Unit Frontages - for Warhammer 40K fic

[jollyreaper]

Granted. We can assume Chaos is in it for the lulz and killing people up close and personal, by hand, is considered more enjoyable than nuking a planet. And if the Imperials want it back, fighting on those terms is more productive than dropping enough rocks to cause a nuclear winter and resettling once the planet thaws out. Orks are also in it for lulz. Tyranids need biomass and shit on thermodynamics so it does make sense in that context that you burn the planet to deny food.

If any faction was simply into winning at all costs, it seems like planet slaggings would be in short order. Gotta keep from justifying the slaggings. Can't sell models if there are no more battles left to fight!

A fimbulwinter on a planet that's been abandoned would make for a hell of a setting. Imperials drop enough rocks to cause an ice age that will last for at least 20 years, guard units and the local survivors are written off and abandoned, must try to survive against chaos forces and see if they can survive until thaw. Imperials believe whole planet will need reseeding for terraforming, nothing left but algae.

[Zinegata]

Krieg is actually a lot like what you describe in the fimbulwinter scenario. They nuked their own world to wipe out the majority of the heretics / traitors.

Also, if you want simple planet-slagging the stories focusing on the Imperial Navy tend to do it more. The Imperium isn't shy about nuking its own worlds - or enemy worlds. The problem is that it apparently doesn't work sometimes especially in the case of Chaos.

[jollyreaper]

There's some gems in the black library and a lot of dross. The best ones I've read so far have been Eisenhorn and the first two Cain books. The Wolves novels passed the time but were hardly memorable. It takes some skill to move beyond grimdark wank to actually tell a good story.

[jollyreaper]

Ps not saying the later Cain books are bad, only that I've only read two.

[Whiskey144]

I know warhammer defaults to rule of cool and we are talking about a setting where the largest battle mechs have castles on their heads and the spaceships look like flying cathedrals. Still, are there any books out there that cover a combined arms doctrine that makes sense for the setting?

I'd like to point out that in the case of flying cathedral spaceships, it's not all as nonsensical as it seems. Given some of the technical assumptions regarding feasible space warfare, it might actually be a case of "well, it's big, expensive, and awesome. Let's make it look the part!", and governmental powers may very well build warships with lavishly designed exteriors, flying buttresses and ornamental prow structures.

Or it we might end up with utilitarian 'form follows function/function defines form' ships.

Side note: WRT good Black Library writing, I find the Ultramarines series to be pretty good.

[Purple]

Also, given that the the ships in question are expected to traverse the resident demon ridden hell dimension all the time the whole religious aspect of their design might in it self actually serve a purpose. After all we know for a fact that the IOM relies on religious symbols and blessings as major mechanism for defense against the warp. And you don't go more religiously symbolic than making the whole ship resemble a church.

[jollyreaper]

I know our entire sense of proper spaceship appearances is subject to zeerust. Tailsitters were 50's, we had some strange horizontal models in the 60's blending into the Trek look, the 70's gave us highly mechanical models with lots of greedling, battlestars and Stsr destroyers. That lasted through the 80's. We also had biowank out the wazoo. The WWII model inside and out remains very strong.

With sufficient tech, a spaceship could be made to look like anything. Jardowsky's weird ideas could be as valid as flying naked statues from that Posleen guy's books (that was him, right?) to the arbitrary designs from Cities in Flight.

All that being said, flying cathedrals still look dumb to me. Personal taste. Ships as works of art and veneration I can accept. But it's like gilding and scrollwork on a deadly weapon is acceptable but something that no longer even looks functional irks me, even if it does work as intended.

What's never been clear to me is how much of the machine spirit stuff is superstition and how much is vitally necessary. Would not praying over a machine actually cause it to malfunction? And it's never quite clear just what all the manpower is used for on these ships. There's hellish imagery about gun crews and chain gangs in the engine room but I have trouble imagining just how these ships are as manpower intensive as a war galley.

