Alternate history: PRH-Solarian War

kzt wrote:

Jonathan_S wrote:It'd take time to build up the attack runs, then flush a large fraction of your magazines. You'd have to break off, slow down, rendezvous with ammo ship to resupply. But by staying outside of powered missile ranges the significantly more nimble SDs can pick away at the forts with impunity. (To prevent that Home Fleet would need to come out and engage the attacking fleet. But in this scenario with Manticore defeated would Haven have left a large enough fleet to be able to tangle with the SLN outside of support range of the forts?)

It would take a very long time, and an absurd amount of missiles. The forts can maneuver at something like 30g, so given that this takes about a week per pass and the forts know your vector at launch, they will just move a few million KM. And form up so that the only shot the missiles have if they somehow get into range is a few milliseconds on the flanks of a few forts. I suspect the forts will run out of food or develop major maint issues before you’d get more than one or two.

If the SDs are firing SDMs from outside the range of the forts' SDMs, then their own SDMs are also out of range -- or nearly so, because missile performance is likely to be different. We don't know how good SLN missiles are in 1913 compared to PN and captured RMN tech.

Compared to missile acceleration, SD or fort acceleration is a rounding error. We can approximate by saying that the missile finishes the powered run exactly on target to intersect with the ship it's targetting. To avoid being targeted, the ship needs to be far enough away that its acceleration would place it far enough from where the missile expected it to be. If an SLN SD can pull 400 G to evade and the fort can pull 50 G, then the fort can evade by 1/8 as much as the SD can. For example, if the SD is far enough that it could move 50,000 km, then the fort can move 6250 km.

The attackers can also jump to hyper, but the forts can't. So if they're positioned at 5 minutes of missile flight time (3 powered, 2 ballistic) and it takes 10 minutes to cycle the hypergenerators and hyper out, the SDs can fire for 10 minutes and all those launches will arrive, but only the first 5 minutes of forts' missiles will be a threat.

Advantage attackers.

On the other hand, the forts can probably fire more missiles over the same time period. Both forces may come with pre-deployed pods (this assumes that the SLN has learned how to do that), but since the forts don't have to tow them, they probably have more pods pre-deployed. However, since neither are pod-layers, after deployed pods are exhausted, everything is coming from internal tubes. Each fort has probably as many tubes as 4 SDs and they can fire twice as quickly (at least) than SLN SDs, plus they're firing either PN or RMN missiles. That means Each fort is equivalent to at least 10 SLN SDs.

So if there are 120 forts, the SLN would need to bring some 500 SDs to the party.

And this is assuming that ballistic missiles are effective at all. They drop gravitic sensors as there's no wedge any more, but they only have minimal manoeuvring jets left to reposition. At their terminal velocity, they spend 2.4 seconds in the normal range of CMs. I'd argue that CMs and PDLCs can engage from much further out, as those ballistic missiles can't dodge very well.

Plus, 2 minutes beyond the range means an extra 9.75 million km on top of the 7.3 of the powered range. How effective is the SLN targetting at 17 million km? PN targetting, helped by captured Ghost Rider tech, would be far better.

ThinksMarkedly wrote:If the SDs are firing SDMs from outside the range of the forts' SDMs, then their own SDMs are also out of range -- or nearly so, because missile performance is likely to be different. We don't know how good SLN missiles are in 1913 compared to PN and captured RMN tech.

Compared to missile acceleration, SD or fort acceleration is a rounding error. We can approximate by saying that the missile finishes the powered run exactly on target to intersect with the ship it's targetting. To avoid being targeted, the ship needs to be far enough away that its acceleration would place it far enough from where the missile expected it to be. If an SLN SD can pull 400 G to evade and the fort can pull 50 G, then the fort can evade by 1/8 as much as the SD can. For example, if the SD is far enough that it could move 50,000 km, then the fort can move 6250 km.

The attackers can also jump to hyper, but the forts can't. So if they're positioned at 5 minutes of missile flight time (3 powered, 2 ballistic) and it takes 10 minutes to cycle the hypergenerators and hyper out, the SDs can fire for 10 minutes and all those launches will arrive, but only the first 5 minutes of forts' missiles will be a threat.

Advantage attackers.

On the other hand, the forts can probably fire more missiles over the same time period. Both forces may come with pre-deployed pods (this assumes that the SLN has learned how to do that), but since the forts don't have to tow them, they probably have more pods pre-deployed. However, since neither are pod-layers, after deployed pods are exhausted, everything is coming from internal tubes. Each fort has probably as many tubes as 4 SDs and they can fire twice as quickly (at least) than SLN SDs, plus they're firing either PN or RMN missiles. That means Each fort is equivalent to at least 10 SLN SDs.

So if there are 120 forts, the SLN would need to bring some 500 SDs to the party.

