KenV :Please don't cherry pick.
Didn't realize I'd done that. Sorry.
I did not suggest at any time that it could be used as a replacement for proper calculation.
I did not realize I suggested you suggested any such thing. Sorry I gave that impression.
However these systems are actually quite accurate and reliable.
The ones I've been involved with weren't either accurate or reliable. Nor were they easy or cheap to maintain.
But more to the point, if your manual system is so bl...dy foolproof then why has there been two or more recent cases of such major, and potentially fatal, errors.
I did not realize I had called the manual system bl...dy foolproof. Sorry I gave that impression. As to why there have been errors, the reasons are varied, but most relate to imperfect humans trying to do precise and detailed work in a pressure cooker environment.
Even a poorly calibrated loadweigh would pick a 100 tonne finger fault.
Maybe. Maybe not. It could also indicate a 100 tonne error when there was no error at all. When you have an unreliable mechanical system that generates false alerts, it gets ignored. Perhaps that's worse than no mechanical system at all.