How much evidence is there for Imperial magic? Beyond just psykers. Do prayers work? Is there any divine intervention from the Emperor? From everything I've seen, only evil magic from the Warp works. There's no white magic and no gods of order, just chaos.

[Ahriman238]

There used to be Sensei, the Emperor's descendants who served as equivalents to Chaos Champions and fought against the corruption of the Imperium. I do believe they've been ret-conned out though.

Beyond that? The soul-binding ritual of the astropaths works exactly as advertised, supposedly the Emperor can speak to his servants in dreams and through the Emperor's Tarot, and there's a good chance he created the Warp Storm commonly called the Storm of the Emperor's Wrath.

There are also Living Saints, heroes of the Imperium who are gifted with incredible powers from the Emperor, sometimes even rising from the dead to wield their new powers and smite the enemies of the Imperium.

[PeZook]

Actually the Emperor has been suggested to directly intervene from time to time based on some mysterious factors, and there's a whole bunch of various "good" Warp spirits, Saints et al.

So prayers can work somewhat directly, but they also serve to make you focus and stop feeding Chaos with your impure thoughts...or stuff. Most Adeptus silliness is just ritualised procedures made to look magical for the peons, though, so they don't actually just pray over machines to make them better.

[PeZook]

There used to be Sensei, the Emperor's descendants who served as equivalents to Chaos Champions and fought against the corruption of the Imperium. I do believe they've been ret-conned out though.

What is it with GW retconning out all the interesting concepts?

[Ahriman238]

Ah, google-fu still works.

To the Inquisition, particularly the Ordo Malleus, the Sensei are one of the great threats to the Imperium, the Inquisition seeing the Sensei as dangerous mutants and heretics.
The Inquisition has discovered that the extremely rare negative psychic energy used in psyk-out and psycannon weaponry can be produced from rendered-down Sensei - the only other source in the galaxy is from the byproducts of the Emperor's metabolism.
The Sensei have inherited great power from the Emperor. They also possess unique abilities of their own. Because they harbour none of the emotions or concepts embodied by the Chaos Powers, they are largely invisible to them, and can draw on the energies of the Warp to use their psychic powers without attracting daemons or other malicious forces of the Warp. Due to their harmonious relationship with the Warp, the Sensei are invisible to psychic senses, even to those of the Emperor.
The Sensei are all naturally connected to the Star Child, in a similar way the Champions of Chaos are bonded to their Chaos Patron gods; ultimately Sensei can achieve apotheosis, disappearing into the warp and merging with the Star Child.
Sensei wander throughout the galaxy. In contrast to the servants of the Emperor, Sensei are natural rebels. As well as being enemies of Chaos, Sensei are enemies of oppression. They and their followers operate as outlaw bands, and appear across the Imperium to fight against repression and injustice. In this way, they often come into conflict with the Imperium.
The Imperium regards the Sensei as dangerous bandits and nihilists who, if not actually in league with Chaos, are weakening the Imperium's defence against Chaos. Because of their powers and militantly anti-authority natures, they are hunted down and killed by Imperial forces, which in turn forces the Sensei to operate as outlaws.

[jollyreaper]

The retconning is tough to keep up with. They used to have space dwarves and now they don't. They ever explain why chaos stole the primarch babies but didn't just kill them?

[Rogue 9]

The retconning is tough to keep up with. They used to have space dwarves and now they don't. They ever explain why chaos stole the primarch babies but didn't just kill them?

They still do; Squats get a mention in the appendices of the 6th edition rulebook. They just stopped printing a codex for them, and said the Tyranids ate their home systems to explain why, but as one might expect with a spacefaring people, taking their planets didn't take all of them.

As for the Primarchs, I have no idea.

[Imperial528]

They ever explain why chaos stole the primarch babies but didn't just kill them?

I'd venture a guess that they didn't kill them because of well, you know, Chaos. Look at how much chaos resulted from the Horus Hersey. Had they just killed the Primarchs the Emperor could very well be quite alive and the Imperium much more of a threat to Chaos than it is now.

