Do we actually need SD(P)s?

Galactic Sapper wrote:
@theemile

the Nike was 25 mk 16 tubes in each broadside, and can fire them offbore. the cycle time is 18 seconds per salvo or 54 sec for a 3 double broadside alpha launch.

As described in text, the four ships were launching 350+ salvos of double broadsides at 20 second intervals. The only way that's possible is all four ships pumping out a broadside every 10 seconds. Sang Bs have 42 total tubes each and 50 from Phantom gives 352 missiles per double launch. This is close to the 12 second launch cycle I remembered for Mark 16 tubes.

The Mk 16 and Mk 23 require an additional 5 seconds to spin up their reactor - this is done in a special armored port in the feed tube, not done prior to the launch sequence as was done in capacitor missiles (were all missiles in the magazine were sent live plasma all the time, thus were ready for launch.


from Shaddow of Saganami:

Without the redundant manpower Hexapuma didn't have, there was no way to manually reclaim those missiles, so his ship was down to an effective total of only 1,155. The cycle time on his launchers at maximum-rate fire was one round every eighteen seconds, twice the time an older ship, like Warlock, would have required. Partly because the missiles were simply larger, but even more because of the need to light up the Mark 16's onboard reactor before launch. Still, in theory, each launcher could fire fifty-four times before anyone else on either side was in range to do the same . . . except for the fact that he had only thirty-three rounds per tube.

(Bolding mine)

tlb wrote:

locarno24 wrote:Implying that the warhead and 'countermissile drive' are at the same end - i.e. the front.

kzt wrote:It's not just a pretty dumb implementation when there is no exhaust issue. It's a "why would you possibly do that?" kind of thing.

Is it possible that the first stage is jettisoned, like current multi-state rockets to eliminate excess mass?

To save mass? Probably not. To adjust where the drive nodes are in relation to that mass? Definitely.

Impeller nodes have to be located within 10-15% of the ends of the ship/missile they're generating a wedge for. Missile impellers only have one ring of nodes, at the rear end. Affixing the second stage to the back of the missile would put the first stage's drive nodes in the middle of the resulting missile stack, which would interfere with their ability to generate a wedge that stack. Sticking the second stage on the front of the first stage, in the place the warhead bus is usually fixed, maintains the first stage's drive nodes in a location where they can properly generate a wedge for the missile.

The same logic applies for the second stage: the CM drive nodes would be located in the middle of the missile if the first stage wasn't jettisoned. Thus we can assume the first stage is indeed jettisoned before the second stage activates. And it really wouldn't take much of a delay between the first stage going down and the second stage powering up to get that separation - especially since you don't care if the first stage hits the wedge of the second stage as it starts up.

In GA DDM/MDMs, all of the rings on the missile are located very close to one another on the aft end of the missile, so all of them fall within the specified 10-15% without having to dump a stage at all. In all cases (GA or Sollie tech) the drives are at the aft end because the interchangeable warhead modules are located at the front because that's where the targeting sensors have to be.

Theemile wrote:The Mk 16 and Mk 23 require an additional 5 seconds to spin up their reactor - this is done in a special armored port in the feed tube, not done prior to the launch sequence as was done in capacitor missiles (were all missiles in the magazine were sent live plasma all the time, thus were ready for launch.

So basically what we have is what in canon happened in Hypatia was flatly impossible according to the known technical details of the ships in question. Well, it wouldn't be a first.

No plausible alternative exists to explain 350-ish missile salvos every 20 seconds. That would require one 50 missile launch from Phantom and three launches from each B at 6 second intervals, each consisting of 34-ish missiles. The layout of the missile tubes on the B's doesn't show any obvious reason they'd be firing 34 when to do that they'd have to be in a position to launch a 40 if not 42.

