LAC not so useful after all?

The E wrote:You are assuming that Honorverse fusion plants are 100% effective at converting the energy of the fusion reaction into usable energy.

You are also assuming that the Honorverse plays by the same rules as our universe.

Well no, I'm assuming BOTH are 100% effective. If you can only get 50% then 400 kg of fuel = TWO shrikes worth of 100% pure Pu239. Which is, incidentally, far more then critical mass.

As your second line amounts to "It's magic!", I just laugh and agree. That was exactly the argument that I was supporting.

kzt wrote:

Vince wrote:
Second, it isn't just the reactor mass of each system that has to be accounted for, it is also both the mass and the volume of each system and its supporting equipment when deciding which is system is preferable for a specific ship's requirements.

Lets look at this:

A kg of Pu239 produces 83.61 * 10^9 Joules.

A kg of Hydrogen concerted into Helium produces 6.4 x 10^14 Joules (With even more if you continue the process to iron).

So fusion yields (at least) roughly 100,000 times more energy than fission by fuel mass. Hence the energy produced by fusing 200kg of hydrogen to helium is roughly equivalent to the energy that could be produced by fission of a mass of Pu239 equal to an ENTIRE SHRIKE.

So, keeping that in mind, can you explain how this works?

How much space (volume) does the hydrogen take up? How are you storing it? How much mass and volume does the equipment to store it take up? How much power does it take to run the equipment to store the hydrogen?

More importantly, what is the minimum size (mass and volume) you can build a GRAVMAK reactor? (We know there is a minimum size limit.) And how much power produced by the GRAVMAK is used to sustain the fusion reaction and keep it contained?

For a size comparison of how small you can make a fission reactor, I remember reading about a real world (breeder, IIRC) fission reactor in Britain some decades ago that was the size of a coffee can.

Its a system problem. Different systems for different requirements.

I need to go to bed now, so I won't quote the text, but when the new LACs were introduced the claim was that old lacs had such a short range due to "bunkerage". Since 200 kilos of hydrogen (which - if you store as liquid hydrogen for some crazy reason - takes up 3 cubic meters, under a cubic meter if you store it as water iirc) has the same energy in fission as the entire mass of a shrike I find this claim absurd. And when calculating how dense you can store fissionsables, do keep in mind that if you exceed critical mass your shrike will expand omnidirectionaly at about 10,000 km/sec. So don't pack it in too tight.

Fusion/Fission Its one of those things you and then go back to reading the books. Kinda like his "control links".

I was reading SftS and I came across this "brilliant" ROFL moment:

Just as Michelle Henke can postulate her force at New Tuscany with 680 missile tube launchers able to fire off 26,000 missiles or 38 rounds of ammo before coming into the engagement range of Byng. 6BCL(50) + 8SAGC(40) + 5Rolland(12) Of course her Rolands only had 20 rounds, and her SAG-C only has 30 rounds of ammo leaving Ms Henke 18 rounds and 8 rounds per tube short on the DD and CA... On top of this foo-pah, if you do the simple math, the smallest number or control links each ship type would have under Michelle Henke's ruminations are:

Total Salvos controlled:
18s cycle time
6 minute duration(2*180)
6*60/18 = 20. Call it 19, but whatever, who is counting among friends...

Control links according to Admiral Ms. Henke in SftS. Not the inner city bully junior high drop out idiot.

BCL: 50*20 = 1000
SAG-C 40*20 = 800 even though we are told in the next book they only have 128 even though Ms Henke was more than willing to shoot at exactly 18s cycles till her ammo supply was more than gone in the previous book.
ROLAND 12*20 = 240 even though we are told in a pearl they only have 36.

Or another way of putting it: 19 ships, fire 680missiles/salvo * 20 Salvos = 715 control links on average per ship.

Or, lets try and "solve" this problem using known control links for SAGC and ROLLAND:

36*5 + 128*8 + 6BCL*x = 680*20
180 + 1024 + 6BCL*X = 13,600
X = 2066/BCL

So, um, yea. Maybe the BCL with its small keyholes has 2000+ control links. Makes "normal" keyhole 1 with around 4-5000 I suppose since BCL has "light" keyholes. Or, roughly what AoV was stating for a Harrington-A.

Of course if AoV and Ms. Henke in SftS are not fibbing; then it gets back to another roll your eyes moment in AAC.

