NZR DF class (1954)

New Zealand D^F class (English Electric)

English Electric DF 1501 on display outside Sims-PMI in Otahuhu, Auckland. The locomotive has since moved to the Diesel Traction Group, Ferrymead Historic Park.

Type and origin Power type Diesel-electric Builder English Electric, United Kingdom Build date 1954

Specifications AAR wheel arr. 2-C+C-2 UIC class (2'Co)(Co'2) Gauge 3 ft 6 in (1,067 mm) Length 18.7 metres (61 ft 4 in) Adhesive weight 73.4 tonnes (72.2 long tons; 80.9 short tons) Loco weight 110 tonnes (110 long tons; 120 short tons) Prime mover English Electric 12SVT Mk 2 RPM range 750 - 850 rpm Engine type V12 Diesel engine Aspiration Turbocharger Generator English Electric 828A Traction motors Six English Electric 525 / 2A Cylinders 12 Cylinder size 254 mm × 305 mm (10.0 in × 12.0 in)

Performance figures Maximum speed 97 km/h (60 mph) Power output 1,120 kW (1,500 hp) Tractive effort 180 kN (40,000 lbf)

Career Number in class 10 Numbers 1500 - 1509 (1954 to 1965) 1300 - 1309 (1965 to 1975) Locale North Island First run July 1954 Last run 21st June 1975 Disposition 1 preserved 9 scrapped

The New Zealand D^F class locomotive of 1954 was the first class of mainline diesel-electric locomotives built for New Zealand's national railway network, built by English Electric. It should not be confused with General Motors Electro-Motive Division DF class of 1979.

They had a wheel arrangement of (2'Co)(Co'2) under the UIC classification system, generated 1120 kW (1500 hp) of power, and could achieve a maximum speed of 97 km/h. They started the process of displacing steam motive power from main lines in New Zealand, but were soon displaced themselves by the D^A class of 1955.

Initially, 31 D^F locomotives were ordered, but this order was amended to ten D^Fs and 42 D^G class locomotives, which in appearance was essentially half a D^F but with a similar Bulldog nose cab design. The D^F locomotives were lighter than the later and slightly less powerful D^As and were used to haul freight trains on the North Auckland and East Coast Main Trunk lines in Northland and the Bay of Plenty from which the D^As were prohibited by dint of the higher axle loading of the D^A class. The DF class were confined to the North Island, although they did all visit Dunedin for overhaul at Hillside Workshops. The locomotives did not run in service during their journeys to and from Hillside, instead being towed. They were allowed to move under their own power once there and haul transfer freight trains to and from Port Chalmers and Mosgiel as part of tests before returning to service.