Is there anywhere else in text where a Nike launches at max rate? I'm thinking there may be a technical reason why their tubes might be able to launch faster than a C or a Roland could. Maybe they have dual feed tubes such that one missile can be spun up while the other is loaded into the tube and fired or some other support systems that can be built on a Nike but just not physically fit on anything smaller.

Galactic Sapper wrote:

Theemile wrote:The Mk 16 and Mk 23 require an additional 5 seconds to spin up their reactor - this is done in a special armored port in the feed tube, not done prior to the launch sequence as was done in capacitor missiles (were all missiles in the magazine were sent live plasma all the time, thus were ready for launch.

So basically what we have is what in canon happened in Hypatia was flatly impossible according to the known technical details of the ships in question. Well, it wouldn't be a first.

No plausible alternative exists to explain 350-ish missile salvos every 20 seconds. That would require one 50 missile launch from Phantom and three launches from each B at 6 second intervals, each consisting of 34-ish missiles. The layout of the missile tubes on the B's doesn't show any obvious reason they'd be firing 34 when to do that they'd have to be in a position to launch a 40 if not 42.

Is there anywhere else in text where a Nike launches at max rate? I'm thinking there may be a technical reason why their tubes might be able to launch faster than a C or a Roland could. Maybe they have dual feed tubes such that one missile can be spun up while the other is loaded into the tube and fired or some other support systems that can be built on a Nike but just not physically fit on anything smaller.

David addressed the feed issues on the board here before - all the Mk 16 and Mk 23 launchers are supposedly limited to the 18 second feed rate due to the 5 second reactor initialization. Usually, the larger the ship, the slower the feed rate, due to complications in the feed system the armoring, distance, and number of launchers creates. But as we know, there is always <PLOT>.

We've also been told that the Sag-B and the Mk 14 specifically cannot fire more than 135 degrees offbore (so the missiles can only fire offbore into adjacent aspects, not completely around the ship) and the Sag-B doesn't have enough firecontrol to control them all anyway. Of course, as others have mentioned above, the Nike's KH-Is could have been controlling ALL the missiles (again, something not see before, except from pods) and the Sag-Bs could have been rolled so their Wedges were facing the targets, allowing all missile to fire less than 135 degrees offbore. Again, possible IF the Nike was controlling the missiles, not done previously, and not specifically mentioned in the text.

locarno24 wrote:Based on the Torch of Freedom description:

"The Cataphract was a rather basic concept, actually—they'd simply grafted what amounted to an entire counter-missile drive unit onto the end of a standard shipkiller. Coming up with an arrangement which let them cram that much impeller power and a worthwhile laser head into something they could fit onto the end of a standard missile had demanded quite a bit of ingenuity (and not a few basic compromises), but it had been a far easier task than duplicating a full scale multidrive missile would have been."

Implying that the warhead and 'countermissile drive' are at the same end - i.e. the front.

You see, I read the same passage and come to the exact opposite conclusion. I read that as saying the counter-missile drive is at the end of the shipkiller: the back. Maybe you're thinking like a sword ("stick them with the pointy end!", Jon to Arya Stark) or in the expression "business end of a gun". But for me, I considered that the "front" or the "start" was the leading edge, orienting the missile in the direction of movement. That places the "end" at the trailing edge.

Also, this was an intuitive leap for me: multi-stage rockets fire the engine furthest to the back, then jettisons it and lights up the next stage. There's nothing saying that impellers have to work like that (and given that a ship needs two rings, one of them in the front), but the analogy was there.

locarno24 wrote:Implying that the warhead and 'countermissile drive' are at the same end - i.e. the front.

kzt wrote:It's not just a pretty dumb implementation when there is no exhaust issue. It's a "why would you possibly do that?" kind of thing.

tlb wrote:Is it possible that the first stage is jettisoned, like current multi-state rockets to eliminate excess mass?

Galactic Sapper wrote:To save mass? Probably not. To adjust where the drive nodes are in relation to that mass? Definitely.