[PeZook]

I thought it was because they couldn't just spawn a Bloodthirster in the facility due to defences set up by the Emperor, which they just penetrated momentarily, so they did what they could before Jesus himself cut them off?

[Sea Skimmer]

What's never been clear to me is how much of the machine spirit stuff is superstition and how much is vitally necessary. Would not praying over a machine actually cause it to malfunction? And it's never quite clear just what all the manpower is used for on these ships. There's hellish imagery about gun crews and chain gangs in the engine room but I have trouble imagining just how these ships are as manpower intensive as a war galley.

Given how crummy the ship designs are externally, and how slow the FTL system is much of the crew is likely just spread across the age scale to replace the men as they get too old on long missions, and to carry out damage control when all that random crap gets blown up or turns into massive internal fires. Plus if the pipework and wiring was made out of junk, which seems likely, you could keep an awful lot of people busy fixing it and pumping blackwater out of the crew quarters.

Also, some historical basis exists for people just packing on crazy numbers of men for no clear purpose, as somehow the Nazis managed to make heavy cruiser Prinz Eugen need over 1,500 men while Bismarck, three times her size and carrying large prize crews, needed 2,200, meanwhile a US heavy cruiser could get away with a thousand people and mounted more guns then Prinz. I bet if you scaled the manning of Eugen to some of the 40K ships they'd be undermanned in comparison.

[jollyreaper]

Yeah, but we are talking the difference between 20th century navy ships and 40th century starships. But it looks like most of the look and feel is still from pulps. Mining is done by hand, not with strip mining machines.

Making sense of 40k can be like trying to rationalize the setting of Cowboy Bebop, can't be done!

[Sea Skimmer]

What does date matter? Your manning requirements are set.. by the number of men you need and that's gone up and down with dates and roles. Late 19th century battleships had half the crew of a 20th century heavy cruiser because they just didn't have that much stuff in them to operate or maintain. Meanwhile a three decker ship of the line was only a third the size of either of the above type of ship, but needed nearly as many men as the heavy cruiser because while far less technologically complicated it simply had huge numbers of discreet systems, be they only a specific rope to pull on or gun to man, that just ate manpower like crazy in a small space. They also needed HUGE amounts of dockyard work on top of all this to remain operational. We saw a surge of manning in the world wars because ships gained lots of non automated equipment. That's gone back down as we shifted to engines which are very simple like gas turbines, and weapons which mainly consist of a few ready to fire missiles the ship is incapable of maintaining. Actually that goes for a lot of systems on modern ships, cannot be maintained on board to any serious degree. The ships are built and operated on the assumption that they will last a few decades of service, and that's with many overhaul time in the yard. If you had to go a couple decades out of dock... the rules really change. In WW2 the USN found it couldn't even fit all repair ship functions into one ship anymore (a factor I assume in why repair ships died out), now if we had to integrate all of that into a battleship the thing would turn into H-44 real quick.

Change from any modern practices for reducing manning seems to be a given in 40K when I get the impression you could use up several years just to get around the Galaxy one way. I doubt they have power plants as elegantly simple as gas turbines for example, which are maintained by complete removal from the ship anyway. If you had to make a ship able to fully look after itself, and it was already old and breaking, or built badly, this could massively drive up manning and even high levels of automation wouldn't help because all the automation needs to be maintained. This would also push up demands for space to access everything, which pushes up the size of the ship and of its hotel requirements like power and water systems.

I'd be interested in specifics in any case, because I only ever see vague figures thrown around for 40K ship manning as being 'high' and in the 'thousands'. I assume they need some margin of crew just for dealing with supernatural bullshit when people get sucked into hell when the toilet breaks.

[jollyreaper]

The specifics are what I'd like to see. I hear what you are saying about manning requirements but there's never really any specifics. Same with Star Wars. An ISD has 35k crew but there's never further elaboration on what that means. Granted, the tech is all imaginary to begin with but there doesn't seem to even be internal guidelines to account for scaling, keeping things at least proportional.