And this is assuming that ballistic missiles are effective at all. They drop gravitic sensors as there's no wedge any more, but they only have minimal manoeuvring jets left to reposition. At their terminal velocity, they spend 2.4 seconds in the normal range of CMs. I'd argue that CMs and PDLCs can engage from much further out, as those ballistic missiles can't dodge very well.

Plus, 2 minutes beyond the range means an extra 9.75 million km on top of the 7.3 of the powered range. How effective is the SLN targetting at 17 million km? PN targetting, helped by captured Ghost Rider tech, would be far better.

So what is going on here? The SDs are running in to maximize their velocity with high speed missiles that can't be tracked or are they trying to remain just out of powered range at low velocity?

These are very different cases.

In case 1, you simply can't hit. The forts will simply move. If needed they can just continually move in a coordinated but random fashion.

In case 2, you get your ass shot off. Because if your SDs can keep the forts in your targeting basket you can be targeted by the forts. And given the garbage-scow like maneuvering capability of SDs, it's very hard to keep fort missiles from entering effective attitudes, as the front of the wedge is very, very large.

This ignores the ability of the forts to basically interlock their wedges if the threat is on one defined axis.

kzt wrote:[So what is going on here? The SDs are running in to maximize their velocity with high speed missiles that can't be tracked or are they trying to remain just out of powered range at low velocity?

These are very different cases.

I was going for case 2.

In case 1, you simply can't hit. The forts will simply move. If needed they can just continually move in a coordinated but random fashion.

In case 2, you get your ass shot off. Because if your SDs can keep the forts in your targeting basket you can be targeted by the forts. And given the garbage-scow like maneuvering capability of SDs, it's very hard to keep fort missiles from entering effective attitudes, as the front of the wedge is very, very large.

The idea would be to remain outside of range, but then both are outside of each other's range.

This ignores the ability of the forts to basically interlock their wedges if the threat is on one defined axis.

Wait, what? Can you describe this a little more?

Anyway, the high speed attack gave me an idea.

Translate far enough out and accelerate to 0.3c. At this base velocity, the powered range of thee attackers' missiles is not 7.3 million km but nearly 26 million km, while the defender's remain at 7.3. So start your hypergenerators so you translate at 7.5 million km out from the forts and fire at any point in the last 3 minutes. Even if you can fire only 3 salvos, those 3 salvos will be in powered range when they hit. They won't have guidance from the motherships for the last 69.1 seconds, but they will still have better luck than the defenders' missiles.

The defenders' missiles won't hit at all.

Cycle the hypergenerators again, deploy more pods and translate down, coming from another direction.

Here's where this may fail: in order to reach 0.3c from a standing start, it takes an SD force accelerating at 320 gravities nearly 8 hours and 1.3 billion km (72 light-minutes). If the forts' gravitic range is even 30 light-minutes, that means they have 90 minutes to prepare from the moment the enemy attack run is detected. And that might mean calling up a force to pods along the trajectory and lie in stealth. When the SD force is in point blank range, they fire a hundred thousand missiles and hyper out. Tables turned: now the SD force can't hyper away fast enough to avoid the missiles, but the ambush force can avoid the return fire.

Plus the ambush force knew exactly where the attacking SDs were, so they could set up very accurate firing solutions. The return fire would be panicked, haphazard.

No, when they start their attack runs we’ll have our LACs each stealthily tow 2 million tons of pods out to meet them. Then at an appropriate point we’ll fire the pods and blow the SLN away, as well as shooting down all their missiles! A battle tested solution!

kzt wrote:No, when they start their attack runs we’ll have our LACs each stealthily tow 2 million tons of pods out to meet them. Then at an appropriate point we’ll fire the pods and blow the SLN away, as well as shooting down all their missiles! A battle tested solution!

No need for the infinite improbability LACs.

If the attack run is detected 30 light-minutes out, the defenders have 90 minutes to bring reinforcements from Trevor's Star. The defenders then accelerate as far as they dare under wedge power, then switch to a Cerberus-style reaction jet with no wedge while they're in the SLN's detection range.

They can position themselves anywhere within 1.5 million km of the trajectory and fire at sprint mode (sprint mode range is 1.6 million km).

ThinksMarkedly wrote:
Anyway, the high speed attack gave me an idea.

Translate far enough out and accelerate to 0.3c. At this base velocity, the powered range of thee attackers' missiles is not 7.3 million km but nearly 26 million km, while the defender's remain at 7.3. So start your hypergenerators so you translate at 7.5 million km out from the forts and fire at any point in the last 3 minutes. Even if you can fire only 3 salvos, those 3 salvos will be in powered range when they hit. They won't have guidance from the motherships for the last 69.1 seconds, but they will still have better luck than the defenders' missiles.

The defenders' missiles won't hit at all.

Cycle the hypergenerators again, deploy more pods and translate down, coming from another direction.