Impeller nodes have to be located within 10-15% of the ends of the ship/missile they're generating a wedge for. Missile impellers only have one ring of nodes, at the rear end. Affixing the second stage to the back of the missile would put the first stage's drive nodes in the middle of the resulting missile stack, which would interfere with their ability to generate a wedge that stack. Sticking the second stage on the front of the first stage, in the place the warhead bus is usually fixed, maintains the first stage's drive nodes in a location where they can properly generate a wedge for the missile.

The same logic applies for the second stage: the CM drive nodes would be located in the middle of the missile if the first stage wasn't jettisoned. Thus we can assume the first stage is indeed jettisoned before the second stage activates. And it really wouldn't take much of a delay between the first stage going down and the second stage powering up to get that separation - especially since you don't care if the first stage hits the wedge of the second stage as it starts up.

In GA DDM/MDMs, all of the rings on the missile are located very close to one another on the aft end of the missile, so all of them fall within the specified 10-15% without having to dump a stage at all. In all cases (GA or Sollie tech) the drives are at the aft end because the interchangeable warhead modules are located at the front because that's where the targeting sensors have to be.

just so everyone has a basis for conversation, here is an image of the Mk-16 from Storm from the Shadows

https://drive.google.com/file/d/1vTgKDlsdG8tWlIbHWKgKT28RRLWFKrnk/view?usp=sharing

let me know if you cannot reach the image.

ThinksMarkedly wrote:

locarno24 wrote:Based on the Torch of Freedom description:

"The Cataphract was a rather basic concept, actually—they'd simply grafted what amounted to an entire counter-missile drive unit onto the end of a standard shipkiller. Coming up with an arrangement which let them cram that much impeller power and a worthwhile laser head into something they could fit onto the end of a standard missile had demanded quite a bit of ingenuity (and not a few basic compromises), but it had been a far easier task than duplicating a full scale multidrive missile would have been."

Implying that the warhead and 'countermissile drive' are at the same end - i.e. the front.

You see, I read the same passage and come to the exact opposite conclusion. I read that as saying the counter-missile drive is at the end of the shipkiller: the back. Maybe you're thinking like a sword ("stick them with the pointy end!", Jon to Arya Stark) or in the expression "business end of a gun". But for me, I considered that the "front" or the "start" was the leading edge, orienting the missile in the direction of movement. That places the "end" at the trailing edge.

Also, this was an intuitive leap for me: multi-stage rockets fire the engine furthest to the back, then jettisons it and lights up the next stage. There's nothing saying that impellers have to work like that (and given that a ship needs two rings, one of them in the front), but the analogy was there.

I am in the same boat as Locarno24 - the important issue is separation of the nodes to protect them against feedback. The Manties can do their magic with their special gravitonic drive baffle - everyone else needs space as an insulator.

Scotty even alludes to it in Ashes of Victory:

but if they wanted to accept bigger launchers and lower missile load-outs, they could probably match the extended range capabilities of Ghost Rider's offensive side. Heck, build the suckers big enough, and they could do it with off-the-shelf components, Stew!"
"Hmph! Have to be really big brutes to pull it off," Ashford grumbled. "Too big to be effective as shipboard weapons, anyway."
"What about launching them from a pod format for system defense?" Tremaine challenged. "For that matter, put enough of them in single-shot launchers on tow behind destroyers and light cruisers, even if they had to trade 'em out on a one-for-one basis with entire pods of normal missiles, and they could still get a useful salvo off.