Given the 40k penchant for schizotech, I assume they probably have a crew of hundreds just for painting the ship while under way, a thousand more to scrub the decks with brushes dipped in wooden buckets, black gangs shoveling frozen lumps of fuel into the fusion furnace, plenty more brass polishers, a clerical contingent of thousands with choirs and priests and incense bearers.

In trying to imagine hard sf starships, many people come up short trying to imagine what the tech would be like and therefore what it would take to keep a ship spaceworthy. It pretty much devolves into pulling out hair in short order. It's tough to imagine what the top navy combatant will look like in 50 years.

The guess I've heard that I find interesting is self-healing materials that have capillaries with fluids inside that fill cracks with hardening fluid combined with maintenance bugs that can crawl where needed for more elaborate work. Can't promise that isn't wank but I'm not expecting to see it next Tuesday.

[Brother-Captain Gaius]

I'd be interested in specifics in any case, because I only ever see vague figures thrown around for 40K ship manning as being 'high' and in the 'thousands'. I assume they need some margin of crew just for dealing with supernatural bullshit when people get sucked into hell when the toilet breaks.

Grand Cruisers (roughly analogous to pre-dreadnoughts): ~110,000 to ~145,000
Battlecruisers: ~100,000 (seems to be much less variation than older grand cruisers)
Cruisers: ~85,000 to ~90,000
Light Cruisers: ~60-70,000
Smaller warships (destroyers, frigates, corvettes, et al): ~15-27,000

Those numbers are all from Battlefleet Koronus. It has no data on battleships, so if I had to hazard a guess, probably around 150,000 men.

[Sea Skimmer]

Rocket artillery is ALL alpha strike, though. Reloading times are vastly longer than tube almost by definition, AND the rocket artillery set it more vulnerable while reloading, because it needs to hoist the rockets into their launch configuration ; tube artillery has far less delay between request for a fire mission coming in and delivering it ; It can also switch targets faster, and carries the ammunition internally (or in dedicated armored ammunition carriers).

No reason exists why the delay in executing a mission between tube and rocket artillery would be different with comparable levels of technology. If anything rocket artillery should be faster because you don’t have to load the weapon, it’s carried loaded, just elevate and traverse it, and since close support missions are ruled out, you can accept less then utter precision in the firing calculations. M270A1 MLRS can lay the launcher, worst case, in 16 seconds. Locking out the suspension before laying takes a couple more seconds, so what, 25 seconds or so when we include a few more seconds to decide to pull the trigger. Nothing is going to beat that by much.

As for armor protection, yeah you can armor rocket launchers. The US MLRS is armored, and the majority of armor on self propelled guns is near paper thin anyway. Other then the US M992 FAASV no armored ammunition transporter for large caliber howitzers and guns has been popular since WW2; some militaries like the USSR/Russia have completely ignored this type of vehicle. Meanwhile, no reason why you can’t armor a rocket launcher ammunition carrier, China actually has the Type 89 which carries an armored rack of reloads on the launcher and I believe Yugoslavia produced a similar but wheeled vehicle. Several German systems in WW2 were mounted on armored halftracks which carried reload ammunition internally

Most people neglect armored ammunition carriers of all sorts because they are just too expensive, and beyond that reduce mobility and as a result ones ability to conceal the vehicle, ability to go get more ammo from the rear. Rocket ammo is bulky, but it also has much more firepower as a counter balance.

Few rocket launchers are armored precisely because they can fire so quickly, and then move away so quickly to avoid counterfire that it just isn’t a big deal. But it’s not like you can’t armor them. I don’t see why rocket artillery should be judged significantly more vulnerable reloading. The gunpowder for artillery charges is even more vulnerable then rocket motors, and time to reload the vehicles is in fact pretty similar. Even The US Crusader with totally automated ammunition handling on the ammunition vehicle and howitzer was to take about 11 minutes to move 48 complete rounds.