A possible improvement on this manouver is to leave a reasonable number of ships a low velocity relative to the forts out closer to the high speed ship's launch point. The high speed ships hand off control of the missiles to the low speed ships as they hyper out. Fire control is degraded controlling them from 15 - 20 million km out; but not as much as simply losing it entirely.


Basically if the forts don't have a mobile force to assist them there appear to be various tactics by while the

But for that matter, at 50g a fort can only change its position by 14,122 km in 4 minutes, while a Scientist class, with it's fairly sluggish 337.8g safe accel can displace by over 95,000 km. A laserhead's standoff range is about 30,000 km. That implies that a large number of SDs holding back at 12 million km can fairly easily bracket the maneuver zone of a fort, despite the missiles being unable to maneuver during the last minute of their flight. But against their higher acceleration the forts couldn't practically return the favor. So you don't even seem to need the high speed pass.

Fairly static defenses, without a fleet to support them, are a delaying force - not one that can be assumed to drive off a skilled enemy who planned for the best way to take them down. (Now MDMs, and especially Apollo/Mycroft change that somewhat; but in the SDM era...)

Based on turn rates and such that David posted, the vector change possible by an SD is much less than people think. Even roll is slow. Garbage scow.

So while they can stop accelerating, thei space their possible location can be in expands fairly slowly compared to what you might think. Their ability to turn the open mouth of the wedge away is also limited in a SDM engament.

Manuverability of forts, in terms of can they move sideways or roll, has never been discussed. I would tend to think they are less manuverable, but don’t know. It certainly is implied that their bubble sidewalls are signficantly more effective than a SD sidewall.

kzt wrote:Based on turn rates and such that David posted, the vector change possible by an SD is much less than people think. Even roll is slow. Garbage scow.

So while they can stop accelerating, thei space their possible location can be in expands fairly slowly compared to what you might think. Their ability to turn the open mouth of the wedge away is also limited in a SDM engament.

Manuverability of forts, in terms of can they move sideways or roll, has never been discussed. I would tend to think they are less manuverable, but don’t know. It certainly is implied that their bubble sidewalls are signficantly more effective than a SD sidewall.

Supposedly Manticore has developed other technologies to significantly increase Fort's hardiness and their lethality. What are they? Tum-te-tum...

Jonathan_S wrote:But for that matter, at 50g a fort can only change its position by 14,122 km in 4 minutes, while a Scientist class, with it's fairly sluggish 337.8g safe accel can displace by over 95,000 km. A laserhead's standoff range is about 30,000 km. That implies that a large number of SDs holding back at 12 million km can fairly easily bracket the maneuver zone of a fort, despite the missiles being unable to maneuver during the last minute of their flight. But against their higher acceleration the forts couldn't practically return the favor. So you don't even seem to need the high speed pass.

Still, the problem with a missile gone ballistic is that it's, well, ballistic. Its trajectory is well-known. Unless the attackers deployed ECM prior to the missiles losing wedge power, the defenders know pretty well the vector the missiles were following. It's not perfect because that was a couple million km away, the missile's position inside the wedge is a statistical prediction and the missile has some positioning jets so it can still move a little.

But those missiles can't evade a CM sent their way. Without their own wedge to cause wedge-to-wedge destruction, the CM will continue on brooming the ballistic missiles (think Barricade). And manoeuvring jets aren't sufficient to evade PDLC shots either.

So if you send the missiles in ballistically, expect that at least 90% will be picked off before entering attack range.

Fairly static defenses, without a fleet to support them, are a delaying force - not one that can be assumed to drive off a skilled enemy who planned for the best way to take them down.

Agreed. The problem in this tactic I outlined is that the static defenders will have known this incoming force is coming for at least 90 minutes. That's sufficient time to have a relief force sent in from Trevor's Star. Or from Manticore itself.

ThinksMarkedly wrote:
I'm not disagreeing that the SLN could take the MWHJ and still have ships left. The problem is that it takes another 1000 SDs to take the Haven capital. So by attacking the Junction forts and whatever the Alliance would have left there, the SLN would need to move 1000-1200 SDs off the Core, for the duration of the war. Even if they have already put 200 more in service, that leaves too few for them to defend the Core systems as well as attack in the Haven Sector.

The Core and Haven sector are at that point connected with the MWHJ because the SLN would control both sides of the Manticore-Beowulf leg, whatever is deployed in Manticore can in an emergency be redeployed to the Core within a few weeks. The advantage here is that if the SLN has 1,000+ SD’s in the Haven sector, the republic has to take the threat seriously and they wont be able to launch attacks into the core when the SLN is situated in the Haven Sector, the Republic would have to try to recapture the Junction, they cant risk attacking the core because the fleet that defends the junction could be easily redeployed to defend the core should the need arise so if the PN deploys a sizable fleet to attack the core it will leave their territory exposed for months or years. With a lot of escorts the SLN can conduct raids and scout the Republic which could include the Haven itself, if they find out that the PN is missing a significant portion of their fleet they can hit Trevor’s Star, then Haven, occupy them and be back in the core before the PN offensive fleet can get notice.

