My goodness, how about a padded cell! :-D
I like the bike chain and padlock he shouldn't get through that.

What a nightmare for you, how old is he, is he in his teenage years? I hope that he will settle .
To be honest if I had a dog that was so distructive when out, so that you could not even contain him without him going through doors, or crates (if tried) how about the best option of just popping a muzzle on him whilst you are out for your quick pop outs, though the 4 hours it would probably be cruel to do so, or perhaps kennel him in the garden to stop the distruction whilst out.