1st war - Rolling wedge tradeoffs as a defensive tactic

One of the Q&As at Honorcon got me thinking about an interesting point about the defensive tactic of rolling wedge against enemy fire. (And I'm thinking primarily 1st war period; before bow or stern walls, before keyhole allowed CM fire while rolled, etc)

When you roll wedge you obviously put your impenetrable impeller bands directly toward the enemy; and missiles that fire into them have wasted their shot. But what about missiles that end up ahead or astern of you?

Ok you probably don't have a solid enough track to try to hit them with a CM as they're clearing the wedge angle, so it's a race between the missile and the PDLCs on the hammerheads. (So far nothing new here)

But one of the BuNine guys made the point that especially for a missile attacking the bow the throat makes an awfully tall opening, it seems many of your chase PDLCs won't have an angle on the missile as it clear the wedge (other parts of the hammerhead get in the way)

Also sidewalls extend fore and aft to the ends of the wedge. So when you are broadside on to the enemy not only can your CMs and broadside PDLCs attempt to engage any missiles that dive in for a down the throat shot but unless they fire down the 20km wide corridor between the sidewalls they're still going to be degraded by the sidewalls. At .6c that give the missile about 110 microseconds to cross that 20 km zone. (It'd be a bit more because you can angle the shot in slightly, but not a lot more because the ship is many km back (roughly 150 km back for an SD), so the firing angle isn't that much greater than the opening size). But the missile has a bit more freedom to position above or below the plane of the ship because the opening between the wedge planes is much larger than the 20km opening between the sidewalls; twice as bit at the after (40 km) and 9.5x more at the fore (190 km).

But when the ship is rolled that sidewall tunnel is also rolled. So now instead of the throat having a 20 km wide by 190 km tall tunnel it's got a 20 km tall by 190 km wide one. Missiles can probably align themselves to be along it before clearing the wedge and then they get almost 10 times as long to get a sidewall free shot.

Plus if they fire quickly, or delay a bit, they've got a good chance to put at least some laser head beams into the largely unarmored dorsal, or ventral, surfaces of the ship. Possibly even hitting the backside of the aft impeller ring, which is between the missile detonating in front of the ship and the protective armor of the aft hammerhead.



Now to some extent this can be mitigated by careful positioning of formations, giving ships in company with you a chance to use their point defenses to try and pick off missiles boring in for a down the throat shot on you (even while rolled).

Also if you only partially roll your wedge the sidewalls won't be parallel to the missile's line of travel, and the further from parallel you are the "shorter" the effective opening becomes. Similarly, if you apply to port (or starbord) turn after rolling down that'll angle your nose up (or down), however that's probably easier for missiles to see and reposition themselves to still fly across the center of your wedge opening.


The real question I have is how freely a ship can maneuver away from the geometric center of the wedge. I know it can displace some, but can it also rotate some? If it can then it can cause its sidewalls to cease to be perfectly parrallel to the sides of the wedge - and that's something a missile shouldn't be able to see until it actually clears the wedge; at which time even against a rolled ship it doesn't have time to adjust its positioning noticeably before it flies across the opening and the far wedge against blocks the shot.


Anyway, random thoughts and speculation. I look forward to any feedback.

The whole maneuvering of ships has really made no sense as presented. Ships in the honorverse should be incredibly maneuverable, able to roll and turn very fast independent of their size. The ability of the ships to survive a compensator failure means that the structure of the ships is at least 500 times stronger than what is required for normal operation, so there really is no structural reason for the limit. The compensator cancels any impact on the crew too.

Jonathan_S wrote:But one of the BuNine guys made the point that especially for a missile attacking the bow the throat makes an awfully tall opening, it seems many of your chase PDLCs won't have an angle on the missile as it clear the wedge (other parts of the hammerhead get in the way)

(Bold mine)

I have to take exception with this part right here. The PDLCs are as far forward (or aft) along the sides of the hammerhead as possible without actually putting them on the face of the hammerhead. In fact, the actual emitters are *beyond* the face of the hammerheads on most, if not all, of my meshes. Therefore, there shouldn't be *any* part of the hammerhead "in the way" of the PDLCs.

OTOH, CM tubes (on older ships that have chase CM tubes) are usually placed midway between the fore and aft ends of the hammerheads.

This is one way that my models differ from the art in HoS, and when I first started doing these, I *was* placing the PDLCs as they are shown in the book, but was told to place them at the edges of the hammerheads, as they are now.

