Warhammer 40K 3rd/4th edition rules misc analysis thread
Plus the following bits:Connor MacLeod wrote: Tyranid codex 2001 (thats how I think of it at least.. so I'm guessing 3rd edition.)
Page 2Size and scope of a Hive Fleet.The Tyranid hive fleet consists of millions of living craft, each home to billions of creatures.
So now, some of Connor's first big numbers:Page 40 wrote:
In their [hive fleet] wake was left a bare rock orbiting a star, scoured of every organic particle, stripped of all but the most basic elements. Nothing was left of the farming world of Langosta III, there were no testmaents to the humans who had once lived there. Now all that was left was an airless asteroid, the unmarked deathpalce of three million people.
1. You don't need to make water and air reach escape velocity by application of energy delivered by weapons, just pull matter off the ground high enough for the orbital ships to absorb it and/or sheath themselves with this matter (see below). Tyranids come to harvest worlds in large numbers, so this shall prove enough to divide the required effort, as you'll see.Connor MacLeod wrote: Page 41STripping the air off a planet requires 3e26 joules of energy. STripping the ocean off requires something on the order of 9e28 joules of energy. actual power generation figures depend on time and number of ships, but even then this gives us a broad indication of their power (and by extention, Imperial capabilities)As resistance is overcome more and more of the planet's surface is stripped bare by continuous harvesting until the hive fleet concludes its actions by draining the planet's atmosphere and seas. AT this point many hiveships will calve, adding to the fleet's numbers of drone-vessels and immature bio-ships.
2. As pointed out, no indication of time is given. The process could be long. How this should then be representative of firepower or else?
A full day of work is 1440 minutes spent doing the draining. That's already three orders of magnitude down from the energy figures.
3. The hive fleet has millions of living crafts. Depending on how many ships are involved in the draining, you could probably lower the total energy figures by four orders of magnitude if not more.
4. How is the draining achieved? Are physics respected (Newtonian physics instead of gravity nullifying stuff or some such)?
This page, which cites an entire section from Tyranid Codex, The Spawning, hints at towering filaments that grow up, reaching for the skies and beyond, into orbit, to which the bio-ships connected for nourishment. Capilarity making things easier for molecules to go up, and most important, the work wouldn't be done by the ships in orbit.
Why these things couldn't be used to inhale the atmosphere and suck the oceans, especially since the text precisely says "drink oceans"?
When everything is taken literally, why not now?
Also, "hive ships would cluster in tighter", perhaps coming closer to the planet for the final phase of the operation.
Last but not least, from here, I got the following quotation:
Got it? At the very beginning of the operation, hive ships already fly at low orbit. So escape speed is not needed to gather water and air (although it will partially required to complete what's neede to leave later on).Strictly speaking the consumption of the planet under attack is continuous from the moment the hiveships achieve low orbit and release organisms into the atmosphere. -p.41 3rd ed. Tyranid Codex
Now, we happen to have a detailed example:
The ships descend into the atmosphere, and even if we took Connor's energy figures at face value, we'd go with the inferior atmosphere-relative one, since the ships take it first, which dramatically eases the task of "drinking" the water, largely turning into gas.Transmitted: Magos Biologis
Research Station:
New Hallefuss
Received: Talasa Prime
Subject: Tyranid Planetary Assimilation Analysis
Date:3205766.M41
Astropath: Prime Felnun
Ref: INQ.XR.01044/A
Horizontal Rule
Lord Commanders,
I bring you grave news. The threat we face may be far more vast than we ever dreamed. Technical analysis of Dalki-Prime pre Tyranid consumption survey information when cross-referenced with the data from Dalki-Mons post Tyranid consumption shows some startling information.
Dalki-Prime was an agricultural planet with a diameter of 12,500 km, slightly smaller than Terra. The Tyranid fleet was able to remove the following quantities of material from the planet within 100 days [Terran Standard].
1.55 billion cubic km water, one cubic km of sea water weighs over 1 trillion kg.
