WH40k: Logistics, and the space force

[Jedi Master Spock]

Over the past few weeks, I've been reading through a lot of material that isn't within the limited scope of my formal debate with Thanatos (which is focused just on ground warfare technology).

The more WH40K material I read, the more I am convinced that almost nobody active in the VS actually reads this stuff carefully and all the way through.

For example:

I am now pleased that some of the ''Empire of a million worlds crap'' has been disproved, if thier are that many hive worlds then their must be more humans per world than we first thought, a useful tool in vs. discussions.

And yet, the "million worlds crap" is one of the most consistent pieces of fluff in WH40K sourcebooks. It gets repeated a lot. It typically looks something like this:

Despite being beset by alien attacks from without as well as treachery, mutation and heresy from within, it is the greatest empire in human history, encompassing over a million worlds.

It's pretty solidly canonical. No other figure, to my knowledge, is ever given; just the very consistent "over a million worlds" figure - yet in the incident I quoted above, a VS debater was suggesting glossing it over in favor of what? Pure conjecture with no supporting evidence. Of course, "over a million" is not precise:

Storms are constantly forming and dying down, at any time at least 10% of the galaxy's solar systems will be inaccessible because of storms.

Systems tend to drop out of contact with the Imperium, and there are a number of misplaced colonies joining (or rebelling) at any given time. However, if there were even two million worlds in the Imperium at any given time, we would expect to read something other than "over a million." It's probably between 1 and 2 million worlds.

We actually have a pretty good idea how they are distributed, too; there are ~32380 hive worlds. Non-hive worlds seem to be pretty sparsely populated – millions, frequently. If the average hive world had only 100 billion people and the average other world had 1 billion and 2% of worlds were hive worlds (meaning 1.6 million worlds in the Imperium), then hivers would represent two thirds of the population. That reduces our uncertainty to about a single order of magnitude: It seems a pretty sure thing the population actually ruled by the Imperium is 3-30 quadrillion.

The sourcebooks are also pretty consistent in describing the size of the Imperial Guard: Billions of men, millions of tanks, fighting in thousands to tens of thousands of conflicts. The juxtaposition suggests that tanks are in the very high millions, while the number of the Guard are in the lower billions; the ratio of tanks to men in the Imperial Guard doesn't seem that bad. The Guard are deployed in lots that don't seem to typically exceed a few million.

Recruitment reflects this, too:

As Krieg stands today it is a true war-world, its tithes are the maximum possible for the planet's population, raising tens of regiments each year, where a comparable sized might be expected to tithe one regiment every decade.

Krieg was a hive world, incidentally, but wasn't noted as a special source of troops before civil war ripped it apart. At most, we might be talking about a million troops a year from Krieg, but I doubt there are that many war-worlds.

As we see, the maximum tithe is several hundred times the typical tithe; given it's measured in regiments, rather than number of Guards, I suspect there's probably a factor of a thousand between fervently loyal war-worlds and the minimum tithe, with most worlds trying to tithe as close to the minimum as they can get away with. That would explain how a few worlds supply such a large fraction of Imperial troops.

If the mean tithe of all worlds is one regiment per decade, then we have 100,000 regiments per year. Might PDFs outnumber the Guard by a factor of ten to one? Sure. Might >90% of Guard personnel drafted serve in logistical support roles off-planet from the conflicts that the combat wing of the Guard are active in? Sure.

So, yes, on paper, the Imperium may have a trillion soldiers in its service. But as far troops that the Imperium actually sends around the galaxy and lands on places like Taros, we can be reasonably sure the figure falls within a single order of magnitude: 3-30 billion active combat troops being landed on the galaxy's problems hundreds of regiments at a time.

Bear in mind, it costs a lot to wage interstellar war, and the Departmento Munitorium is not the most efficient spender.

Next: The Navy, and trying to figure out whether or not WH40K has it even worse than the SW EU regarding consistency of ships' power.

[Jedi Master Spock]

The problem with WH40k warships is that Games Workshop seems to mostly be staffed by mil-history buffs, and rather short on space-sci buffs. The result is that spaceships are anachronistic at best, and a bit inconsistent at worst. There are several interesting problems, but most interesting to me is, as usual, the gross problem of order of magnitude.

