This is mostly about dispersed basing:
http://www.canit.se/%7Egriffon/aviation/text/bas/dispersed_basing.html
But it explains the thinking behind the underground
hangars: They were mainly intended for interceptor
squadrons near our largest cities; The rest of the air
force was supposed to rely on dispersal and camouflage.
There's also the matter that you can't build them
everywhere there's an airbase. (We've got one naval wharf
inside a mountain (you can imagine what you need to lift a
periscope out of a submarine), but when it was planned, we
planned for four more but couldn't find a place in the
south - a hangar doesn't take quite as much but most wings
weren't planned with that in mind.

I've recently learned that at F 18 there's a lower level
which was never finished; Just empty space and gravel
floor today.


Since you know so much about this subject could you please tell me
where Sweden would have based the SAAB A-36 nuclear bomber and its
weapon stores had that aircraft actually been built?
Would they have had to build different nuclear bunkers and change
their security around the dispersal area? Also, the SAAB A-36 would
have been a much larger aircraft than your standard Swedish fighter of
the late '50s... any comment?

Rob