NZR DE class

New Zealand DE class
DE 504 in service for Taieri Gorge Railway, shunting at Dunedin.
Type and origin Power type Diesel-electric Builder English Electric, Preston, United Kingdom Build date 1951–1952
Specifications Configuration: ​  • UIC Bo-Bo Gauge 3 ft 6 in (1,067 mm) Length 11.6 metres (38 ft 1 in) Loco weight 52.0 tonnes (51.2 long tons; 57.3 short tons) Fuel type Diesel Prime mover English Electric 6SRKT Mk 1
Performance figures Maximum speed 97 km/h (60 mph) Power output 490 kW (660 hp) Tractive effort 54 kN (12,000 lbf)
Career Number in class 15 Numbers 501–515 (original) 1308–1458 (TMS) First run 20 May 1952 Last run January 1989 Retired April 1984 – January 1989 Disposition 8 scrapped 7 preserved

The New Zealand DE class locomotive is a New Zealand class of shunting diesel-electric locomotives. The New Zealand Railways intended to replace steam locomotives for shunting duties with this class. They are physically similar to the Tasmanian Government Railways X class, which were also of English Electric design.

Although NZR intended to use the class as a heavy transfer shunter, four of the D^Es were used in pairs (each locomotive crewed) on the 1953—1954 Royal Train tour when Queen Elizabeth II visited New Zealand. This was to give a sense of modernity to the public and to show what the class could be capable of. The D^Es was trialed for use on suburban passenger trains in Auckland and Wellington as well as on lesser regional passenger services and branchline freight. The class was also the first to use the new Murupara Branch; for construction then for log trains on the still unsettled track bed. This has given the D^E class an unofficial status of the first mainline diesel electric locomotive in NZR service, a title correctly applied to another English Electric class, the D^F class of 1954.

The class was initially based in the North Island, but four of the class were sent to the South Island in 1981. The class was slowly dispersed to secondary yards on the New Zealand network, such as Napier, Dunedin and Invercargill. In the early 1980s, two DE class members received English Electric 6SRKT Mk 2 engines (which were fitted to the DG class locomotives).

As part of the New Zealand Railways Corporation plan to reduce the number of first-generation diesels in the late 1980s, a number of the class were scrapped or sold for preservation.