It seems the problem was due to the front set "not being able to test the brakes of the rear set, due to some electrical fault", as told to me by one of the many staff scratching their heads at Carlisle. Train was cancelled, so was the 1521. Two road coaches were put on for passengers for Oxenholme (interesting seeing as M6 closed), not sure how the 20-carriage loads of passengers were despatched, as I baled onto the 1450 to Leeds, thence 1748 to Manchester, thence 1925 to Wolverhampton etc etc. My return delayed by only 3 hours.......
Felt sorry for folks doing a S&C day trip from Preston.......