MLRS can reload each pod in 160 seconds, under 3 minutes each. Even allowing some time for switching to the second pod, this is still faster. A BM-21 launcher with 40 manually loaded rockets can still be done in about 10 minutes if the crew hurries.

The problem with reloading is not the time, but the fact that you cannot fire while reloading with rocket launchers, while a self propelled howitzer can within limits. However this would mean the howitzer is one place a long time, and very likely to suffer from counterfire.

[Sea Skimmer]

Grand Cruisers (roughly analogous to pre-dreadnoughts): ~110,000 to ~145,000

Okay, these are the ones that go up to ~6km long right? Using springsharp to be lazy and make a very rough comparison, if I call it a 6000mx600x600m solid box of a ship, it would displace 2,179,419,000 tons in water. This is similar to displacement, but not total enclosed volume, of about six thousand 35,000 ton treaty battleships. If we call the crew of one of those 1,800 men, six thousand of them would need 11,284,405 men. That's a hundred times less men then for 40K, though more like 50 times less if we accounted for a more accurate volume comparison. Still in the ballpark scale of things, such a massive ship isn't very highly manned at all compared to WW2 levels of manning vs size.

[Connor MacLeod]

Change from any modern practices for reducing manning seems to be a given in 40K when I get the impression you could use up several years just to get around the Galaxy one way. I doubt they have power plants as elegantly simple as gas turbines for example, which are maintained by complete removal from the ship anyway. If you had to make a ship able to fully look after itself, and it was already old and breaking, or built badly, this could massively drive up manning and even high levels of automation wouldn't help because all the automation needs to be maintained. This would also push up demands for space to access everything, which pushes up the size of the ship and of its hotel requirements like power and water systems.

I'd be interested in specifics in any case, because I only ever see vague figures thrown around for 40K ship manning as being 'high' and in the 'thousands'. I assume they need some margin of crew just for dealing with supernatural bullshit when people get sucked into hell when the toilet breaks.

It's probably going to vary from source to source like most things. The Rogue TRader Fantasy Fligth GAmes material seemed to be the notable case for upping crew numbers significantly and we honestly don't know why. Cruisers in 40K used to be 3 km and maybe carried ~10K crew at most, whereas now they're 5 km (or sometimes more) and can carry upwards of like 90-100 thousand. Whereas depending on your author, ships can go as few as a few hundred for escorts (Cobra Class destroyers, which by contrast for FFG lists the crew requirement as 15,000, and the Cobra is basically the same length as an ISD (narrower though). Another example is that some novels list the biggest 'common' Battleships (The Emperor class) having crews of only like, 20,000. Whereas in FFG they probably carry hundreds of thousands.

We never really know why they seem to demand such large crews in some cases and not in-universe, other than it may be tradition and lack of automation may be a factor (either because the equipment is broken down, or it might be.) It has been suggested that the large carrying capacity of ships is meant to serve a secondary role f allowing ground attacks from Navy ships (either by the naval ratings themselves as landing parties, or allowing them the limited ability to carry Imperial guardsmen.) It's also been implied that crew complements may vary according to automation or the usage of servitors (some ships are actually all servitor run with little or no human crews, although I can't think of any naval ships exclusively like that.) It may even be for training purposes - from Battlefleet Gothic onwards there was some indication that the Navy keeps a large portion of its fleets (comprising old, reliable, and hard to maintain vessels) in a reserve status to be brought out as needed. The reason BFG gives is largely a cost/logistics one - they simply cannot maintain a large fleet indefinitely, so they keep some/most of their ships in reserve. Large crew complements might be retained in 'non-war' conditions in the event that a conflict breaks out and they need to suddenly activate the reserve. Start stripping out crews from the active ships to help man your vessels and you can probably guarantee at least a skeleton crewing of (reasonably) competent crews.

