as the line ran through forest areas, diesel engines only were used on the line. initially, the de class were used for construction then for log trains on the still unsettled track bed; this has given the de class an unofficial status of the first mainline diesel-electric locomotive in nzr service. from october 1963 a pair of da class diesel locomotives were used, hauling 1,500-tonne log trains. more recently the standard train was a trio of dc class locomotives hauling a gross load of 2,400 tonnes on 53 usl bogie log wagons, with the primary motive power now being a pair of dl class locomotives. the annual tonnage of logs increased from 730,000 tons in 1960 to 1,126,000 tonnes in 1965. after the opening of the kaimai tunnel in 1978 the section to kawerau from hawkens junction was formally incorporated into the east coast main trunk designation with the line to taneatua downgraded to branch status. the section from kawerau to murupara became the"murupara branch", and then the murupara line from 2011.