At the era then, ships were classified by gun size than hull size. 11 inch guns were still classified as battleship weaponry and the heaviest of cruisers never went beyond 8". Hence they can still be considered battleships.
The twenties and early thirties (Deutschland was laid down 1929 and comissioned 1933) were the era of the Washington Treaty, i.e. ships were classified by hull size
and gun size. The Treaty navies were only allowed a certain number of cruiser hulls, and only a smaller number of those were actually allowed to use 8" guns, the rest had to use 6" guns at max.
The point is: The German Reichsmarine was not a Washington Treaty navy at all. The German navy, as nearly everything else in Germany at the time, was limited by the Treaty of Versailles; in short the Reichsmarine wasn't allowed to develop new weapon systems and couldn't have ships larger than 10,000 ts.
The Deutschland class was planned as something
like battleships though; at least the ships used the hull letters A, B and C for battleships while being built. Scharnhorst and Gneisenau were hulls D and E, Bismarck was F, Tirpitz G, the six improved battleships of Plan Z (so called 'H-class') were H through N (there was no I) and the three battlecruisers of Plan Z would have been O, P and Q.
True but I rather think development of ship survivability fell by the wayside. Ship designers were thinking cost rather than actually making the ships survive such ship killing weaponry.
Think about the German studies on battleship survivability that culminated in the (purely hypothetical) Schlachtschiff 1944 (or H-44): A battleship so heavily armoured that it just might survive bomb hits to the deck. To be able to carry this amount of armour while still being useful (i.e. somewhat fast and manouverable) the ships would have had to be enormous: About 360 meters in length, 50 meters beam, draft just short of 14 meters and up to 130,000 tons of displacement.
Survivability fell by the wayside because it would simply not have been reasonable to build a ship able to withstand these weapons; cost is just a part of this.
@topic:
First of all we should look at the reason why any navy uses warships of differing sizes:
- Escorts, i.e. destroyers and frigates, are just that: Escort ships. Fast and manouverable, but hardly self-sufficient, they protect the heavy hitters from anything that is able to use their lacking manouverability against them.
- Cruisers are scouting vessels. They have speed and range on their side to pinpoint the enemy's location, but are able to take out enemy cruisers and escort ships if necessary; nowhere near the fighting and standing power of battleships, of course, because that's just not what they're built for.
- Battleships are heavy hitters, and the means by which any 'government' is able to project its power outward of its area of influence. Slow and cumbersome, but much more able to dish it out and take it than any other class of warship. Useless without scouts and escorts, though, and prohibitively expensive to build and maintain.
So, do the Dark Eldar need battleships? Do they need warships that are fearsome enough to discourage potential enemies from challenging them by their presence alone? Do they need warships able to take on the battleships of other powers one-on-one? Do they need warships that only come into their own in full sized fleet engagements?
I guess not.
What about the other Eldar factions?
Do the Craftworld Eldar need battleships?
The craftworld fleets are there to protect the craftworld from enemy attacks. Seeing that the location of the craftworlds is more or less secret as well as changing constantly protecting the craftworld mostly amounts to clearing its path of dangerous stuff (debris, space hulks, the like) and acting as the scalpel cutting away at the threads of fate wielded by the Farseers.
Would they need battleships for this? IMHO they would need them rarely enough to at least make the effort of building and maintaining them a doubtful one. The Eldar being a dying race and a battleship needing thousands of crew members that would be at risk of losing their lives from the loss of one ship doesn't make it better.
Do the Eldar Corsairs need battleships?
Seeing that they are corsairs, i.e. raiders similar to the Dark Eldar, it makes you wonder what they would want with a battleship, right?
Now, try to look at it through the eyes of a Farseer: The future might hold the need for fleet engagements (disabling a battlefleet heading for the craftworld being the most obvious possibility). But you loathe the prospect of sending thousands upon thousands of Eldar from your craftworld to their death, even if you know it might be necessary. The alternative, of course, would be to send someone else; preferably someone capable (so non-Eldar are out of the question), but expendable. Someone who would happily die to save your craftworld, but whose demise would not be mourned.
Someone coming to mind? ;)