That said, the out of universe reasons tend to be rather straightforward. Aside from the obvious grimdark/thematic crap, there's also the simple fact that the image/theme of the Imperial Navy has changed quite a bit over time. The 'years/decades' long travels and slow transit speeds is largely an artifact of the earlier, Space fleet era. Back then ships were considered rare, precious, and valuable things that could last for hundreds or thousands of years... were basically cities/planets in space with massive crews that could live and die in that space and never know about the outside world (or even know there's war going on.) and baiscally were massive, self sustaining enviroments - they even had machine shops and faiclities for maintaining and repairing the ships simply because their deployments took them away from base for so long. OF course, back then the fleet was alot less static and 'battlefleets' were temporary formations amassed when naval power was needed.

Alot of that dynamic changed with Battlefleet gothic. Instead of temporary battlefleets, battlefleets became permanant formations responsible for the security of a whole Sector. That tends to be a rather major change because a.) ships aren't quite as rare or precious, although they're still hardly 'common' either. BFG is also the first formailized mention of Naval reserves, which reinforces this. b.) permanant formations mean that their operational ranges and responsibilities are much more fixed than they were in Space fleet, which tends to cut down on time and distances as far as travel. Ships can and sometimes do still travel huge distances (EG from surrounding sectors during the gothic war to suppress Chaos, or during the 13th Black Crusade to help defend Cadia) but it's not as common as in Space Fleet.

As another aside, the more 'mainstreaming' of BFG has also lead to, at least among novel authors and such, a general increase in FTL speeds I suspect out of literary convenience. Rather than taking years or decades to cross the galaxy, its now become more common for months or years, although the unreliability still makes that far from certain (decades, or even centuries is still possible.) BFG introduces the ideas of warp routes too IIRC, so that may have introduced a certain measure of 'reliability' to warp travel.

IT's also worth noting that the BFG ERa was the origin of the Rennie novels, which prior to FFG set alot of the standards about how fleets were for many authors, such as the 3 km long, 10,000 man starships. That said, certain notions from Space Fleet still persist (Ships are still viewed as rare and precious, and can serve for long times, and ships can take a long time travelling between planets and people rarely see them, but again here things have become blurred over time as well. The novels too don't help in this regard.)

FFG is yet another change in dynamic with Rogue TRader. It's not a huge change as compared to Space Fleet vs BFG, but its sitll pretty significant. The big changes FFG introduced (aside from yet again increasing the scope of the Navy in many ways.. size of battlefleets and numbers, number of battlefleets, etc.) is bigger ship sizes (5 km cruisers) and more massive crew complenets (more age of sail, I guess?). Ships also were now common enough that they could be purchased, decomissioned, or even scrapped. BFG actually started on the 'decomissioned/scrapped' idea, introducing fire ships and the reserve fleets - which runs against that whole 'every ship is rare and precious and hard to replace' notion, but FFG ran with it by making it possible for civilians to buy starships (at least, very wealthy civilians, so its still relatively uncommon.) FFG also introduces the 'chartist' captains, who basically ran ships with warp drives but without navigators (short range FTL travel.) whereas prior to this it was strongly suggested that the Imperium only had navigator piloted ships (technically non-navigator ships were *possible*, just never explicitly mentioned.) FFG leaves it mostly a civilian practice, but its not far fetched for the Navy to be running a military version of chartist ships to fill out its fleets, given that the Navy has been said to run sublight ships (those without FTL capability) as well.

FFG sort of resurrected some of the old Space Fleet fluff as well, although this resulted in more confusion than anything, since Space Fleet thematically differed from BFG and BFK borrows heavily from BFG as well. But notions like there were different kinds of 'fleet's in the navy - military, civilian, and merchant - has carried over into FFG's fluff.

And that's only the broad strokes. Introducing all the various viewpoints and quirks individual writers bring to the table only complicates what is an already-muddied approach, but this is pretty much par for the course for 40K, or most other shared universes.

[Connor MacLeod]

Okay, these are the ones that go up to ~6km long right? Using springsharp to be lazy and make a very rough comparison, if I call it a 6000mx600x600m solid box of a ship, it would displace 2,179,419,000 tons in water.

