Grand 40K Quantification Thread

[NecronLord]

Cool, I assume just post whatever you have and it'll be organized in the headings?

That's the idea, yup.

[Connor MacLeod]

edit: Oh well.. I'll just post something:

...a flotilla of battleships ought to be enough to level the continent. A couple of barrages from their lance batteries would be enough to excise this cancer, however deeply it was buried.

Of course, the planet would be rendered uninhabitable for generations, but no one in their right mind would be willing to set foot here once the Necron presence was known in any case, so the question was pretty moot.

Firepower references for contintent and extinction-level firepower taken from the main site Planet Killers page, Asteroid impact essay entry.

"level a continent" - around 1e7-1e8 megatons roughly implied and by
"rendered uninhabitable" - 1e9+ megatons is suggested. However, the fact that it specifies the planet is not PERMANANTLY uninhabitable suggests its less extreme than the energgy intput required to boil off the atmosphere (for example.) So probably not more than e12 megatons or so (by my estimate - according to Nine Planets Earth Entry the mass of the Earth's atmosphere is some 5e18 kg. To accelerate that mass to escape velocity requires some 3.5e26 joules. Note, of course, you cannot DIRECTLY heat the atmosphere except perhaps by an omnidirectional explosion, but injecting that much energy into the planet that quickly will create alot of ejecta and secondary effects associated with an extinction event, which means global firestorms, so the output is unlikely to be more than an oder of magnitude more than what I estimate.)

On the other hand, the quote does implie it might "level" a continent-sized area even buried kilometers beneath the crust, so the figure could (and probably is) significantly higher. (For example, melting an area equal in size to North America to the depth of several km would require 10x the energy input of a 1e9 megaton extinction event, approximately.)

Duration: "a couple of barrages" from their lance batteries implies the flotilla fires 2-3 volleys apiece, max.

Number of ships: Not sure how many are in a flotilla. At least 2-4 (IIRC the definition of a flotilla IRL is 2 at least 2 squadrons, and 2 ships per squadron at least.) I'm inclned to believe that, given what I've seen, large numbers of battleships in anyy location is a rarity (half a dozen at most?) Dozens of battleships would be unlikely in the extreme.

Going by the "low end" calcs, assuming 4 battleships and 2 salvos apiece, and going with the 1e9 megaton figure.. the firepower to achieve the above is at LEAST 125 TT per salvo per battleship. Note that aside from what I mentioend above, this is conservatibe because it excludes the fierpower added by other weaponry (weapons batteries, ordnance, and prow armaments included.)

Going by the "upper limit" I mentioned (evacuating the atmosphere) 125 Petatons per lance salvo per ship (going by similar assumptions)

[Connor MacLeod]

Abbadon's Planetkiller from Battlefleet Gothic:

Within [the Planet Killer's] central cavity, we could detect a massive power surge. Energy crackled from a number of ports on the hull. Then, with a blast that blotted the sun from our scanners, it opened fire. The energy beam lasted for about a half hour. Emperor knows how they could generate that much energy. We linked in to the planetary surveyors to see what was happening on the surface. That bolt bored its way through miles of the planet's crust and seared through the mantle beneath. As the attack finished, the magma surged forth through this continent-sized wound, breaking apart Savaven from within. The seas boiled into the skies, the ice caps melted and whole continents sunk beneath the tidal wave. With such an unimaginable release of energy Savaven was blown out of her natural orbit and flipped over on her axis. I guess nobody was alive by then, but if they were they didn't last long. Like a rations pack crushed in your fist, Savaven just crumpled in on herself, then broke up into thousands of fragments. There's just an asteroid field there now, really dense, impossible to navigate. There were fourteen billion people living on Savaven. Fourteen billion dead in an hour.”

There are actually a few differnt examples of Abbadon's planetkiller in action and I'll touch on those individually, but this one is from the fluff directly.

These calcs assume a roughly earthlike planet in terms of mass, gravity, atmosphere, water coverage, etc.

The most readily quantifiable element is vaporizing the oceans (which is implied by "boiling the seas into the skies") and melting the capcs. statistics for the energy inputs are borrowed from the site's asteroid calcs

The mass of the oceans is given in the aforementioned nineplanets earth entry

The mass of Earth's oceans is 1.4e21 kg. Using the site's own base delta zero page, it takes around 2.8 MJ to boil off one kg of ocean water. To vaporize all of the oceans would require, therefore, around 3.92e27 joules of energy. This might be somewhat generous, though, since it also describes "continents falling under the tidal wave", which means that some of the ocean water might have survived.

