How long are space battles in 40k?

[IvanTih]

I am wondering since the older fluff indicated that battles lasted for weeks while the newer fluff suggest shorter times?

[Serafina]

Highly dependant on the situation.
Straight-up engagement last everything from half an hour (mostly escorts, a cruiser or two) over many hours (cruisers, a few larger ships) to a couple of days (large fleets).
However, moving battles can increase that time severely - if the fleets can break of and/or chase each other, you can probably go up to weeks. You would also get such a time for an engagement over multiple nearby systems.

A couple of examples:
-Destroying a large Tyranid Hive fleet orbiting a planet would take several days
-Fighting the same fleet while it's mobile would take a week or two if you can't pin it down
-A fight between an invading fleet and defenders could take days
-an engagement between patroling fleets with cruisers and escorts would take several hours and likely end with one side retreating
-a couple of escorts would finish of each other in less than an hour

[IvanTih]

If I recall correctly in the case of the Damnation Crusade, Chaos and Imperial Vessels were engaged for a whole month above a single planet before any noticeable gain was made in terms of naval dominance.
What about that?
I seem to recall an event where Chaos and Imperial cruisers engaged for a month and it ended with the heavily damaged Imperial Oberon ramming the Chaos ship and overloading her Warp engines. The resulting explosion obliterated both ships and completely devastated the nearby planet,chaos infested planet,wiping out all life and turning it into a Dead World.
Might be wrong though.

[Black Admiral]

Serafina's right, it really does depend on the circumstances.

Taking two examples from the Gothic War, the battle of Gethsemane lasted for almost three weeks, but a lot of that was manoeuvring, with the Imperial fleet trying to force an engagement and the Chaos fleet dodging around them. By contrast, the battle of Schindlegeist was an all-out fleet engagement (with neither side having much room for manoeuvre) that lasted for three days.

Actions between single squadrons or ships tend to be resolved in a few hours, at most.

[IvanTih]

Thanks a lot guys.

[Serafina]

If I recall correctly in the case of the Damnation Crusade, Chaos and Imperial Vessels were engaged for a whole month above a single planet before any noticeable gain was made in terms of naval dominance.

In that case, it is extremely unlikely that we are talking about a continous battle. As i said above, maneuvering can really extend the duration of engaments.

While i don't know anything about your specific example, it's likely that both forces were about equally strong (and perhaps received reinforcements as well that kept the balance), so they had to be careful with their attacks - one wrong move and they would be too weak to win. Hence, they most likely maneuvered a lot, fought the occasional battle and broke off when it did not turn out to be favorable. Battles would occur because one side saw a good opportunity, needed to provide orbital support or escorted troop transports to the planet.

I think we actually have examples of that in real life. Real-life navies would often not engage in actual combat unless there was a particular reason to, even if they had the better odds - simply because their ships were so expensive (particular battleships etc.). Loosing one might be a devastating blow, even if you won. They also often lacked the speed, maneuverability, fire concentration and range to make engagements decisive.
That's pretty analogous to 40K - ships are somewhat limited in concentrating their fire, they are not that maneuverable and they have a reasonable chance of breaking off combat if they want to. They are also very expensive, so you don't want to loose your own ships.

If you look at the likely strategic situation in your example, you have two sides:
-The defenders (imperials): If your fleet takes to much damage, you can not preven the attackers from providing orbital support or bringing in reinforcements whenever they want. You are better off using your fleet as a deterrent against both and wait for reinforcements, rather than trying to fight it out right now.
-The same goes for the attackers (chaos), but you will also need your fleet intact to get your troops off the planet after the invasion succeeds of it it fails.
So both sides have a reason to mostly avoid direct conflict - the risk of it is just too great.

Thanks a lot guys.

Aaand gals

[Justice]

Question: Would battle reports written in an in-universe style count? I ask because the first one was written as a first hand account from the Imperious (At least, I think it was the Imperious. I don't have the issue in front of me), with times, lance salvo timings and other such things.

[Talk738kno]

Keep in mind that just for Chaos and Imperials, which tend to fairly evenly matched. Eldar vs Imperials tend to last minutes at most, due to massive edge Eldar have in firepower over the Imperium.

[Serafina]

Keep in mind that just for Chaos and Imperials, which tend to fairly evenly matched. Eldar vs Imperials tend to last minutes at most, due to massive edge Eldar have in firepower over the Imperium.

That's bollocks. Eldar do NOT have a massive firepower advantage compared to the IoM. Their individual weapons may be better, but their ships have significantly less of them.
Their actual advantage is vastly better maneuverability - and the reason why that shortens engagements in the case of Eldar is that they can not only break off, but run away very easily. Thus, the engagement will often not continue after the initial one, since imperial forces won't be able to catch up.

Question: Would battle reports written in an in-universe style count? I ask because the first one was written as a first hand account from the Imperious (At least, I think it was the Imperious. I don't have the issue in front of me), with times, lance salvo timings and other such things.

Yes, of course. Sometimes, you must take things with a grain of salt, but that doesn't make the source useless.
Treat it like a real-life source - it might be propaganda, but that doesn't make it useless. And many things aren't propaganda, just reports from individuals who have no reason to deliberately lie.