See, when a planet is smashed to flinders, that requires a lot of energy. However, smashing km-scale rock, steel, or future-alloy only a single order of magnitude tougher than steel, or heaps of poorly-bound trash – that's not so high energy.

It gets more complicated, of course, because of the Warp. Caliban, for example, homeworld of the Dark Angels, is assaulted by a bombardment fleet of unknown size. They shell the planet during an epic Primarch-on-companion duel; the codex describes “miles-wide craters” and magma pouring out of them. The planet is actually dispersed, however, by a warp storm.

A crater a couple miles wide? That's maybe a hundred megatons or so. Breaking through the crust? Even if Caliban had a thin crust, that's probably more than a gigaton. Even at the point where the entire crust becomes molten (which, we will note, was not the case) we're around the traditional Saxton BDZ range – 1e25 joules is sufficient. Breaking the planet apart? If Caliban is Earth-sized, that's twenty million times the energy. If the fleet had a hundred ships, and those hundred ships bombarded Caliban for an hour, and melted the whole crust, that would be a “generous” ~30 exawatts average output. If the ships bombarded for ten hours, and there were a thousand, and they provided enough energy to break the planet apart without the warp storm, that would be an “ungenerous” ~6,000,000 exawatts.

We're already starting to see problems. Questions arise in TDIC because destroying the crust is nothing compared to destroying the whole planet. If your ships are capable of destroying the whole planet, we should be seeing instant huge effects. Craters should be much larger than mere miles wide; we should be seeing hundred-mile fireballs visible from orbit, but that description doesn't suggest even TDIC scale effects on the surface of Caliban.

Then there's the Ork problem. Orks like to use Roks and Space Hulks. Roks are converted asteroids. One single gigaton hit should shatter any Rok. Space Hulks are up to hundred-km wrecks “constructed” from random debris of ships that have collected together. Quick lesson: If it's simply being held together by gravity, and it's only a couple hundred km across, gigaton weapons will make very short work of the task of blasting it back into separate pieces. So in order for Roks and Space Hulks to be actual dangers in space combat – which they are – weapons yields need to be sub-gigaton.

What about Imperium hulls? Every bit as bad. See, WH40k ships can take a beating even without their shields. This is a small problem. Adamantium alloy is pretty close to five times as tough as steel per unit volume, as described in Imperial Armour Volume II. So 300 gigajoules per cubic meter should vaporize the stuff, and 60 gigajoules per cubic meter should melt it. Imperium ships, like most ships, have a lot of other stuff and empty space, and are quite a bit narrower than they are long - so 300 exajoules – 70 gigatons – should be enough to blow up pretty much any cruiser. 1 gigaton should cause huge amounts of damage – that's enough to melt a solid 400 meter cube of adamantium alloy, which means causing massive damage all across the ship.

The gigaton range is about the limit for the damage vs other capital ships, and these aren't fast firing weapons. Hundreds of gigatons every minute – necessary for the Caliban bombardment, and lining up with the 610 gigaton torpedo reference trotted out so frequently – simply can't be justified based on ship-to-ship combat.

It gets even worse. See, small starships and Titans are on close par with each other, and some of the same vessels used for close air support are also used in space to attack capital ships. The Tau Mantas, which engage Imperial Titans on the ground, also engage Imperium cruisers in space, and they are hardly the smallest bombers in play; one Tau Manta “squadron” in BFG represents a single Manta. Other bomber “squadrons” represent multiple smaller bombers.

This is a 382T 52x32x8m ship. Its weapons are powerful, yes, but sub-nuclear. Even if it carried massive fusion bombs when loaded for anti-warship work, those bombs are unlikely to fall higher than the gigaton range. Further, it's something like 1/100,000th the size of an Imperial escort vessel, and yet a carrier launching eight of these is important – and so, we expect it to be more powerful for its size than the larger warship with its normal weapons. The Manta is certainly under a kiloton per second, so we expect the escort to be less than a hundred megatons per second.