Melting the ice caps as a secondary estimate: According to this entry the volume of Earth's ice caps are 3.3e7km^3 (or about 3.3e16M^3, if my math is right.)

Ice has a density of 900 kg/m^3 and roughly 900 kilojoules per kg to melt. THis means melting the ice caps requires some 2.7e25 joules of enegy to melt. If we assume that the ice caps were also vaporized like the seas, that would require an additional 6.7e25 joules..

These are the most reliable calcs, but however, they are SECONDARY effects, really, and as such represent more of a lower limit. As an upper limit, we know from what is described above that the planet was not "mass-scattered" in a brute force manner (shattered, yes, but that was actually by technobabble effects, not brute force.) As such, we can ascribe a 2e32 joule absolute upper limit to the incident.

In any case, the primary result of the weapon was the blasting a continent-sized hole through crust and mantle. These calcs are to be considered the *primary* calcs, but because of the number of assumptions tied to them, they should be considered more of an estimate at best between the lower and upper limits.

Assuming a North-American sized continent:

I assume two possible mechanisms for creating the "hole" in question. One is simply is shattering/cratering (conservative), the other is vaporization (generous). The true value is assumed to fall somwhere betwene the two.

Now, according ot the nineplanets site above, the crust + mantle extend nearly 3000 km down into the planet. Conseravtive is simply plugging a 6000 km diameter asteroid into the asteroid destruction calculator, which incidentally suggests a yield somewhere between e10-e12 megatons as I can work out (between e25 and e27 joules.) Which accords fairly nicely with above (it would also create massive amounts of ejecta that would heat teh atmosphere, creating the secondary effects described above.)

Now, assuming vaporization:
Googling the area of North America yields a figure of around 9.6 million square kilometers. That gives us the area affected (1e13 square meters.) With that known, now we make two separate calcs:

1.) Vaporization of the crust: Assuming a density of silicon (see silicon asteroid calcs above for variables) and assuming 300K starting temp, the total energy input to vaporize the crust is about 1.22e28 joules.

2.) Vaporization of the mantle: Now, this is ab it more tricky. The mantle is already over 1000K in temp even at the upper levels, and over twice that IIRC at the lower ones) so for an average calc I am goign to assume it is already molten. Thus, I will be assuming iron composition and using the 6.34 joule latent heat of vaporization (if you want an upper limit, use the 7.6 MJ figure instead.)

Assuming over 2830 km depth and the aforementioned surface area, the mass affected is roughly 2.23e23 kg. This means it requires 1.41e30 joules to completely vaporize. (the 7.6 MJ/kg figure yields somethign closer to 2e30 joules, if you're wondering, so the difference isn't that extreme.)

Conclusion: Given the above range of values and the half-hour timeframe, we can estimate that the sustained firepower of Abbadon's Planetkiller is somewhere between e22watts and e27 watts of firepower.

(note that, given the reactions to its effects as outlined above, this could be reasonably be treated as an "upper limit" on the conventional firepower of Imperium warships and probably on most Chaos and Eldar and ork ships as well.)

[Connor MacLeod]

Orbital bombardment descriptions:

The veteran Space Marines of the 1st Company led the lightly armed defence auxilia in a tenacious defence of the fortresses, holding every wall and trench until the last possible moment before it was overrun by the swarm. Slowly the troops withdrew ever deeper into the fortress while making the Tyranids pay in blood for every yard of ground. The Titans of Legio Praetor stalked the ice fields and drove smoking furrows through the onrushing Tyranid hordes with shells and plasma. Crippled Ultramarine ships which Calgar had left in orbit above hurled down bolts of ruby flame and megatons of explosive death at the Tyranids, but still they came on.

This seems to be describing the Imperium's battle against Hive Fleet Behemoth at MacCragge (no idea of the source, I just picked it up sometime in the past.) Note the reference of "multi-megatons" being used on the Tyranids.

Enormous fleshhounds of Khorne loped forward in their wake. Titans armed with specially constructed siege weapons lumbered inte position. Battle cruisers dropped megatons of explosive death onto the defenders.

