You might have more success with it than using the chatting up tips in a video I've just found. If you have a spare five minutes, have a look - it's pretty tongue in cheek. My favourite tip is on the opening question:
"Try and ask a question that requires more than a 'yes' or 'no' answer. Don't ask "does this train stop at Victoria?" as they can simply say "yes", and end the conversation. Instead, ask an "open question" like "how do you get to Victoria?" as they will have to reply with a more detailed answer which will help you get a conversation going.
However, do expect them to look surprised that you've spoken up, and be prepared to repeat the question if they are startled. If they're genuinely interested in you they will be happy to start chatting. You'll be able to tell if they are not interested. If it is going badly, and you feel embarrassed, just get off at the next stop!"