Today, I drove the service 1A34 to Brighton, after loading passengers at East Croydon, I wasn't able to move anymore...I have to admit that I was a minute late... When I wanted to depart, the train didn't react anymore...and the PIS screen showed a whopping 24 car vehicle... Going further down the train I remarked, that a Gatwick Express had coupled to my 377 while I was loading passengers... Shouldn't there be a red light somewhere behind me, that should have prevented this?