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Re: SLN Reserve | |
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by kzt » Mon Apr 17, 2017 1:26 am | |
kzt
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They don't have to pay a premium, the fact that you get at least twice as many deliveries is where you make your money. The construction loan amortization is where the big costs are. You have a multi billion credit ship that you have to make payments on every month. And they are not small payments. Crew cost is a minor sum compared.
For example, a 3 billion ship on a 50 year 7% note means you have an 18 million per month payment before operating expenses. So your crew cost change from 60 crew to 90 crew goes from 500K to 750K month if you are paying them all 100K/year. If you can get twice as many runs I suspect it will work out. |
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Re: SLN Reserve | |
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by Jonathan_S » Mon Apr 17, 2017 9:43 am | |
Jonathan_S
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I rechecked - I did make a mistake on the first one; for some reason I typoed and calculated the acceleration time to 0.4 c not 0.5 c. As for the rest, as I suspected from your footnote you were calculating these with relativistic effects thrown in. But for whatever reason David doesn't have Honorverse wedges work that way - the ships and missiles manage to reach velocities and distances as if relativistic effects didn't slow their acceleration. (probably because it made the author's math easier - but I haven't seen an in-universe explanation or acknowledgement) One obvious example would be when Honor first describes MDMs and she gives almost relevant parameters for a 1/2 power shot (omitting only the well known (3 * 180 s) 540 second 1/2 power endurance that we see many times later): 46000 g 540 seconds 65,000,000 km range 0.81 c terminal velocity But those only correlate in Newtonian calculations. If you allow for relativistic effects it would take: 918 seconds [earth time] at 46,000 g to reach 0.81 c and it would have traveled 140,506,355 km. Or if it traveled 65,000,000 km at 46,000 g it would take 578 seconds [earth time] and reach only 0.6569 So I did my ship calculations as straight Newtonian physics; as RFC seems to do in the books. |
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Re: SLN Reserve | |
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by Theemile » Mon Apr 17, 2017 10:00 am | |
Theemile
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The difficulty would probably be if going mil-spec meant you went from 60 to 600 personnel to deal with the added maintenance, and required 10's of millions of credits in spare parts each year. OR - if mil spec meant more time in a shipyard getting major service, regularly, that would decrease the profits. Currently, it feels like Freighters need a serious overhaul every 2-3 decades. If you suddenly had to pay 100 million every 5 years to replace the ships's nodes (and have it in the shop for a month to do so), that would severely change the economics of the ship's viability. Obviously, if those added costs (the ammotorized cost of the construction upgrade, the increased personnel costs, and the upgraded maintenance parts costs, increased downtime) are more than what you could get with your extra capability, you would have to charge a surcharge for expedited services. This might not be viable for general bulk freighters, where ore or the like is being shipped in a steady stream of goods on multiple ships, but there should be a class of shipping where perishable goods, or time sensitive cargos, can warrant a surcharge to make such shipping viable - and profitable. I'm in the US Rustbelt, and a decade ago, one of the local shippers sent a 747 of freshly slaughtered pork products (non-frozen) to Hong Kong every night around midnight. There was such a demand for fresh pork there that it was not just economical, but profitable, to fly fresh pork 12+ hours around the world to sate the desire. They no longer do that, the economics changed and the company moved on to other business, but there are many other expedited cargos today. So, while not universally necessary for the Honorverse, I cannot imagine that in the industrialized heartland of the SL, there is not a demand, somewhere, for an expedited service for cargos too large to fit in a DB. ******
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." |
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Re: SLN Reserve | |
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by Somtaaw » Mon Apr 17, 2017 10:26 am | |
Somtaaw
Posts: 1203
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Found the quotes I was remembering regarding fast freighters.