It's not quite as dramatic as Star Wars, where fighters less than one millionth the size strafe Star Destroyers and have an actual effect, but if we don't assume the existence of powerful bombs carried by Mantas, much more powerful than the missiles and railguns they use when attacking ground targets, we have every bit as much of a gap as between Keven J. Anderson and Curtis Saxton – decidedly sub-kiloton fighters threatening ridiculous ICS-scale warships.

As if that weren't bad enough, we have actual Titans – obviously not carrying a bomb load – shooting down a massive Sky Fortress:

The great Sky Fortress bore Rogal Dorn and the remnants of the Imperial Fists to the inner palace. The loyal old general was determined to stand and die with his Emperor in the final hour. The Sky Fortress raced away from the palace in a desperate attempt to reach Jhagatai Khan and return him to the palace. It was destroyed by a blaze of fire fron the Death ́s Heads Titan Legions. Even in death its commander wrought havoc on the enemy, bringing the crippled vehicle down into the entre of the Chaos Horde. It seemed as if a new sun was born on Earth as the plasma reactor exploded, blasting out a crater three kilometres across. Those within the palace knew they were cut off; now they were truly alone. Only a miracle could save them.

Titan weapons smash tanks. Most KT range weapons generally produce giant mushroom clouds and big craters. We have a mighty Sky Fortress being killed by ground-to-air fire from weapons that might top out in the kiloton range.

On top of that, the dying Sky Fortress's overloaded reactor only puts out tens of megatons. We clearly have the contradiction; the question is, which piece of the pie should we actually run with?

Fire control is similarly inconsistent. On the one hand, Battlefleet Gothic describes warships fighting at tens of thousands of kilometers, perhaps even hundreds of thousands of kilometers, hitting mobile targets only a few km wide while maneuvering; on the other hand, from orbit, Imperium warships are constitutionally incapable of providing accurate fire support for ground forces, on a scale of combat where even a fraction of that accuracy is sufficient. The tens-of-kilometers-deep siege lines of Vraks, for example, would be rendered moot by the ability to land shots within a given 10 kilometer circle from a predictable orbit, a task far easier than nailing an evading starship on the fly.

[Jedi Master Spock]

In order to better understand why WH40K firepower figures have been stated as they have, I've been reading through Connor MacLeod's analyses on SDN, which for the most part either are, or are closely related to, what is cited on SDN or SB.com regarding WH40k yield by WH40k fans.

I am struck by a remarkably consistent pattern; conventional ship firepower simply does not measure up to multiple gigatons per shot when measured against any actual effect on a given target. Computations exceeding a gigaton per shot, for a conventional Imperial cruiser, rely upon one of two things:

• Torpedo yield figures from fluff, which in a couple instances refer to many gigatons for a torpedo.
• A series of somewhat arbitrary, if not terribly unreasonable, assumptions (such as the contrasting figures for Caliban I give above).

The former I believe the result of accidental error; the latter can easily be adjusted by multiple orders of magnitude by adjusting the parameters. However, when we have any hard and fast effect on a target, it generally implies sub-gigaton weapons.

For example, in Execution Hour, we have a planetary bombardment:

Armaments that could hurl energy hundreds of thousands of kilometers across space now turned their power on the planet's surface in an awesome display of destructive capability, gouging wounds hundreds of meters deep into the rock and soil of the hills in search of the silos, command bunkers and generator caverns buried there.

A 200 MT nickel-iron projectile can penetrate a kilometer of hard rock.

A 4 MT yield nickel-iron projectile at, say, 17 km/s (about a 30m hunk of rock) will lose most of its energy in the atmosphere, but will still penetrate to 300m, the depth of an Inquisition fortress in Shadow Point.

For a surface-detonated nuclear device, we can have higher yields than for a dense kinetic penetrator - the Castle Bravo test only produced a 75m deep crater, after all, but we're still not talking about more than a gigaton.

A plasma Bomb is a large missile typically used by or against spacecraft. They are also used for planetary sieges. The missile energies at launch, converting into a mass of seething plasma - each missile becomes a ball of boiling energy sufficient to melt a city block.

