Weaknesses of the MPS

This report tries to solve an unsolvable problem: to foresee problems or incidents in the operation of the LHC that are not covered by the machine protection or beam interlock systems. It is evident that this task is not easy to fulfil but nevertheless what still can be done is to scrutinise the logic of the LHC machine protection system and to compare its structure with “unexpected” incidents that occurred in other large storage rings. Going through the history of these rings and mainly profiting from discussions with the experts, this contribution summarises events that are normally not published in conference reports, sometimes they are not even mentioned in internal papers. By the definition of the subject this reflection cannot be complete but there is hope that it will enlighten topics and failure scenarios that are worth to be considered in the LHC operation.