Mistletoe 2

JPMorgan wrote:Point defense lasers are used to protect against larger pieces of debris if the debris is not hidden by some sort of RAM. Railguns were mentioned as being used long ago in the Honorverse for exactly this purpose. Running headlong into thousands of steel slugs caused significant damage at any fraction of C.

Railguns are offensive systems, that fire high mass slugs, and even in honorverse would have a few seconds to cycle. The missile tubes are technically railguns, and even on destroyers have around 8 second cycle times (although, I admit that could be actually loading the next missile in the tube). Depleted uranium, and related high-mass things are ideal for a railgun, where steel is a bit soft.

What you were thinking of, were simply auto-cannons, commonly mounted on virtually the entire Solarian superdreadnought fleet in mothballs. Very few of them, compared to the whole, ever got updated to point defense lasers. And missiles detonate well beyond the range most autocannon can sling their rounds in time.


And autocannon round would likely be, for all intents, small caliber rounds, can't imagine even superdreadnoughts to be using much larger than .45cal because they also have to store large amounts of autocannon ammo (not an issue with lasers).

Taking out debris with autocannons just turns it from one mass into either a cloud of pellets, or dust, either of which could cause even more damage to a habitat by making multiple holes, over a large area than a single chunk making one hole.

Jonathan_S wrote:Also an missile impeller wedge is destroyed if it touches a sidewall or another wedge - so there's a relatively narrow angle at which an impeller head missile can even reach a warship (basically down the throat or up the kilt through a 20km wide corridor formed by it's sidewalls - not coincidentally those vulnerable aspects are exactly where all its chase point-defense is aimed.

Sidewalls are the reason antiship missiles stopped trying for wedge impact and first gained nuclear warheads (see the armor essay in the anthology In Fire Forged)

Now if JPMorgan is proposing to use them against dispersed missile pods, as Mistletoe has been, you don't need to worry about sidewalls or point defense. On the other hand, the nuclear warheads seem to be able to proximity kill pods out to a radius of around 30,000 km (because any unused towed pods are apparently destroyed when the enemy's first salvo of laserheads detonates; and that's their standoff range)
The wedge on a SAM (as an example of a tiny impeller head missile) probably only has a danger area of, to be quite generous, 6,500 square km (1/2 km wide wedge, and a 13,000 km range (about the range the shuttle ground attack missiles used against the courier ship in EoH had). So against targets vulnerable to proximity kills a big nuke seems more effective.

(However amusing the thought of a swarm of impellers chewing their way through everything in their path is)

Keep in mind that a wedge is used only for propulsion. A wedge is two gravitational fields inclined to provide motion. A single field provides shielding that nothing but photons can penetrate. The field itself will disassociate particles down to it's atomic, maybe sub-atomic, structure. So an item that is a meter long and .3 meters in diameter can generate an inclined wedge that is a hundred meters or more wide. If you strip it down to just 1 field with no thought of motion or need for navigation the item shrinks in size even more. If hundreds are dumped in the path of a ship by a ghostrider platform and they are stealthed to avoid radar detection they can be scooped up into the ships wedge quite easily. If they are remotely activated when they are a second or two from impact and suddenly hundreds of planes?(I can't think of the technical term David uses for the single gravitational plane) come up and the ship plows into them the ship is Swiss cheese if they are lucky. Since you can't shoot through a wedge point defense is useless against it. However, since it is a single plane there is a 50% chance the unit comes up with the field facing in the wrong direction. Still we are talking about a very inexpensive but crippling weapon that can be deployed in huge quantities. A serious last ditch weapon nobody would expect but very effective when you have few ships of the wall left.

JPMorgan wrote:Particle screens are only designed to stop atoms, molecules and dust. These screens only work up to .8 C hence the speed limit for all ships. While the throat of an impeller wedge is many kilometers across the ship itself is only several hundred meters across. Point defense lasers are used to protect against larger pieces of debris if the debris is not hidden by some sort of RAM. Railguns were mentioned as being used long ago in the Honorverse for exactly this purpose. Running headlong into thousands of steel slugs caused significant damage at any fraction of C.

Not in the modern honorverse. Particle screens are good for objects into at least the single digit meter scale.

Somtaaw wrote:

JPMorgan wrote:Point defense lasers are used to protect against larger pieces of debris if the debris is not hidden by some sort of RAM. Railguns were mentioned as being used long ago in the Honorverse for exactly this purpose. Running headlong into thousands of steel slugs caused significant damage at any fraction of C.

Railguns are offensive systems, that fire high mass slugs, and even in honorverse would have a few seconds to cycle. The missile tubes are technically railguns, and even on destroyers have around 8 second cycle times (although, I admit that could be actually loading the next missile in the tube). Depleted uranium, and related high-mass things are ideal for a railgun, where steel is a bit soft.

