The 13:05 from Shenton to Shackerstone was climbing slowly through a speed restriced stretch of track near Carleton on Wednesday 30th December 2020. Derby Suburban DMBS M51131 was leading GRCW DMBS M55005. Why is the bubble car not coded DMBSD or DDMBS? It has two driving cabs but the code does not distinguish the unit from one that has only one.