BoMa1

Home Fleet engagement RMN fire off 158,000 missiles
42SDP ~400 control links average, even though 7X this number(7 salvos stated as their maximum), so clearly they have more than 400. Why RFC bothers to state they had average of 400 I do not know. But, still only 400(7) on average for a tad over 2000, or no more than what Ms. Henke under the best scenario was going to fling around with her BCL and small keyholes. Only a few SDP ships were not Harrington-A/Invictus class ships. In AoV RMN SDP Harrington A were controlling 5000 missiles a piece. Per AoV, the Harringtons/Invicuts's alone should have been able to fire more missiles than the 158,000 without even adding the standard SD's and small fry.

Which brings up other roll your eyes moments that you just have to accept and move on.

Um, why were the 12 BCP in Home Fleet not firing along with the other cruisers, light cruisers, and LAC's??? Did they magically lose their tractors? Did the pods magically lose their tractors too? Oh wait, even Terekov was smart enough to tractor pods on his ships before going into battle using "old school" tactics in SoSag. A battle every commander in the alliance fleet had just got done reading the precis on as it was the most recent in the news dispatch and being the "conscientious professional warriors" they are, they wanted to stay up to date with what is going on right? Wrong. Guess D'Orville got really stupid though he is not alone in getting stupid during BOMA.

The Home Fleet BCP probably did not have keyholes as AJAX BCP was the first to have keyhole per HoS. All of these ships could have controlled more POD's from the standard SD's with their MDM's yet they did not... We are even told LAC's can tow/fire, in this case fire, as the SD's were doing the towing, a POD or 3 and yet in the biggest baddest do or die battle of their lives they do not? Okaaay there... Had what? 3000 LAC's? Or at minimum another 30,000-100-000 missiles that could have been launched and were not? Really? This is supposed to be in the defense of your planet? Is mass suicide in vogue? Nah, we would not want to fire at minimum another 20%-60% more missiles! We are 3m tall pull missiles out of space with our bare hands, invincible Manties!!! We don't need no stinking missiles! Our eyes are phased array grasers! Bow before our gaze!

Here is an out: Probably had the light units computed, but for simplicity of telling the story did not factor this in? RFC didn't have the RHN BC/CA/CL etc hauling pods either even though we know they do and should have launched pods of MDM's as well. Biggest baddest battle in the universe and they do not come dressed? Of course he did not have Kuzak, Tourville, or Chin rolling pods in the second part of the battle even though they all knew it was going to happen. Especially when it is common procedure they have all been doing so for the past 15 years, so, uh, um. Nope, only Honor can roll pods, she is the Hero after all.

kzt wrote:

Vince wrote:
Second, it isn't just the reactor mass of each system that has to be accounted for, it is also both the mass and the volume of each system and its supporting equipment when deciding which is system is preferable for a specific ship's requirements.

Lets look at this:

A kg of Pu239 produces 83.61 * 10^9 Joules.

A kg of Hydrogen concerted into Helium produces 6.4 x 10^14 Joules (With even more if you continue the process to iron).

So fusion yields (at least) roughly 100,000 times more energy than fission by fuel mass. Hence the energy produced by fusing 200kg of hydrogen to helium is roughly equivalent to the energy that could be produced by fission of a mass of Pu239 equal to an ENTIRE SHRIKE.

So, keeping that in mind, can you explain how this works?

Lord Skimper wrote:AS STATED SOMEWHERE PEARLS I THINK MDM'S CAN BE FIRED INTO ANY FIELD OF FIRE. LERM / ERM INTO ADJACENT. PRE LERM MISSILES WOULD ONLY BE FIRED BY THE ASPECT, BROADSIDE OR CHASE. LIKE A CANNON.

Please don't use all-caps in your messages. The way you inserted your responses directly into the quoted text makes it rather hard to read.

I believe you are mistaken about the limitations on missiles. Old missiles could not turn by that much simply because they weren't designed to. They didn't bother to build them with the capability to turn into a new aspect because they were never used that way. I believe that modern single-drive Manticoran missiles can turn into any aspect.