This seems to have come from a description of Horus's attack on Imperial Terra (presumably his BC's are dropping the explosives.) Again, no source, but if I find one I'll post the referencee. And once again, notice the "multi-megaton" bombardments being used. (This is of no surprise, given the effects ascribed to the bombardment later on in other sources.)

[Connor MacLeod]

Extermintus:

The attacking fleet is escorting Extermiantors, ships capable of laying waste to entire planetary populations or even obliterating all life on a world in a matter of hours.

All had heard of Exterminatus with fusion torpedoes, virus bombs and mass drivers, but to know the enemy had the ability to destroy an entire planet, not just all life on it, must have been the most chilling thought that any naval crewman had ever faced.

The text in the fluff specifies that any "capital ship" can become an exterminator (by having its prow weapon replaced) which means that cruisers and battleships can be exterminators. Since a cruiser isn't as powerful as a Battleship, and these are conservative calcs (for the present) Also, as this is the prow weapon only, this means that broadside and turret armaments aren't included.

Extinction threshold for complex life (from the site's planet killer page):

1e9 megatons minimum.

Duration: 2-24 hours ("matter of hours - between 7,200 and 86,400 seconds)

For a single cruiser's prow weapon: Between ~12 and ~139 gigatons per second.

Addendum - note that while not all Exterimatnus are brute force (some are technobabble - ie virus bombing and cyclonics) the kinds I outlined from BFG DO include brute force examples (fusion torpedoes and mass drivers.) which means that in order to achieve the desired effect the ship has to have the power to do it (which correlates to the offensive capability of the vessel.)

Also note that in any known exterminatus scenario where the calculated effects are known (And it is a known exterminatus, and the number of ships are known) the above timeframe can be applied to derive a lower-limit estimate.

Lastly, I reiterate that these are conservative calcs. the 1e9 megaton figure is a low end one, even for an exiticntion event (according to the site's BDZ page it still relies on long-term consequences. ) Additionally, it assumes all *complex* life (it disregards bacterial or microbe forms of life, aquatic life, etc.) I've heard of examples of an exterminatus "sterilizing" planets and destroying the biosphere (which would require more firepower). Given infestations by Chaos, Tyranids, Orks, and the like, and the pervasiveness and resilience of hte life, its quite possible that the destruction of "all life" is literal (meaning each and every form, including simple forms of life and aquatic life. For example, wiping out microrganisms can req uire superheating the atmosphere to thousands of K, while destroying ocean life would require boiling off the atmoshpere.. both require orders of magnitude more firepower than a 1e9 megaton attack.)

The estimates in this figure will be revised as further evidence and examples come to light.

[Chris OFarrell]

This a large transcript from the EOT campaign when one of the Blackstone fortresses under the control of Aabadon commences an orbital bombardment against a major Cadian fortress on the planet.

There are some interesting tibits on technology, plots and firepower scattered through it...and its a cool story

The lance beam tore through the mid-deck of the Bastion of Light, vaporising its plasma reactor in a heartbeat. The rear quarter of the ship heaved as the colossal energies released tore her apart in an explosion that lit up the darkness of space above Cadia with oxygen-rich flames.

Admiral Quarren watched its demise through the viewing bay of his battle-scarred flagship, Gathalamor, and felt what little chance of victory they had had in this battle slip away.

Over a dozen Imperial vessels were little more than blazing hulks drifting in space and hey had barely scratched the surface of the corrupted Blackstone Fortress. The Eldar ships had taken a savage beating, their alien magicks unable to protect them from the horrendous amount of firepower directed against them. Two listed drunkenly, their curved foresails sagging and broken across their ripped hulls and a third blazed from
prow to stern. But the fourth…

Whoever its captain was, Quarren had to admit he was a master of manoeuvre, slipping through the deadly barrages from the Chaos fleet like liquid. Men and ships of the
Imperial Navy were dying to give the Eldar ship the opportunity to close with the Blackstone Fortress, and Quarren just hoped their sacrifice would not be in vain.

