War with the Solarian League?

Okay, so I'm late and catching up, but Brian McDonald
<Brian_knowspam.McDonald DeleteThis @shaw.ca> wrote on Fri, 18 May 2007 00:04:15 GMT in
alt.books.david-weber :
>On Wed, 16 May 2007 19:43:40 -0500, "deowll" <deowll DeleteThis @bellsouth.net>
>wrote:
>
>>> fire was the big killer of wooden ships not cannonballs. to sink a
>>> ship you need to hit it below the waterline and that isn't the easiest
>>> thing to do with a blackpowder cannon. damage above the waterline
>>> other than masts was readily repairable using onboard resources which
>>> isn't gonna be the case with modern warships much less starships.
>>
>>
>>You might be right about them not sinking at least on a calm day. Readily
>>repairable as in you can do the entire job yourself all the way back to full
>>operating specs is not likely if you got seriously worked over. You'd need a
>>dry dock at the least. Then a lot of the crew might not be operational
>>either.
>>
>>Patched up after a fashion is more likely unless the damage was minor.
>>
>>
>>
>>
>you read some of the rn history and it's amazing the amount of damage
>they could self repair after a battle.

Not all that surprising Considering that most sailors weren't
great swimmers, and you were still a long way from shore even if you were;
as long as the ship hasn't sunk you can make repairs ...

tschus
pyotr

--
pyotr filipivich
The two oldest cliches in the book are "The Good Old Days were
better." and "After all, these are Modern TImes."
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Okay, so I'm late and catching up, but Brian McDonald
<Brian_knowspam.McDonald.DeleteThis@shaw.ca> wrote on Thu, 17 May 2007 23:55:24 GMT in
alt.books.david-weber :
>On Wed, 16 May 2007 19:54:35 -0500, "deowll" <deowll.DeleteThis@bellsouth.net>
>wrote:
>
>
>
>
>>
>> A big semi with a full load may have trouble with acceration but drop the
>>trailer and how fast can one move?
>>
>
>>> --
>>> pyotr filipivich
>>> The two oldest cliches in the book are "The Good Old Days were
>>> better." and "After all, these are Modern TImes."
>>
>
>semi top ends are limited by the gearing in their transmissions.
>without rebuilding the whole tranny and assorted rear ends etc the top
>end isn't going to change much loaded or not. how fast you get to the
>top end would improve nicely though.
>
>we should stop using analogies based on wet ships because the physics
>is mucho different from star ships.

Yep. In space, c is a max constraint on speed. There isn't a "sea"
limit.

And we keep comparing accelerations (changes in rate) with speeds. I
can accelerate "faster" than a car, at least through the first couple feet
.... but after that, no joy.


tschus
pyotr
--
pyotr filipivich
The two oldest cliches in the book are "The Good Old Days were
better." and "After all, these are Modern TImes."
 >> Stay informed about: War with the Solarian League? 

Okay, so I'm late and catching up, but Brian McDonald
<Brian_knowspam.McDonald.DeleteThis@shaw.ca> wrote on Thu, 17 May 2007 23:59:16 GMT in
alt.books.david-weber :
>On Wed, 16 May 2007 20:01:57 -0500, "deowll" <deowll.DeleteThis@bellsouth.net>
>wrote:
>
>
>>> reasonably it's hard to see how you are going to dump enough cargo to
>>> make much of a difference in top end speed.
>>
>>Have you looked at how 2 or three times the speed would compare to a warship
>>or improvised pirate hull some of which once were merchant ships?
>>
>>Besides the pirate wants the cargo. My memory is they normally couldn't sell
>>the captured ships back into legal use. Running off chasing an empty ship
>>and abandoning the cargo is going to be a hard choice if the pirates thank
>>they can do some sort of recovery.
>>
>>
>>
>how long would it take a modern container ship to discard a
>significant part of it's cargo at sea?
>
>and even if you did manage to drop enough cargo to matter what are the
>pirates going to do with hundreds or thousands of the spacegoing
>version of TEU floating aimlessly in space?

Capture the cargo ship, and make them reload the TEUs. Then kill them
all.

pyotr

--
pyotr filipivich
The two oldest cliches in the book are "The Good Old Days were
better." and "After all, these are Modern TImes."
 >> Stay informed about: War with the Solarian League? 

