Would you know what it was if you saw one though?
Obviously they've been safe to use until now...and this was someone working on it...so not the 'usual' circumstances.
Would it not be better to have them above ground all the time? Just a thought.
I get that they'd want to limit the time when they can be used, but automate an opening on them rather than having the whole thing rising out of the ground surely?
In terms of safety, when working on hydraulic systems never position yourself underneath the lifting platform (load). The piston in a single activating cylinder can come down at an alarming rate in the event of a fractured hose.