Attacking Darius:

tlb wrote:

Jonathan_S wrote:I thought it uses a special type of sidewall generator.

Certainly SVW doesn't say anything about it being generated via impeller nodes - "the [Hancock] base wasn't totally helpless. It mounted no offensive weapons, but it was fitted with generators for a spherical sidewall "bubble" almost as strong as Nike's own"
and
"A few navies have experimented with the idea of mounting the sidewall bubble generators used to generate 360° "sidewalls" around fixed fortifications in their capital ships for use in hyper-space engagements, but the sheer mass of the system is self-defeating. A ship so equipped has an enormous advantage in hyper, but the volume consumed by the generators cuts deeply into that available for weapons, which places the same vessel at an even greater disadvantage in normal-space combat."

I suppose it's not impossible that they also tie into the impeller nodes - but I can't recall every seeing anything indicating that

I agree that there is something special about the generator and cannot find any mention of what nodes are used. But a warship generates sidewalls using the nodes that we know about, so I conjecture that the spherical sidewalls might also use the nodes that we know. Unless RFC is explicit, this will fall into the set of unknowns.

Jonathan_S wrote:Which is a bit odd because I thought forts normally had impellers down and spherical sidewalls up.

Though they do make a point that the Junction forts need to rotate back periodically so they can turn off their sidewall generators for maintenance.

So, I'd have expected most of those Galton OWP forts to have sidewalls up at any given time - and thus been pretty well protected from a surprise missile strike.

ThinksMarkedly wrote:

Jonathan_S wrote:Which is a bit odd because I thought forts normally had impellers down and spherical sidewalls up.

Though they do make a point that the Junction forts need to rotate back periodically so they can turn off their sidewall generators for maintenance.

So, I'd have expected most of those Galton OWP forts to have sidewalls up at any given time - and thus been pretty well protected from a surprise missile strike.

Now that you mention it, I also found it strange when reading this passage that the Galton forts would bring wedges up, not bubble walls. Maybe it was all the discussion here about how the Junction forts used bubblewalls that made me think that was always the case for any fort, without supporting textev.

Bubblewalls are good, but not as good as a full wedge: the former can be penetrated with enough energy or persistence via missiles or energy weapons, while there's no known weapon that can penetrate a wedge, short of a bigger wedge. There's no way you could attack using a bigger wedge than a fort because the only thing that could mount such a wedge is another fort and forts aren't offensive installations. They're mobile, but they're slow.

Maybe the important distinction is location: the Junction forts are at the Junction, so they're only protected by a 1-light-second hyperlimit and at the mercy of a sudden and unexpected transit. Old-style SDMs could sprint 2.3 million km in 60 seconds, which is not enough warning time to bring up a full wedge even if your nodes are on standby. But planetary orbital forts are inside of the star's hyperlimit and could thus be expected to have sufficient advance warning of any attack. They'd have 10 to 12 light-minutes of range and even during the Battle of Manticore Honor had said she couldn't attack from 8 light-minutes away with certainty of hitting. If the Galton defenders assumed that Honor had to reach about the same distance at which she trounced the RHN Fifth Fleet (say, 5 light-minutes), they'd have counted on the GF coming 5 to 7 light-minutes into the hyperlimit. At 600 gravities, that would be between 130 and 154 minutes.

And yet the Battle of Galton was practically entirely fought from the hyperlimit, with a 20.7 to 24.4-minute flight time for every missile. That means Apollo improved a lot in those intervening 3 years.

(The return fire with 2-stage Cataphracts would need to cover about 160 to 195 million km ballistically with just the velocity of the first stage, for a total of ~35 to 42 minutes)

Jonathan_S wrote:The wedge is impenetrable - but it also forces you to open up at least one unprotected aspect in your defenses - because even with bow/stern walls you can't close both ends of a wedge simultaneously.

(If you're Manticore you can probably partly protect the other aspect with a buckler wall - but those seem to cover a very small arc so you're still quite vulnerable to fire from that end -- they're better against energy weapons in a 1-on-1 pursuit since you can keep your protected nose pointed straight at the enemy)

So a wedge and sidewalls are useful if you need to reposition the fort; and having two aspects that no weapon can hurt you through it nice. But it that's the way forts were intended to fight then why would the designers waste the (apparently very considerable) mass and volume also installing the bubble generator?

And probably less important now with pods and off-bore CM firing, but if you plan to fight with a 360 sidewall then you can install missile and CM tubes, and PDLC into the arc where warships can't because their fire would be blocked by their own wedge.