Okay, so I'm late and catching up, but jdc RemoveThis @smof.fiawol.org (John Cochran)
wrote on Thu, 17 May 2007 22:00:00 GMT in alt.books.david-weber :
>In article <gafp43ten9ictumak5pfl9ijk0jb408ffg RemoveThis @4ax.com>,
>pyotr filipivich <phamp RemoveThis @mindspring.com> wrote:
>>Okay, so I'm late and catching up, but "deowll" <deowll RemoveThis @bellsouth.net>
>>wrote on Wed, 16 May 2007 19:39:02 -0500 in alt.books.david-weber :
>>>
>>>"Offbreed" <offbreed_106 RemoveThis @hotmail.com> wrote in message
>>>news:gNCdnVL2PaG_ktbbnZ2dnUVZ_hKdnZ2d@scnresearch.com...
>>>> Brian McDonald wrote:
>>>>
>>>>> make much of a difference in top end speed.
>>>>
>>>> Ahhh, what you'd be wanting in space is "acceleration".
>>>>
>>>> <G>
>>>
>>>Un I'd say true but do these ships have top speed limits? They may under
>>>sail.
>>
>> As I understand it, yes and no. There is no top speed limit (aside
>>from the speed of light), but practical matters like radiation shielding
>>put a defacto top speed on stuff. I seem to recall that the military
>>limits itself to .80 c at the top end, but they have "tons" of radiation
>>shielding. Merchants, again, having other priorities, have lesser
>>shielding, and hence, lesser allowable top end speeds.
>>
>>Hmmm, I need to get my handy calculator out, and see what sort of "speed"
>>limits we are talking about. I.e. how fast can a ship accelerating at 200
>>g reach .80 c, and what about relativistic effects there?
>>
>>tschus
>>pyotr
>
>The relativistic effects aren't too bad at .8 c, I get a tau of only .6.
>So ignoring relativistic effects on time (at most I'll be off by a factor of 1.7),
>I get about 34 hours at 200g to reach 0.80c.

Same here. I suspect the radiation shielding problem is a bit of
techno babble to avoid having to deal with Einstein at the higher ends.

pyotr


--
pyotr filipivich
The two oldest cliches in the book are "The Good Old Days were
better." and "After all, these are Modern TImes."
 >> Stay informed about: War with the Solarian League? 

On 18 May 2007 20:05:01 -0700, "rlbell.nsuid@gmail.com"
<rlbell.nsuid DeleteThis @gmail.com> wrote:

>I always assumed that it was not particles of radiation that were
>being shielded from, but particles of matter. Micrometerorites are
>nasty enough for the space shuttle. Hit one at 0.8c and you are in
>serious trouble, especially if 0.8c happens to exceed lightspeed in
>your hull material-- lots of cerenkov radiation from
>brehmstrellung(sp?) effects. For an example, the speed of light in a
>diamond is only 0.62c, for photons in the visible spectrum.

Yeah, this is the only thing that makes sense.
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On 18 May 2007 19:55:28 -0700, "rlbell.nsuid@gmail.com"
<rlbell.nsuid.DeleteThis@gmail.com> wrote:

>One of the things in Honorverse that has always bugged me is what the
>acceleration compensators actually do. The only thing that would make
>a compensator failure dire and still allow Honor to jigger an unmanned
>freighter to ram a warship in "With One Stone", is that the operation
>of a compensator is not limited by the ship's mass, but by its volume
>and shape. The compensator does not make sure the contents of the
>ship accelerate with the vessel, as this would imply that the vessels
>are capable of handling great stress. The sad fact is that there is
>only one component of even the most powerful and resilient warship
>that can handle an uncompensated acceleration of even a mere (by
>Honorverse standards) 50g, and have some possibility of continued
>function-- the crew (50g accelerations are found in car accidents
>where seat-belted occupants walk out).

Yes, he's blown it badly here. There's no question he considers the
ships that strong--remember the long-ago assassination by compensator
failure? The ship was recovered intact, the passengers had been
squeezed to goo.

>The only problem with this hypothesis is that it cannot explain the
>operation of the compensators when Honor ambushed the Peep task force
>off Hades. However, the absolute ludicrousness of accelerating a half
>million ton warship at 150g's with a reaction drive makes me suspect
>that the number was a brain fart. Especially when the reaction drives
>in question are attitude jets and docking thrusters.

He needed that acceleration to make the intercept so that's what he
used. Apparently he didn't consider whether it was reasonable or not.
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On Sat, 19 May 2007 01:29:09 -0400, Don Sample <dsample.TakeThisOut@synapse.net>
wrote:

>In article <1179543901.455028.219940.TakeThisOut@o5g2000hsb.googlegroups.com>,
> "rlbell.nsuid@gmail.com" <rlbell.nsuid.TakeThisOut@gmail.com> wrote:
>
>> I always assumed that it was not particles of radiation that were
>> being shielded from, but particles of matter. Micrometerorites are
>> nasty enough for the space shuttle. Hit one at 0.8c and you are in
>> serious trouble, especially if 0.8c happens to exceed lightspeed in
>> your hull material-- lots of cerenkov radiation from
>> brehmstrellung(sp?) effects. For an example, the speed of light in a
>> diamond is only 0.62c, for photons in the visible spectrum.
>
>Even individual atoms or molecules are a problem at those speeds. An
>alpha particle is just a helium nucleus, after all.

