The first regular outing by a DG class locomotive was that of DG 750 in August 1955 when it was sent with 88-seater railcar RM 100, an English Electric DF class locomotive, and a newly arrived Drewry DSB class shunting locomotive to the Wanganui Industrial Fair. Shortly after the class took over workings in the Wairarapa area following the completion of the Rimutaka Tunnel and also the Murupara Branch from the older DE class. These locomotives usually worked in multiple as they were relatively low-powered, although they did occasionally run on their own.