Just how big is Frontier Fleet?

lyonheart wrote:Honor-verse hyperspace starships don't expend fuel in hyper because they tap a tiny fraction of the hyper energy.

Quibble: Honorverse starships don't expend fuel when using Warshawski Sails in a Grav Wave. They do when traveling under Impeller Wedge drive.

Jonathan_S wrote:Although the particular example in SoS seemed odd to me.
"Plot us a least-time course to the Spindle System, if you please, Ms. Zilwicki," Terekhov requested courteously

Also, why does she have to calculate anything? That is, why isn't the least-time course from the Lynx terminus to Spindle already on file in the ship's computer?

She's a midshipwoman. It's part of her training. See also Ms. Midshipwoman Harrington.

Weird Harold wrote:

lyonheart wrote:Honor-verse hyperspace starships don't expend fuel in hyper because they tap a tiny fraction of the hyper energy.

Quibble: Honorverse starships don't expend fuel when using Warshawski Sails in a Grav Wave. They do when traveling under Impeller Wedge drive.

Exactly. And Impeller Wedge through the rifts is was I was referring to as "cross country". (probably should have spelled that out)

And I imprecisely said they "burn way less fuel" in grav waves, when they could (and merchants apparently routinely do) shutdown their reactors and use no fuel.

(Though writing this out now I'm not sure if a warship, in wartime, would be willing to actually shut down it's reactors. Depending on reactor start-up time it might well want to keep them running at some minimum power level in case it had to evade to a band, or to n-space, where the 'wave doesn't reach)

Bill Woods wrote:Also, why does she have to calculate anything? That is, why isn't the least-time course from the Lynx terminus to Spindle already on file in the ship's computer?

Because unless you are in the exact same place as the last time you figured it out, it´s not the same.
And even if you were, some things move, which might have made the previous route irrelevant (or suicidal) or may have opened another potentially shorter route.

Probably just tiny differences mostly, but still, going slower just because you´re acting lazy?
No military would accept that.

Bill Woods wrote:

Jonathan_S wrote:Although the particular example in SoS seemed odd to me.
"Plot us a least-time course to the Spindle System, if you please, Ms. Zilwicki," Terekhov requested courteously

Also, why does she have to calculate anything? That is, why isn't the least-time course from the Lynx terminus to Spindle already on file in the ship's computer?

There is also the idea that while the Captain might (very well should) already know if there are an Grav Waves in that direction, part of the training would to be sure that the Ensign CHECKED to see what was in the star/hyper maps and allowed for there being- or not being- a Grav wave and the effects it would have on variation of getting to Spindle. If there is one, and she didn't check then that is a problem. If there isn't one you may not- from the command chair- be able to tell if she checked but the regular helmsman (or Sr. NCO watching) would have been keeping an eye on what she was doing.

Jonathan_S wrote:

lyonheart wrote:Hi SYED,

It may depend of the navigation as we saw in SoS, where Helen plots the course to Spindle, which isn't necessarily the most obvious, and the ship's limits in hyper.

...

If the Captain really wanted the least time course why would Helen search for grav waves, or especially consider dropping to a lower wave to stay in one? For pure time savings a grav wave is only useful if you come across it before you reach your top speed; which takes about a day w/o a wave. While accelerating the roughly 10x accel boost a 'wave gives you would cuts some time off your trip, but once a warship's hit 0.6c all a grav wave does is save you fuel; not time.

So a true least time course would have to avoid rogue waves but otherwise shouldn't deviate to follow other grav waves after the first few hours... Should it?

That's not precisely correct. The "speed limit" in hyper is set by the ship's particle screens. Military screens let you go up to .8C, civilian screens only let you go to .6C. The unstated assumption here is that it's in clear hyperspace, where the particles are essentially stationary with respect to the ship's direction of motion.

In grave waves, this assumption doesn't hold. Not only are there particle streams that may change the maximum speed depending on whether you're going with or against the flow, the "wind" isn't always at your back. A lot of time you have to tack back and forth to make progress, which is going to slow you down significantly.

All this is spelled out in The World of Honor Harrington. I'm not at all sure how much RFC actually uses this in the various transits we see. IOW, going through a grav wave saves you fuel at the cost of more wear and tear on the captain's and helmsman's nerves. Whether or not it's faster depends on the flows in the specific grav wave.

JohnRoth wrote:That's not precisely correct. The "speed limit" in hyper is set by the ship's particle screens. Military screens let you go up to .8C, civilian screens only let you go to .6C. The unstated assumption here is that it's in clear hyperspace, where the particles are essentially stationary with respect to the ship's direction of motion.

In grave waves, this assumption doesn't hold. Not only are there particle streams that may change the maximum speed depending on whether you're going with or against the flow, the "wind" isn't always at your back. A lot of time you have to tack back and forth to make progress, which is going to slow you down significantly.

All this is spelled out in The World of Honor Harrington. I'm not at all sure how much RFC actually uses this in the various transits we see. IOW, going through a grav wave saves you fuel at the cost of more wear and tear on the captain's and helmsman's nerves. Whether or not it's faster depends on the flows in the specific grav wave.

.6C and .8C are the particle screen limits in n-space.
In hyper, where the particle densities are higher, the corresponding limits are .5C and .6C; merchant and warship respectively. (The Universe of Honor Harrington doesn't spell that out all that clearly; it just says "The maximum safe velocity in any hyper band remained .6 c". But other books, including SVW, mention the .5 c Merchant ship limit)

But you're right that I'd forgotten about the grab factor on the sails and whether it might have any impact on transit time. We never see it come up in the books, and even 'Universe' says that by 1750 PD (roughly 150 year prior to OBS) "sail tuners had been upgraded to a point which permitted the "grab factor" of a sail to be manipulated with far more sophistication than Dr. Warshawski's original technology had permitted. Indeed, it became possible to create a negative grab factor which, in effect, permitted a starship to sail directly "into the wind," although with a marginally greater danger of sail failure."

It's unclear from that if by 1900 PD there might be any loss of acceleration or speed; in addition to that marginally higher failure rate. It's also unclear if the other limitation mentioned a few sentences before still exists; the inability to cut perpendicularly across a wave, and the loss of efficiency attempting to "reach" at more than 60°.


But, if there is a speed impact from going upstream or, if you still can't cut 'across' a wave efficiently, you would have to factor that into your planned course.




Hmm, crunching some numbers shows that at the highest bands a ship only needs to lose about 16% of it's theoretical top speed in the Theta band before it's just as well off going full speed in the Eta band. So a major "headwind", or detour, might justify dropping a band. But don't forget that you're penalized 56% of your velocity making that drop and another 52% is lost when you climb back up to the Theta band; so the original delay needs to be a lot bigger than you might think before it justifies a band drop...