And also here
Passenger liners and perishable/gourmet food freighters are considerably faster than generic freighters. Two months down to only three weeks, looks to my untrained (& no spreadsheet) eye as being damn near military acceleration curves. At the very minimum a military hyper drive, and possibly the rad shielding to go with it. And Mobius to Montana is the same distance as Montana to Mesa. 3 weeks travel, and from Mesa to Visigoth via wormhole being instantaneously and Beowulf only another 4 days or so (for a military hyper), or the more direct route of Montana through Lynx which is quicker and efficient. But I also don't believe all passenger liners are essentially Atlas liners, even if you ignore that fact the Atlas were built & armed specifically for Silesian runs. You'd still have at least two grades of "passenger liner", similar in nature to the old 747 versus Concord passenger liners. An ultra class passenger liner with the enhanced performance, because even the Atlas liners charged a 'premium' for the luxury of being fast, and pretty much guaranteed to arrive anywhere in Silesia. |
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Re: SLN Reserve | |
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by Jonathan_S » Mon Apr 17, 2017 1:07 pm | |
Jonathan_S
Posts: 8792
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Rounded down to the hour 190 ly for a ship in the Delta bands at 0.5c is 63 days, 17 hours 190 ly for a ship in the Theta bands at 0.5c is 27 days, 18 hours 190 ly for a ship in the Theta bands at 0.6c is 23 days, 3 hours (once they're at speed - all of those ignore the 10-20 hours it takes to work up to full speed) So the ships serving the passenger perishable goods trades seem to have both mil-grade hyper generators and mil-grade rad shielding. But I'd still bet against most of them having mil-grade impellers and compensators - the hyper generator cuts your transit time by 67%, the rad shielding another 17%, but the drive saves you maybe half a day or less no mater how long your travel leg is -- you just hit top speed too soon in the journey for acceleration to matter much. (Even at the 100 gees you can do with just normal grav plates it only takes about 2 days to hit 0.6c - so even instantaneous acceleration could only save you 2 days over the slowest ships in the Honorverse) |
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Re: SLN Reserve | |
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by Jonathan_S » Mon Apr 17, 2017 1:13 pm | |
Jonathan_S
Posts: 8792
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I guess the one possible exception would be the n-space run from a wormhole in to that system's planet (assuming you don't just dump your cargo at a warehouse by the terminus to let other ships do the in-system run). A 7 lighthour n-space run takes a while and lets you build up a good head of steam. I should crunch the numbers and see how much time a military drive on a 4 m-ton ship would save you... Okay, had a chance to crunch some numbers. Assuming negligible start speed and a 7 light hour n-space run at ship capable of: 210 gees will take 33.7 hours and hit peak speed of 0.416 c 360 gees will take 25.7 hours and hit peak speed of 0.545 c So even a round trip from the Junction to Manticore a 4 mton ship with mil-grade drive will only save 16 hours -- equivalent to the time savings from mil-grade rad shielding over each 51.8 trillion km of ship distance covered. (96 hours at 0.5c, 80 hours at 0.6c) So in, say, the Delta bands that's equivalent to an n-space journey of 11.9 light years. (27.3 light years if you're in the Theta bands) And since most trips involve n-space distances a tiny fraction of that, the time savings from improved acceleration don't seem worth much cost... |
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Re: SLN Reserve | |
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by Somtaaw » Tue Apr 18, 2017 8:06 am | |
Somtaaw
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I don't know what we'd do without Jonathon doing the math for us |
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Re: SLN Reserve | |
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by Bill Woods » Tue Apr 18, 2017 12:40 pm | |
Bill Woods
Posts: 571
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I have to go with the unreliable narrator hypothesis. Otherwise.... If a ship is moving at 0.6c (relative to something) and fires a Mk23, how fast will the missile be going at the end of its powered flight? And if its target is approaching at 0.6c, how fast will the missile be going relative to that? (If only Weber had thought to ask you or me to preview his books, and check the numbers.) ----
Imagined conversation: Admiral [noting yet another Manty tech surprise]: XO, what's the budget for the ONI? Vice Admiral: I don't recall exactly, sir. Several billion quatloos. Admiral: ... What do you suppose they did with all that money? |
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Re: SLN Reserve | |
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by Jonathan_S » Tue Apr 18, 2017 2:18 pm | |
Jonathan_S
Posts: 8792
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Haha - crunching the numbers is easy compared to writing the stories. Mostly he's helped by the fact that his hyper limits are so small that ship combat rarely involves significant fractions of c - so he can add, or remove, some range due to relative ship velocities without having to worry overmuch about accidental bumping into the speed of light Though I'm still waiting to see what he says about the top speed of the 4-drive system defense MDMs. If you apply Newtonian accelerations to those you end up with a terminal velocity, from rest, in excess of c. (540 seconds at 46,000 gees + 90 seconds at 130,000 gees = 1.194c Oops). My bet is that he'll declare missiles have a top speed, no mater what, of 0.99c. That would seem to agree with the statement in FiE "and if the Peeps launched at .8 c, their birds' drives would boost them to .99 c before burnout" and would let him continue to basically ignore relativistic effects on acceleration. (I just thought to run that scenario through my spreadsheet and Newtonian calculations also show that in excess of the speed of light -- if there were absolutely no relativistic effect the Peep ships would only need to launch from 0.719c to achieve burnout at 0.99c) Still given the choice between perfect relativistic math and a gripping yarn... I'm quite happy with the books as they are. |
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Re: SLN Reserve | |
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by noblehunter » Tue Apr 18, 2017 2:26 pm | |
noblehunter
Posts: 385
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Weber only makes it look easy. Then you read bad mil-SF and see just how awful info-dumps with plot interruptions can be. I just covert the numbers into qualitative values anyway. So there's normal, faster than normal, WTH is happening fast, and repeated swearing interrupted by physics. The Solly point of view usually sticks with the last option. |
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