APDAF - I think You should listen to ezgo394's advice. Or at the very least to contain Your ambitions a bit.
I really don't think it would be possible to make a zeppelin half mile long with the technology of early XX century.
Note that by making Your theoretical "huge zeppelin" three times as long as the real ones You'll have to roughly keep it's proportions (lenght to diameter), so it's volume would have to increase about 27 times (that's extremely rough calculation, just to show You an order of magnitude, not the exact numbers).
Besides all the challenges with creating a structure of such size (plus hangars for such airships), it would mean that to move this thing against the wind (and that's a damn big area to blow at) You'll need LOTS of engines. LZ-127 had 5 engines, each 550 hp. For a ship about 30 times larger? Do the math...
And if You want them to be steam engines, remember that they are far less efficient then combustion engines, so to produce the same amount of power they will have to weigh much more and the same applies to their fuel (if You're thinking about coal, then... well, that's just too crazy for me to even seriously consider, while making oil-burned steam engines for airships carrying normal aircraft with normal engines is like reaching to left ear with right hand under your knees
).
If You really insist on mega-zeppelins, try to stick to something with a volume roughly twice as big as LZ-127. Perhaps it was doable on this level of technology. But such airship would be about just 1/5 - 1/4 of a mile long.