Two technical questions

My first question is rather trivial: There are impeller driven shuttles and small rockets (such as the one fired on Honors shuttle on Grayson) operating within the atmosphere. Now, knowing the catastrophic effects of impellers on matter, how do they affect the atmosphere? I see the risk of creating poisonous gases etc.

My second question is: Missiles have huge impeller wedges, in the sizes of (at least) kilometers. Now, how can a bunch of them started simultaneously from within a broadside or, even worse, a pod with much smaller dimensions?

markusschaber wrote:My first question is rather trivial: There are impeller driven shuttles and small rockets (such as the one fired on Honors shuttle on Grayson) operating within the atmosphere. Now, knowing the catastrophic effects of impellers on matter, how do they affect the atmosphere? I see the risk of creating poisonous gases etc.

My second question is: Missiles have huge impeller wedges, in the sizes of (at least) kilometers. Now, how can a bunch of them started simultaneously from within a broadside or, even worse, a pod with much smaller dimensions?

Certainly there are small impeller head missiles used in atmosphere (another was used against the aircar of Constance Palmer-Levy, Secretary of Security for the People's Republic of Haven, as preparation for Rob Pierre's coup against the Legislaturalists); and the Peep assault shuttles Honor's crew stole from Tepes had a "limited number of impeller-head missiles, designed for combat with other small craft" (though they used them during the breakout from Tepes - so they had to use the more numerous chemical warhead ground attack rockets to kill Camp Charion's courier boat)

But pinnaces and shuttles also have lifting body fuselages and/or wings, counter grav, chemical rockets, and air breathing turbines -- specifically so they aren't using their wedge in atmo.

The small wedges on the missiles probably do some unpleasant things. But they also last for just a few seconds, and seemingly aren't more than a few square meters across. So even if the insane gravitational effect on the atmosphere creates some toxic gasses it wouldn't have time or volume to convert all that much of that atmosphere.


For your second question, I think a couple of things are in play. One, the wedges are pretty flat (RFC once said that the higher the acceleration the less the wedges were inclined -- and anti-ship missiles are far higher accel than any ship) So they're km wide, but probably only a couple of dozen meters thick. (Think of the side of the ship kind of like laying an 8 slot vertical toaster on it's side. Each slice of bread is vastly taller an wider than the separation between the slices, and you could think of each slice as the two wedges with the missile between)

Still, that's not enough for multiple "gun decks" of missiles on a single broadside (or the multiple missiles packed tightly into a pod, or one-shot canister launcher) - so I'm assuming that they also stager the missiles ever so slightly within the salvo. Even at an anti-ship missile's half-power drive setting it's accelerating at 46,000g and even 1/10th of a second after wedge ignition that missile has already shot forward 45 km -- so now there's room behind it to launch another missile and bring up its wedge.

Then as the missiles move further from the ship they can spread out and adjust courses to use slight differences in total travel path to tighten up their arrival times into something closer to a true time-on-target strike. (Or if you're using MDMs they can also play with slight delays between activating the subsequent drives as another way of correcting for any time dispersion caused by the salvo launch)

Your 2nd question is on of those things no one is supposed to actually apply a calculator to because one QUICKLY runs out of real estate, or has to make up new "physics". But sure why not

WHY? DW has stated that the missiles do not activate their wedges till OUTSIDE the wedge of mama ship... That is ~150km. If they could activate before this, the CM wedge, or Missile Wedge would COMPLETELY block any incoming fire or outgoing PDLC fire, making a ship effectively IMMUNE to any Laser/Graser fire. <<Must remember this>> If we violate this aspect, the entire series "build" falls apart.


He later said activate wedge outside the sidewall(Handwavium) gun barrel grabs the sidewall and makes a 10km barrel to accelerate... Of course how this works when the sidewall goes down... all of a sudden you LOSE your missile launcher as well, uh . This is still 10km outside the hull and initial velocity of the missiles becomes a different problem.

Invictus has 84 CM tubes
Harrington II has 64 CM + 24Missiles

Wedge Size: ~1km(CM's are larger?) * Number of wedges = 84km of wedges + separation

Separation: Lets call it 0.25km*84 ~= 21km

Total "length of wedges" =105km/salvo
8s/salvo

Velocity required for no bumping and grinding of missile wedges
13.1km/s for Invictus class SDP

Gun barrel "length" ~ 10km to edge per info dump which is now blank over at thefifthimperium.com, the links are there, but no text shows up,

v = a*t 13.1km/s/1s a = 13,100m/s
13,100m/s/9.81ms^2 = 1330G


Ok enough yanking numbers, time for bed. Assuming I didn't bumble finger it

Not sure why he states initial velocity is important... 13km*180s is a mere ~2300km or so extra range...