What you were thinking of, were simply auto-cannons, commonly mounted on virtually the entire Solarian superdreadnought fleet in mothballs. Very few of them, compared to the whole, ever got updated to point defense lasers. And missiles detonate well beyond the range most autocannon can sling their rounds in time.


And autocannon round would likely be, for all intents, small caliber rounds, can't imagine even superdreadnoughts to be using much larger than .45cal because they also have to store large amounts of autocannon ammo (not an issue with lasers).

Taking out debris with autocannons just turns it from one mass into either a cloud of pellets, or dust, either of which could cause even more damage to a habitat by making multiple holes, over a large area than a single chunk making one hole.

I should not have run those two sentences together. They should have been paragraphed since they are to subjects.
Point defense lasers for debris protection vs railguns for offensive weapons.

Railguns were used from hundreds of millions of kilometers away as system defense. Usually from a fixed position. Fired in large quantities into the path of a ship was very effective if the ship did not deviate from it's flight path. And whether you use soft boiled eggs or steel the effect was the same when a pellet at .2c struck anything moving at .5c. However since it is a railgun the ammo must be magnetic. And railguns are capable of firing thousands of rounds a minute. Clouds of projectiles would be sent into the path of oncoming enemies.

JPMorgan wrote:Keep in mind that a wedge is used only for propulsion. A wedge is two gravitational fields inclined to provide motion. A single field provides shielding that nothing but photons can penetrate. The field itself will disassociate particles down to it's atomic, maybe sub-atomic, structure. So an item that is a meter long and .3 meters in diameter can generate an inclined wedge that is a hundred meters or more wide. If you strip it down to just 1 field with no thought of motion or need for navigation the item shrinks in size even more. If hundreds are dumped in the path of a ship by a ghostrider platform and they are stealthed to avoid radar detection they can be scooped up into the ships wedge quite easily. If they are remotely activated when they are a second or two from impact and suddenly hundreds of planes?(I can't think of the technical term David uses for the single gravitational plane) come up and the ship plows into them the ship is Swiss cheese if they are lucky. Since you can't shoot through a wedge point defense is useless against it. However, since it is a single plane there is a 50% chance the unit comes up with the field facing in the wrong direction. Still we are talking about a very inexpensive but crippling weapon that can be deployed in huge quantities. A serious last ditch weapon nobody would expect but very effective when you have few ships of the wall left.

Sidewalls eat missile wedges. Your swarm of dinky little wedges would get wiped out if the ship maneuvered in any way to bring a sidewall to bear on the threat. Killing ships by slamming a wedge into it has been a non-threat for quite some time now.

kzt wrote:

JPMorgan wrote:Particle screens are only designed to stop atoms, molecules and dust. These screens only work up to .8 C hence the speed limit for all ships. While the throat of an impeller wedge is many kilometers across the ship itself is only several hundred meters across. Point defense lasers are used to protect against larger pieces of debris if the debris is not hidden by some sort of RAM. Railguns were mentioned as being used long ago in the Honorverse for exactly this purpose. Running headlong into thousands of steel slugs caused significant damage at any fraction of C.

Not in the modern honorverse. Particle screens are good for objects into at least the single digit meter scale.

I don't recall ships being able to nudge things the size of a house aside. They were always careful when maneuvering around asteroid belts and asteroid belts are mainly composed of items smaller than this. A couple of planetoids, thousands of chunks a kilometer or so in diameter and literally billions of house size or smaller pieces spread out over a stupendous volume of space.
But I'll take your word for it(and reread the series again).

JPMorgan wrote:Keep in mind that a wedge is used only for propulsion. A wedge is two gravitational fields inclined to provide motion. A single field provides shielding that nothing but photons can penetrate. The field itself will disassociate particles down to it's atomic, maybe sub-atomic, structure. So an item that is a meter long and .3 meters in diameter can generate an inclined wedge that is a hundred meters or more wide. If you strip it down to just 1 field with no thought of motion or need for navigation the item shrinks in size even more. If hundreds are dumped in the path of a ship by a ghostrider platform and they are stealthed to avoid radar detection they can be scooped up into the ships wedge quite easily. If they are remotely activated when they are a second or two from impact and suddenly hundreds of planes?(I can't think of the technical term David uses for the single gravitational plane) come up and the ship plows into them the ship is Swiss cheese if they are lucky. Since you can't shoot through a wedge point defense is useless against it. However, since it is a single plane there is a 50% chance the unit comes up with the field facing in the wrong direction. Still we are talking about a very inexpensive but crippling weapon that can be deployed in huge quantities. A serious last ditch weapon nobody would expect but very effective when you have few ships of the wall left.

I'm still having trouble seeing this as a viable weapon.

If the missile is pointing towards the ship then, by definition the open face of it's wedge it pointed towards the ship's point defense. So the mini-missile's wedges can't shield them from point defense. The wedge opening at the front gives visibility to the missile body from about a 120 degree vertical arc - so if you're pointed even vaguely towards the ship it has a shot at you.

