These were operated with 201 Class locomotives, although in the past 121 Class locomotives were also used. It remains unknown whether these sets were ever hauled as normal coaching stock by non–push–pull fitted locomotives. The sets originally operated in the Dublin outer-suburban area and on the Limerick to Limerick Junction shuttle, but were gradually moved to mainline InterCity routes out of Dublin Heuston after the introduction of railcar sets elsewhere. The entire Mark 3 fleet was withdrawn in September 2009 and scrapped in 2014.