Anywhoo, bed is calling

Can't remember where I saw it, but I do remember that they are launched by rail gun type launchers at a high speed so they are already separated somewhat anyway.
On reflection it may have been Megan's prelaunching technique?

Relax wrote:Your 2nd question is on of those things no one is supposed to actually apply a calculator to because one QUICKLY runs out of real estate, or has to make up new "physics". But sure why not

WHY? DW has stated that the missiles do not activate their wedges till OUTSIDE the wedge of mama ship... That is ~150km. If they could activate before this, the CM wedge, or Missile Wedge would COMPLETELY block any incoming fire or outgoing PDLC fire, making a ship effectively IMMUNE to any Laser/Graser fire. <<Must remember this>> If we violate this aspect, the entire series "build" falls apart.

Only if they'd turned sideways first - a missile launches perpendicular to the ship, which means the wide open nose of its wedge is pointing towards the enemy. So fire could (potentially) come straight past the missile and still hit. But also if my toaster analogy holds then the slide of toast which is the wedge is so narrow that most of the toaster top isn't obscured by it (though if you're looking more to one side it does create a "shadow" where it blocks the view of much of the toaster top.

[edit - ignore this next bit. I suffered a catastrophic units failure and compared meters to kilometers as if they were the same length. :embarrased:]
And even if one started up flying parallel to the broadside of a ship it's not going to cover the whole ship. A missile wedge is probably, what, a 10km wide square? 15? Even a modern destroyer like a Wolfhound is ~400m long and an SD(P) is ~1400. So at any given time the missile wedge is covering somewhere between 3% - 0.7% of the hull length.
[edit: ignore zone over]

But the other issues is how quickly missiles accelerate - an anti-ship missile can only cover some portion of the hull for somewhere between 0.9-3.25 seconds before its acceleration flings it clear. And a modern CM would be worse, between 0.3-1.1 seconds, due to its far higher accel.

Then, as you noted, if it's blocking the incoming fire its also blocking PDLC fire (at least from parts of the hull) which is going to be a problem once it's flown clear of the hull because if any missiles are coming just after it's flown clear they got reduced defensive fire but still get a clean shot at the ship.



And yet, having listed many reasons why it doesn't seem to be a universe breaking thing, I will in all fairness mention that it was done once. During the Manticore Ascendant series I recall there was one time they did use a missile (a training one?) wedge to cover the vulnerable side of the ship. But their missiles were far sower back then, so the coverage lasted longer, and it was still a very special situation that made it worthwhile.

But yeah, the initial velocity from the missile launcher is a bit of a mystery. It's apparently very important, and why old-style pods weren't considered effective, and yet if you crunch the numbers from any fight where he givens enough of them to calculate it's clear that to get the time, distance, and terminal velocity numbers he gives for the missiles their initial velocity has to be indistinguishable from the firing ship's base velocity. (IOW he doesn't appear to have included any launcher applied velocity when he ran the numbers to put into the book)

markusschaber wrote:My first question is rather trivial: There are impeller driven shuttles and rockets (such as the one fired on Honors shuttle on Grayson) operating within the atmosphere. Now, knowing the catastrophic effects of impellers on matter, how do they affect the atmosphere? I see the risk of creating poisonous gases etc.

My second question is: Missiles have huge impeller wedges, in the sizes of (at least) kilometers. Now, how can a bunch of them started simultaneously from within a broadside or, even worse, a pod with much smaller dimensions?

Adding to the rest:

Modern Pods are a development that added a low cost grav launcher to the pod's missile cells, to achieve a similiar effect to ship launchers, and match the initial velocity of ship launched missiles. Like a ship, they launched the missiles from a grav launcher with tens of thousand of Gs of acceleration.

Pods and "Box" launchers had been used previously in low cost combat units, but these used a mechanical (spring) or chemical (rocket) apparatus to impart a small initial velocity, and usually launched their missiles one at a time. The downside, their slow launch rate didn't produce overwhelming salvos, and When used with units with grav launched missiles, the lower initial velocity caused then pod launched missiles to trail the Grav launched missiles, making the launch easier to intercept over time. (Box launchers are just a pod permanently fixed to the side of the launching ship, using the ship's firecontrol. they do not have Grav launchers or reload systems. They are usually used on LACs, defensive satellites, or low tech combatants).