8.67 billion cubic km gases, at STP theoretically they could reduce this to 1 tenth its volume by super cooling and pressure (3 atm, and 0ºC).
72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km.
It is nearly inconceivable how they were able to accomplish this in such a short time, much less explain where the materials were taken, as the typical hive fleets encountered historically are not capable of transporting even a fraction of this volume. Over 10 billion cubic kilometres of material was removed from the planet. This would require untold millions of ships and is far beyond the scope of the entire Adeptus Mechanicus to accomplish given a decade. Most astonishing is that this is insufficient to sate their hunger and they strike again and again, often within months. We must somehow determine if these fleets are somehow sending material back to their home systems for it seems obvious that they are not using all the materials.
Detailed analysis of devastated worlds have yielded the following data in conjunction with orbital surveillance satellite and data recordings which were recovered.
TYRANID PLANETARY ASSIMILATION: DALKI-PRIME
Analysis of records from Dalki-Prime have indicated invasion began quietly without any full-scale assault. A drop pod was detected entering the atmosphere of the southern hemisphere; this occurrence is the first known indication of Tyranid activity. We have chronologically designated this as day 0 insertion.
Day 7: PDF forces engaged and destroyed over 137 individual Tyranid organisms in an uninhabited area where the mycetic spore landed. No record exists of the elimination of a Hive Node creature but the mission was designated a success by the lax planetary governor, against the registered complaints of the PDF commander.
Day 9: Two separate outbreaks of Tyranid infestation were encountered, both over 200 kilometres from the initial insertion point. PDF were dispatched along with considerable forces of the IG garrison.
Day 13: Tyranid organisms were dredged from the main fishery areas on the northern coast some 700 kilometres from initial insertion point. Conflicts continued in both other fronts. Basolithic infestation is assumed to be progressing unchecked at this time.
The Planetary Governor issues a distress call.
Day 37: Major sections of all surface areas within 2,000 kilometres of the insertion point are firmly within Tyranid control. Basolithic infestation is verified by PDF navy submersibles which are destroyed 5,000 kilometres from main insertion point. Undersea agricultural complexes are attacked and destroyed.
Desalination plants along the coast were invaded from within and destroyed, access being easily gained from the large pumping stations.
Day 42: Planetary Governor and staff abandon the planet to the control of IG commander Gal Markit, who immediately orders orbital planetary bombardment with little success.
Day 48: IG forces are sorely pressed at all junctures, field reports indicate exponential growth in the numbers of Tyranid creatures. (Rough estimates indicate doubling every 2.5 days.)
Day 50: All psychic contact with Dalki-Prime is cut off by the overpowering presence of the Tyranid hive fleet which drops from warp space around the planet. Preliminary estimates place the numbers of space borne creatures at 1.46 billion. All escape attempts from this point on are intercepted and destroyed.
Mycetic poison spores are released into the atmosphere. These rapidly grow on all organic material, rhizomes burrow deep into organic tissue releasing enzymes to begin the rendering of the material. These aid the Rippers and also render any exposed material useless to other creatures as a food source as the fungus is highly poisonous to most life forms. Living creatures exposed to high concentrations of spores [200 per m3] typically develop lethal mycetial infestations within the lungs. Death occurs within 24 hours.
Day 51: Primary consumption of all biomass on Dalki-Prime commences with little resistance. Brood ships land on the planet and release the Ripper larvae, billions upon billions of them. These voracious creatures spread out, divesting the planet of all organic material and returning to the reclamation pools to deposit the nutrient broth. Capillary towers relay the material to orbit. Brood ships periodically return to orbit and unload this material to the great brood factories and feeder ships. Surface and aerial mobile lifeforms which do not succumb to the spore clouds are hunted and eliminated in the initial stages. This continues for approximately 8-10 days non-stop, accomplished primarily by Gaunt species, the carcasses left to the Rippers and the spores. These hunter swarms return to the Rippers to obtain regurgitated digested food.
