Firstly my bus was late so I missed the local stopping service to Birmingham New Street [BHM] so I was going to get the 1016 Virgin Trains service to BHM. However the 0916 was running nearly an hour late due to technical difficulties so I got on that. We crawled out of Coventry. The stopping service was in front but we had a green signal out of Coventry. We then went fairly slow all the way to International. We left International slowly as well. We then got to Proof House Junction just outside BHM (This is where the cross-city line joins the Coventry to Birmingham line). I assume we stopped at a signal. Then the problems started. The train moved forward a little bit but started rolling backwards. This happened a few time. The train manager then announced that the train didnt have enough power to get up the bank and asked everyone to sit down. About five minutes later he announced that we may have to be stuck outside BHM for up to an hour to let the transformer cool down. However after another five or ten mimutes we started moving again. The train got into BHM about an hour and half late. This caused me to be late for my tutorial at University