But cosmic rays hit at velocities *FAR* in excess of this even if
you're standing still. Whether you're doing 0 or .8c isn't going to
make a lot of difference.

Against micrometeorites, however, it's another story. My take on it:

We have radiation shields but no combat shields other than the
wedge/sidewall and they work on a different basis.

Why aren't radiation shields useful in combat? And why do they max
out at .8c?

The only thing that makes sense to me is that they are subject to
local overloading when something like a speck of dust at .8c hits
them.
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rlbell.nsuid RemoveThis @gmail.com wrote

> One of the things in Honorverse that has always bugged me is what the
> acceleration compensators actually do. The only thing that would
make
> a compensator failure dire and still allow Honor to jigger an
unmanned
> freighter to ram a warship in "With One Stone", is that the operation
> of a compensator is not limited by the ship's mass, but by its volume
> and shape. The compensator does not make sure the contents of the
> ship accelerate with the vessel, as this would imply that the vessels
> are capable of handling great stress. The sad fact is that there is
> only one component of even the most powerful and resilient warship
> that can handle an uncompensated acceleration of even a mere (by
> Honorverse standards) 50g, and have some possibility of continued
> function-- the crew (50g accelerations are found in car accidents
> where seat-belted occupants walk out).

You are saying that a star freighter or even a warship cannot be
designed and built to withstand even 50g. This would imply that 900g
missiles are totally impossible too.

Without more this is just assertion on your part. In another forum I
and others were obliged to point out that as early as 1944 vacuum tube
radar sets were designed and mass produced that could be fired out of
AA guns ("proximity fuses"). It is left as an exercise to the reader to
calculate the acceleration assuming a mach 2 shell from a ten foot gun
barrel.

--
Mike D
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On Sat, 19 May 2007 16:01:47 -0400, Don Sample <dsample.TakeThisOut@synapse.net>
wrote:

>In article <464f1738$0$3063$c3e8da3@news.astraweb.com>,
> Loren Pechtel <lorenpechtel.TakeThisOut@hotmail.invalid.com> wrote:
>
>> On 18 May 2007 19:55:28 -0700, "rlbell.nsuid@gmail.com"
>> <rlbell.nsuid.TakeThisOut@gmail.com> wrote:
>
>> >The only problem with this hypothesis is that it cannot explain the
>> >operation of the compensators when Honor ambushed the Peep task force
>> >off Hades. However, the absolute ludicrousness of accelerating a half
>> >million ton warship at 150g's with a reaction drive makes me suspect
>> >that the number was a brain fart. Especially when the reaction drives
>> >in question are attitude jets and docking thrusters.
>>
>> He needed that acceleration to make the intercept so that's what he
>> used. Apparently he didn't consider whether it was reasonable or not.
>
>He could have just moved their start point. Honor knew the vector that
>any peep ships would likely be coming in on. She could have
>pre-positioned her ships so that they were already in place to ambush
>anyone coming in on that path.

No, that would mean leaving them in deep space rather than at the
planet.
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On 20 May 2007 14:04:47 -0700, "rlbell.nsuid@gmail.com"
<rlbell.nsuid RemoveThis @gmail.com> wrote:

>None of the 'delicate' components in a proximity fuse weigh more than
>a pound, so the 2000g acceleration out of the barrel only subjects
>them to a ton of force. While that is a lot of weight to place on
>your foot, or chest, it is not outside the bounds to build a vacuum
>tube that can take it. A half-million ton warship dragged by its
>impeller rings at 500g's will have stresses of two hundred and fifty
>million tons to deal with. The warship does not have a proportionally
>equivalent cross-section to divide the load to the same pounds per
>square inch of the artillery shell fuse, so it is much more stressed
>at only a quarter of the acceleration.

It's the same square-cube law that restricts big creatures.

>If the compensators work, at all, the hull of a starship never
>experiences the inertial stresses from its acceleration, so there is
>no reason for it to be able to handle more than the attitude jets and
>docking thrusters can deal out (which is probably less than twenty g's
>and no good reason for it to be more than one). If a warship's hull
>handles more inertial stresses than a merchant, it is only as a happy
>accident of making the vessel tough enough to endure weapon strikes.

Agreed.