Day 80: Ripper swarms, having systematically divested the land masses and basolithic planes of soil and dermis, board the brood ships and return to space. Once this has been completed the huge hive ships descend into the upper atmosphere. These creatures, which resemble primitive radiant life forms with long tentacles, then drop into the atmosphere and begin removing it. As the atmospheric pressure is reduced, the water of the oceans begins to evaporate and it too is vacuumed up. As the tectonic plates begin to move due to the shift in planetary pressures caused by the removal of the vast oceans, volcanic activity increases dramatically. Devoid of the huge weight of the oceans many areas rupture, spewing hot gases and lava onto the surface. As the hive ships take the last remnants from the planet, they retreat into the warp leaving the barren sphere in its death throes.
Day 100: Imperial Navy arrives in response to the distress call finding the planet lifeless.
Nevertheless, we have ample evidence that we certainly don't have to use those 3e26 J and 9e28 J figures.
1. The sheathing doesn't require any absorption of energy aside from what would be spent to bring matter into orbit, nor does the cooling of air and water molecules, obviously done naturally.Connor MacLeod wrote: PAge 42Various points of interest:They [Tyranids] would strip away its atmosphere and drink its oceans, covering their mile-long bodies with frozen sheaths of oxygen and hydorgen, nitrogen and chlorine in preparation for the journey ahead.
...
"You led the Cobra squadron to Tethris and participated in the Exterminatus."
"Aye, though there was little honour in dropping out of the warp to launch cyclonic torpedoes and then fleeing."
...
"They actually managed to block a third of our torpedoes but the rest hit cleanly. I saw the fire vortexes spread and multiply. The planet burned."
****************
On Tethris, an endless ash-plain shifted and then cracked apart as the first of the newly pupated rippers burrowed its way up to teh surface and hissed its definace at an empty sky.
- "Mile long" tyranid vessels. No idea of what they are, but it may be implied to be hive ships (small ones?) Again they strip off the water and atmosphere of the planet. Interestingly, they "sheathe" it around themselves, suggesting they not only can expend the energy, but absorb huge quantites as well.
- Cobra destroyers (if properly equipped) can conduct exterminatus operations as well (which seems to be an exception to the BFG-oriented rules) Presumably the weapons are fired out of hte torpedo tubes. (If there are about 6 8 destroyers in a squadron, there were probably between 20-30 torpedoes, tops, if they fired only one salvo.
- The Destroyers launched upon exiting the warp. This can mean one of two things. Either a.) the Destroyers dropped out of teh warp some distance in system before launching (possible, but unlikely) or b.) they launched from some distance away (probably the edge of the system.. many AU off) and targeted the planet. This seems liklier, as we already know of long range bombardment examples, and this simply reinforces that torpedoes and missiles can engage at extremely long ranges (millions or billions of kilometers)
- We dont know for sure if these are technobabble cyclonic torpedoes or brute force ones, but the latter (Based on TActica Imperialis) seems liklier. The fact it triggers firestorms and needs multiple warheads seems to suggest this, ,but its not certain The effects are pretty straightforward though - they trigger global firestorms and basically heat the atmosphere to what can be termed sterilization temperatures. The fact that it basically incinerates everyhting on the surface of the planet suggests this (cremation temperatures are in excess of 1000-1200K) Generating those levels of energy would requier billions of megatons easily.(5e18 kg of air on an earthlike planet, about 1.2 MJ per kg to heat the atmosphere to 1500K) This does assume high efficiency, so it could be alot higher, but probably not massively so since its purpose-built for "airburst". The fact that a Tyranid can burrow undeground to avoid the attack also reinfores the airburst nature of the attack.
This also means each cyclonic torpedo generates hundreds if not thousands of teratons.
2. Going by wikipedia, a squadron is about 2 to 6 such ships. Destroyers have a pair of torpedo tubes, likely used for this operation. Now, why assume only one salvo? Since the implication is that such destroyers aren't generally used for Exterminatus ops, and are therefore modified, why not consider the plausibility that they're also jammed with cyclonic torpedoes?