Another notable quote mentioned, yet mostly ignored, in those threads. Melting a city block is not gigaton range either. Then, of course, we have a few other incidents in Shadow Point, such as the Rok scene:

The torpedo wave's target had been the two largest rok-fortresses in the enemy front line. The roks were massive, one of them easily over eight kilometres from tip to tip, and possibly as many as four kilometres across. Eight torpedoes s truck it, the remaining six finding the other one. Normally, it might have taken several dozen torpedo strikes to destroy targets this large. Not today, however. Today the Imperium warships were using new ordnance: so called "rock-buster torpedoes", specially designed for the task at hand.

The torpedoes struck the pitted and cratered surface of the roks, their armoured nose-cones spinning like giant drill-bits and boring into the porous rock. The missiles burrowed deep into the bodies of the asteroids, drilling through hundreds of meters of rock in seconds. When the high-speed drill motor burned itself out at the end of its short lifespan, it triggered the warhead payload. The torpedoes exploded. Their payload was not the conventional plasma-fusion warheads used in normal ship-to-ship actions, designed to melt and destroy ship's hulls and set their internal compartments ablaze. Instead, the rock-busters warheads were packed with high-explosive seismic charges, designed to shatter and pulverize rock, setting off a chain-reaction of aftershocks within the structure of their asteroid targets far in excess of the payload's explosive yield.

The Drachenfel's lance batteries gored into the sides of another rok, blasting away or vaporising hundreds of tonnes of soft, porous rock.

An 8x4x4 km cylinder of what's mostly described as porous rock is not going to hold up well against gigaton weapons. The torpedoes in this case are clearly designed to shatter rock with minimal energy wasted on vaporization - a hundred megatons each is quite sufficient. For the regular torpedoes, several dozen gigatons would be severe overkill.

This is justified by Connor et al by appeal to unmentioned unconscious WAUGH structural integrity fields - a rather arbitrary assumption, and circularly justified in any argument over WH40k yields.

Shadow Point also gives what seems to be an individually quantifiable weapon strike greater than a gigaton - except it's from Abbadon's planet killer, not a conventional cruiser, and treated as something truly exceptional that would take a fleet of lance-armed ships to accomplish.

These patterns are repeated over and over again. It's perfectly fine to use "ballpark" calculations as in the BDZ technique to give you a general idea of things, but with the vague descriptions common in WH40k, they're not precise, and therefore stand inferior to the descriptions of actual effect against actual targets. Including, as I mentioned above, ships. While clearly superior, adamantium is still within an order of magnitude of conventional materials.

In short, examining the calculations from which pro-WH40k debaters on SDN and SB.com have drawn ICS-level firepower for WH40k ships, I find them mostly without merit. We are very evidently working with sub-gigaton weapons. The stated hundreds-of-GT total yield for torpedoes is temptingly specific, but clearly contradicted by actual effects in the fluff and novels.

[Thanatos]

Quickly point out a few things.

. Non-hive worlds seem to be pretty sparsely populated – millions, frequently

Depends on the type of world. Civilized worlds which form the bulk of planets generally have around hundreds of millions to billions of people living on them though the more remote and peculiar ones have lower populations in the tens of millions.

At most, we might be talking about a million troops a year from Krieg, but I doubt there are that many war-worlds.

There's a map of 40 "notable" tithe worlds in the 5th edition rule book with yearly recruitment of at least 5-10 million a year. Krieg is part of the 11 50+ million a year club along with other sunny vacation spots as Catachan, Tallarn, Valhalla and Armageddon.

There's also a list of Fortress Worlds that are even heavier recruitment centers as well as being fortified but it doesn't give their annual recruitment. Its also missing a large number of notable high recruitment worlds like Necromunda (which has a population that can easily get into the double digit trillions), so its by no means a complete list.

The high regimental tithe worlds with minimal populations basically have troops as their only tithe and resources. Places like Valhalla and Tallarn have higher populations but their environments make for good specialized troops. Especially since they've seen to have adapted to a high degree to the environment. Valhallans keep their rooms at meat locker temperatures (They sweat profusely at normal room temperature) and run around in fatally cold conditions like it was a chilly day for example.

The juxtaposition suggests that tanks are in the very high millions, while the number of the Guard are in the lower billions

There's and I quote "Billions of Billions" of guardsmen and "Millions and millions of regiments". There's also a quote saying that there are millions of guardsmen for every Space Marine.

