Last week I was on this train: http://www.realtimetrains.co.uk/train/P70469/2015/06/04/advanced As you will see, it lost 77 minutes between Wembley and Harrow. This was caused by (what seemed like) an emergency stop which finished in a neutral zone. The train had no power, couldn't move, and had to be rescued. We were told what had happened but not why it had happened. It's not something I've come across before so I'm interested in the details of neutral zones, how long they are, how fast a train needs to be going to get through one etc. I'm assuming that drivers would normally avoid stopping in them like the plague, so something odd must have happened here. What could have caused it? Please note that I am not complaining or "having a go" at anyone, just genuinely interested by something I was previously unaware of.