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Re: Fortress Command | |
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by kzt » Tue Dec 29, 2015 12:34 pm | |
kzt
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It really isn't important who is moving fast. The vectors still add up the same in the frame of reference where you are running fast at a stationary target or whether it's the frame of reference of the stationary target seeing you run at it. In the few hundreds of seconds of missile flight the launching ship is still moving very fast towards the stationary target, and the RMN missiles have both a longer powered range and better seekers.
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Re: Fortress Command | |
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by Somtaaw » Tue Dec 29, 2015 12:55 pm | |
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Except it is important, because the leaders of the Haven attack on Manticore aren't stupid like Sword Simmonds (First Yeltsin), or Thurston (Fourth Yeltsin). In HotQ, recall Theisman briefing Sword Simmonds, when they lost exactly one ship, on the first fortress?
Single-drive, or multi-drive missiles, the tactic is the same. Fire from far enough out, not only is the fortress totally at the mercy of the ship, it is totally unable to fire back with anything more than curses. Forts are best used where Manticore had them primarily... near the Junction where it's the FORT that controls the engagement range and not the ship. |
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Re: Fortress Command | |
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by Jonathan_S » Tue Dec 29, 2015 3:25 pm | |
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Back in the SDM days that worked if you were willing to throw ballistic burned out missiles at the forts - because you could launch from far enough away to skew your course after launch and defeat any burned out ballistic missiles the forts had launched back at you. Though against 'modern' (for the era) forts, which even the Grayson's main forts weren't (much less the armed resource extraction stations the Masadans were beating up) ballistic attacks are relatively ineffective unless you're willing to get a half-day running start to send it high frac-c ballistic missiles. At even < 100g the forts can manouver to screw up the ballistic attack (4 minutes accel can displace them almost 30,000 km enough that some laserheads might not be in range anymore - or at least enough that the fort might be able to angle a wedge towards all the missiles; giving them no practical shot. But even the main Grayson forts didn't have spherical sidewalls, wedges, or modern point defense. But in the era of MDMs, max range is mostly down to fire control. Even if you launch far enough back you need a ballistic segment the forts could choose to use some of their (presumably significantly deeper stockpile of pods) to engage you. Might be low probability, but you can't count on being able to bombard them from far enough back to be completely immune to return fire. (And of course the further back you fire the less effective your fire control will be against the massive ECM tonnage, and shoals of decoys, that the defensive forts can employ. I'm not saying that only forts are the way to go, but I don't think most forts are quite as useless, unsupported, as you seem to imply. |
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Re: Fortress Command | |
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by Somtaaw » Tue Dec 29, 2015 3:55 pm | |
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A good valid point, but getting upto high c-frac velocities seems to be something that gets handwaved as needed to suggest a 'threat'. It was used as such in both First, Third, and Fourth Yeltsin and off-hand I think it was a threat in a few other battles. Math suggests it's not as easy as they make it sound, but from the way Honor + staff in those three battles, ballistic c-frac strikes are not only very very dangerous, but very very easy to pull off. For the fire/return fire, probably need someone with a good spreadsheet to punch in the numbers, but Manty MDM's have what max range from rest (Fort pod), and then the RHN velocity imparted on their slightly slower missile gives them how much extra range?
Even if you come loafing in at at, what I think even in BoMa Tourville's ships made it well above 0.3c when he and Home Fleet actively launched? Now you don't have to launch from absolute max range. After all, Haven does know they can't do that and face Manticoran ECM, so they'll probably launch from somewhere between their absolute maximum range where the fort's cant possibly engage and where the fort's MDMs will start hitting regularly.
Fully granted, but it's almost a case of David & the Goliath here. David being ships, Goliath being the forts. In regards to ECM, we don't actually know exactly how much of their tonnage is dedicated to ECM do we? Grayson gave it's Peep captured superdreadnoughts ECM just as good as most 16 million ton forts (presumably Manty forts), which suggests it's more than possible unless the fort was only recently launched, that the much newer RHN ships have better ECM/ECCM outside of the tethered Ghost Rider decoys. I don't believe forts are totally useless, but using MDM's or SDM's, if you can dictate the range and have the freedom to move around to "line up a shot" so to speak, forts are far less capable than ships. Guarding something stationary, like the Junction, however gives every single edge to the fort except the element of surprise. You know when you're coming through, the forts dont/cant... and like the early wargames circa 1890-1910, Honor saw what wargames showed; namely that the RHN can sacrifice something like 10% of its Battleships, and destroy about 10x those battleships in fort tonnage, and something like 100:1 in crew kills to losses. So even in their "prime" environment, it didn't pay to be a fortress crewmen. |
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Re: Fortress Command | |
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by Louis R » Tue Dec 29, 2015 5:53 pm | |
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No, it is _not_ the same situation as in Yeltsin.