There's also the fact that if every Hive world had a recruitment rate of that of Minea (1.2 Million a year), there would be an annual recruitment of 38 billion a year alone. However, a number of those are also tithe worlds too.

Might >90% of Guard personnel drafted serve in logistical support roles off-planet from the conflicts that the combat wing of the Guard are active in?

Not really since the AdMech and Munitorium handle almost all of the Guard's logistics thanks to the Horus Heresy. Regiments tend to be purely combat focused with support units from other branches attached to them.

Might PDFs outnumber the Guard by a factor of ten to one

PDF, militia and reserve recruitment is done separately.

That would explain how a few worlds supply such a large fraction of Imperial troops.

Well, they're the "Regiments of Renown" and they're simply the most known. There's a ton of places that put out generic troops that fill out most of the ranks of the Guard that you hear about. Stories generally tend to follow the Renown as they're more interesting and already fleshed out before hand. Its like the Space Marines, there's about two thousand chapters but you mostly hear about 20 of them.

[Jedi Master Spock]

Quickly point out a few things.

. Non-hive worlds seem to be pretty sparsely populated – millions, frequently

Depends on the type of world. Civilized worlds which form the bulk of planets generally have around hundreds of millions to billions of people living on them though the more remote and peculiar ones have lower populations in the tens of millions.

I actually bumped into a really interesting entry after I posted that, in the Black Templars Codex:

Until a sect known as the Divine Army gained control, Lastratl was an unremarkable hive world in Ultima Imperium.... only two and a half million inhabitants were left of a world that once boasted a population of fourteen billion.

I had been under the impression that hive worlds were always more than that. Still, I'm going to stand by my original estimate on population.

There's a map of 40 "notable" tithe worlds in the 5th edition rule book with yearly recruitment of at least 5-10 million a year. Krieg is part of the 11 50+ million a year club along with other sunny vacation spots as Catachan, Tallarn, Valhalla and Armageddon.

50 million is far more than I expected from IA vol V. That would imply very large regiments if they're only sending "tens." That's a pretty quick shift on their part.

I don't suppose I could entice you to post the list? I haven't seen the 5th edition rulebook yet. It would be interesting to analyze, and at the least, sets a pretty firm lower limit on total recruitment.

IMO, given the "typical" base tithe for a world Krieg's size is given at 1 regiment per decade, I really do think that a few worlds supply most of the ground troops. There's a line in the 4th edition Codex: Imperial Guard that makes me think a number of worlds don't even supply troops:

When a tithe is taken as troops, soldiers will be recruited in much the same way as the planetary defense force is recruited.

When a tithe is taken as troops. It sounds a lot like the Athenian League: "Send gold or ships!" Athens always sent ships; others almost always sent gold. Result was that the navy was mostly Athenian.

There's also a list of Fortress Worlds that are even heavier recruitment centers as well as being fortified but it doesn't give their annual recruitment. Its also missing a large number of notable high recruitment worlds like Necromunda (which has a population that can easily get into the double digit trillions), so its by no means a complete list.

It may be. I suspect a very significant fraction recruitment would be from the top 100 contributing manpower worlds, and a definite majority from the top 1,000, but that would push us to the higher end. I may also have overestimated how heavily mechanized the average Imperial Guard unit is based on the composition of one sample force (6 million Guard with half a million tanks).

The high regimental tithe worlds with minimal populations basically have troops as their only tithe and resources. Places like Valhalla and Tallarn have higher populations but their environments make for good specialized troops. Especially since they've seen to have adapted to a high degree to the environment. Valhallans keep their rooms at meat locker temperatures (They sweat profusely at normal room temperature) and run around in fatally cold conditions like it was a chilly day for example.

And the Imperium is large enough to have specialists in every terrain, just about.

There's and I quote "Billions of Billions" of guardsmen and "Millions and millions of regiments". There's also a quote saying that there are millions of guardsmen for every Space Marine.

The last quote qualifies for the "which of these things is not like the other" award. Since there are not too much under a million Space Marines, millions per would be trillions, rather than billions, and typical regiments seem to be in the <10,000 range.

The one thing that really pressed my estimates downward is the "millions" of tanks, but I may have overestimated how heavily mechanized Guard forces are.

