Earlier this week there were serious signalling problems between Manchester Oxford Road and Slade Lane resulting in the continued operation of trains but with northbound trains using the south bound tracks and vice versa. Later in the day there were a series of cancellations resulting in passengers being denied boarding. A perfect storm of Northern stock shortages and Infrastructure failure seemed to occur from 15.00 hours onwards. I have only ever seen the switching of tracks in limited circumstances before - usually to terminate a late runner to the airport. Does anybody know what went wrong ? It was announced as "Signalling Problems" but this seems to have been an extreme event.