The Graysons' forts were truly orbital structures. Despite all the upgrades, the one thing that couldn't be done without rebuilding them from the keel out - which couldn't be done in the first place, since they didn't _have_ keels - was to put drives into them. The SKM's fixed fortifications are 'fixed' only in the sense that you can't tap them for out-system missions. They don't have fixed orbits, and many probably don't have orbits at all; their trajectories are altered on a random pattern [hmmm... OK, pseudo-random, or they couldn't coordinate area coverage] that makes it impossible for an attacker to predict their positions accurately enough to fire on them without locking them up in fire control first. The exceptions to this would be the original space stations, which because of their decidedly haphazard growth wouldn't have the structural integrity to be moved like that, and is something subject to review in the near future anyway.
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Re: Fortress Command | |
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by Somtaaw » Tue Dec 29, 2015 6:24 pm | |
Somtaaw
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You're dodging that point with your knee-jerk reflex response Louis, would you care to rephrase? The specific forts from First Yeltsin were stationary, yes I'll concede that point. HOWEVER they were rebuilt to SKM-level performance well before Third Yeltsin (when Parnell came to town), let alone Fourth Yeltsin. And not only were they rebuilt, they were built to what Grayson specs they wanted, not just buying off-the-shelf Manticoran forts The point still remains in both situations, the mobile ships that should have been defending, or working WITH those forts, chose to court near-certain suicide, JUST so those forts could survive. And what happened? well in First Yeltsin, Admiral Courvosier and Admiral Yankakov bought it, Fourth Yeltsin two of the six captured Peep superdreaqdnoughts bought it (Honor was willing to accept 100% casualty rate if that was required to defend Yeltsin) In BoMa, Home Fleet also went charging off, where the Junction Forts (or the alleged forts that are sitting in planetary orbits) also could not fire upon the attackers in concert with the fleets.
And also incorrect, almost all of the forts ARE fixed.... they're fixed to the Junction, which is admittedly a full light-minute across which turns into a rather large space for them to be guarding. But it's fixed when you consider the scale of solar systems, the majority of the forts are in a rather tiny predictable amount of space. Yes, they are capable of limited movement, but that's like saying because continents float on magma, they're mobile with their few centimeters moved per year. Compared to nearly anything, forts are immobile, and you could almost dance rings around one using an aerosol canister and wearing a spacesuit [ok, not quite that extreme, a fort might be capable of upto 100g, but we no evidence of either that number OR how long they can actually sustain that speed before they have to stop] |
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Re: Fortress Command | |
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by Jonathan_S » Tue Dec 29, 2015 7:28 pm | |
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Ok I broke out and hacked up my missile acceleration spreadsheet to try to put numbers to this and show that it doesn't mater which party is accelerating. Any closing speed extends everyone's missile envelopes. Continuously powered range from rest for the Mantie Mk23s is about 67 million km. Assume the RHN missiles have a 62 million km max range from rest (it's probably a little higher, but it doesn't much matter as they can't hit anything from that range anyway). If their SD(P)s are closing at 0.2c they can launch from just over 95 million km away and the missiles will still burn out at the same spot 540 seconds later. However, at burnout the RHN ships will only be 62 million km behind the missiles (assuming they don't accelerate) the same distance away they'd have been with a launch from rest. That means that if the Manties launched at the exact instant as the RHN ships did, the Mantie missiles would still hit before the RHN missiles did due to their higher acceleration. I haven't done the comparative acceleration numbers crunching to get the exact spot, but at a guesstimate somewhere around 65 million km from the forts. Now if you assume the attacking force will go to full deceleration after they launch the defenders have to wait slightly longer than if they assumed they'd keep coasting straight in; but only slightly. (But the math here is just the same as if the attackers were at rest and began accelerating away the instant they fired) So lets run numbers if the RHN ships pile on full decel as soon as they launched (even though the increased distance at burnout means their fire control would be even worse). I'm assuming that a current RHN SD(P) can do 500g flat out and that they'll use 90% accel; call it 452g. (This is based on the highest percentile accel gain I've noticed from any RHN ship; the Mars-B from SoS at 125% the accel of a pre-war ship of that displacement) From that same 0.2c launch velocity, in the 540 seconds the missiles are in flight the SD(P)s can cancel out 0.008c and end up at 63.3 million km from the forts instead of 62 million km. But Mantie missiles launched when they were at 95 million km would still reach them with power on their drive somewhere a little inside 67 million km. |
