I've always wanted to do this! Seems so simple to do, until you start researching costs ....
I just found out a few years ago that my great-grandfather used to design & build steam engines for all applications. I don't have so much as one note on a napkin from his era.
DAMN!! Sad that all that knowledge is lost. I could be building the things for a living right now!
I think building a suitable boiler to handle the pressure is where all the money & effort will be spent ...... then when you build it, how do you test it so you know at what pressure it will level your house & other buildings without wrecking all your work?
I'm sure with some scrap steel, a lathe & a welder it could be done in a pinch. I would imagine some steel as thick as my Harman would work. I'd have to do some testing in the woods first before I'd be comfortable with 800+ psi steam being anywhere near me or my property!