is because the hyper generator is normally kept online, sustaining (as opposed to initiating) the hyper translation field so that the ship [may] maneuver freely up and down within the bands. It isn't necessary for this to be done, but a ship cannot leave its current hyper band without its generator, and the wear and tear involved in initiating the field is much greater than the wear and tear involved in maintaining the field. The field cannot be maintained in normal-space, because the very act of bringing it up moves the ship into hyper, but it can be maintained in hyper.

When a ship translates out of hyper into normal-space, the field can no longer be sustained. This produces the flash of "transit energy" which has been described in the books from the very beginning. That energy bleed-off automatically takes a hyper generator out of "Translation" mode and drops it back down into "Stand-By" mode. In most civilian vessels, unless the captain specifically orders otherwise, the generator is dropped into "Normal Readiness" mode, since this is so much easier on the hardware (and safer for the ship).

What this means is that our 8,000,000-ton superdreadnought would be required to spend an absolute minimum of 4 minutes in normal-space between translations. In fact, it would almost always spend longer than this, because of the need to make astrogation observations and calculate the next hyper translation on the basis of those observations. When Third Fleet made its double micro jump, it jumped to a carefully pre-calculated position, but it still had to spend at least a few minutes reorienting itself. The total cycle time on Admiral Kuzak's hyper generators was only four minutes; the time she actually spent in normal-space between [jumps] was closer to eight minutes.

When Honor made her micro jump, one of the primary reasons that she had Kgari make it in a single translation was because she was unwilling to spend those additional seven-plus minutes or so getting into position to engage Fifth Fleet.

Please note that I'm using 8,000,000 tons for all of my calculations because that's where my current pre-calculated tables stop. That's another reason I didn't want to go into lots of detail in the books, both because I need to extend them, and because I'm trying to decide whether or not I want to allow for additional new technology which would affect cycle times.

I try to give you guys as much information as I can without utterly losing you in the underbrush, but there are lots of things I haven't spelled out specifically that are covered in my notes but not in the books (to date, at least) either because of infodump phobia or because I haven't felt you needed to know it or else I'm reserving the right to adjust it. Once I've put something out there in one of the books, I'm pretty much stuck with it, so I try to keep my options open.