There's also the fact that if every Hive world had a recruitment rate of that of Minea (1.2 Million a year), there would be an annual recruitment of 38 billion a year alone. However, a number of those are also tithe worlds too.

I don't think Minea is strictly average. I suspect that it's an "examplar" world - what the Imperium bureaucracy would like all hive worlds to be just like.

Not really since the AdMech and Munitorium handle almost all of the Guard's logistics thanks to the Horus Heresy. Regiments tend to be purely combat focused with support units from other branches attached to them.

PDF, militia and reserve recruitment is done separately.

Again - and more to the point, I'll add the next sentence:

When a tithe is taken as troops, soldiers will be recruited in much the same way as the planetary defense force is recruited. Sometimes, the regiments raised are identical, the tithe being drawn from the PDF.

Now, of course, the quality and numbers of the PDF may vary widely, but I think that overall, the PDFs of the Imperium probably outnumber the Guard by about an order of magnitude. This is especially supported by the older third edition codex, which had a line about "one part in ten" of a lord's armies being his tithe.

Now, when a world rebels, of course its PDF can expect to be vastly outnumbered, because it's being oppressed with troops drawn from many other worlds, and the Guards are likely to be better trained and equipped.

Well, they're the "Regiments of Renown" and they're simply the most known. There's a ton of places that put out generic troops that fill out most of the ranks of the Guard that you hear about. Stories generally tend to follow the Renown as they're more interesting and already fleshed out before hand. Its like the Space Marines, there's about two thousand chapters but you mostly hear about 20 of them.

The last I heard, there were about one thousand chapters, not about two thousand. Has this been changed with 5th edition?

[Jedi Master Spock]

Having established roughly the level of firepower (common weapons best measured in megatons, but lots of them and lots of ammunition) for ships, and having briefly mentioned the size of said ships, we then come to the sticky point:

The logistics of the Imperial Navy. There are two primary functions of the Navy. One is transporting Guardsmen:

Formerly known as the Righteous Fury, the vessel was accompanying fourteen Navy transports (carrying thirty two thousand guardsmen, fifteen hundred battle tanks, and over ten thousand auxiliary staff and vehicles)

In this instance, we see one tank per 21 Guardsmen. The capacity is several thousand per transport. If Guards spend 10% of their time in transit, and each transport on average is transporting one regiment, the Navy needs one transport per ten regiments. That's a ballpark.

First estimate: A sector Battlefleet is typically 50-75 capital ships and deals with a region roughly eight million cubic light years. It would take about a million sectors to fill the galaxy - at close to one sector per inhabited Imperium world.

That would be more than one capital ship per world. Actually, that would be one Battlefleet per inhabited world. Accordingly, I'm going to dismiss that estimate.

Alternative estimate: There are five Segmenta. We know a bit about the Segmentum Obscurus fleet:

The Lunar class cruiser forms the mainstay of Battlefleet Obscuras with over six hundred ships serving throughout the Segmentum and more than twenty ships fighting in the Gothic War.

Unfortunately, this is going to end up being a little bit off from our original estimate. We have a Segmentum fleet, of which 600-odd cruisers form a "mainstay."

I assume it's not a majority, so the Segmentum should have more than 1200 capital ships. There are presumably less than seven hundred and only nine capital classes represented in the Gothic fleet, so the "backbone" should be at least of average number, meaning the Segmentum should have less than 6300 capital ships.

6 of the 32 "notable" ships mentioned are Lunar class vessels. Based on this ratio, my "best guess" is therefore 3500 capital ships in the Segmentum Obscurus fleet. This would correspond to 45-70 BattleFleets (best guess 60) and a similar number of sectors.

If the Segmenta have similar sized fleets and similar numbers of sectors - a substantial but reasonable assumption - the total inventory of the Imperial Navy should include around 17,500 capital ships (6,000-30,000). This would be supplemented by several times this number of escorts, but the total number of genuine dedicated warships does not seem like it should greatly exceed 100,000.

Note this represents roughly an order of magnitude difference, something which has consequences in the number of sectors. This would mean, however, that the actual inhabited volume of the galaxy is about 2 billion cubic light years, or a rather small percent. Not only are inhabited planets within a sector nearly isolated, but patrolled sectors sparsely inhabit the galaxy.