AGILITY COMES WITH ACCELERATION. WHILE HIGH SPEEDS LIMIT AGILITY. CARS CAN BE AGILE OR FAST, AT 100+ MPH A CAR IS NOT AGILE, AT 200 EVEN LESS SO. MISSILES ARE LIKE DRAGSTERS, NOT F1 CARS. IN SPACE IT IS MORE LIKE A HOVER CRAFT. YOU CAN CHANGE THE ANGLE OF THRUST BUT YOU'RE STILL ONLY GOING TO NUDGE THE DIRECTION A LITTLE.

ALSO FOR CM THE MISSILES ARE ON THEIR FINAL ATTACK TAKING WHATEVER FINAL MANUEVER TO GET INTO FIRING ANGLE. IT IS SURPRISING CM MISS SO OFTEN.

FOR INTERCEPTIONS WHERE NO ONE EXPECTS AN INTERCEPTION WAY OUT, THE MISSILES AREJUST BUILDING SPEED. NOT USING COUNTER MEASURES AND NOT TAKING EVASIVE MEASURES WHICH WILL EFFECT THEIR FINAL DESTINATION. SCATTERING MISSILES HALF WAY TO THERE TARGET WILL CAUSE ALOT OF MISSES.

If you wish me to use a different word than agile, that's fine. You can suggest a better term.

What I meant is that the higher acceleration of a counter-missile allows it to change course to intercept it's target, even when the target suddenly changes course.

Suppose an attack missile suddenly veers to the side to avoid interception. There is a small delay before the counter-missile can respond. If the counter-missile has the same acceleration as the attack missile, it may not be able to adjust to ensure interception. If the counter-missile has a much larger acceleration than the attack missile, it has a much better chance of being able to intercept.

"Scattering missiles half-way to their target" won't change much. They still have plenty of boost to head back to the target. Dodging doesn't take them that far out of their way. At that point, they haven't even turned directly toward the target yet.

THESE OLD SD ARE NOT THAT OLD, THE OLDEST GRYPHON IS 21 YEARS OLD, THE OLDEST SHRIKE B IS 14 YEARS YOUNGER? THEY ARE NOT 2-300 YEARS OLD. 7 YEARS NEWER THAN THE STAR KNIGHTS.

I didn't mean to imply that they were ancient. I only meant that they were older than the podnaughts, and are not new designs taking advantage of the newest Manticoran technologies. Thus "old" design versus "new" design. I wasn't saying that they weren't still useful.

kzt wrote:

Vince wrote:
Second, it isn't just the reactor mass of each system that has to be accounted for, it is also both the mass and the volume of each system and its supporting equipment when deciding which is system is preferable for a specific ship's requirements.

Lets look at this:

A kg of Pu239 produces 83.61 * 10^9 Joules.

A kg of Hydrogen concerted into Helium produces 6.4 x 10^14 Joules (With even more if you continue the process to iron).

So fusion yields (at least) roughly 100,000 times more energy than fission by fuel mass. Hence the energy produced by fusing 200kg of hydrogen to helium is roughly equivalent to the energy that could be produced by fission of a mass of Pu239 equal to an ENTIRE SHRIKE.

So, keeping that in mind, can you explain how this works?

The simplest explanation seem to be that the minimum grav pinch field capable of containing any fusion requires 99.99999999...% as much energy as you generate from that fusion. And if increasing the fusion rate also ramps up the grav field's energy requirement almost as quickly; you're going to have to be pushing a lot of fuel through before you overcome those fixed and parasitic losses. (Way more than a LAC would carry, and generating way more power than it needs)


Now I've no idea why the physics would work that way (other than RFC wants them to [G] ) but that should generate an efficiency curve for the GRAVMAK plant that would make for a very fuel inefficient fusion reactor for a LAC; but have achieved decent efficiency for a CL and quite good by the time you're pumping enough power for an DN.

SWM wrote:

Lord Skimper wrote:AS STATED SOMEWHERE PEARLS I THINK MDM'S CAN BE FIRED INTO ANY FIELD OF FIRE. LERM / ERM INTO ADJACENT. PRE LERM MISSILES WOULD ONLY BE FIRED BY THE ASPECT, BROADSIDE OR CHASE. LIKE A CANNON.

Please don't use all-caps in your messages. The way you inserted your responses directly into the quoted text makes it rather hard to read.

I believe you are mistaken about the limitations on missiles. Old missiles could not turn by that much simply because they weren't designed to. They didn't bother to build them with the capability to turn into a new aspect because they were never used that way. I believe that modern single-drive Manticoran missiles can turn into any aspect.

