Upcoming designs: regarding the Apollo ACM...

WLBjork wrote:

SharkHunter wrote:Regarding the "off bore" launching capability of the Rolands, I've sort of assumed that it accomplished two things: longer missiles (the Mark 16's) in a thinner ship, and as stated, the ability to fire a missile out of the front and back of the ship while maneuvering. The "firing in two different directions bit" in this thread got me thinking though, "out the front can pretty much go straight ahead, out the back has to use the 120 degrees to turn and then go straight ahead", and the launch times are synchronized to make it all line up. Alternatively I could see the DD slewing "in position" with "no accel briefly" and launching in a position that would resemble the horns of a bull.

Then the "stacked salvo" thought kicked in and says "ny-ope..." because even with say a 15-30 timing difference, that's still a huge distance at "battle speed and accel". Because we're told that the missiles acceleration is preset and doesn't vary after it's lit off, about the only solution I've come up with is that the "stack" missiles are timed to arrive on target nearly simultaneously (or at least within a single "countermeasure time period", vs. the same number of missiles in pods being precisely the same speed/accel because all of the missiles light off simultaneously, an easier task altogether.

Am I missing something?

Well, off-bore mostly seems to involve bring bows-on to the target (minimise target area), so the missiles don't have to travel any further.

Not sure if broadside off-bore (180 degree) is possible, but if it is, "all" that is required is to step down the acceleration of the direct missiles to enable the off-bore missiles to catch up.

From SoS

Hexapuma and Aegis were the only ships in Terekhov's riven Squadron with the off-bore capacity to fire both broadsides at a single target.

Dafmeister wrote:In the past, the powerful mass drivers on shipboard launchers served two purposes. The first was to increase the missile's starting velocity, thereby increasing its powered range and reducing the window for the target's CMs and PDLCs to engage it. That requirement has been significantly reduced with the advent of MDMs and DDMs, and with off-bore targeting the loss of initial velocity is made up for by the ability to put in double broadsides at twice the rate that could be managed with old-school 'staggered ignition' salvos from a single set of broadside launchers.

However, the other purpose is still very much in evidence - the need to get the missiles clear of the ships wedge perimeter as quickly as possible.

But how much shove do you need to satisfy only that second purpose? If the missiles are a bit slower to get out, that's not the limiting factor for fire rate - that's a matter of moving missiles from magazines to launchers, goosing the capacitors, etc. And sheer fire control becomes a bigger factor than how many missiles you can get out there at a time anyway.

On the other hand - for all we've read, or that I can recall at least - maybe the more recent launchers have dropped the mass driver power considerably and have ended up similarly sized due to the additional systems to feed the missile capacitors before launch.

Bill Woods wrote:

WLBjork wrote:Not sure if broadside off-bore (180 degree) is possible, but if it is, "all" that is required is to step down the acceleration of the direct missiles to enable the off-bore missiles to catch up.

From SoS

Hexapuma and Aegis were the only ships in Terekhov's riven Squadron with the off-bore capacity to fire both broadsides at a single target.

But that quote isn't clear if they can fire both broadsides by:
a) pointing end on (controlling all of them through fire control links mounted on the fore (or aft) hammerhead. -or-
b) broadside to the enemy, but rolled behind their wedge (unlikely w/o a keyhole - since controlling missiles through your own wedge doesn't really work) -or-
c) firing the far broadside and having those missiles u-turn back towards the target.

Jonathan_S wrote:But that quote isn't clear if they can fire both broadsides by:
a) pointing end on (controlling all of them through fire control links mounted on the fore (or aft) hammerhead. -or-
b) broadside to the enemy, but rolled behind their wedge (unlikely w/o a keyhole - since controlling missiles through your own wedge doesn't really work) -or-
c) firing the far broadside and having those missiles u-turn back towards the target.

You're right, that quote doesn't. However, it is explicitly stated elsewhere. The original off-bore capability only permitted about 90 degree turns, but the current generation of off-bore firing allows 180-degree turns. A modern Manticoran ship can have the port broadside toward the enemy and still fire the starboard broadside at it. Or in the case of the Roland--a Roland can fire both its bow and stern chaser tubes at an enemy ship in a stern chase.