Due to the small size of a pod, we've discussed the launcher timing issue on modern pods (and the effects of momentum kickback), but from the heterogenous timing of the missiles, it appears that they launch either together, or extremely rapidly, with the missile initiation timing coordinated to have the missiles arrive in 1 coherent salvo.

Jonathan_S wrote:

Relax wrote:WHY? ...If they could activate before this, the CM wedge, or Missile Wedge would COMPLETELY block any incoming fire or outgoing PDLC fire, making a ship effectively IMMUN

Only if they'd turned sideways first - a missile launches perpendicular to the ship, which means the wide open nose of its wedge is pointing towards the enemy. So fire could (potentially) come straight past the missile and still hit. But also if my toaster analogy holds then the slide of toast which is the wedge is so narrow that most of the toaster top isn't obscured by it (though if you're looking more to one side it does create a "shadow" where it blocks the view of much of the toaster top.

And even if one started up flying parallel to the broadside of a ship it's not going to cover the whole ship. A missile wedge is probably, what, a 10km wide square? 15? Even a modern destroyer like a Wolfhound is ~400m long and an SD(P) is ~1400. ] So at any given time the missile wedge is covering somewhere between 3% - 0.7% of the hull length.

1) Turning sideways absurdly easy with a reaction thruster
2) No reason you couldn't have a station keeping 'wedge' with giant wedge and zero acceleration(or minimal) just like a ship.
<< Cough Cough Keyhole COUGH Cououuuuuggggh >>
3) Heck, such a wedge would be superior to any sidewall in terms of pure defense. So, if you could activate a wedge inside your ships wedge "plates", dropping your sidewall, turning on your station keeping wedge would completely violate the spirit of the series and make ships completely immune as a 10km wide wedge at even 10km on a 1km(BC) or even 1.3km long(SDP) would block effectively the entire length of the ship forcing the incoming laser to look through the distorted sidewall(assuming both could function simultaneously) at ~30 degrees or greater if using more than one wedge blocker and also fire its laser at over 30 degrees through said sidewall, and heaven help anyone who would have 2 "stationary" wedges covering their sidewall just outside of their sidewall. The series just falls apart.
4) 10km? Yea, DW said something like that in an info dump and ~1km was a pinnace. I purposefully grabbed the Pinnace wedge size to make a minimum threshold since DW has never said so in actual cannonical books and to make the calculation more feasible using onboard launcher.
5) If I went with 10km wedge or larger, one quickly needs "guns" which fire at over 100,000G which makes one ask--> Why Missiles have a compensator field at all which is cannon.

In short there is an obvious reason DW "banned" station keeping wedges as "sidewalls" or extra sidewalls even though it would seem a VERY obvious thing to do using in universe centuries old tech.

PS: Your percentage covered, yes, if outside the wedge, but even then not really as the MOST vulnerable aspects would be covered forcing the incoming LASER fire to take the hypotenuse of the angle instead of the shallowest depth of the sidewall. And forcing the offensive missiles into a narrower corridor making them MUCH more likely to be picked off by PDLC/CM's.

PPS: Making ships "immune" from any distance or direction is just a BAD can of worms to open in any book universe... Of course I laugh every time someone on a forum brings up wet naval "history" of BB's "immune" zones... As if that was true in ANY battle between BB's, BC's, CA's, etc at ANY time in their history.

Relax wrote:1) Turning sideways absurdly easy with a reaction thruster
2) No reason you couldn't have a station keeping 'wedge' with giant wedge and zero acceleration(or minimal) just like a ship.
<< Cough Cough Keyhole COUGH Cououuuuuggggh >>

IIRC Keyhole has a wedge as only as backup, but normally is held in place by tractor/pressor units.

Relax wrote:3) Heck, such a wedge would be superior to any sidewall in terms of pure defense. So, if you could activate a wedge inside your ships wedge "plates", dropping your sidewall, turning on your station keeping wedge would completely violate the spirit of the series and make ships completely immune as a 10km wide wedge at even 10km on a 1km(BC) or even 1.3km long(SDP) would block effectively the entire length of the ship forcing the incoming laser to look through the distorted sidewall(assuming both could function simultaneously) at ~30 degrees or greater if using more than one wedge blocker and also fire its laser at over 30 degrees through said sidewall, and heaven help anyone who would have 2 "stationary" wedges covering their sidewall just outside of their sidewall. The series just falls apart.
4) 10km? Yea, DW said something like that in an info dump and ~1km was a pinnace. I purposefully grabbed the Pinnace wedge size to make a minimum threshold since DW has never said so in actual cannonical books and to make the calculation more feasible using onboard launcher.
5) If I went with 10km wedge or larger, one quickly needs "guns" which fire at over 100,000G which makes one ask--> Why Missiles have a compensator field at all which is cannon.

