NEXT GENERATION SDs

ThinksMarkedly wrote:

Jonathan_S wrote:The internal launchers we've seen for microfusion powered missiles have a cycle time of 30 seconds; and so you'd need 135 such tubes to achieve a 270 missile per minute throw rate.
The highest number we've seen on any SD was the 8.5 mton Benjamin the Great-class with 94 (38 on each broadside and 9 in each hammerhead) -- and they didn't have to make room for a Keyhole or Keyhole II.

It's not just the average throughput of missiles that counts. A non-pod design also loses the ability to mass a salvo over the course of many minutes to attempt to overwhelm the defences of the other side. We don't know how long a missile can loiter before its wedges are activated, but the best we've seen is two sequential cycles (the double double broadside). I don't see any reason you couldn't a bit wait longer, except if the host ship is still accelerating, in which case the missiles start falling behind (or falling forward).

But it's not going to be long. I doubt the missiles can loiter for several minutes as the salvo builds up. Meanwhile, deployed pods can continue to be powered from the host ship and keep the missiles in pre-launch ready state.

For this reason, your Alpha launch size is also reduced, since you're limited by definition to the number of pods carried externally, as those are the only ones you have.

Sag-Cs can do a triple, double broadside, with 2 salvos launched with delayed drives - they have firecontrol for 128 missiles. This is probably the upperlimit on dropped salvos, or not - but we do know that this much does work!

Jonathan_S wrote:Another random thought -- how many tubes you'd need to equal the steady throw weight of an SD(P)


All the SD(P)s to date have a 12 second cycle time and 6 pod launchers. At 9 missiles per pod they can keep up 270 missiles per minute until they've shot themselves dry.

The internal launchers we've seen for microfusion powered missiles have a cycle time of 30 seconds; and so you'd need 135 such tubes to achieve a 270 missile per minute throw rate.
The highest number we've seen on any SD was the 8.5 mton Benjamin the Great-class with 94 (38 on each broadside and 9 in each hammerhead) -- and they didn't have to make room for a Keyhole or Keyhole II.


Even disregarding the point defense issues, how big a ship would you need for its tubes to come close to matching the Apollo firepower the pod laying gives you?

Microfusion salvo time is 18 seconds, not 30 seconds. 30 seconds is the RMN capital missile standard sustained fire rate, though the modern launchers can fire far faster than that.

cthia wrote:I suggested in another thread a more inherently survivable SD design may be needed when attacking Darius. If the MA manages to get within the boxer's longer reach, that boxer better be able to take a hit. And another. And another. And another...

Let's call this new design, beaters. They will need to be able to tread deeply into the system in search of Spiders.

Except they're not more inherently survivable.

They're inherently structurally stronger -- maybe as much as 5-10% structurally stronger. But by the time structure breaks up the ship was long ago combat ineffective and defenseless.

So that extra structural strength is effectively irrelevant to survivability.


An SD(P) has the same armor and sidewalls as an SD, so in terms of hits that make it through the defenses its internals and critical systems are just about as well protected as a non podlaying SD. (Marginally less because they're less dispersed due to needing to make room for a contiguous pod bay as opposed to separate magazines -- but still very very close)

However, because it doesn't have to spend broadside space (or as much broadside space) on offensive weapons, the podlayer it can mount far heavier defense (many more CMs and PDLCs) for its size. Those defenses are a significant improvement to its survivability.

(Now at the BC size range the squeeze to fit in a pod bay is a much larger compromise to survivability because for a useful number of pods it has to take up a far larger percentage of the internal volume and thereby forces critical systems to move to less protected areas)

Theemile wrote:

Jonathan_S wrote:Another random thought -- how many tubes you'd need to equal the steady throw weight of an SD(P)


All the SD(P)s to date have a 12 second cycle time and 6 pod launchers. At 9 missiles per pod they can keep up 270 missiles per minute until they've shot themselves dry.

The internal launchers we've seen for microfusion powered missiles have a cycle time of 30 seconds; and so you'd need 135 such tubes to achieve a 270 missile per minute throw rate.
The highest number we've seen on any SD was the 8.5 mton Benjamin the Great-class with 94 (38 on each broadside and 9 in each hammerhead) -- and they didn't have to make room for a Keyhole or Keyhole II.