SWM wrote:

Jonathan_S wrote:But that quote isn't clear if they can fire both broadsides by:
a) pointing end on (controlling all of them through fire control links mounted on the fore (or aft) hammerhead. -or-
b) broadside to the enemy, but rolled behind their wedge (unlikely w/o a keyhole - since controlling missiles through your own wedge doesn't really work) -or-
c) firing the far broadside and having those missiles u-turn back towards the target.

You're right, that quote doesn't. However, it is explicitly stated elsewhere. The original off-bore capability only permitted about 90 degree turns, but the current generation of off-bore firing allows 180-degree turns. A modern Manticoran ship can have the port broadside toward the enemy and still fire the starboard broadside at it. Or in the case of the Roland--a Roland can fire both its bow and stern chaser tubes at an enemy ship in a stern chase.

You guys are as bad as my Scouts! A throwaway comment turns into a full blown discussion.

The Rolands engaging FF BCs - was that Saltash? - I think settled that question, but I couldn't at the time of the earlier post bring any specific incident or statement to mind, hence my hedging.

Bill Woods wrote:

Dafmeister wrote:In the past, the powerful mass drivers on shipboard launchers served two purposes. The first was to increase the missile's starting velocity, thereby increasing its powered range and reducing the window for the target's CMs and PDLCs to engage it. That requirement has been significantly reduced with the advent of MDMs and DDMs, and with off-bore targeting the loss of initial velocity is made up for by the ability to put in double broadsides at twice the rate that could be managed with old-school 'staggered ignition' salvos from a single set of broadside launchers.

However, the other purpose is still very much in evidence - the need to get the missiles clear of the ships wedge perimeter as quickly as possible.

If the ship is maneuvering, kick them out the stern and the ship'll leave them behind at several km/s2. It works for missiles in pods; it'd work for individually-launched missiles.

It'll take several seconds, if my maths is right. A ship of the wall's wedge is about 300km long, so the kilt is about 150km astern of the forwardmost broadside launchers. If the ship's accelerating at 5kps squared, it'll take between seven and eight seconds for the missile to clear the kilt, and as soon as the missile clears the sidewall (and the radiation and particle shields between the sidewall and the hull) it'll be vulnerable to a soft kill. Pods dropped astern, on the other hand, can stay between the sidewalls all the way to the kilt, and can be pushed out faster with half a dozen tractors on the aft hammerhead - it's a lot easier to do that for six pods than for 30+ missiles.

Bill Woods wrote:

Dafmeister wrote:In the past, the powerful mass drivers on shipboard launchers served two purposes. The first was to increase the missile's starting velocity, thereby increasing its powered range and reducing the window for the target's CMs and PDLCs to engage it. That requirement has been significantly reduced with the advent of MDMs and DDMs, and with off-bore targeting the loss of initial velocity is made up for by the ability to put in double broadsides at twice the rate that could be managed with old-school 'staggered ignition' salvos from a single set of broadside launchers.

However, the other purpose is still very much in evidence - the need to get the missiles clear of the ships wedge perimeter as quickly as possible.

If the ship is maneuvering, kick them out the stern and the ship'll leave them behind at several km/s2. It works for missiles in pods; it'd work for individually-launched missiles.

Dafmeister wrote:
It'll take several seconds, if my maths is right. A ship of the wall's wedge is about 300km long, so the kilt is about 150km astern of the forwardmost broadside launchers. If the ship's accelerating at 5kps squared, it'll take between seven and eight seconds for the missile to clear the kilt, and as soon as the missile clears the sidewall (and the radiation and particle shields between the sidewall and the hull) it'll be vulnerable to a soft kill. Pods dropped astern, on the other hand, can stay between the sidewalls all the way to the kilt, and can be pushed out faster with half a dozen tractors on the aft hammerhead - it's a lot easier to do that for six pods than for 30+ missiles.

