You've done well to avoid plod so far. At least they are rarely armed in the UK. I can see the fascination with exploration, but you need to be a risk-taker for this. I think a primary reason for putting up barriers it to prevent people getting injured, but they also want to keep out the vandals, druggies and other undesirables.
Did I see you have a portable ladder? Would that be classed as burglary equipment?
It could be but there's usually nothing worth stealing in these places. A crowbar would be incriminating. Ladders are standard Urbex gear, as are grappling hooks for the more adventurous.