Even disregarding the point defense issues, how big a ship would you need for its tubes to come close to matching the Apollo firepower the pod laying gives you?

Microfusion salvo time is 18 seconds, not 30 seconds. 30 seconds is the RMN capital missile standard sustained fire rate, though the modern launchers can fire far faster than that.

Oops -- just double-checked and you're right. I should have done that before instead of relying on my memory. (The annoying this is that I had double-checked the pod cycle time; just not the missile tube's time)

That drops the required number of tubes to just 81; a more manageable number (though you still need room for Keyhole II on the broadside)

Jonathan_S wrote:Another random thought -- how many tubes you'd need to equal the steady throw weight of an SD(P)

The internal launchers we've seen for microfusion powered missiles have a cycle time of 30 seconds [edit: 18 seconds]; and so you'd need 135 [edit: 81] such tubes to achieve a 270 missile per minute throw rate.

NIT: It is 30 seconds firing time, but 12s of that 30 is spent in a "PRE" charge chamber for MK16. Making the actual cycle time 18s

Nit: Must assume micro fusion MK16 charge/dwell time is same as MK23 or MK23E. This seems a bit problematic of an assumption with a MUCH larger missile in the case of MK23E. Though we are ALSO told RD's also use Micro Fusion plants... Does not mean they are all the same size or startup time.

Theemile wrote:

Varangian wrote:Postulating about what if any consideration there would be to a follow-up generation of SD by Manticore, Grayson or Haven.

All are building SD(P), but I was thinking about a 'old school' waller kind of like what was done with the Nike BC.

There are known weaknesses of pod carriers-pod rails,

The other point is SD(p)s moved from 4-5 dozen energy weapons in a broadside, to just 1-2 dozen massive ones, combined with removing or limiting the # of missile launchers, this freed up massive amounts of space for the Keyholes, firecontrol, and antimissile systems.

Add back in the 30 Missile tubes on SNIP .... for their ECM doctrine. The Harrington II sacrifices 6 Grasers, 20 CM launchers, and an unknown quantity of fire control ability in each broadside to carry their 24 missile tubes - not that an additional 60 missiles (12 more in the bow) every 18 seconds isn't a nice to have - but the loss of 46 CMs overall can make a difference on defense (Invictus 206 - Harrington II 160 - a 22% reduction in CM defenses.)

The line of battle Triangle Trade-offs are NOT being discussed... Speed, Firepower, Armor.

In HV Speed is essentially disregarded so we have a duopoly especially in age of FTL controlled pod launched missiles.

#1 Missile Laser Head throughput is still increasing in EVERYONE's navies. This necessitates an increase in armor

#2 HV Armor is NOT physical but rather SIDEWALLs. Or not directly physical. Via Sidewall GENERATORS. Here we are told they take up physical real estate on the surface. By Necessity of #1 and number of missiles incoming at any given time, Armor MUST be massively increased.

So, anything in modern HV SD freeing up surface area for active systems and Sidewall generators is GOOD and anything obstructing this goal is BAD. Here Keyhole II is a VERY bad thing. Currently necessary. Missile tubes are bad. Besides, we have CM's called VIPERS's if you want to fire off a single missile for some reason. Maybe make it so one can have a few special CM tubes/broadside that can mate 2 CM's together for longer range and a true DDM CM that just happens to also have a light laser head.

Just as in the 300,000 notional modern RMN DD where a large chunk of that excess mass is JUST for increased sidewalls, this must also be FAR MORE true on an SD.

So, IMO, kick off every human being on an SD possible other than ONLY senior officers(forget maintenance insitu) dropping total to somehere around ~150 personnel for a true 4 watch shift schedule so this frees up all the boat bay space for Keyhole II to be placed there instead freeing up broadside area.

This way, if you are keeping the BC'L around(I know I have argued against it), the BCL will have a more defined role carrying more troops etc which the SD's do not. Of course if you need that many troops... You need hundreds of thousands not a company or battalion as in the case of Kammerling.

Theemile wrote:

ThinksMarkedly wrote:
It's not just the average throughput of missiles that counts. A non-pod design also loses the ability to mass a salvo over the course of many minutes to attempt to overwhelm the defences of the other side. We don't know how long a missile can loiter before its wedges are activated, but the best we've seen is two sequential cycles (the double double broadside). I don't see any reason you couldn't a bit wait longer, except if the host ship is still accelerating, in which case the missiles start falling behind (or falling forward).

