10:45 "I still don't understand train signaling" is the best summary of Factorio's midgame I've ever heard. Protip: The simple lesson is that if you have a piece of track where trains can run both directions, you need chain signals whenever you enter that piece of track. That prevents that specific type of deadlock situation. The problem is that the intersection didn't have a chain signal, so the inbound train entered the intersection without a place to go, blocking the intersection for the outbound train. The bigger protip is that this also counts for straight track that connects to an intersection. Other solutions include making the crossing section larger, or putting multiple regular signals (with plenty of space) behind the loading station, so trains will sit and wait behind the station instead of hogging up the rest of the track.