Chapter 7 wrote:"And finally, the R&D boffins have come up with something really nice for these ships." Truman smiled at her audience like a shark. "As we all know, it's impossible to close the bow or stern aspect of an impeller wedge with a sidewall, right?" Heads nodded once again. "And why is that, Lieutenant Takahashi?" she asked genially.
The lieutenant looked at her for a moment, with the expression of someone whose Saganami Island days were recent enough in memory to make him wary of leading questions. Unfortunately, she was a senior-grade captain and he was only a junior-grade lieutenant, which meant he had to answer her anyway.
"Because cutting off the stress bands' n-space pocket with a closed wedge prevents you from accelerating, decelerating, or using the wedge to change heading, Ma'am," he replied. "If you want the math—?"
"No, that's all right, Lieutenant," she said. "But suppose you don't want to accelerate or decelerate? Couldn't you generate a 'bow' sidewall then?"
"Well, yes, Ma'am, I suppose you could. But if you did you'd be unable to change—" Takahashi stopped speaking suddenly, and Lieutenant Commander Stackowitz gave a sharp, abrupt nod.
"Exactly," Truman told them both. "The idea is that LACs will attack single starships in sufficient numbers that it will always be possible for them to close obliquely. The new missile tubes, coupled with the recent improvements in seekers, molycircs that can handle higher-grav vector shifts, and a higher acceptable delay between launch and shipboard fire control's hand-off to the missile's on-board systems, will let them fire effectively at up to a hundred and twenty degrees off bore. That means the Shrikes can engage with missiles—and launch counter-missiles against incoming fire—even on an oblique approach. Once they reach energy range, however, they turn directly in towards their targets and bring up their 'bow' sidewall . . . which has only a single gunport, for the graser, and is twice as powerful as the broadside sidewalls. That makes it as tough as most dreadnought's sidewalls, people, and according to the Advanced Tactical Course's simulators, a target as small as a bow-on LAC should be much harder to hit than a larger warship engaging broadside-to-broadside even under normal circumstances. When you add the sort of electronic warfare capabilities these ships have, they turn into even harder targets, and the presence—and power—of their 'bow' sidewalls should make them harder to kill even if the bad guys do manage to lock them up."

penny wrote:I came across something early on in the climactic battle in the Galton System.

Honor wanted to roll pods before they entered the system to immediately launch on the forts. The Admiralty wouldn't let her. Meghan Petersen argued against attacking the forts (civilians) as well.

Anyway, Honor's musings stated that forts of that size can't possibly keep their impellers online.

Unless the impellers' were continuously online, which was extraordinarily unlikely, given the power demand and relatively short operational life of impeller nodes that size, that strike would have gone home before they could bring up the protective bands of their wedges.

I didn't know that forts have that severe a problem with Pac Man eating sprockets, cogs and nodes.

The RMN must be playing musical chairs with their forts a lot more than I thought. Though their forts are smaller.

Jonathan_S wrote:Which is a bit odd because I thought forts normally had impellers down and spherical sidewalls up.

Though they do make a point that the Junction forts need to rotate back periodically so they can turn off their sidewall generators for maintenance.

So, I'd have expected most of those Galton OWP forts to have sidewalls up at any given time - and thus been pretty well protected from a surprise missile strike.

penny wrote:Honor's musings stated that forts of that size can't possibly keep their impellers online.

The RMN must be playing musical chairs with their forts a lot more than I thought. Though their forts are smaller.

tlb wrote:

penny wrote:Honor's musings stated that forts of that size can't possibly keep their impellers online.

The RMN must be playing musical chairs with their forts a lot more than I thought. Though their forts are smaller.

The key point is "of that size", an extra large fort would require much more power to generate the appropriate sized wedge or spherical sidewall than a regular one resulting in extra wear. Wouldn't the power required go up as the surface area, so R squared. Plus the Manticoran forts are now smaller than their prewar predecessors and have the Beta-Squared nodes. There has been no sign that the junction forts spent a significant amount of downtime for maintenance.

tlb wrote:All the weapons around the junction have targeting radar and we have no reason to suppose that the spider drive ships are invisible to radar.

tlb wrote:

Jonathan_S wrote:The wedge is impenetrable - but it also forces you to open up at least one unprotected aspect in your defenses - because even with bow/stern walls you can't close both ends of a wedge simultaneously.

That is not correct, you can completely close the bow and stern with sidewalls, if you have enough sidewall generators. Here is the explanation from Echoes of Honor[snip]The next book, Ashes of Victory, introduced a LAC with four sidewall generators and At All Costs introduced the buckler, which allowed the ship to accelerate and maneuver, since the aspect was not completely closed.

Ashes of Victory - Ch. 24 wrote:Accordingly, BuShips had used the last scraps of the internal volume freed by removing the graser to shoehorn in an additional sidewall generator. Just as powerful as the new "bow-wall" that closed off and protected the front of a Shrike's wedge as it bored into energy range, the Ferret's "sternwall" closed off the rear of the wedge. Power requirements and the physics of the wedge meant only one aspect, bow or stern, could be closed at any given moment, but it gave a Ferret's skipper a much more flexible choice of breakaway vectors.

House of Steel wrote:Another advantage of the Saganami-C design are its two-phase bow and stern wall generators. A traditional endwall closes off the wedge at one end or another, reducing acceleration to zero for as long as it is active, but the two-phase generators carried by the Saganami-C allow the ship to produce what the RMN refers to as a “buckler.” This is a smaller endwall projected across the throat or kilt but not directly connected to the wedge. Its arc of coverage is not as wide as a traditional endwall and leaves vulnerable gaps in some engagement geometries, but the ship retains the ability to accelerate and maneuver when it is active.

tlb wrote:All the weapons around the junction have targeting radar and we have no reason to suppose that the spider drive ships are invisible to radar.

penny wrote:I agree that that should be true. But only if all else is equal. All else is NOT equal IF the RMN keeps its forts energized. The power meter outside of RMN forts is spinning like crazy when the power company checks the meter. LOL

Might they be? The smart fabric says it is able to bend light. And the Michelson-Morley experiment showed us that light is a wave. Radar is a wave.*

IINM, the Navy's retired F-117 Nighthawk utilized radar resistant (absorbing) paint?

*The double-slit experiment proved light to be both a point source and a wave. Particle wave duality.

Jonathan_S wrote:Actually it's the next book, AoV, that makes it clear than you can't completely close both bow and stern at the same time. That's what I was referring to when I said you were forced to leave one aspect vulnerable.