OK, this one is unusually long, in comparison to other threads. 4 pages to wade through, this time we're clearly dealing with big weapons and thus, big numbers.
The CC series appears to give good ranges for infantry weapons. Kill zones for lasguns and else are around 300 meters, with the possibility of reaching good hit ratios at greater ranges.
Artillery spam in conjunction with infatry fire helps. Orks seem to rush like twats most of the time.
Or perhaps "effective" as I fly through a barrage of enemy fire concentrated on few converted cargoships into dropships, indeed.Connor MacLeod wrote:
Page 22-23
- the cargo hauler Cain is riding in takes fire from Ork ground weaponry shortly after entering the atmosphere. Even accounting for probable reentry speeds (at least 8 km/s, but possibly as high as 13+ km/s) and the fact the Orks do not evidently understand (or care) about the concept of effective weapon's range, this is still many kilometers/tens of kilometers distant.
That's crossing fingers for *some* shots to connect with targets, but like a walk out into the rain, I have little chances of avoiding getting wet.
A rather sluggish ship.Also, according to Cain, it would have taken hours for the hauler to abort its current trajectory and return to orbit - the life support would give out long before they could return.
Refined promethium, perhaps yes.It should be noted, I believe, that the shuttle here was implied to be running on promethium (like alot of 40K vehicles of that size.) Not unreaosnable for a shuttle, however its chemical reactions would have to be extremely powerful - as Mike has noted numerous times, it takes a minimum of 60 MJ/kg to escape an earthlike gravity well (far more than modern gasoline or diesel) This, along with other evidence, tends to suggest Imperium chemical explosives and engines are probably alot more powerful than our modern equivalents (potentially at least - efficiency is still an issue.)
We later find two posts touching on this subject, on page 2:
http://bbs.stardestroyer.net/viewtopic. ... 8#p2372688
http://bbs.stardestroyer.net/viewtopic. ... 9#p2374759
Of use, a piece from Iron Hands:
Petrochemical. Burning. This will be of importance later on.Iron Hands, FIVE, MORBUS EX MACHINA, The Foothills of the Argentum Mountains wrote: Gdolkin turned his head to survey the battlefield passing beneath them through an armacrys porthole and considered the enemy they were about to face.
The thick black smoke rolling into the skies from the burning promethium refineries - kilometres of petrochemical production plants all washed with flames - obscured the view through the porthole momentarily.
Doesn't sound that good. A melee weapon is just as good as its (weakest) materials, and no matter the strength of the Ork, if the weapon isn't as tough as the armor, it would bend, break or literally shatter, the greater the Ork blow the more violently.Connor MacLeod wrote: Page 32
- Cain comments that Ork axes, crude as they are, can shear through Astartes armour when driven by ork muscles. This either comments on the nature of 40K materials science, Ork Strength, or both.
So the question is what's crude about these axes? Perhaps the fact that they're mere axes, with no fancy monomolecular edge or force field.
That or the weirdo Waaagh unquantifiable buff anything gets when numbers don't look nice enough, I suppose.
Like always, his definition of conservative leaves something to be desired.Connor MacLeod wrote: Page 33There are 10 orks total (as mentioned by Cain on page 31), minus 2-3 already destroyed by the heavy bolter. There were also 3 squads or so disembarked (30 lasguns), probably plus the command section (andother 5-6 ppl IIRC) as well as the Chimaera with its heavy bolter (only one is mentioned, and the others probably weren't offloaded yet.)I don't suppose they even knew what hit them: suddenly struck by the concentrated fire of a couple of score of lasguns, not to mention the unrelenting hail of heavy bolter fire, there was nothing much left of them apart from some unpleasant stains on the snow within seconds. Sulla ambled over to inspect the mess, and spat a small gobbet of ice on it.
The quote implies that the gunfire (lasguns plus the Chimaera's bolter) basically exploded and/or vaporized the orks in a matter of seconds.
The problem is, though, we dont know the actual ratio between lasguns and bolter fire. given above, its likely though that the bolters could only take out a 2-3 orks "in a few seconds", possibly a few less. which means that 4-6 orks were destroyed by the Valhallans.
Assuming 4 orks, and a mass of around 200 kilos per ork (about 2-3x more massive than a huhman, which may be conservative since other sourcese like Ghostmaker imply 400+ kilos for an ork), is 800 kg. Assuming 70% water composition, is 560 kg.
Conservative: Assuming the lasgun fire merely boiled that much water (boiling point), a minimum of ~200 MJ must be injected (remember, lasguns cauterize as well as explode, hence the conservative term) Assuming 40 lasguns ("a couple score", even though i mentioned above only 30, 35 with the command section were probably actually there and Cain might have been rounding up.) and 3 seconds worth of fire, we come out with a sustained output of 1.67 megawatts per lasgun.
Assuming total vaporization of the 560 kg mass, the energy input becomes 1.5 gigajoules (boiling point plus vaporisation) Again assuming 40 lasguns over 3 seconds comes out to 12.5 megawatts per lasgun.
Note that at least SOME vaporization should be considered liekly, so the low end is EXTREMELY low. It also ignores inefficiencies, number of orks destroyed, any armour the orks were wearing, etc.
The heavy bolter was mounted on a turret. It's a heavy automatic weapon with a high rate of fire, that fires explosive self-propelled shells.
Connor puts too much emphasis on the lasguns, while only a handful scores of them ever fired, compared to the unrelenting hail of HB fire.