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Re: Fortress Command | |
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by Somtaaw » Tue Dec 29, 2015 7:55 pm | |
Somtaaw
Posts: 1204
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Ah, lots of math, excellent. Now, I was under the impression that if you and I are both capable of throwing snowballs at more or less exactly the same distance and we're exactly that distance apart, we'll pelt each other. Same situation, but you're unable to move, and I'm three steps out from where you can hit me 100%. if I take one step, throw and stop on that second step.... I should be able to hit you, and no longer get hit. On a somewhat related issue, with MDM's, you can set stage 1 (launch stage) for endurance, coast ballistically for a short period, middle stage 2 corrects for any (major) movements from the fort again on endurance 45k gravs or so, and then stage 3 comes howling in at the full 92k gravs. You said a fort, assuming 100g acceleration, should only be able to move almost 30,000 km in a 4minute span. So an RHN sd, with 4.5x the acceleration while not able to move quite as much due to inertia from accelerating towards the fort, shifts rather more distance because it's moving in 2 axis' and had velocity prior to evasive. Which should throw off one heck of a lot more missile's than the fort could do the same to, right? |
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Re: Fortress Command | |
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by kzt » Tue Dec 29, 2015 8:00 pm | |
kzt
Posts: 11360
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It's all vector math. If you can shoot at a target, the target can shoot back. As the RMN missiles are both faster and longer ranged, yeah, not a safe occupation.
In addition, there should have been tens of thousands of Apollo pods on hand, so consider return fire consisting of 4 forts each guiding 800 pods per salvo at 30 second intervals. The don't habe KH2, but it should still be impressive. Combine with the greatly improved long range terminal guidance of Apollo, I think it would be a memorable fight for the survivors. And how long does it take for you to stop your ship moving at 0.2c? |
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Re: Fortress Command | |
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by Jonathan_S » Tue Dec 29, 2015 9:01 pm | |
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Ah, but this analogy is leading you astray for 2 reasons. One, the transit time of the snowball is too fast relative to your stepping speed, and two your ability to stop is far greater (relatively) than an honorverse ship. Yes if you could stop instantly in a ship, after that 2nd step and before the 3rd then you could launch from 90 million km and stop before you crossed the 67 million km continuously powered range of the defending missiles. But any velocity low enough that you could kill it before entering the enemy's missiles range is too low to boost your missiles powered range noticeably. It took those RHN SD(P)s about 23 minutes, and 4.3 million km to build up to 0.2c (and will take them just as long to stop). True which means all the talk about velocity extending the range is almost pointless. You can fire an MDM virtually as far as you want if you're willing to let it coast long enough. The real issue becomes how effective they are when they arrive - and (baring Apollo) if the ships/forts providing your fire control are more than about 55 million km away the missiles when they transition to autonomous control for their terminal attack runs your chance to hit anything are depressingly low. (Lower for the RHN than the RMN, but still depressingly low). So even if you figure out a magic geometry that lets you fire your missiles without getting fired on in return, do do that you'd have to be so far away that you're just throwing away your missiles anyway.
The fort with 100g managed to move just under 30,000 km; actually 28,800 km (in 4 minutes). The RHN SD(P) with 452g managed to move about 1,300,000 km (in 9 minutes). (Ok, technically it reduced its forward travel by 1.3 million km relative to what it would have been had it not bothered to accelerate directly away from the fort; but the math is the same). In 4 minutes that same ship could have displaced 130,176 km; or 4.65x as far. |
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