A simple way to pack more missile tubes into modern hulls

Daryl wrote:To keep the salvos coherent the ship would have to stop accelerating while launching, otherwise they would be spread out before ignition.

Spreading the launch out to prevent wedge fratricide is kind of the point in staggering launch times. If you stop accelerating, you have to devise some other stratagem for avoiding fratricide.

Perhaps, but consider how far a ship accelerating at 500gs could travel between launches. There is staggered and then there is scattered. Perhaps reducing acceleration to an optimal spread wouls work better?

Weird Harold wrote:

Daryl wrote:To keep the salvos coherent the ship would have to stop accelerating while launching, otherwise they would be spread out before ignition.

Spreading the launch out to prevent wedge fratricide is kind of the point in staggering launch times. If you stop accelerating, you have to devise some other stratagem for avoiding fratricide.

Weird Harold wrote:

Daryl wrote:To keep the salvos coherent the ship would have to stop accelerating while launching, otherwise they would be spread out before ignition.

Spreading the launch out to prevent wedge fratricide is kind of the point in staggering launch times. If you stop accelerating, you have to devise some other stratagem for avoiding fratricide.

Daryl wrote:Perhaps, but consider how far a ship accelerating at 500gs could travel between launches. There is staggered and then there is scattered. Perhaps reducing acceleration to an optimal spread wouls work better?

Enh, not very. If that ship unloads two missiles 100 seconds apart, they'll be 25,000 km apart. If they're launched simultaneously, then 25 million km downrange, at a terminal speed of 0.5c the trailer would be 0.2 seconds behind the leader.

Bill Woods wrote: Enh, not very. If that ship unloads two missiles 100 seconds apart, they'll be 25,000 km apart. If they're launched simultaneously, then 25 million km downrange, at a terminal speed of 0.5c the trailer would be 0.2 seconds behind the leader.

Wouldn't that depend on the aspect of the target? Your math would seem to be accurate for a target at 0 deg, or dead on the nose of the launch ship's vector. Or, for an aspect of 180 deg, or directly aft.

If the aspect is 90 or 270 deg, then all missiles would arrive at the same time. Assuming, of course that they all start simultaneously -- which we can't assume. It would be safer to assume that missile ignition times would be staggered so that the all arrive at the same time at any aspect.

Weird Harold wrote:

Bill Woods wrote: Enh, not very. If that ship unloads two missiles 100 seconds apart, they'll be 25,000 km apart. If they're launched simultaneously, then 25 million km downrange, at a terminal speed of 0.5c the trailer would be 0.2 seconds behind the leader.

Wouldn't that depend on the aspect of the target? Your math would seem to be accurate for a target at 0 deg, or dead on the nose of the launch ship's vector. Or, for an aspect of 180 deg, or directly aft.

If the aspect is 90 or 270 deg, then all missiles would arrive at the same time. Assuming, of course that they all start simultaneously -- which we can't assume.

Sure; I was trying to look for the worst case.

It would be safer to assume that missile ignition times would be staggered so that the all arrive at the same time at any aspect.

That too. Though fratricide is an issue at the other end too, so maybe making the salvo a little three-dimensional is a good thing.

A lot of this is pretty easily correctable by varying ignition timing, by adjusting acceleration, and/or by varying the trajectory to make it longer than an optimal course would be. And given the absurd amount of computing power in even a small obsolete ship I would assume it is done.

Daryl wrote:To keep the salvos coherent the ship would have to stop accelerating while launching, otherwise they would be spread out before ignition.

We already have that with spinning the ship to use the offside tubes and stacked salvos. The spread is obviously not enough to matter. (And might actually be a good thing--you probably want your EW birds mostly in front. Thus launch them last.)

I would suspect that providing for that is a reason why the RMN designs for any power setting between 0 and max.

Hard to be sure since AFAICT we've never seen any settings other than 50% & 100% in practice. Which, come to think of it, is hardly surprising: can you imagine the whinging if a critical battle scene was interrupted so the TacO could explain the reasoning behind using a 46% setting for the 1st birds and 56% for the next lot?

kzt wrote:A lot of this is pretty easily correctable by varying ignition timing, by adjusting acceleration, and/or by varying the trajectory to make it longer than an optimal course would be. And given the absurd amount of computing power in even a small obsolete ship I would assume it is done.

Weird Harold wrote:More tubes could be squeezed into any broadside by using the same technique, but at the cost of seriously increased vulnerability to battle damage. Plus, such clusters would required better/heavier/thicker cofferdamming in bigger ships.

Possibly. But a Roland crams 6 tubes together. A pod crams 9-14 (depending on the pod and missile). But in both cases it's then a good long way to the next cluster of launchers. So the missiles have room to spread out to a) avoid killing each other off as their wedges light off and b) allow the launching ship to establish individual narrow beam fire control links to them.

Cramming that number of launchers into a single ship's broadside (less than 1km separation for even the largest ships) might rapidly run into issues that DD squadrons keeping hundreds of km of separation (or pods with probably dozens of km separation) wouldn't have.

Louis R wrote:I would suspect that providing for that is a reason why the RMN designs for any power setting between 0 and max.

Hard to be sure since AFAICT we've never seen any settings other than 50% & 100% in practice. Which, come to think of it, is hardly surprising: can you imagine the whinging if a critical battle scene was interrupted so the TacO could explain the reasoning behind using a 46% setting for the 1st birds and 56% for the next lot?

Or with MDMs explaining why a constant 50% or 100% setting is rarely the best profile for all 3 drives?
Sure, crunch the numbers and for anything before the crazy extended range enabled by Apollo you're always better off running the 1st drive at 100% power - but again having to explain why the missile accel drops (or even briefly coasts) after 60 seconds is a heck of a thing for a TacO infodump .