Eldrad Ulthran, Farseer of Ulthwé, felt utterly blind, senses attuned to the whispers of futures not yet born rendered mute by the encroaching darkness. He could sense nothing of the future and his sudden impotence left him feeling cold and alone. Was this how the Mon-Keigh felt all the time? How could they stand to live in such blindness, stumbling towards the future with no possible idea of what awaited them? For a brief second he was moved to pity this sightless, upstart race, before remembering the injustices they had
inflicted on his race; the unthinking xenocidal massacres, the theft of Eldar Maiden worlds and the arrogance to believe that the galaxy was theirs to do with as they wished.

White-hot fires leapt from the Chaos fleet, but Craftmaster Kaelisar was the best ship’sc aptain of Ulthwé and he deftly piloted his vessel through the storm of fire unscathed. The corrupted Talisman of Vaul loomed before them, its twisted spires warped beyond the subtle grace crafted long ago by Eldar hands. Hundreds of explosions burst around
it as the combined Eldar and Imperial ships fought desperately to reach the Talisman.

Behind Eldrad, a cabal of Warlocks surrounded a swirling blue nimbus of light, weaving their psychic powers into one powerful lance of energy that sought to unlock the ancient seals holding the wraithgate aboard the Talisman closed. Powerful wards held it shut, but now the Warlocks sought to undo those wards and allow their Farseer to travel through the webway and board the Talisman. Even as he watched, a dazzlingly bright light flared beneath the Talisman, a blazing column that speared towards the surface of the
planet below. “Hurry,” said Eldrad. “We are running out of time.”


III
Lieutenant Escarno slumped against the rockcrete parapet of the Kasr’s bastion, feeling blood pouring from the gaping wounds in his side. He felt dizzy from blood loss and
fatigue. On any normal engagement, he and his men would have been rotated away from the front line, but this was no normal engagement. There were simply no more men to feed the war machine and any man capable of holding a gun stood before the enemy. The soldiers of the Imperial Guard had fought beyond the limits of endurance and only their
determination to do their duty to the God-Emperor kept them fighting.

Thudding booms marched through the ruins of the outer Kasr, its bastions reduced to rubble by constant bombardment from daemonic artillery. All that remained was the
inner keep, its high adamantine walls proof against anything the enemy could throw at it. The fighting around him raged with undiminished ferocity as he collapsed to his knees, though the sounds seemed tinny and far away. He saw comrades and foe


The Isha’ra rocked with nearby explosions from ordnance launched by alike, struggling top blood-slickramparts, bullets and lasbolts ricocheting around him as the rockcrete of the firing step rushed up to meet him and slammed into his face. He rolled onto his back,
realising he was lying on the ground as he felt warm blood pool beneath him – though he could feel no pain. Through the shattered parapet, he could see tens of thousands – more
even? – of the warriors of the enemy massing before the walls. They stretched as far as the eye could see and even as his vision blurred, he knew there was no way they could
stand before such a monstrous horde.

But then he saw a miracle, a shining light piercing the heavens that lit up the clouds with a pure brilliance that could only be the fury of the
Emperor come to punish these traitors that dared to defile His world. He smiled and watched as a rippling cascade of blazing light dropped from the skies and touched
the surface of Cadia, setting its surface alight. White-hot fires leapt from the ground , a thousand metre high pillar of light that incinerated everything in its path. Distant screams echoed from far off and Escarno wept tears of joy as the kilometres-wide curtain of fire scorched the Chaos filth from the surface of his world.
They had held for long enough and he smiled as he died, content to know that he had done his duty.

IV
“We’re finished…” said one of Creed’s advisors, watching the incandescent curtain of fire searing its way towards the inner keep.

Though tens of thousands of the enemy were dying, the lethal energy was slowly, but nexorably, moving towards them. It would kill those opposing them, but it would destroy
them also, and with them, the last Cadian bastion of the east. Ursarkar Creed rounded on his advisor and snarled, “I won’t hear that kind of talk, damn it. Anyone else voices an opinion like that and I’ll shoot him myself.”

“Sir,” said Jarran Kell, softly. “He may be right. If the xenos do not succeed soon, there will be nothing left of Kasr Partox. The lexmechanics calculate the energy beam will reach the walls of the keep within the hour.”
Creed said nothing, his face set in an expression of grim resolve as he stared across the blasted wasteland towards the deadly beam that reached from space to destroy his world.
“Come on,” he whispered, raising his head skyward. “Do not fail us…”

V
An explosion of psychic energy lashed around the bridge of the Isha’ra, crackling arcs of lightning leaping from the cabal of Warlocks and felling them with powerful
psychic backlash. Eldrad clutched his head, gritting his teeth in pain as the screaming darkness of the long- sealed webway portal rushed free in a wash of shrieking souls. A
howling gale of warp-spawned energies rippled from the rent in space, smashing delicate wraithbone columns and tearing gracefully curved panels free from the walls.

