Craftworld defenses (WH40K)

[Lord Revan]

what kind of defenses do the eldar craftworlds have? Are they totally dependent on their (escort) fleets for protection or do they got shields and/or weapons of their own?

[Black Admiral]

The Path of the Eldar trilogy is explicit that Craftworlds have their own defensive batteries and shields. Quoting from Path of the Warrior;

An Imperial frigate hove into view, so close that Morlaniath could see its white hull and golden eagle-headed prow.
[...]
Flashes rippled from bow to stern as it opened fire with deck after deck of guns, the flashes cut through by the searing beams of laser turrets arranged along a crenelated dorsal deck. Alaitoc responded, a storm of lightning and laser leaping from the craftworld’s defence turrets and anti-ship guns.
- pg. 345

A massive shape loomed through the dome, dozens of armoured doors opening along its side to reveal bristling gun batteries. Defensive fire converged on the cruiser and its shields rippled, dissipating the blasts with actinic flares. Its bow erupted with blossoms of orange and moments later the streak of torpedoes hurtled towards Alaitoc, breaking into hundreds of smaller missiles as they crashed into the craftworld.
[...]
More salvoes from the cruiser’s gun decks slammed into Alaitoc, crashing against the energy shields that protected the domes. This time the ground did shudder, so close were the impacts of plasma and rocket. The barrage continued for some time and then fell silent, the flare of laser and shell replaced by the small pinpricks of assault craft engines.
- pgs. 346-347

[Ahriman238]

The Farseers arrange for threats to be distracted. Plus they have attendant fleets, so I doubt their weapons or defenses are often an issue. Still, if you lived in the WH40K universe, wouldn't YOU want your flying-city home to be armed to the teeth?

That said, I do recall hearing that at one point a single Astartes chapter was able to destroy a minor Craftworld all on their own. Then a bigger Craftworld wiped out the chapter in retaliation.

[Lord Revan]

Not all craftworlds are equal, Alaitoc mentioned there is one of 5 "major" craftworlds (Alaitoc, Biel-Tan, Saim-Hann, Iyanden and Ulthwé) so it's probably better equipped then a lot of the minor craftworlds, that said even a single SM chapter is quite a major military force if used all at once.

[Elheru Aran]

It would probably be fairly safe to consider Craftworlds to be more or less equivalent to a massive mobile space fortress.

And, really, it's 40K... if it's in space, it's armed. This includes planets (big honking space guns); Craftworlds are like baby planets (ish), so why not have space guns of their own. There's always the chance some force might overpower its escort fleet.

[Ahriman238]

Ah found it. 5th Ed. SM codex. The Invaders chapter of Space Marines (Imperial Fists stock) engaged the tiny Craftworld of Idharae, leaving it a life less wreck but taking heavy casualties. Forty three years later Alaitoc destroyed the Invader's chapter-world of Ogrys in retaliation, only three companies survived to regroup as a fleet-based chapter.

Eighteen years after losing their homeworld, the Invaders participated in the purging of Jollana a planet containing the greatet library in the Imperium, ransacked by Ahriman and his warband. There was an enormous sorcerous booby trap that killed all the Guard units on Jollana and many Marines, while flooding the place with demons. The surviving invaders, eventually reduced to a dozen of the three hundred sent to Jollana, held out for several days before the Grey Knights showed up to relieve them. The unfortunate chapter later fought Hive Fleet Leviathan, so it's possible that they're just unreasonably badass. Or cursed.

In the process I also found the latest Eldar Codex speaks of an Imperial Sector Fleet that was annihilated attacking a Craftworld, the Battle of Blood Nebula. From here on out, it will be the Imperium's policy to thwart Eldar interests instead of attacking them directly.

[Gunhead]

If you can get your hands on the rule book to Doom of the Eldar boardgame, I'm pretty sure it has a short story about the battle of craftwold Iyanden against an incoming tyranid hive fleet. I could be remembering it wrong though, we used to play it back in the 90's. I do think the Iyanded is still in a bad shape from the attack even in the current 40K canon and the attack has been mentioned in other places too.
Again from memory, I recall the world itself is not exactly heavily armed and mostly relies on the fleet for protection. It's not completely unarmed either but for the most part it's a huge habitat platform not meant to engage enemies by itself. The boardgame is in fact designed so you really can just lessen the number of tyranids getting on the craftworld and after that it's Eldar ground forces against the various nid forms that do all the major fighting.

-Gunhead

[Bedlam]

I've got that game although I don't know how well its rules can be considered 'canon' as their very abstract, however, it does suggest the craftworld has integral weapons as three of the 9-10 locations can directly 'attack' incoming Tyranid ships. It also suggests that elder ships can be built fairly quickly as another 2 locations can bring in new ships during the game which is supposed to take places over week to months although this could be repairing rather than building. It is shown that the defensive fleet is the majority of the space based defences for the craftworld.

From that I can remember of the fluff the general tide of battle was that the Eldar craft could keep off most of the outlying hive fleet but were slowly warn down in a battle of attrition until the craftworld itself was boarded and the ground forces managed to bottle up the beachheads but again were slowly ground down in attrition (something that will almost always favour Tyranids). The tide was turned when the remaining fleet elements were reinforced by a returning group of Eldar scouts who had previously been exiled from the craftworld. They managed to clear away most of the hive fleet before landing and wiping out the remaining invaders.

It was a rather pyrrhic victory as the majority of the craftworld was in ruins, much of the population had been slaughtered and most of the infinity circuit had been disconnected to raise as Wraithguard.

[Delta_Squad]

That battle has a write up in the last Tyranid codex if anyone has access to it to check if it mentions anything of worth. Im not sure if its in the new one that just came out.

[Boeing 757]

Just how big are most craftworlds anyway? Their size might let us guesstimate how many weapons they can accomodate and what their power-generation can handle.

[Ahriman238]

I believe they range in size from very large city to very small moon.

[Lord Revan]

Just how big are most craftworlds anyway? Their size might let us guesstimate how many weapons they can accomodate and what their power-generation can handle.

latest codex describes them as "continent sized" IIRC, but that could mean a lot of things.