Easiest way to map the crane seems to be to draw a single area encompassing all the rail for moving and tagging:
abandoned:man_made=crane
crane:type=gantry_crane
crane:mobile=rail

For the proving grounds, I would only draw area around actual visible remains of objects. And tag perhaps with historic=military.

It's fine if you don't have time for micro-mapping of cuttings and embarkments, but there should not be ways tagged as abandoned railway. The railway is simply not there any more.