I know it's not exactly anything new, especially considering the season, but I was quite surprised at what happened this afternoon on departure from Ham Street at 16:10 on a 171 heading to Ashford International. We slowly pulled out but before long it was obvious that things didn't sound right and we almost came to a stop, but fortunately we continued on towards Ashford. In a minute or so the guard or driver (I'm not sure which) informed us all that the train was experiencing great difficulty getting up the incline due to poor railhead conditions because of the wet weather and leaves that had fallen. As we'd been this way earlier, albeit southbound, in the rain I was quite surprised to see that we were struggling. We got to Ashford with only a delay of a minute or two, but it's not a pleasant thought to imagine being stuck! Out of curiosity, if whatever reason a 171 found itself stuck between Ham Street and Ashford, what would be done? Would a unit have to come down from Selhurst to rescue it?