As far as I can work out, 4 231s were out on the Rhymney line today. 231004 was on the passenger turn, 231006 on the Rhymney-Rhymney 3R05, 231002 on 3741-4, but I don't know what was on 3730-6 Canton - Ystrad Mynach and Caerphilly. It passed me at Llanishen moving at a fair whack, impossible to...