3. Firing upon exiting warp actually means the Imperium squadron didn't want the Tyranids to have time to react to their arrival. Therefore, the more distance the squadron would put between itself and its target, the more time the Tyranids would have on their hands to detect and intercept the missiles.
Besides, notice that the leader saw the fire vortexes spread and multiply. I suspect this to be quite hard when either sitting at a long distance, still intra-system, and rather absurd if the ships had actually fired from an extra-system position.
That and the fact that the ships departed and then fled, which is completely antinomic to the idea of these ships moving closer to Tethris to observe the devastation.
Actually, there's more information from the Tyranid Codex (4th Ed.).
As we see, the squadron was actually very close to Tethris, no doubt about that.The cell was small, no more than three paces from one iron wall to the other. The presense of the Space Marine, even stripped of his armour, reduced it to nothing. Brass and steel chirugeon-machines were hooked into the giant's black carapace, labouring to repair the deep burns seared across it. Inquisitor Kryptman viewed the hulking Space Marine impassively, weighing his ability to report against his evident pain. The warrior's heavy-jawed face was stoic, and he spoke first.
"I am fit to report, Inquisitor, I've suffered worse."
"You led the Cobra squadron to Tethris and participated in the Exterminatus."
"Aye, though there was little honour in dropping out of warp to launch cyclonic torpedoes and then fleeing."
"Tyranids are creatures without any concept of honour. You had to fight anyway by all accounts."
"They had a double ring of pursuit drones and deep space mines stationed around the planet. We covered the other ships' retreat and... I'm sure you know the rest."
"Precisely, but you were best positioned to observe the planet itself and the impact of the warheads. What did you see?"
"Tethris was completely changed. It looked verdant like a jungle planet but with strange coloured clouds in the atmosphere. There were... spines which projected up from the surface into space which some of the Tyranid ships were connected to. They actually managed to block a third of our torpedoes but the rest hit cleanly. I saw the fire vortexes spread and multiply. The planet burned."
4. Well of course, as mere observers, we don't really learn what in "Tactica Imperialis" really pushes us to discard the technobabble option for the raw power one.
I don't even know if there's a problem pointing out the issue that only such few ships could run such a devastating Exterminatus. Why the need for the bigger ships then, and all the impression that when such larger ships arrive, it's doom time for a world? (that said, the Space Marines' large battle barges are explicitly meant to carry on Exterminati).
Yes, the planet burned, which is just as vague as it can get, unless you want to take it literally, as always. Still, when a car is said to burn, it doesn't mean every cubic centimeter of the materials that compose it are on fire. When a city is said to burn, it's not literally sheathed in a fire storm that slags its foundations.
Now, an Exterminatus is supposed to be complete, but a third of the entire load of missiles was intercepted.
Besides, there are important points to make:
a. The squadron was called Cobra Squadron. However, does this really mean the ships were Cobra destroyers?
b. The squadron "participated in the Exterminatus." Were they really alone or not?
c. "We covered the other ships' retreat" seems to imply the presence of other ships. The leader of Cobra Squadron identified his group, thus far, as Cobra Squadron. Now it's "we", and we helped "other ships" to retreat. It would seem that Cobra Squadron was involved in the protection of other ships, which is the point of destroyers after all.
Sidenote: A quotation contained the following information:
Rather interesting, Hive Fleets obviously elude detection systems.Page 41 wrote:
The bio-ships which comprise the fleet may either exit the warp simultaneously at the edge of the system or, in many reported instances, exit in deep space and drift towards their objective. This latter approach renders the hive fleet virtually invisible to long-range augury and astrotelepathic detection.
Can't spot some drifting stuff?
It implies this particularity also applies to other ranges of sensors from various races, otherwise that technique would prove completely worthless.
Therefore sensors are not capable of long range (several LY) deep space scanning.