AGILITY COMES WITH ACCELERATION. WHILE HIGH SPEEDS LIMIT AGILITY. CARS CAN BE AGILE OR FAST, AT 100+ MPH A CAR IS NOT AGILE, AT 200 EVEN LESS SO. MISSILES ARE LIKE DRAGSTERS, NOT F1 CARS. IN SPACE IT IS MORE LIKE A HOVER CRAFT. YOU CAN CHANGE THE ANGLE OF THRUST BUT YOU'RE STILL ONLY GOING TO NUDGE THE DIRECTION A LITTLE.

ALSO FOR CM THE MISSILES ARE ON THEIR FINAL ATTACK TAKING WHATEVER FINAL MANUEVER TO GET INTO FIRING ANGLE. IT IS SURPRISING CM MISS SO OFTEN.

FOR INTERCEPTIONS WHERE NO ONE EXPECTS AN INTERCEPTION WAY OUT, THE MISSILES AREJUST BUILDING SPEED. NOT USING COUNTER MEASURES AND NOT TAKING EVASIVE MEASURES WHICH WILL EFFECT THEIR FINAL DESTINATION. SCATTERING MISSILES HALF WAY TO THERE TARGET WILL CAUSE ALOT OF MISSES.

If you wish me to use a different word than agile, that's fine. You can suggest a better term.

What I meant is that the higher acceleration of a counter-missile allows it to change course to intercept it's target, even when the target suddenly changes course.

Suppose an attack missile suddenly veers to the side to avoid interception. There is a small delay before the counter-missile can respond. If the counter-missile has the same acceleration as the attack missile, it may not be able to adjust to ensure interception. If the counter-missile has a much larger acceleration than the attack missile, it has a much better chance of being able to intercept.

"Scattering missiles half-way to their target" won't change much. They still have plenty of boost to head back to the target. Dodging doesn't take them that far out of their way. At that point, they haven't even turned directly toward the target yet.

THESE OLD SD ARE NOT THAT OLD, THE OLDEST GRYPHON IS 21 YEARS OLD, THE OLDEST SHRIKE B IS 14 YEARS YOUNGER? THEY ARE NOT 2-300 YEARS OLD. 7 YEARS NEWER THAN THE STAR KNIGHTS.

I didn't mean to imply that they were ancient. I only meant that they were older than the podnaughts, and are not new designs taking advantage of the newest Manticoran technologies. Thus "old" design versus "new" design. I wasn't saying that they weren't still useful.

limited choices with tablet, hey Ijust found the bold option above does this make it either to read?

Lord Skimper wrote:limited choices with tablet, hey Ijust found the bold option above does this make it either to read?

Yes, it is easier, thank you. But you shouldn't have to emphasize your entire text if you make proper use of the \[quote\] and \[/quote\] markers.

Remember the missiles don't dodge or change direction. They are flying for several seconds or minutes at high 70,000+ g accelerations. If they could stop and go left they would have other problems these are not one missile but swarms of thousands of them. If some change direction they will crash into others. They will also need to shift 90 degrees to have any change on their direction. The missile will shift a little but not much. If it is moving for 100 seconds forward then moves for 3 seconds at 90 degrees it will still at best only move 3% of the direct axis. Still moving forward at the built up speed. It would then need to shift 180 degrees. Pretty good for a missile that can't turn, then accelerate back for 6 seconds plus how every far off axis it moved while turning the 90 degrees and 180 degrees and then again shift 180 degrees and another 6+ seconds and then get back into the swarm and get back on track. The missiles will be 20-30 seconds behind any missiles that didn't dodge. And accelerating as if they went into a ballistic phase add in they will need to switch drives or further go off course and any missile that doesn't dodge will risk crashing into the one that does. It is more likely that they will just not dodge and hope for the best. The missile swarm needs to move like a school of fish. Otherwise they will collide. Strange that these missiles have AI that is dumber than a small fish. One would think that an Apollo missile could guide all the schools of missiles to there targets in large 1000's of numbers not just 8.

SWM wrote:

Lord Skimper wrote:limited choices with tablet, hey Ijust found the bold option above does this make it either to read?

Yes, it is easier, thank you. But you shouldn't have to emphasize your entire text if you make proper use of the \[quote\] and \[/quote\] markers.

Hard to do on a touch screen. Easy to do with a mouse.