British Rail MK6 EMU Motor Bogie, first introduced in 1967, was used as the motor bogie initally for 4-VEPs and then for Phase 2 4-CIGs introduced in 1970. It was also used for the experimental PEP stock. Upon refurbishment of the 4-CEP stock in mid 70s early 80s, their previous motor bogeys located on the DTSO's were swapped for MK6s bogeys, fitted with cab steps and pickup shoes.
Of note is a variant of this bogie was used under the Class 73s, albeit fitted with raising shoes.