New Zealand DF 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 Configuration: ​  • AAR 2C-C2  • UIC (2′Co)(Co2′)  • Commonwealth 2Co-Co2 Gauge 3 ft 6 in (1,067 mm) Wheel diameter 3 ft 1 in (0.940 m) Minimum curve 297 ft (90.526 m) Wheelbase 52 ft 0 in (15.850 m) total, 12 ft 0 in (3.658 m) rigid Length 58 ft 0 in (17.678 m) over headstocks Width 8 ft 4 in (2.540 m) Height 11 ft 6 in (3.505 m) Axle load 11+3⁄4 long tons (11.9 t; 13.2 short tons) Adhesive weight 69 long tons (70 t) Loco weight 105 long tons (107 t; 118 short tons) Fuel type Diesel Fuel capacity 600 imp gal (2,700 L) Prime mover English Electric 12SVT Mk 2 RPM range 750 - 850 rpm Engine type four stroke, four valves per cylinder Aspiration Turbocharged Generator English Electric 828A Traction motors Six English Electric 525/2A Cylinders 12 vee Cylinder size 10 in × 12 in (254 mm × 305 mm) MU working 110V, 10 notch electro-magnetic control Loco brake air, dynamic Train brakes air
Performance figures Maximum speed 60 mph (97 km/h) Power output 1,500 hp (1,100 kW) gross, 1,370 hp (1,020 kW) net Tractive effort 38,500 lbf (171.3 kN) at 25% adhesion starting, 27,700 lbf (123.2 kN) at 16 mph (30 km/h) continuous
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 21 June 1975 Disposition 9 scrapped 1 preserved

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,^[1] built by English Electric. It should not be confused with General Motors Electro-Motive Division DF class of 1979.

Introduction

They had a wheel arrangement of (2′Co)(Co2′) 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,^[2] which in appearance was essentially half a D^F but with a similar bulldog nose cab design. The D^F locomotives were heavier than the latter 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. Their axle loading was 12.2 tonnes (12.0 long tons; 13.4 short tons).^[3]

The D^F 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, they were 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.

On the arrival of the Phase III D^A class locomotives in 1964, the D^F class was renumbered from the 1500 series to the 1300 series in November 1965 in order to free up the 1500-series numbers for the new D^A locomotives.^[4]

Withdrawal

The D^Fs were unreliable and needed frequent repairs.^[5] This contributed to their short lifespan; withdrawal began in 1972 and the last, D^F 1301, was withdrawn in June 1975. A plan to shift the whole fleet to the South Island to join their smaller but more versatile D^G siblings was proposed. They were to operate on the hilly Dunedin to Oamaru section of the Main South Line but a new locomotive type was chosen in the D^J class.

Preserved locomotive

D^F 1301, the first locomotive built, was donated to the National Federation of Rail Societies NZ (now Federation of Rail Organisations of New Zealand) in 1975. It was placed on static display at Sim Pacific Metals Limited in Auckland, replacing K 900. As part of this it was renumbered to its original number of 1501, but with V-shaped nose stripes in place of the original wing-shaped ones. Initially displayed in the open, a limited shelter was built over the locomotive at a later date although this did not halt the progressive deterioration of the locomotive. Various proposals were put forward for the restoration of the locomotive, but did not amount to anything.

In 2007, with Sims Pacific requiring the area where the D^F was located for redevelopment, owners Federation of Rail Organisations of New Zealand concluded an agreement with the Diesel Traction Group (DTG) to have the locomotive moved to their premises for restoration. The first stage of this relocation took place in August 2008 when 1501 was re-railed and then was towed to Westfield Depot for assessment. In January 2009, members of the Group accompanied the locomotive on a three-day 1,100 km trip to Christchurch, from where it moved to their Ferrymead Railway base a few days later.

Following the completion of D^I 1102 in late 2018, 1501 is now currently undergoing a restoration to mainline condition by the members of the DTG.