MaxxQ wrote:

Jonathan_S wrote:But one of the BuNine guys made the point that especially for a missile attacking the bow the throat makes an awfully tall opening, it seems many of your chase PDLCs won't have an angle on the missile as it clear the wedge (other parts of the hammerhead get in the way)

(Bold mine)

I have to take exception with this part right here. The PDLCs are as far forward (or aft) along the sides of the hammerhead as possible without actually putting them on the face of the hammerhead. In fact, the actual emitters are *beyond* the face of the hammerheads on most, if not all, of my meshes. Therefore, there shouldn't be *any* part of the hammerhead "in the way" of the PDLCs.

OTOH, CM tubes (on older ships that have chase CM tubes) are usually placed midway between the fore and aft ends of the hammerheads.

This is one way that my models differ from the art in HoS, and when I first started doing these, I *was* placing the PDLCs as they are shown in the book, but was told to place them at the edges of the hammerheads, as they are now.

I may have misunderstood what he was saying, but I thought he said the PDLCs would have trouble bearing on a missile that was popping down from just over 30 degrees up angle from the bow. (But maybe I got the reason wrong, or maybe he misspoke)

So when the ship is rolled so the top is pointed towards the missiles, the lower PDLCs, the one just below the face of the hammerhead, can still angle upwards over 30 degrees... Interesting, I'd have guessed that they'd have had traversal limits imposed by the hammerhead geometry.


Anyway thanks for clarifying where they're placed on the current 3D models.

Jonathan_S wrote:I may have misunderstood what he was saying, but I thought he said the PDLCs would have trouble bearing on a missile that was popping down from just over 30 degrees up angle from the bow. (But maybe I got the reason wrong, or maybe he misspoke)

So when the ship is rolled so the top is pointed towards the missiles, the lower PDLCs, the one just below the face of the hammerhead, can still angle upwards over 30 degrees... Interesting, I'd have guessed that they'd have had traversal limits imposed by the hammerhead geometry.

Anyway thanks for clarifying where they're placed on the current 3D models.

I don't think it's so much hammerhead geometry, but more along the lines of wedge geometry and the limits of how far off-centerline the emitters can be aimed. Depending on the size of the wedge and/or sidewalls, there's a limit (as you noted before) to the angle of fire, which of course works both ways for the incoming missile/laserhead fire and outgoing PDLC fire.

Obviously, PDLC mounts on the far side of the incoming attack are going to have issues with aiming, but as I said before, they're placed to provide as much coverage as possible. I suppose you could think of it like a B-17's nose guns - the one on the left side can deal better than the one on the right with incoming aircraft on the left. Granted, in this case, there *is* a bit of the aircraft nose blocking the opposite gun, but I think you get what I mean.

TBH, I don't even know what a PDLC mounts field of fire is. All I know is that whatever it is, it should be maxxed out for all PDLCs on the hammerhead because there's no other part of the ship blocking any particular angle. Look at this image of the Star Knight CA: http://maxxqbunine.deviantart.com/art/S ... -475462450

The PDLCs are the projections around the face of the hammerhead. Nothing there I can see that could block any reasonable firing angles, and even if they are grav-aimed, I doubt very much you can bend the beam more than 30 degrees off-center, and more likely, it's 15-20 degrees. But that's just my guess, as we haven't really discussed that.

As MaxxQ stated, there is nothing in the way of the emitter covering the entire throat/kilt between the sidewalls. If some designer placed the PDLC so it can't actually cover the throat... some engineer needs to be fired. The PDLC's do not have to be perfectly aligned with the longitudinal axis of the ship. If for instance they can only "traverse say 20 degrees off axis" and the throat is 60 degrees wide, then you place your PDLC's on top of your hammerhead "up" by ~15 degrees, to cover the extreme top, allowing a 5 degree overlap with the bottom hammerhead PDLC's that are likewise oriented in the same fashion. If the angle of PDLC 2X traverse is less than 1/3 that of the throat open angle, kilt angle is miniscule, then either one has to assume no shot will go in at that angle or one has to place maybe one dedicated PDLC completely off angle to cover this aspect. Either way, it can be covered fairly easily and there is no real justification for designing a ship with a completely undefended aspect to an UNARMORED portion of your ship.

This would fall under the heading of, minuscia, not fit for placement in the books, or even a pearl IMO.

As for the "get 10X longer" shot time. Not sure what velocities were used etc, but this has always been true for the throat. Thought that was stated fairly clearly and early in the books in both OBS and HotQ. The Kilt on the other hand is just about as narrow of a slit top to bottom as side to side. Per the Geometry sidewall drawing over on the fifth imperium, the throat angle is roughly 60 degrees. From memory. Sidewall angle to throat/kilt is 2.5 degrees or so. Either that is 2.5 degrees total, or 2.5 degrees off axis for 5 degrees total for a difference of either 12X~25X.

Anyways, jealous of those who could attend Honorcon.