[IvanTih]

Off-topic:I feel that I should put this issue in this thread,about IOM plasma reactors.
How do they generate that amount of power,don't they require massive amount of fuel?

[Serafina]

Off-topic:I feel that I should put this issue in this thread,about IOM plasma reactors.
How do they generate that amount of power,don't they require massive amount of fuel?

It is strongly implied that they are powered by the warp (if not outright stated, but i don't recall such a source right now). They are certainly not fusion reactors - the Imperium has those as normal power generators (Astartes Power Armor is powered that way), and they are nowhere near as violent and actually behave like actual fusion reactors (albeit very compact ones). They are not creating giant explosions or any of the other sci-fi brainworms regarding reactors. Unlike plasma reactors, who do just that if sufficiently damaged.

Fuel consumption and exact mechanism are pretty much unknown, but the former appears to be low and the plasma is not actually used up but merely used to channel power from the warp trough it.

[IvanTih]

Wrote.

I remember that Index Astartes mentioned that Imperium had used warp to generate power.I'll need to check my Index Astartes.
Also Squats have those neo-plasma warp generators which were powered by warp cores and contained by use of zero energy field.
AdMech once tried to reverse engineer that,but it resulted in Contagion of Ganymede.

[Serafina]

Squats do not exist. Period. Saying they do is an insta-ban offense. Goodbye!

( In case you don't know - it once was on the official GW-forum. Not here, of course, don't worry - but they are still not part of the continuity)

[IvanTih]

Squats do not exist. Period. Saying they do is an insta-ban offense. Goodbye!

( In case you don't know - it once was on the official GW-forum. Not here, of course, don't worry - but they are still not part of the continuity)

In Ravenor one guy says about his Squat heritage and later says that most people think that they are a myth.

[andrewgpaul]

Some of the things the Squats did are still referred to - the battle on Golgotha where Yarrick was captured by Ghazgkull for example - but without mentioning it was Squats. Grimm the Squat is still in the Inquisition War trilogy, too.

[IvanTih]

Some of the things the Squats did are still referred to - the battle on Golgotha where Yarrick was captured by Ghazgkull for example - but without mentioning it was Squats. Grimm the Squat is still in the Inquisition War trilogy, too.

We also have Squats in the novel Space Marine,but that is a heretic tome and thus it's not cannon.

[NecronLord]

Squats canonically existed. Their civilization was canonically eaten.

Tyranid biology is amazing, but even they cannot eat things that do not exist.

[IvanTih]

Squats canonically existed. Their civilization was canonically eaten.

Tyranid biology is amazing, but even they cannot eat things that do not exist.

Tyrands are also immune to the Nurgle diseases,they fought Death Guard and it was stated that they were immune to the Plague God's gifts,but I think that this immunity fails when they face greater daemons of Nurgle.

I have a theory that the Imperium destroyed them,not Tyranids,they couldn't stand an abhuman empire near the heart of the Imperium.
I wonder why would Nids attack barren worlds with little biomass.
Then we have Squats military strength which should be able to defend itself from one hive fleet.
That's just my theory,my take on "Nids have eaten Squats".

[IvanTih]

Also what are calcs for Nova Cannon,I remember that Connor calced it at 21 petatons(I couldn't edit the post above).

[IvanTih]

Is that 610 gigaton Hellfire torpedo from 1st edition of Space Hulk still cannon?

[Black Admiral]

Is that 610 gigaton Hellfire torpedo from 1st edition of Space Hulk still cannon?

The rule is that things are canon (note the spelling - "canon" and "cannon" are two different things) unless explicitly contradicted, or in the case of certain Black Library materials marked with the Heretic Tomes symbol. If, for instance, we were to have two mentions of the same Titan, but one of those marks it as a different class to the other mention (and it owuld have to be explicitly the same one), that would be a contradiction (ignoring for a moment the Case of the Incredible Shrinking Imperator from the Heresy novels).

The figures for the Hellfire torpedoes being uncontradicted, they stand.

[Connor MacLeod]

It's also a 560 gigaton warhead. 112 5-gigaton submunitions.

[IvanTih]

It's also a 560 gigaton warhead. 112 5-gigaton submunitions.

Yeah I fail on basic math.

[Xon]

Does this include the days some WH40K factions can spend getting from the outer solar system to habitable planets?

Actual combat length greatly depends on who is fighting who. A few Necron cruisers basicly drop on top of where they want to go, do something and leave. Eldar where already there, via a hidden Webway gate. Orks are throwing themselves towards where ever a good fight maybe, etc.

[IvanTih]

Does this include the days some WH40K factions can spend getting from the outer solar system to habitable planets?

Actual combat length greatly depends on who is fighting who. A few Necron cruisers basicly drop on top of where they want to go, do something and leave. Eldar where already there, via a hidden Webway gate. Orks are throwing themselves towards where ever a good fight maybe, etc.

I don't what is speed of 40k ships since we have 0.75 stuff in Sabbath Maytr,Flight of Eisenstein and in Nemesis(I'll read it one guy told me about the speed).
Then we have Andy Hoare who loves his single digit G accelerations in Rogue Trader novels and in RPG.