Eldrad picked himself up as the screeching subsided and saw a dark edged ripple of energy gently spinning in a circle of dazed Warlocks. Some, he saw, were
already dead, their spirit stones cracked and dark and he felt a great sadness at the thought of their souls devoured by the Great Enemy.

He glanced over his shoulder, seeing the Talisman’s deadly beam still blazing in space, a column of unimaginable power that would scour the surface of the Mon-Keigh planet
bare of life. He limped across the buckled deck of the Isha’ra, shouting, “Warlocks! With me!” before plunging into the newly reopened wraithgate.

VI
The walls were abandoned, the stonework first vitrifying, then melting as the fiery beam swept slowly onwards. Where it had passed, the ground was nothing more than
molten slag, smoking and dead, barren forever more. The outer walls of the keep were gone, its proud towers and barbicans sliding from the walls like wax from a candle,
and Ursarkar Creed knew he had failed. They could not hold Kasr Partox and the only option left to them was retreat. The Commissars talked of dying to a man, but Creed
knew that while there was still a chance to resist, they would not be needlessly sacrificing themselves. The order to pull out had been given and the soldiers of the Guard and
the Space Marines were pulling back to the docks and loading bays at the shores of the Caducades Sea, ready to make for Kasr Gallan to stand once more. Crushing disappointment settled over him like a shroud and he cursed the name of the Despoiler.
He cursed the Eldar seer for giving them hope and, most of all, he cursed himself for his own failure to defeat the Emperor’s enemies.
By Graham McNeill
VII
Eldrad felt his soul smothered with darkness as he set foot on the perverted Talisman of vaul. He retched, feeling the corrupted heart of the Talisman thirst for his essence.
Like a dark mirror of the spirit stone he wore around his neck, it hungered to drink his very soul and torment it forever within its crystalline depths. A handful of Warlocks had managed to join him, two fighting to hold the wraithgate open that they might escape. Wasted effort, knew Eldrad, but he could not bring himself to tell them that. He limped towards the centre of the chamber, a Warlock collapsing before him as his soul was drained from his body by the corrupted, thirsting heart of the Talisman. He passed the corpse, little more than a shrivelled sack of bones, making his way to where a great basalt wall displayed the furious battle raging outside. The Imperial ships were taking a heavy beating and it would not be long before they were annihilated. He squatted in the centre
of the chamber, slowing his breathing as he entered a trance-like state that would allow him to commune with the Talisman’s heart – the corrupted spirit stone at its centre. If he could somehow reach the part of it that remembered the glory it had once possessed, then there was a chance. A chance, nothing more than that, but it was all he had.


VIII
Admiral Quarren clutched the brass rail of his command lectern as another impact slammed into the side of the Gathalamor, red warning runes flashing and the sacristy bell chiming in alarm. Flames and smoke spewed from cracked vents and he could tell
his vessel was dying. Through the viewing bay, he could see predatory Chaos battleships closing with his vessel and knew that this was the end. A shark-nosed enemy cruiser
turned its prow towards the Gathalamor and Quarren knew that a salvo of torpedoes was seconds away from being launched.

But then a series of rippling explosions blossomed along the flanks of the Chaos ship and portions of its hull were ripped from its structure as flaring bolts of lightning enveloped it.
Confused, Quarren shouted, “Wide aperture on viewing bay!”

Seconds later, he saw a sight that he had never expected to see in all his years with the Imperial Navy. Huge, silvered ships, shaped like crescent moons swooped across the
Chaos battle line, crackling bolts of energy hammering the Chaos vessels with devastating close-range firepower as they raced towards the Blackstone. Quarren’s heart skipped a beat as he saw enemy ship after enemy ship reduced to wreckage by the
unexpected arrivals. Quarren recognised the alien ships from the briefings he had attended at Cypria Mundi.

Necrontyr.