In FFG terms Grand Cruisers go up to some 7-8 km, although in other novels (mostly Abnett's recent stuff) you get Grand cruisers of 9-12+ km. Of course some authors have made battleships as small as 6 km too (while others can make them 10, 20, 30+ km long) Escorts can range from a few hundred metres to 4 km long, and cruiser sizes have varied from 2 km to 30 km (although the last was probably an outlier, the more common 'upper' end is 8 km or so, and may still be an error.)

I really doubt that size is a significant factor in starship role. Basically escorts seem to be meant for supporting bigger ships and doing the bulk of the grunt work - antipiracy and convoy/escort duties, for example. Cruisers are built for long range/independent operations and balance between various traits to pull this off. Battleships and Battlecruisers seem to be the vessels specialized for actually duking it out, but are still relatively rarer than actual battleships but given what I already said its hard to be absolute when things have changed and could change yet again.

This is similar to displacement, but not total enclosed volume, of about six thousand 35,000 ton treaty battleships. If we call the crew of one of those 1,800 men, six thousand of them would need 11,284,405 men. That's a hundred times less men then for 40K, though more like 50 times less if we accounted for a more accurate volume comparison. Still in the ballpark scale of things, such a massive ship isn't very highly manned at all compared to WW2 levels of manning vs size.

Its quite likely that for all intents and purposes, they really don't need huge crews to man the ships. It wouldn't surprise me if for grimdark reasons the sole reason to carry men onboard ships was simply to have people on hand to fight in boarding actions to defend ships, (or the occasional case where they attack and board an enemy ship), or just because they wanted a large pool of recruits to draw new crew members from via some (fatal) darwinian process. Or simply because thats the way they always did things due to some obscure (retarded) ruling by some random Navy dude. Fuck, this being 40K it could very well vary from sector to sector.

One of the changes FFG made (at least for the sector they made up for 40K ) is that the Navy actually relies far more on volunteers than on conscription/impressment to fill out its ranks:

Contrary to popular belief, many Navy ratings are volunteers—the pay is good and the conditions are better than those on many Imperial worlds. The Navy can make generous promises when it knows barely half the ratings will survive a cruise and collect their gelt at the end.

Which I guess, by 40K terms is an improvement of sorts if you ignore that whole 'constant risk of death' thing. Oh well, Grimdark and all that.

[Sea Skimmer]

Its quite likely that for all intents and purposes, they really don't need huge crews to man the ships. It wouldn't surprise me if for grimdark reasons the sole reason to carry men onboard ships was simply to have people on hand to fight in boarding actions to defend ships, (or the occasional case where they attack and board an enemy ship), or just because they wanted a large pool of recruits to draw new crew members from via some (fatal) darwinian process. Or simply because thats the way they always did things due to some obscure (retarded) ruling by some random Navy dude. Fuck, this being 40K it could very well vary from sector to sector.

When your ship is the span of metro area around a big city, I tend to think a large force to repel boarding is reasonable, provided your ships aren't likely to just explode if damaged badly enough to be boarded. A fucking 30km long cruiser.... the enemy could board and fucking set up his own towns and cities and start farming if he brought dirt or composted the shit in the blackwater tanks, and begin raising a new generation of troops on board while still fighting you if you lacked the forces to sweep him out. Also random tasks like making sure all light bulbs are working would consume enormous numbers of man hours as men need maps just to find the way around a single deck. Even with fairly tall 3m decks, allowing for each deck being really thick to hold the damn thing together... a 600m tall ship would have 200 decks. That's as many decks as the Burj Dubai has floors counting the pesudo floors in the spire! But I'd expect the 30km long ship to be much taller anyway. The largest steel mill earth ever had was IIRC Sparrows Point with about 30,000 workers, and you could fit it into the belly of a beast like this and call it the shipfitters shop.

Springsharped 30,000x2500x2500m solid block ship, it thinks it would displace 189,185,700,000 tons. This is for an object which floats.. space warship is likely to be denser, though its water displacement for the immersion would of course be exactly the same. I think you'd measure the amount of welding rod needed to assemble it in astronomical units.