Most of the retrofitted rakes are the old shabby ICF Krupps rakes which have been many times causing derailments, fire or delays..Please do not blame the new technology..I have personally interviewed motorman at Mahalaxmi car shed who themselves feel uncomfortable in these old trains...but are forced to operate them due to obstinacy of IR and delay in procurement of newly furnished Bombardier rakes..I hope this conversion would remove the old rakes along with the retrofitted ones..
Please note, as a Mumbaikar, I do not condemn the old rakes as they have been serving the city for a long time but its just the time and we need to change with the time.