DC class locomotives were rebuilt with new cabs and prime movers from EMD G12 model (DA class) first introduced in 1955. Most are still in service, a testimony to EMD quality!
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.