The locomotives were introduced as the Phase III units of the DA class, built by General Motors Canada between 1961 and 1967.

They can be readily identified as they are considerably shorter than the DF and DX classes and have their paired headlights arranged horizontally, rather than vertically on the DFs.

Changes came during the 1980s; the deregulation of land transport saw rail freight volumes decline and the opening of the North Island Main Trunk electrification saw the locomotive fleet reallocated.

In March 2001, the Rail & Maritime Transport Union threatened to set the maximum speed of the DC class to 50 kilometres per hour due to corrosion found on cab mounts.

Work was carried out at both Hutt and Hillside workshops, most were back leading trains within a couple of months.

[14] DC4588 was shipped to Tasmania (along with QR class locomotives) in December 1998 for use for TasRail, then part-owned by Tranz Rail and its parent Wisconsin Central through the Australian Transport Network.

[15][16][17][18][19][20][21][22] The locomotive was purchased outright by TasRail after an initial period used lease, but was placed into storage in October 2002 after suffering an engine problem.

[23] In 2020, six DC class locomotives were sold to Martinus Rail for use on construction trains on the Carmichael coal mine railway line from Abbot Point in Queensland, Australia.

[24] DCs 4041, 4444, 4571 and 4692 were overhauled and repainted at Hutt Workshops before being shipped to Brisbane, while 4104 and 4634 were purchased for spare parts and scrapped.

All locomotives in service with Auckland Transport were fitted with controls for the carriage doors and later received Electronic Train Protection (ETP) equipment.

One of the MAXX-painted locomotives, DC 4732, was heavily damaged when it derailed at Westfield as an empty service on 2 March 2014.

On 19 November 2021 both locomotives were trucked to the Port of Auckland's Bledisloe Wharf for export to South Africa and then on to Namibia.

The DCP classification was retained on these locomotives after the purchase of Tranz Scenic by Toll NZ in 2004 and continues to be used by KiwiRail.

The practice of reclassifying has now been abandoned by KiwiRail, though most DCs, including all those previously used on Auckland commuter services, have received the bogie ropes.

In 2014, six of the class were fitted with fire suppression to run passenger services through the 8.8-kilometre (5.5 mi) Rimutaka Tunnel on the Wairarapa Line due to a change in requirements resulting from the Commission of Inquiry in the Pike River Mine disaster.

In mid-2015, KiwiRail confirmed the 12 DCs were purchased by Progress Rail for their 645 V-12 prime movers, and other usable parts to be salvaged and the hulks scrapped.

[44] In August 2017, KiwiRail announced it was in discussions with global suppliers including General Electric, Electro-Motive Diesel, Alstom, CRRC and Stadler Rail to construct replacements for the remainder of the class.

[13] In September 2018, it was announced ten DCs were to be withdrawn following the commissioning of the 15 new DL class, with 15 units to remain in service until 2021/22.