He knew them for the deadliest enemies, yet here they were attacking the Chaos ships!


IX
Centuries of malice and hatred filled Eldrad’s mind. Centuries of pain, torment and anguish. The heart of the Talisman burned with rage at what had been done to it, and as he opened his mind to its pain, he knew that he had made a grave mistake in attempting to reach out to what had once made this ancient Talisman Eldar. The anguished remnants of the Talisman’s consciousness had long since died, replaced with a vile, hateful core of
ever-thirsting darkness, and as it reached out to claim him, he realized in horror that it was no random power of the Dark Gods that had corrupted the Talisman. It was the
power of She Who Thirsts, The Great Enemy… Slaanesh!

Eldrad tried to free his spirit from the Talisman, but it was already too late. The darkness reached out to swallow him and his soul was dragged screaming into the depthless heart of the Blackstone Fortress for all eternity.


X
Ursarkar Creed stood on the shores of the Caducades Sea. He had watched with heavy heart as the dazzling beam of light from the heavens destroyed the last remnants
of Kasr Partox. Its proud walls had collapsed in a blazing pyre, smoke billowing into the sky from the destruction of the fortress as intolerable heat advanced towards the
shoreline. Though the beam had since vanished, the day here was lost, any fool could see that. All that was left to them was vengeance. The Eldar had been obliterated and the alien ships that had unexpectedly come to their aid were gone; wiped out in an instant by the Blackstone’s terrifying defences. Admiral Quarren had informed him that victorious Imperial ships from other sectors were even now converging on Cadia, forcing the Blackstone to disengage – though the damage it had inflicted before departing was incalculable.

“Sir,” called Jarran Kell, from the open hatch of a Valkyrie flyer. “We have to go.”
“We lost…” said Creed, his voice hollow and flat.
“This time,” replied Kell, “but there will be other times, sir. Kasr Gallan still stands and while we live, we have hope. The Emperor protects.”
“Aye,” agreed Creed. ‘The Emperor protects…”

Creed took one last look at the ruins of his fortress and turned to join his soldiers.

[Connor MacLeod]

I had this tidbit squirreld away that I forgot about.. I believe Black Admiral may have mentioned it to me once:

At the magos's command, the truly stellar levels of energy contained within the ship's plasma reactors were released into the warp engines

Edit: Necronlord: Regarding calcs involving human beings: roughly 60-70% of the body is water, not the entire thing (might want to modify your calcs.) (I've got some stuff regarding total destrtuction fo human body, but it s a pain in the ass and will take time.. I'll deal with that later.

Laeresh spun as a Kroot drooped from the trees behind her. The powerful alien reared over her, shaking the quills on the back of its head and hissing a challenge. She twisted, bringing her rifle to bear, but the enormous Kroot swung the blade attached to his primitive firearm up and hacked through the barrel as she pressed the firing stud. The rifle's charging chamber exploded in a searing white fireball and Lareesh fell, burnt and half-blinded. Most of the Kroot's head had been blasted awaya nd it toppled forwards, pinning her against the tree.

She's an Eldar Ranger, and I think she's armed with a laser rifle (anyone confrim/deny this?). Anyyhow. 3-5 kg mass for a human head, about 70% water composition. 2-3 kg (roughly.) Which means the rifle probably puts out some 5-8 megajoules per shot, roughly.

[Falkenhayn]

Orbital bombardment descriptions:

The veteran Space Marines of the 1st Company led the lightly armed defence auxilia in a tenacious defence of the fortresses, holding every wall and trench until the last possible moment before it was overrun by the swarm. Slowly the troops withdrew ever deeper into the fortress while making the Tyranids pay in blood for every yard of ground. The Titans of Legio Praetor stalked the ice fields and drove smoking furrows through the onrushing Tyranid hordes with shells and plasma. Crippled Ultramarine ships which Calgar had left in orbit above hurled down bolts of ruby flame and megatons of explosive death at the Tyranids, but still they came on.

This seems to be describing the Imperium's battle against Hive Fleet Behemoth at MacCragge (no idea of the source, I just picked it up sometime in the past.) Note the reference of "multi-megatons" being used on the Tyranids.

Enormous fleshhounds of Khorne loped forward in their wake. Titans armed with specially constructed siege weapons lumbered inte position. Battle cruisers dropped megatons of explosive death onto the defenders.

