This is the original forum of the Bristol Railway Archive that existed between 2003 and 2013. I finally rescued it after it seemed unrecoverable after a large crash. I have made it available for viewing. It is locked, all posts to the new version please!
I understand it was the heat exchangers that froze and split the small bore tubes within on the Peaks. The radiator coolant then went into the oil system and sump as a result. Something which has even occurred in recent times with diesel locos in preservation.