The DF class were built by EMD Canada and entered service in 1979 and were rebuilt with turbo in 1990s and then BrightStar and other upgrades. Nearly all remain in service, including 7335 which now wears the new corporate uniform.
Trains on 3' 6" (1.067m) track from Whangarei to Bluff with virtually heritage rebuilt EMD and GE locomotives still the mainstay power. The network was privatized in 1990's and operated by Toll until 2008 when state owned KiwiRail was established.