Galactic Sapper wrote:
Is there anywhere else in text where a Nike launches at max rate? I'm thinking there may be a technical reason why their tubes might be able to launch faster than a C or a Roland could. Maybe they have dual feed tubes such that one missile can be spun up while the other is loaded into the tube and fired or some other support systems that can be built on a Nike but just not physically fit on anything smaller.

found it - Storm from the Shadows aboard the Artimis who was in a Sim pretending to me an Invictus firing Apollo pods:

For the purposes of today's simulation, HMS Artemis had been promoted from a battlecruiser to an Invictus-class SD(P). Every unit of the squadron had undergone a similar transformation, which meant that instead of the sixty Mark 16s each ship could normally fire in a single double-broadside salvo, each of them could deploy six full pods of Mark 23s. Normally, that would have meant that each ship rolled one pattern of Mark 17 "flat pack" missile pods, each of which contained ten Mark 23s, every twelve seconds. In this case, however, they were rolling the Mark 17, Mod D, which contained only eight Mark 23s . . . and a single Mark 23-E.
So instead of sixty Mark 16s every eighteen seconds, with a maximum powered attack range (without a ballistic segment, at least) of only a shade over twenty-seven million kilometers and "cruiser range" laser heads, they were firing forty-eight attack and dedicated EW Mark 23s every twelve seconds.

The 60 mk 16s is repeated twice, and originally had me wondering if production Nikes had 30 broadside launchers instead of 25. But HoS states only 25, as does the Nike graphic at the end of SftS.

https://drive.google.com/file/d/1-0OucLLZtgIebOpi7tBzmKjiA1DM7Bdn/view?usp=sharing

Also we find it later when planning on firing at Byng

Michelle pulled harder on her ear lobe while she did the math. At that velocity, the Sollies would cross through her Mark 16s' range to her ships in about thirteen minutes. At one launch every eighteen seconds her shipboard launchers could fire forty-three missiles each in that timeframe, and she had six hundred and twenty tubes aboard her Nikes and Saganami-Cs, alone. That worked out to better than twenty-six thousand missiles, which she suspected—decoys or no—would be a fairly significant case of overkill.

Been loving all the discussions of Nike capabilities, B capabilities, and wondering about any late-breaking upgrades to ships, missiles, control or whatever. Dang, I appreciate this as a great mental playground for a "designed tech future universe".

That said, the military truism I've liked best probably comes from Filareta himself just prior to getting all his ships blown out of space, that is,

That was scarcely the stuff of military derring do; then again, professional naval officers were supposed to avoid derring do whenever possible. “Derring do” was usually what happened only after someone had screwed up by the numbers and had to figure out how to save his ass from his own mistakes. In --A Rising Thunder

I think I'd be most likely fall between Andrea Jaruwalski and Bill Edwards. Tactically oriented but with heaping doses of "what else can we do to screw with the enemy's head", "what else can we do with the tech?" and access to the ATC simulators, after action reports, etc.

Needs me my own Honorverse book to write.

kzt wrote:

locarno24 wrote:[

Implying that the warhead and 'countermissile drive' are at the same end - i.e. the front.

It's not just a pretty dumb implementation when there is no exhaust issue. It's a "why would you possibly do that?" kind of thing.

The Cataphract has been described as a 2 stage (rather than a 2 drive) missile. That hints that the first stage is dropped at some point - and for what it's worth every missile design we've seen puts the drive nodes at the rear; so, as GalacticSapper said it's not clear if a missile drive can even work when it's stuck 60+% of the way up the missile body. So you might need to drop spend stages when the impeller rings have wide physical separation.

If the first stage is dropped after burning out the original drive nodes (and exhausting it's capacitors) then the sensors and warhead would need to be on the 2nd stage. If so, sticking it in front of the 1st stage lets the sensors try to look at the target the whole way; rather than staring at the south end of a northbound missile for 70% of the flight. Plus it seems easier to drop the first stage if you can accelerate away from it -- instead of having to drop it in front of you and use thrusters or something to get far enough clear than you don't run back into it when the 2nd stage's CM drive activates.

Still, my inferences could be wildly off base. sut that's how I imagined it from the limited descriptions. A CM derived detachable upper stage, with smaller warhead and quite possibly smaller diameter, grafted onto the top of a conventional missile body that's just had it's warhead and sensors removed.