I was travelling by 12846 BNC-BBS SF Express, on 26/10/2010 form YPR to BBS (then the train originated from YPR instead of BNC). It was an exceptional experience as on that day several wrong things happened that particular day with our train.
1) It's regular LOCO failed at YPR itself and thus the train departed an hour late with an offlink WAG-5 in lead.
2) At Nellore, it was made to stand for an hour, just to let Sanghamitra Express overtake it and thus was delayed by 2 hours.
3)...
more... However, it had recovered all the delay by the next day and was only delayed by 10-15 minutes while departing BAM, but upon reaching Balugaon(BALU), our train was detained there for more than 4 hours. The reason was that the LOCO of a passenger running ahead of us failed before reaching any station and thus all the traffic on the busy MAS-HWH mainline came to a standstill until that passenger moved.