This would also mean about 4000 inhabited worlds per sector, and about 60 inhabited worlds per capital ship. Since the Imperium is supposedly ~99% at peace when we compare the number of conflicts to the number of inhabited worlds, this actually isn't terribly unreasonable.

Third estimate: Let's say we have 5 million regiments of Guard, and on average, one warship will be escorting every ten regiments in transit, with 90 other regiments on station (per the above 10% in transit assumption). Then we have 50,000 escorting warships. If the Navy divides its time equally between escort and patrol, we then have... 100,000 warships, according to assumptions that are reasonable, if fairly arbitrary.

This is not terribly far from the second estimate, whose assumptions are a little more grounded in actual numbers (ratio of Lunar class to other vessels, number of Lunar class in the Obscurus Segmentum, estimated ratio of Lunar to non-Lunar capital ships), so I believe I will take the second estimate as best, for the moment.

[Dabat]

I might as well admit up front, and many of you can likely tell from my sig, that 40k is my favorite sci-fi reality. I know I am new here, so I know my word does not yet hold much sway, but trust me when I say that dispite my personal prefrence I have no ax to grind in which universe is the best, or will win in a stand up fight, it is a matter of pride for me that I attempt to remain as unbiased as possible in all things.

I am a long time fan of 40k, I have been a fan for the last 17 years or so, starting when I was eight. And in that time I have learned several things about the universe. (I am not saying you guys do not know all of these already, I just want it known that I know them)

-One of the first things everyone must remember about 40k is that is it unabashed Science Fantasy. No one is saying the EoM is real or follows any of our normal rules. In the official cannon, there are object and technologies that make mockery of the laws of physics. I am not saying that these are common, but they are there.

-Second is that the technology level inside the Empire of Man varies wildly (Even though the technology level of the armed forces remain fairly consistent).

-Third, and this has been admitted by the likes of Gavin and Andy, much of the fluff written for 40k is wrong. Not just an accidental mistake or in merely in contridiction to something else that was written. I mean that the fluff itself was intentionally written to be incorrect or misleading. Either because the fictional author had incorrect information, or said fictional author deliberately lied, or (rarely)it was only meant to apply to a particular area. The incorrect fluff is often easy to spot; "Genestealers function poorly in close combat."(Paraphrased from the Uplifting Primer) to things that most have no way of knowing are false; 'There are only three remaining C'tan." (Four are outright given names, and another two to four have given refrence to**). Cannon fluff for 40k has been refrenced to as like a puzzle, each piece a part of the whole, but each piece may not be what you think... Which I guess is part of my attraction to the setting.

**note I can't really prove there are more then three. But a list of at least seven names has been given mention to more then once. Off the top of my head I think they are Deceiver, Nightbringer, Dagon(Also Dragon, Star Dragon or Machine Lord.. Yes that Machine Lord), The Sleeper (sometimes refrenced in plural), The Wanderer(also sometimes plural, but absent in one), The Uncaring, and The Lost.

I agree with Jedi Master Spock on his assessment of size the Imperial Navy, your final figure of around 100,000 was fairly close to what I worked out on my own. I also agree with your assessment on Imperial Firepower (I worked that out back when I thought 'mere' Megatons was a lot, apparently most debaters seem to say Gigatons+ or go home).

I do, however, believe that Thanatos is closer to the size of the Imperial Guard. All Guard, except high ranking officers, are front line soldiers. Army Group+ level communications as well as all logistics is the domane of the Munatorium. At one point the Sabbat Worlds Crusade (which took place in the fourth century, M41) had five billion Guard fighting on fewer then a dozen worlds at a time. (with two billion having already been killed). Cadia listed billions of Guard killed during Abbadon's 13th Black Crusade. It is due to those facts that I believe Jedi Master Spock's estimate of 30 billion serving at any one time needs to be at least an order of magnitude higher, and even triple that number would not suprise me (though that is about my high end estimate). Otherwise concentrations the likes of which were seen at the Sabbat Worlds and Cadia would not be possible.



I enjoy this site and I am looking forward to becoming a loyal member.