In HoS it describes the Nike class BC, because of keyhole-two and it's off-bore tubes, as being the first warship that can fight the entire battle with it's wedge to the enemy

HoS also describes the Roland class destroyer as having 6 launchers in each of it's hammerheads but with off-bore launchers it is able to bring all missiles to bear on a single target. This is what happened when the 5 Rolland DDs took on 4 SLN BCs. And as each launcher is a double launch variant, the 5 DD's were able to send a "broadside" of 120 missiles at each SLN BC. The battle between the 5 Rollands and the 4 SLN BCs I believed talked about having "staggered" launches from fore and aft launchers to allow for a solid wall of missiles.

I would think that the missiles under powered launch would be much harder soft kill targets than tractored pods.

One of the things I have realized much more clearly during the course of this thread is that there's got to be a "control links times salvo" relationship going on, otherwise a ship could only fire X missiles every few minutes. That makes the "update the missiles" speed of the ACM the true force multiplier at the level described -- forcing Theisman to go for it a la the Battle of Manticore or have "all be lost".

Keeping with this thread's starting topic, "rotating" links at 3:1 or letting the Apollo simply dupliate the same targeting instructions to multiple missiles a la Barnett still seems like it would be about 20x more effective than light speed links at anything significantly shorter than maximum range, because the final update could still be much further downrange.

So I come back to the questio of "do the uber geeks find a way to update the Mark-16's to slave to an Apollo or not?"
I still say yes. That would make any RMN ship plus a Mycroft and an ammo supply a "fleet of one", for most battles.

Yes/no?

SharkHunter wrote:One of the things I have realized much more clearly during the course of this thread is that there's got to be a "control links times salvo" relationship going on, otherwise a ship could only fire X missiles every few minutes. That makes the "update the missiles" speed of the ACM the true force multiplier at the level described -- forcing Theisman to go for it a la the Battle of Manticore or have "all be lost".

Keeping with this thread's starting topic, "rotating" links at 3:1 or letting the Apollo simply dupliate the same targeting instructions to multiple missiles a la Barnett still seems like it would be about 20x more effective than light speed links at anything significantly shorter than maximum range, because the final update could still be much further downrange.

So I come back to the questio of "do the uber geeks find a way to update the Mark-16's to slave to an Apollo or not?"
I still say yes. That would make any RMN ship plus a Mycroft and an ammo supply a "fleet of one", for most battles.

Yes/no?

Well there was a quote from Storm from the Shadows saying that the had to incorporate changes into the Mk23 to make it Apollo compatible. Sure, it sayd they were minor enough that they didn't cause breaks in the production schedule; but that doesn't mean it's a field modification.

So I'd say that yes you could build a Mk16 that could listen to an Apollo control missile - but it'd probably have to be a 'factory' or at least 'depot' level modification to the Mk16s. So likely not something you could quickly improvise on the spot.


So I wouldn't expect to see if, even though there's no complete technological prohibition that I can see.




As to the "control links times salvo", its definitely something I've though about. I'm not sure how RFC visualized it; because there are some odd things about it - since the ships definitely can have several salvos in flight at once.

One oddity is that, IIRC, it's specifically mentioned that the Sag-Cs have extra control links to allow them to fire double-stacked salvos. But if you had to have one control link per missile, and could have 2 or more salvos in flight already, then double-stacking a salvo shouldn't take any extra control links (because the same number of missiles are in flight; its just the first salvo delayed drive ignition by a handful of seconds to arrive at the target simultaneously with the second salvo.

Even with SDMs you had up to a 3 minute flight time, and a launcher capable of pumping out a missile every 15-20 seconds on rapid fire. So you could theoretically have 9-12 salvos in flight simultaneously. But nobody back then did a double or triple stacked launch; even though there appeared to somehow be fire control for way more missiles than that. I'm not sure why you'd have enough fire control to handle them when they're 15-20 seconds apart, rather than the same number of missiles some only 1-2 seconds apart.

Well Duh,

"Everyone knows"

2+2 is different than 2x2 ...