Is that worth it? I'm arguing it isn't, because it left most of the Alliance intact and able to attack.

Problem is the SLN cannot defend its territory if Haven wanted to attack, the League has 1,700 members, even if the SLN were to protect only 10% of those systems this would mean an average of 11 SD’s/system. The Republic on the other hand can abandon the majority of their systems because they aren’t of real value to the war effort, keep the shipyards and the most heavily industrialized systems protected and let the others fend for themselves, once the war is over if the Republic is still around they can recapture what they lose.

The best the SLN can do to protect the entire League is bring the war to Haven and force Haven to attack the Junction by themselves or at best keep their fleet close to home. Even if they strip each and every ship of the wall from the entire republic, concentrate on one fleet and attack they would still be at a disadvantage numerically against the SLN because I doubt the IAN would send that many wallers once their territory is actually threatened, Haven might actually end up abandoning Erewhon especially if the League Captures Joshua because they would need those ships closer to home. Once you are smack in the middle between Haven and the Empire their alliance starts collapsing.

Yes, similarly the SLN would still be facing a largely intact alliance, possibly even larger (fewer ships to defend Erewhon instead of Manticore). But it also leaves the SLN much stronger. Instead of 800-1000 wallers remaining, they'd have around 1800. The difference can be used to raid the other Havenite shipyard systems, like Honor did in the real timeline, or to put together a Raging Justice to take on Haven but not completely uncover the Core.

The only way the SLN can protect the core is if they take an objective that Haven MUST retake thereby focusing all of their efforts on that objective leaving the core/shell alone. An objective that would split the Alliance fleet in three distinct groups that cannot mutually support each other easily.

Fair enough, so it takes 200 SDs. The SLN can send even 300 much more easily and much more successfully than the 800 to 1000 that it would take to take on the Manticoran Junction. And unlike Manticore where they'd take a couple of hours, any forces positioned at Trevor's Star would take 5 days to relieve Erewhon. By that time, the battle would be over and the SLN could send in reinforcements from Joshua.

They will still face 680 SD’s, 240 DN’s and 370 BB’s rather than facing those ships in 3 distinct groups and two of those groups will be forced to attack your forces in an effort to dislodge you. You have can have virtually the entire SLN on either side of the WH that can launch an attack at any time into the republic, and the PN would not know whether they will attack Trevor’s Star or Haven so they have to picket both while facing every system in the republic being scouted and if found undefended raided by the SLN BC’s.

The picket can't be that strong at Joshua, in Erewhon and elsewhere in the Alliance at the same time. The SLN would attack both sides more or less at the same time. Doesn't need to be completely accurate timing, but within a couple of hours it suffices to make sure the Erewhon defenders can't hold both.

They can redeploy from Haven and New Berlin to Joshua in a matter of days due to their internal lines of communications, and with the SLN’s natural inclination to attack the enemy capital system and their lack of intelligence on pretty much both of the allies and their distrust and distaste for the RMN and SKM’s government in exile because they are noebarbs that lost a war against neobards the Alliance has to guard only a few systems. Haven, New Berlin, Trevor’s Star, Manticore, Erewhon and Joshua if they hold it.Between the IAN and the PN there are 680 SD’s that due to training, experience, leadership, technological advantage and size are probably equal to 1.5 SLN SD’s so that right there is 1,020 SD’s. Then they have about 240 DN’s which would be 1 to 1 with the SLN’s SD’s because most would be similar size to the SLN SD’s, for the DN’s we will ignore the training, experience, leadership, technological advantage and for the BB’s we can calculate them as equal to 220 SD’s for a total of 1,480 SD’s worth of firepower. They can take risks with the smaller systems, picketing them with lighter units and concentrating their heavy units in important systems and as a reserve from which they can draw for offensives. They have to be strong in the key systems that the alliance depends on, shipyards and industrial systems that support the war effort, anything can be rebuild once the CD(P)’s and MDM are brought into service. And most importantly, the SLN would have to attack two objectives 350+ LY apart within a tight window, with overwhelming force on both sides, and if they let the Joshua side slip through their fingers and go back home the long way that would be basically through the League, hundreds of systems they have no way of protecting and a fleet they might not be able to track.


All of this depends on the SLN having the means to actually maintain an expeditionary force hundreds of LY from their nearest base of 800-1,000 SD’s. In the books on numerous occasions we have been made aware that the SLN does not have the logistic capabilities to support more then a portion of their wall far from base, they might have been stretching their limit with Crandal and Filaretta already so that makes any 1,000 SD offensive a no go right from the start.