That and seconds, in the heat of battle, could have easily been far more than three mere seconds. Some of those few Orks were at knuckle range, so even any partial vapourization would largely prove problematic to the Imperial troops.
Flash vapourizing, at the very least, 560 kg of water, implies some safety issues. Taking into consideration the complete spectrum of overpressures and eardrum ruptures would be interesting to begin with, considering the energies involved and a battle taking place at melee range. Then comes the burns caused by hot vapour. It's rather hard to imagine hundreds of megajoules deposited into something fleshy less than two meters away, at best, from someone's face that is barely protected, and not suffer.
However, if vaporized meant turned into cold mist instead of hot vapour, it works much better.
The mention of the ionization actually reminded me that I wish I had found a figure about how much air a single las-bolt would ionize.Connor MacLeod wrote: Page 55- Two details of interest. First, full-auto on a Valhallan lasgun seems to empty the power pack in a matter of seconds. We know the powerpack was full, but we dont know the exact number of shots. If we assume it took 4-5 seconds, and assume 50 shots (40-60 shots per pack seems to be average), the rate of fire on a lasgun seems to be around 600-720 RPM. If the timeframe is shorter, the rate of fire could go up to 800, 900, or 1200 RPM. or more.Either luck or the Emperor was with me, because she'd left it on full auto. As my panic-spasmed hand locked on the trigger a hail of las bolts sprayed the chamber, blowing chunks of ice from the walls and defeaning us with the roar of ionising air and ice flashing into steam. The creature screamed and fled, even more terrified than I was, and as the power cell died and relative silence descended on our ringing ears, Penlan stirred.
The other interesting detail of note is that the lasgun impacts cause ice to "flash into steam" (there is mention of ice blowing chunks in the wall too.)
With ionization energy in mind, and taking a look at the width of a typical lasgun beam, we may get an absolute and sure lower end for the weapon's power output. Something about turning x atoms of oxygen and nitrogen into ions, within y cubic centimeters, over a given distance of several hundred meters.
If we consider maximum range before the beam is too weak, we'll get an idea of the beam's muzzle power, considering that the laser will have to ionize up to x meters of nitrogen and oxygen, after breaking their molecular bonds. That said, my memories on that stuff are waaaay diluted, to say the least, so either someone else will do it, or I'll have to recollect enough data to remember how doing this right.
Also, the "roar" from the ionized air is rather curious. One would think a maelstrom of "cracks" would be more deafening that, well, what could artistically be considered the sum of thunder-like echoeing "booms".
Yet weapons were discharged, apparently.Connor MacLeod wrote:- here, Cain mentions that the lasgun had melted "small pits" in the wall, though above he mentions chunks of ice and vaporization (IE steam.) The best answer would probably be that all three (to varying degrees) occured. Note that some vaporization would be needed for fragmentation (blasting chunks), while you could expect some vaporization along with melting (if the ice/water reaches boiling point, which is likely.)I took a glance around the chamber. It looked bigger from down here, and the hail of las bolts had melted a number of small pits into the walls. Something seemed to be embedded in one, and I tried to focus on it, to stop my head spinning.
Who ever said the pits were hand sized, or that they even melted or vaporized that much ice?Connor MacLeod wrote: Page 56- This provides us with our best estimate of the dimensions of the holes melted/vaporised in the ice. "hand sized" implies at least 10 cm in diameter, but the hand is open, so this is probably conservative (I'd say less than 20 cm.. so maybe 10-15 cm.)It was a human hand, severed at the wrist, the stump scored with viscious bite marks.
Assuming a perfectly hemispherical crater 10 cm in diameter would melt/vaporise about .25 kg worth of ice per shot. 15 cm would melt/vaporise .8 kg of ice. According to the stats provided on SD.net, we can infer roughly .51 MJ/kg for melting, and 2.71 for melting/vaporization (at least.) This means melting is between 122-475 kilojoules per shot, while vaporization would be 650 kilojoules and 2.2 Megajoules per shot. The actual value falls somewhere between those to.
This seems rather low for lasgun values compared to other calcs I have done, but we know most lasguns have variable charge settings (even though Valhallan lasguns are never mentioned as having them it is a reasonable supposition.) It may also be that the lasgun accepts a lower overall "per shot" output for a much higher rate of fire.
They just saw a hand embedded into an ice wall, paying more attention to the surroundings, after the shooting at the ambull.
See:
Not only pits were only melted, but the violence of the reaction itself would cause surrounding ice to shatter, and the very fact that one could recognize a hand and not bits of fingers spat out of the newly made hole is largely due to the fracturing blast precisely not reaching that far.CoI wrote: I took a glance around the chamber. It looked bigger from down here, and the hail of las bolts had melted a number of small pits into the walls. Something seemed to be embedded in one, and I tried to focus on it, to stop my head spinning. Then my brain finally interpreted what I was seeing, and I regretted my curiosity at once.
'Looks like we found our missing miner,’ Penlan said, with what I felt was rather unseemly relish.
'Almost,’ I agreed. It was a human hand, severed at the wrist, the stump scored with vicious bite marks.
Clearly his values don't match what he thinks happened.
But the most amusing part here is that the correct interpretation of the text may allow for greater pits if we wanted to, because at no point the book says the hand was revealed through a hole or anything, but just that they saw it stuck in the ice after paying more attention to the walls.