>If the hull actually experienced the inertial forces of its
>acceleration, how could the freighter in "With One Stone" accelerate
>to ram the peep BC at over ten times its rated acceleration?

Except he goofed--in that case the hull *IS* taking the g's!
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On Mon, 21 May 2007 14:10:29 -0700, an orbiting mind-control laser
made Loren Pechtel <lorenpechtel DeleteThis @hotmail.invalid.com> write:

>>If the hull actually experienced the inertial forces of its
>>acceleration, how could the freighter in "With One Stone" accelerate
>>to ram the peep BC at over ten times its rated acceleration?
>
>Except he goofed--in that case the hull *IS* taking the g's!

I'm pretty sure that the hulls *are* taking the loads.

These ships are pretty tough, he just doesn't see the need to
highlight the structural detail.

-JPB
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rlbell.nsuid.TakeThisOut@gmail.com wrote

> > You are saying that a star freighter or even a warship cannot be
> > designed and built to withstand even 50g. This would imply that
900g
> > missiles are totally impossible too.
> >
> > Without more this is just assertion on your part. In another forum
I
> > and others were obliged to point out that as early as 1944 vacuum
tube
> > radar sets were designed and mass produced that could be fired out
of
> > AA guns ("proximity fuses"). It is left as an exercise to the
reader to
> > calculate the acceleration assuming a mach 2 shell from a ten foot
gun
> > barrel.

> None of the 'delicate' components in a proximity fuse weigh more than
> a pound, so the 2000g acceleration out of the barrel only subjects
> them to a ton of force. While that is a lot of weight to place on
> your foot, or chest, it is not outside the bounds to build a vacuum
> tube that can take it. A half-million ton warship dragged by its
> impeller rings at 500g's will have stresses of two hundred and fifty
> million tons to deal with. The warship does not have a
proportionally
> equivalent cross-section to divide the load to the same pounds per
> square inch of the artillery shell fuse, so it is much more stressed
> at only a quarter of the acceleration.
>
> If the compensators work, at all, the hull of a starship never
> experiences the inertial stresses from its acceleration, so there is
[...]

The units of stress are not tons.

OK I am not DW and don't know how compensators do it, so let just look
at missiles since these don't use compensators.

Try a back of the envelope calculation, assume the thrust from the
impellor ring is mechanically transmitted to the rest of the missile,
and estimate the maximum acceleration.


--
Mike D
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rlbell.nsuid DeleteThis @gmail.com wrote
> On May 22, 6:47 am, "Michael R N Dolbear" wrote:

> > OK I am not DW and don't know how compensators do it, so let just
look
> > at missiles since these don't use compensators.
> >
> > Try a back of the envelope calculation, assume the thrust from the
> > impellor ring is mechanically transmitted to the rest of the
missile,
> > and estimate the maximum acceleration.

> My bad for using non-SI units. A ton is a measure of force. It is
> the force needed to accelerate a mass of two thousand slugs (slug the
> unit, not slug the gastropod) at a rate of one foot per second
> squared. It is equivalent to the force needed to hold up 907kg's
> against gravity at the Earth's surface. While a metric tonne and a
> mass that weighs one ton are not interchangeable, they are close
> enough for government work.
>
> For simplicity, we will make the known wrong assumption that the
> impeller ring is at the end of the missile. MDM's are up to 300
> tonnes in mass and accelerate at upwards of 75,000 g's. The force is
> 22,500,000,000 * 9.8 N. This is close enough to 225 GN to just call
> it that. The impeller ring must be strong enough to support a mass
> that weighs as much as 22.5 megatonnes on Earth's surface, and it
must
> be small enough to fit in a missile tube, and it must be included in
> the 300 tonne mass of the missile.
>
> Actually, things get easier if the ring takes up much of the mass, as
> the load on the ring decreases. A more important question is if the
> impeller does not grab the whole ship, what part does it grab. If it
> just grabs thest impeller nodes, than each of the eight nodes (or is
> it sixteen) must share the 225GN of force, which will be a shear!
> Shears are a niussance, as most physics classes do not bother with
> them, and I did not take any courses in civil or mechanical
> engineering.
>
> It is much simpler to assume that the impeller grabs the whole object
> and the compensators deal with the problem with the gravitic field
not
> being uniform at all points in the ship. Missiles can undergo
> rediculous accelerations for the simple reason that they are very
> small, so little compensation is needed. The compensator limit has
> less to do with mass than with enclosed volume and geometry

Please estimate the maximum acceleration. Ignore shear if you wish.

Hint, on your approach the calculation for the strength required for an
orbital elevator/beanstalk are similar.

--
Mike D
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