NZR ED class

New Zealand ED class
ED 103 at Ferrymead
Type and origin
Power type Electric
Builder English Electric, UK (1),
New Zealand Railways (Hutt Workshops - 7, Addington Workshops - 2)
Specifications
Configuration:
 ​
 • UIC 1-Do-2
Gauge 1,067 mm (3 ft 6 in)
Length 14.1 m (46 ft 3 in)
Loco weight 89 short tons (81 t; 79 long tons)
Electric system/s 1,500 V DC overhead lines
Current pickup(s) Pantograph
Performance figures
Maximum speed 88 km/h (55 mph), restricted to 70 km/h (43 mph)
Power output 1 hour: 925 kW (1,240 hp),
Continuous: 670 kW (898 hp)
Tractive effort 80 kN (18,000 lbf)
Career
Operators New Zealand Railways
Number in class 10
Numbers 101–110
TMS: 15, 21
Locale Wellington region
First run 10 May 1938
Last run March 1981
Disposition 8 scrapped
2 preserved

The New Zealand ED class locomotive was a class of electric locomotive used in Wellington, New Zealand. They were built by English Electric and the New Zealand Railways Department between 1938 and 1940, and hauled mainly passenger trains on the Wellington region's 1500 V DC electrification, and banked freight trains on the steep section between Paekakariki and Pukerua Bay.

The locomotives featured a unique wheel arrangement, 1-Do-2 under the UIC classification system, and incorporated a quill drive to the driving wheels.

They were found to be hard on the tracks, leading to speed restrictions on these locomotives and their replacement by EW class locomotives on the Johnsonville Line after the introduction of the EW in 1952. The EW was considered more suited to passenger services than the ED and replaced them on most passenger services on other lines.[1]

Classification

Like all other electric locomotives in New Zealand, the leading letter of the locomotives' classification is E. There are two predominant theories about how the ED class acquired the second letter, D. The first is that it comes from the "Do" of its 1-Do-2 wheel arrangement. The second is from its original allocation to two locations, Wellington and Otira - Arthur's Pass, hence "duplicated". Official records provide no confirmation of either theory.[2]

Introduction

New Zealand Railways purchased one ED class locomotive in 1938 from English Electric, No. 101, for use on the newly opened Tawa Flat deviation, which incorporated two long tunnels. This locomotive was known as The Sergeant because of the three longitudinal stripes on each side of the body that were unique to this locomotive.

The tender required the supply of locomotive components for the other locomotives required, as it was thought desirable to carry out manufacture in New Zealand in NZR workshops. A further seven locomotives were assembled at the Hutt Workshops, and two at Addington Workshops for use on the Otira - Arthur's Pass section of the Midland Line. The two South Island locomotives were later transferred north.

Steam boilers

Each locomotive (Ed 101 to Ed 108; not Ed 109 & ED 110) originally had oil-fired water-tube boilers for passenger carriage steam heaters, supplied by the Sentinel Waggon Works. The boiler could supply 1,250 pounds (570 kg) of steam per hour at a pressure of 40 pounds per square inch (280 kPa), and the water and oil tanks had capacities of 400 and 500 imperial gallons (1,800 and 2,300 l) respectively, so could steam for four hours before refilling.[3]. However they were shut down or removed in 1950 due to "on-going reliability problems"; air turbulence particularly in tunnels or when trains passed on double track resulted in downdraughts affecting the boiler and in passenger discomfort in winter. In June 1951 the DME said that the cost of fitting suitable boilers for the section from Paekakariki to Wellington was not warranted as the carriages leaving Paekakariki had residual heat, and a steam loco could pre-heat carriages before they left Wellington. In 1954-55 two boilers were installed in the Wellington station basement (and in 1958 one went to the NZR Road Services garage in Rotorua). The CME then wanted eight locos to have boilers for the 1955 winter, but parts were not available for the obsolete boilers and "refurbishing did not proceed". It was also found that the boilers were unreliable as the burners had been amended to be outside the normal operating specifications.[4]

Withdrawal

With the introduction of DA class diesels on the Paekakariki via Pukerua Bay to Wellington electrified section in 1967, eight of the class were withdrawn from service in 1969 and scrapped. The remaining two were kept in sporadic service until March 1981, when both locomotives were sold into preservation. There were plans to send them back to the Otira - Arthurs Pass section but nothing came of this. ED 101 is preserved by the Silver Stream Railway, while ED 103 is preserved by the Canterbury Railway Society.

Class register

Key: In service On lease Out of service Preserved Overhaul or repair Scrapped
Original number TMS number Introduced Withdrawn Status Notes
101 15 May 1938 March 1981 Preserved Preserved, Silver Stream Railway.
102 May 1939 June 1969 Scrapped
103 21 June 1939 March 1981 Preserved Preserved, Canterbury Railway Society.
104 November 1939 June 1969 Scrapped
105 December 1939 March 1970 Scrapped
106 March 1940 March 1970 Scrapped
107 March 1940 March 1970 Scrapped
108 May 1940 June 1969 Scrapped
109 March 1940 June 1969 Scrapped
110 February 1940 June 1969 Scrapped

References

  1. ↑ "ED class of 1938". English Electric Railway Traction in New Zealand. Retrieved 14 April 2017.
  2. ↑ Sean Millar, From A to Y Avoiding I: 125 Years of Railway Motive Power Classification in New Zealand (New Zealand: self-published, 2001), 31.
  3. ↑ Hoy, D.G. Rails out of the Capital p. 64 (NZRLS, 1970)
  4. ↑ Shake, Rattle and Roll: The Ed electric locomotives by David Parsons: "New Zealand Railfan", March 2017 page 51: Volume 23 No 2
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.