Sag-Cs can do a triple, double broadside, with 2 salvos launched with delayed drives - they have firecontrol for 128 missiles. This is probably the upperlimit on dropped salvos, or not - but we do know that this much does work!

NIT: Haven multiplied number of control channels by ***6*** at Battle of Manticore for "slightly" less accuracy by control channel sharing. (Also had said sharing on Manticore's side but I digress)

So, technically, a SAG-C if it wanted to have "slightly" less accuracy should be able to dump roughly 50% of its missiles out in a single salvo... Of course this is not what has happened in the books since then so...

One would think a BCL should be able to to the same thing... yet at Hypatia it did not happen and rather died with almost all of its missiles in its holds . I would have to conclude DW decided it made his universe too messy to write and ditched this perspective.

Relax wrote:

Jonathan_S wrote:The internal launchers we've seen for microfusion powered missiles have a cycle time of 30 seconds [edit: 18 seconds]

NIT: It is 30 seconds firing time, but 12s of that 30 is spent in a "PRE" charge chamber for MK16. Making the actual cycle time 18s

Nit: Must assume micro fusion MK16 charge/dwell time is same as MK23 or MK23E. This seems a bit problematic of an assumption with a MUCH larger missile in the case of MK23E. Though we are ALSO told RD's also use Micro Fusion plants... Does not mean they are all the same size or startup time.

Agreed that we're just assuming that the cycle times for Mk16 and Mk23 launcher are the same (and that a notional Mk23E tube would also be the same).

But once I went back and looked at it SoS seems pretty clear on Hexapuma's cycle time. Where did you find the 30 total seconds?

Shadows of Saganami - Ch. 58 wrote: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.[...]"Guns," he said to his youthful acting tactical officer, "your target is the lead bogey. I want double broadsides at twenty-five-second intervals.

(And from later context it's clear that he means firing from all remaining tubes on each broadside -- not double pumping a single broadside's launcher)

Jonathan_S wrote:Agreed that we're just assuming that the cycle times for Mk16 and Mk23 launcher are the same (and that a notional Mk23E tube would also be the same).

But once I went back and looked at it SoS seems pretty clear on Hexapuma's cycle time. Where did you find the 30 total seconds?

In DW's replies further justifying why the SAG-C has broadside launchers but the Roland does not. Was not in books. Start up time for the micro fusion was longer than the launch cycle period not only requires a LOT more beam depth, but a lot more tonnage as well as must be armored to somehow contain a failed micro fusion reactor... Uh, we aren't supposed to ask how that miracle happens though....

Relax wrote:

Jonathan_S wrote:Agreed that we're just assuming that the cycle times for Mk16 and Mk23 launcher are the same (and that a notional Mk23E tube would also be the same).

But once I went back and looked at it SoS seems pretty clear on Hexapuma's cycle time. Where did you find the 30 total seconds?

In DW's replies further justifying why the SAG-C has broadside launchers but the Roland does not. Was not in books. Start up time for the micro fusion was longer than the launch cycle period not only requires a LOT more beam depth, but a lot more tonnage as well as must be armored to somehow contain a failed micro fusion reactor... Uh, we aren't supposed to ask how that miracle happens though....

Well, not so much contain as convince to vent primarily outward instead of back into the ship.

runsforcelery - 29-May-2011 RE: Pods / Tubes wrote:The actual "spinning up" interval on the Mark 16 is actually closer to 5 seconds from initiation to completion.
[snip]
Missile tubes are also fitted with massive containment armor and a "blow out" design to vent plasma outboard rather than inboard. (I realize "venting" is a relative term when we're talking about plasma, but it is an aspect of the design philosophy,

Also, while not mentioned it is possible that in addition to passive armor the ships try to use grav fields to encourage the plasma to blow out, rather than in.

Also, I went through my cache of RFC postings (which is where I found the quote above) and couldn't find anything about the cycle time of Mk16/Mk23 launchers. (Except for the 5-seconds of spin-up; which doesn't explain how long the total process takes) So I'm still confused about the apparent discrepancy between the claim of 30 seconds total and the book saying Hexapuma could launch on 18 second intervals.