Also miniature wedges seem to have far less accel than full up anti-ship missiles. I'd guestimate the SAM that hit Honor's pinnace at closer to 1000g than the 92000g a shipkiller at full accel can pull. So if it's only good for 1000g then for the couple second run you wanted it has to start within 20km of the ship. That's roughly 130km inside the throat of the wedge. If you can get a ship to literally run over your missile then yeah it could do damage. But a RMN laserhead lying doggo and overrun by the ship could have done the same from 50,000 km out, or a contact nuke would be totally devastating from over 1000 km out....

Duckk wrote:Sidewalls eat missile wedges. Your swarm of dinky little wedges would get wiped out if the ship maneuvered in any way to bring a sidewall to bear on the threat. Killing ships by slamming a wedge into it has been a non-threat for quite some time now.

Once an object is swallowed into the throat of a wedge you CANNOT interpose a sidewall. Assuming you even see the stealthed items before its to late sure you could turn sideways and interpose a sidewall.
A ship is a dinky little item compared to a wedge. A wedge is 100 times larger than a ship and the 2 planes of a wedge are many kilometers apart with the ship sandwiched between them. Imagine 2 sideways sheets of newspaper half a foot apart with a little pencil eraser suspended between them. This is why rolling ship is so effective.

JPMorgan wrote:

Duckk wrote:Sidewalls eat missile wedges. Your swarm of dinky little wedges would get wiped out if the ship maneuvered in any way to bring a sidewall to bear on the threat. Killing ships by slamming a wedge into it has been a non-threat for quite some time now.

Once an object is swallowed into the throat of a wedge you CANNOT interpose a sidewall. Assuming you even see the stealthed items before its to late sure you could turn sideways and interpose a sidewall.
A ship is a dinky little item compared to a wedge. A wedge is 100 times larger than a ship and the 2 planes of a wedge are many kilometers apart with the ship sandwiched between them. Imagine 2 sideways sheets of newspaper half a foot apart with a little pencil eraser suspended between them. This is why rolling ship is so effective.

First, if you have a buckler or full bow wall then it's only 10km out in front of the ship -- over a hundred km within the wedge.

But you don't need to turn far enough to put a sidewall between the missile and the hammerhead; only enough to cause the missile's wedge against either of the sidewalls. That's only a 20 km wide slot the missile is trying to fly down (sidewalls are 10km out from the hull's broadsides) and those sidewall project the full length of the wedge.


Even so, most likely you can't sideswipe every missile that might light up within the throat of your wedge. But getting something undetected to within 150 km of your target (or within 20km if my previous time/accel calculations were right) is virtually impossible to begin with. Not to mention the huge unlikelihood of being able to stealthily place a ballistic or stationary "mine" such that a ship actually runs it over.

JPMorgan wrote:I don't recall ships being able to nudge things the size of a house aside. They were always careful when maneuvering around asteroid belts and asteroid belts are mainly composed of items smaller than this. A couple of planetoids, thousands of chunks a kilometer or so in diameter and literally billions of house size or smaller pieces spread out over a stupendous volume of space.
But I'll take your word for it(and reread the series again).

http://infodump.thefifthimperium.com/en ... gton/126/0
"The lower-velocity, "killer ball-bearing" forms of attack would be even less effective. First, all high-value system infrastructure in the SKM (and now in Yeltsin) modules comes with built in particle-shielding of the sort installed in hyper ships. Unless your ball-bearings come in at a very high fraction of light-speed, the particle shielding can probably handle them. Remember that this shielding is designed to protect ships moving at up to 80% of light-speed, and while the average particle level in deep space is very low, it is also designed to deal with the occasional "Oopsie! Didn't see that coming!" lump of matter too small for a decent radar return. That sounds to me very like the size range in which your ball-bearing would fall, and unless your attack unit spent a lot of time accelerating before launching them, they would be coming in much slower than .8 cee. And if your attack unit spends the time to accelerate before launch, it will be sighted, the probability of an attack will be allowed for even if it hypers back out before interception, and defensive measures will be initiated."

An Introduction to Modern Starship Armor Design
"The space between the sidewall and the hull is filled with particle and radiation shielding to deal with natural space hazards. These shields plow debris and radiation out of the ship’s path using a weaker gravitic field. Instead of the sidewall’s small localized region of incredibly high acceleration, these shields are more gradual. They typically work on particles for longer periods, pushing their trajectories away from the vessel’s hull. Specially mounted detection systems and the ship’s energy weapon projectors vaporize the rare piece of debris too large or fast for the particle shields to deflect by themselves. High grade systems render normal space speeds of 80% lightspeed relative safe under most conditions. These shields also provide a slight defocusing capability against incoming beams."