Concepts: Today's similarities and differences to the HV

tlb wrote:

tlb wrote:The ship could have an active sidewall on the upward side and fire through a gunport.

Jonathan_S wrote:Um, unless it has a spherical bubble sidewall a ship can't have a sidewall active without a wedge active. And activating a wedge while you're on the ground (or in the ocean) is going to end.... badly.

While I will agree that a sidewall without a wedge is not nearly as strong, I find it strange to hear that a sidewall requires a wedge. For example a buckler is a sidewall that is not attached to a wedge. More importantly every gun range uses a sidewall as a backstop (even those on planets) and clearly those do not require a wedge.

It seems to me that on a ship, they use the same nodes, but they have different generators. So what's the situation?

Short Victorious War wrote:The sides of the impeller wedge, unlike its ends, could be closed by gravity sidewalls, a much weaker version of the impeller stress band. A warship's sidewalls were its first and primary line of defense, extremely difficult for missiles to penetrate (though there was an unending race between missiles with better sidewall penetrators and defensive designers' efforts to build ever tougher sidewalls) and invulnerable to even the most powerful energy weapons at ranges in excess of 400,000 to 500,000 kilometers (approximately forty percent of effective range against targets without sidewalls).
[snip]
The Warshawski sail is essentially a highly modified and very powerful impeller stress band projected in the form of a disk at right angles to the hull, not as a wedge above and below it. The sail, which is just as impenetrable as an impeller wedge, extends for three hundred kilometers (as much as five hundred for really large vessels) in all directions. This not only makes chase armaments even more important but also deprives the warship of the protection of its wedge against fire from "above" or "below." Indeed, it deprives a ship even of its sidewalls, for there are no roof and floor for the sidewall to stitch together.

Mission of Honor wrote:Which, in turn, meant that instead of two broadsides, a spider-drive ship had three... none of which could be protected by the impenetrable barrier of an impeller wedge. That meant both that areas no impeller-drive ship had to armor did require massive armor protection aboard a spider-drive warship and that there was no wedge floor and roof for a side wall to stitch together. And just to make matters even more interesting, the spider drive could not be used through a spherical sidewall like the ones fortresses generated.

Jonathan_S wrote:A buckler is a new and possibly special case. It certainly doesn't stitch into the wedge like a normal sidewall, even like a full bow/stern wall, does. But RFC has not clarified whether or not it still relies on the presence of a wedge. (Though we know that 360 spherical bubble sidewalls do not)

Short Victorious War wrote:The sides of the impeller wedge, unlike its ends, could be closed by gravity sidewalls, a much weaker version of the impeller stress band. A warship's sidewalls were its first and primary line of defense, extremely difficult for missiles to penetrate (though there was an unending race between missiles with better sidewall penetrators and defensive designers' efforts to build ever tougher sidewalls) and invulnerable to even the most powerful energy weapons at ranges in excess of 400,000 to 500,000 kilometers (approximately forty percent of effective range against targets without sidewalls).
[snip]
The Warshawski sail is essentially a highly modified and very powerful impeller stress band projected in the form of a disk at right angles to the hull, not as a wedge above and below it. The sail, which is just as impenetrable as an impeller wedge, extends for three hundred kilometers (as much as five hundred for really large vessels) in all directions. This not only makes chase armaments even more important but also deprives the warship of the protection of its wedge against fire from "above" or "below." Indeed, it deprives a ship even of its sidewalls, for there are no roof and floor for the sidewall to stitch together.

The highlighted final sentence is where it tells us that (normal) sidewalls won't work without a wedge to "stitch" to.

And we're told that again in MoH, for why Ghosts, Sharks, and LDs lack sidewall protection

Mission of Honor wrote:Which, in turn, meant that instead of two broadsides, a spider-drive ship had three... none of which could be protected by the impenetrable barrier of an impeller wedge. That meant both that areas no impeller-drive ship had to armor did require massive armor protection aboard a spider-drive warship and that there was no wedge floor and roof for a side wall to stitch together. And just to make matters even more interesting, the spider drive could not be used through a spherical sidewall like the ones fortresses generated.

Maybe, if a buckler can work while the wedge is down, then you could mount a buckler generator elsewhere to project such a defensive disk. (Mind you a single buckler is less than twice the diameter of a ship's maximum beam -- so it's going to protect only a small fraction of the length of its flank. And we don't know if you can merge them together or overlap them)
OTOH since a buckler is described as the first stage of a two stage bow wall - and we're told in SoS that the forward impellers have to be designed to be compatible with a bow wall generator (you need to gut the forward impeller room to refit one) - so maybe even the buckler requires compatible impellers and so wouldn't work if they weren't powered up.

But unlike the Solarian Navy’s warships, the throats of current-generation Manticoran warships were no longer the traditional gaping chink in their armor. The bow-wall and its smaller cousin, the buckler, had finally provided the equivalent of a sidewall — and a very powerful sidewall — to cover that lethally vulnerable aspect of the wedge.

The jacketed slug exploded through the equally anachronistic paper target's "X" ring in a shower of small, white fragments, then vanished in a fiery flash as it plowed into the focused grav wall "backstop" and vaporized.

The strength of the wedge does affect the effectiveness of the sidewall, but it isn't the decisive factor in sidewall strength. It's the sidewall generators which determine that.

A sidewall is basically a "plate" of focused gravitic energy, and the bigger (and stronger) its generator, the stronger and tougher the sidewall plate is going to be. The logical implication of this is that larger ships with more tonnage for generators and a larger energy budget can produce stronger sidewalls, and that's the real reason ships-of-the-wall, for example, have sidewalls so much tougher than a battlecruiser's or a destroyer's. It's also the reason the Nike-class battlecruisers have stronger sidewalls than the Agamemnons; the BC(L)'s designers devoted the tonnage and the power to generate them because toughness and survivability were higher priorities in the Nike's concept design stage.

Now, where the basic size and power of the ship's impeller wedge come in is in the "stitching" — the interface where the sidewall and the wedge come together. The sidewall is strongest at the center, with the strength (the gravitic "depth," if you will) of the "plate" dropping off proportionately as one approaches its boundaries. That means the upper and lower edges of the sidewall are the "sweet spot" where the attacker really wants his energy weapon shot to hit, and the stronger or "deeper" the impeller wedge is, the more its "shadow" protects that "seam" from incoming fire. The sidewall actually reaches up into the impeller wedge (where the two of them are tuned to interface and interlock), much as the impeller wedge reaches across the alpha wall to siphon in additional power to maintain the wedge once it's up. The effect in this case is much less noticeable in terms of power supply, but the interface also "bends" or slightly deforms the surface of the impeller wedge, pulling it "downward" to the edge of the sidewall plate, which is where the defensive "shadow" originates, and the stronger the impeller band, the stronger (tougher) that shadow becomes. In combination these factors significantly reinforce the strength of the sidewall edges where they are inherently weaker, which means that the same sidewall generator will produce a more effective sidewall when it has a stronger or "deeper" impeller wedge with which to interface. It's not that the sidewall itself is actually stronger, but rather that it is able to use its strength in a more inherently efficient fashion. This is only a factor for hits that would come in through that reinforced area, and the reinforcement itself is a small enough factor in the sidewall's overall power that this is not a significant element in the difference of sidewall strength between, say, a Nike and an Agamemnon. It would, however, be a very significant element in the difference between the strength of an SD's sidewall and that of a CA.