In short there is an obvious reason DW "banned" station keeping wedges as "sidewalls" or extra sidewalls even though it would seem a VERY obvious thing to do using in universe centuries old tech.

PS: Your percentage covered, yes, if outside the wedge, but even then not really as the MOST vulnerable aspects would be covered forcing the incoming LASER fire to take the hypotenuse of the angle instead of the shallowest depth of the sidewall. And forcing the offensive missiles into a narrower corridor making them MUCH more likely to be picked off by PDLC/CM's.

PPS: Making ships "immune" from any distance or direction is just a BAD can of worms to open in any book universe... Of course I laugh every time someone on a forum brings up wet naval "history" of BB's "immune" zones... As if that was true in ANY battle between BB's, BC's, CA's, etc at ANY time in their history.

If you're station keeping then an RD would seem a far better platform -- it can run it's wedge for hours rather than the 3 minutes a missile drive can last, or the 75 seconds even the best CM drive can last. And they can definitely be set to match the ship's accel -- where a CM drive apparently has no ability to adjust it's acceleration rate (RFC once said that was one of the tradeoffs to get the higher accel over an anti-ship missile), and an anti-ship missile has some but I'm not sure even RMN missiles (which lack hard-coded accel rates) can be dialed down to 1/150th of their base acceleration.


Of course it'd be a really bad day if you turtled up behind your invincible drone wedge and a laserhead pulled off a down the throat shot on the drone half a second before the rest of the salvo smashed into you (It also wouldn't protect from missiles that were going to pass ahead or astern of you to fire their laserheads down your throat or up your kilt -- but would block your ability to see them coming or engage them with CMs and PDLCs until they popped over the rim of the escorting wedge.

But even with those possible downsides I think you're right that it's mostly that RFC doesn't allow it because that's not how he wants his naval combat narratives to go.
(Though, as mentioned, in one very special situation long, long, ago it was done)

Regarding the momentum kickback, apologies to Newton, but with gravity that doesn't seem to be an issue. Earlier on it was mentioned that a pulser dart had the same kinetic energy as a 50cal Barret. Seeing as how a pistol sized and weight pulsar fired single handed can send out hundreds of darts a minute without breaking the shooter's wrist, there must be some compensating physics. An early contributer (Namelessfly) who owned a 50cal, and I discussed this at length.

Theemile wrote:

markusschaber wrote:My first question is rather trivial: There are impeller driven shuttles and rockets (such as the one fired on Honors shuttle on Grayson) operating within the atmosphere. Now, knowing the catastrophic effects of impellers on matter, how do they affect the atmosphere? I see the risk of creating poisonous gases etc.

My second question is: Missiles have huge impeller wedges, in the sizes of (at least) kilometers. Now, how can a bunch of them started simultaneously from within a broadside or, even worse, a pod with much smaller dimensions?

Adding to the rest:

Modern Pods are a development that added a low cost grav launcher to the pod's missile cells, to achieve a similiar effect to ship launchers, and match the initial velocity of ship launched missiles. Like a ship, they launched the missiles from a grav launcher with tens of thousand of Gs of acceleration.

Pods and "Box" launchers had been used previously in low cost combat units, but these used a mechanical (spring) or chemical (rocket) apparatus to impart a small initial velocity, and usually launched their missiles one at a time. The downside, their slow launch rate didn't produce overwhelming salvos, and When used with units with grav launched missiles, the lower initial velocity caused then pod launched missiles to trail the Grav launched missiles, making the launch easier to intercept over time. (Box launchers are just a pod permanently fixed to the side of the launching ship, using the ship's firecontrol. they do not have Grav launchers or reload systems. They are usually used on LACs, defensive satellites, or low tech combatants).

Due to the small size of a pod, we've discussed the launcher timing issue on modern pods (and the effects of momentum kickback), but from the heterogenous timing of the missiles, it appears that they launch either together, or extremely rapidly, with the missile initiation timing coordinated to have the missiles arrive in 1 coherent salvo.