This seems to have come from a description of Horus's attack on Imperial Terra (presumably his BC's are dropping the explosives.) Again, no source, but if I find one I'll post the referencee. And once again, notice the "multi-megaton" bombardments being used. (This is of no surprise, given the effects ascribed to the bombardment later on in other sources.)

The source was originally 2nd Edition Codex Tyranids, but I can't give you a page number.

[Dark Hellion]

I would also say to note that in both examples that Connor/Falkenhayn quoted, this is an example of Naval vessels performing close fire support and thus does not necessarily represent the full firepower of the larger weapons of the ships (actually it certainly does not, given the described effects of Nova cannon, Bombard cannon and Magma Bombs). It is indicitive of the massive firepower that can be thrown around the battlefield of 40K, and is strongly suggestive that canon existant theatre shielding is small enough, portable enough, and affordable enough to be utilized quite often (which is also suggested by books such as Malleus, Last Chancers and others).

[NecronLord]

Edit: Necronlord: Regarding calcs involving human beings: roughly 60-70% of the body is water, not the entire thing (might want to modify your calcs.) (I've got some stuff regarding total destrtuction fo human body, but it s a pain in the ass and will take time.. I'll deal with that later.

Quite. They're lower limits (hence, only using heat of vaporisation and so on, and assuming everything is water. I have been meaning to refine it...

I'll edit the rest of this stuff in this afternoon.

[NecronLord]

This might be somewhat generous, though, since it also describes "continents falling under the tidal wave", which means that some of the ocean water might have survived.

I'm summarising this, and linking to your post, now, but anyway, the Warp Storm (BFG expansion) has a third person description of the death of Savaven on page, where they've presumably corrected this error, as the tidal wave is described before the vaporisation of the seas.

[NecronLord]

Updated to the present. I'm eager to get some stuff on accellerations of IoM sihps, too.

[Azazal]

Updated to the present. I'm eager to get some stuff on accellerations of IoM sihps, too.

I will see what I can get for you. I just read Acceptial Loses from Let the Galaxay Burn last night and 50000 KM travelled in 2 hours is jumping to mind, but given that I read about a dozen of the stories last night, I might be mixing numbers. I'll report back later tonight.

[NecronLord]

I will see what I can get for you. I just read Acceptial Loses from Let the Galaxay Burn last night and 50000 KM travelled in 2 hours is jumping to mind, but given that I read about a dozen of the stories last night, I might be mixing numbers. I'll report back later tonight.

Righto. That's not much, mind. Assuming 50% of the journey was spend accellerating, and 50% slowing, coming to a complete stop relative to the observer at either end, that's a mean accelleration of about half a gravity. The Traitor's Hand clocks chaos troop transports (or rather, a chaos fleet with troop transports, but they're going to move at the speed of the slowest ship {unless they want to be picked off one by one as they arrive}, after all) at not less than 70 gravities, anyway.

Dawn of War: Ascension has some weird crap in it about zipping around AUs in minutes (for the necron shroud, that's not so bad, it can travel any speed it likes in realspace, but Marine cruisers?), too. But I'd rather avoid looking into that foetid tome again if I don't have to.

[Azazal]

Dawn of War: Ascension has some weird crap in it about zipping around AUs in minutes (for the necron shroud, that's not so bad, it can travel any speed it likes in realspace, but Marine cruisers?), too. But I'd rather avoid looking into that foetid tome again if I don't have to.

CS GAto = CRAP!!!

Abnett and McNeill = GOLD

[NecronLord]

Abnett and McNeill = GOLD

Pfft *Hits you with an Inquisition War book*

MITHRIL!

[Imperial Overlord]

Some really high acceleration rates are implied in Sabbat Martyr. I'll see if I can dig it up and find some usable passages.

[18-Till-I-Die]

Sabbat Worlds Crusade, and the Gaunts Ghosts books, give some good idea of scale of the Imperium itself, at least one sector of the Imperium. Would that information be applicable or do we only post tech info here? Maybe in the misc listings? It also gives some good, solid idea of weapons and scale of the Imperial Guard.

[NecronLord]

If you take a look, I do believe I've got a 'general scale of operations' post there that needs content.

EDIT: Ahah! "Industry & Scope of Operations"

[Connor MacLeod]

This might be somewhat generous, though, since it also describes "continents falling under the tidal wave", which means that some of the ocean water might have survived.

I'm summarising this, and linking to your post, now, but anyway, the Warp Storm (BFG expansion) has a third person description of the death of Savaven on page, where they've presumably corrected this error, as the tidal wave is described before the vaporisation of the seas.

I've got that and one more thing to post. I'll comment more particularily on those later.


Edit: By the way, regarding the Nova Cannon, since Battlefleet Gothic specifies that the nova cannon's axial mounting is designed to allow the ship to use its engines to counter the recoil, you can either a.) use the momentum/energy figure from a Nova cannon calc to estimate acceeleration (if you estimate a ship's mass) or b.) use an acceleration (and an estimated mass figure) to figure out Nova cannon firepower. This can offer a potentailly useful way of corroborating one calc or another.

[18-Till-I-Die]

Heres some detail on the scale of the Sabbat Worlds Crusade i could find...

Sabbat Worlds Crusade, page 5 the Sabbat Worlds sector contained "over one hundred inhabited systems...with an estimated human population of five trillion".

So no fewer than 100 systems, with no less than 5 trillion humans, circa M37, this is prior to the Chaos incursions in M41 but many worlds, it appears, remained largely free of Chaos for quite some time from all indications so this would be a generally accurate view of the sector.


SBC page 14 describes Slaydo's initial push into the Sabbat Worlds, and comments that between him and his five cheif generals that they commanded "almost a billion Imperial Guardsmen along with massive retinues of armor and artillery, six Chapters of Astartes, and Titan Legions from the Adeptus Mechanicus"

I hop this is useful, i'm going to look through the other books for some stuff and see if i can calc it (though i warn my calc-fu is not strong).

[Lost Soal]

General Technology: Industry & Scope of Operations:

Fleet Numbers of the Imperial Navy

From the Battlefleet Gothic Rulebook pg86

All human-inhabited space is further broken down into sectors, which are most usually cubes of space roughly 200 light years to a side.

Each battlefleet normally consists of between 50 and 75 warships of varying size, although in some sectors this will be more or less, according to the importance of the sector and the number of
enemies it must contend with. As well as these destroyers, frigates, cruisers and battleships, a battlefleet also has access to countless smaller
vessels such as transports, shuttles, messenger craft and long-range patrol craft. In addition to interstellar vessels, a sector will also be protected by numerous ships incapable of warp travel, such
as system patrol ships and defence monitors.
These are backed up by stationary defences – space stations, orbital defence platforms, groundbased defence lasers and missile silos and orbital mines.

According to this site the Milky Way galaxy has a disc thickness of 2,000LY and a Nucleus thickness of 20,000LY

So taking this and assuming a Galaxy of 70,000LY in diameter and 2,000LY thick (ignoring the Nucleus);
We get a volume of ~2.54469E+13LY
A Sector has a volume of 8,000,000LY
Giving ~3,180,862 Sectors across the galaxy

This allows us to get rough ranges of the total fleet size of the Imperial Navy, Assuming Imperium Presense of:
1%= Between 1,590,431 & 2,385,646
5%= Between 7,952,156 & 11,928,234
25%= Between 39,760,782 & 59,641,173

This is in addition to the fleets belonging to the Astartes, Adeptus Mechanicus and the Inquisition.

[Falkenhayn]

White Rabbit and I came up with similar numbers on SB.com.

[NecronLord]

1%= Between 1,590,431 & 2,385,646

That's too high. We know that the Imperial Navy seems unable to post a ship to every inhabited planet, after all.

[Connor MacLeod]

Are those calcs taking into account that the million (or more) worlds of the Imperium are scattered over a fairly large volume of space? IIRC there's quite a bit of "empty" or uninhatbed space (or are they wild zones or something to that effect?) between inhabited sectors/sub-sectors.

This should probably be taken as a rough estimate (possibly an upper limit) rather than as a definite, absolute figure, unless the number of sectors can be more precisely pinned down.

Edit: By the way:

Enormous fleshhounds of Khorne loped forward in their wake. Titans armed with specially constructed siege weapons lumbered inte position. Battle cruisers dropped megatons of explosive death onto the defenders.

This comes from page 14 of the Horus Heresy rulebook.