Wikipedia

NZR ED class

The NZR ED class locomotive[nb 1] was a type of electric locomotive used in Wellington, New Zealand. They were built by English Electric and the New Zealand Railways Department (NZR) 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 Paekākāriki and Pukerua Bay.

New Zealand ED class
ED 103 at Ferrymead
Type and origin
Power typeElectric
BuilderEnglish Electric, UK (1),
New Zealand Railways (Hutt Workshops - 7, Addington Workshops - 2)
Specifications
Configuration:
​
 • UIC1-Do-2 locomotives
Gauge1,067 mm (3 ft 6 in)
Length14.1 m (46 ft 3 in)
Loco weight89 long tons (90 t; 100 short tons)
Electric system/s1,500 V DC overhead lines
Current pickup(s)Pantograph
Performance figures
Maximum speed88 km/h (55 mph), restricted to 70 km/h (43 mph)
Power output1 hour: 925 kW (1,240 hp),
Continuous: 670 kW (898 hp)
Tractive effort80 kN (18,000 lbf)
Career
OperatorsNew Zealand Railways
Number in class10
Numbers101–110
TMS: 15, 21
LocaleWellington region
First run10 May 1938
Last runMarch 1981
Disposition8 scrapped
2 preserved

The locomotives featured a unique wheel arrangement, 1-Do-2 under the UIC classification system, and incorporated a quill drive (the only type of locomotive to do so in New Zealand) to the driving wheels.[1]

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 class in 1952.[2] The EW class was considered more suited to passenger services than the ED and replaced them on most passenger services on other lines.[3]

Classification

edit

Like all other electric locomotives in New Zealand, the leading letter of the locomotive's 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 do not confirm either theory.[4]

Introduction

edit

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.[5]

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 first locomotive was shipped to New Zealand in January 1938.[6] The first locomotive assembled at the Hutt Workshops was completed and undergoing trials in May 1939.[7][8]

By December 1939 the assembly of four locomotives at the Hutt Workshops had been completed, and they were expected to be operating to Paekakariki early in the new year.[9] [10]

The changeover was done gradually, and by July 1940 19 of 20 suburban trains were electric loco-hauled.[11][12] By September 1940 they were hauling most trains, releasing most of the KA class locomotives at Wellington for use elsewhere.[13]

The two South Island locomotives were transferred north to Wellington in 1943. Their cast iron headstocks could not withstand the shock of shunting, and they could not dissapate the heat generated by rheostatic braking (although in Wellington air brakes were adequate).[14]

Renumbering

edit

With the introduction of the Traffic Monitoring System (TMS) in 1979, the two remaining locomotives were renumbered ED15 and ED21.[15]

Steam boilers

edit

Each locomotive (ED 101 to ED 108; not ED 109 and ED 110) originally had oil-fired water-tube boilers for passenger carriage steam heaters, supplied by the Sentinel Waggon Works.[2] 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.[16] They were shut down or removed in 1950 due to "ongoing reliability problems"; air turbulence particularly in tunnels or when trains passed on double-track sections resulted in downdraughts affecting the boiler and in passenger discomfort in winter. In June 1951 the Deputy Mechanical Engineer said that the cost of fitting suitable boilers for the section from Paekākāriki to Wellington was not warranted as the carriages leaving Paekākāriki 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 Chief Mechanical Engineer 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.[17]

Withdrawal

edit

With the introduction of DA class diesel locomotives on the Paekākāriki via Pukerua Bay to Wellington electrified section in 1967, eight of the class were withdrawn from service in 1969 and scrapped.[18] 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.

Accidents

edit

A porter-shunter at Johnsonville was accidentally killed in March 1940 when he stepped into the path of a train being shunted by an ED locomotive.[19]

References

edit

Footnotes

edit
  1. ^ Following the introduction of Traffic Monitoring System (TMS) in 1979, the class classification was capitalised, whereas previously the second letter was a smaller capital letter, that is ED

Citations

edit
  1. ^ Redward 1974, p. 10.
  2. ^ a b Redward 1974, p. 11.
  3. ^ "ED class of 1938". English Electric Railway Traction in New Zealand. Retrieved 14 April 2017.
  4. ^ Sean Millar (2001). From A to Y Avoiding I: 125 Years of Railway Motive Power Classification in New Zealand. New Zealand. p. 31.{{cite book}}: CS1 maint: location missing publisher (link)
  5. ^ Palmer & Stewart 1965, p. 130.
  6. ^ "Electrified Railways: Train and Locomotive". National Library (Papers Past). 27 January 1938.
  7. ^ "Electric Locomotive completed". National Library (Papers Past). 17 May 1939.
  8. ^ "Undergoing Trials". National Library (Papers Past). 19 May 1939.
  9. ^ "Electric Locomotives Wellington-Paekakariki". National Library (Papers Past). 4 December 1939.
  10. ^ "Electric Locomotives Wellington-Paekakariki". National Library (Papers Past). 5 December 1939.
  11. ^ "Use of electric locomotives". National Library (Papers Past). 12 July 1940. {{cite web}}: Missing or empty |url= (help)
  12. ^ "Photo of electric-loco-hauled train at Ngauranga bridge". National Library (Papers Past). 14 September 1940.
  13. ^ "Paekakariki changeover". National Library (Papers Past). 18 September 1940.
  14. ^ Churchman 1995, p. 26.
  15. ^ "Renumbering Electric Locomotives". New Zealand Railway Observer. Vol. 36, no. 4. New Zealand Railway and Locomotive Society. Summer 1979–80. p. 146. ISSN 0028-8624.
  16. ^ Hoy, D.G. Rails out of the Capital p. 64 (NZRLS, 1970)
  17. ^ Shake, Rattle and Roll: The ED electric locomotives by David Parsons: "New Zealand Railfan", March 2017 page 51: Volume 23 No 2
  18. ^ Redward 1974, p. 8.
  19. ^ "Shunting accident at Johnsonville". National Library (Papers Past). 14 March 1940.

Bibliography

edit
  • Churchman, Geoffrey B. (1995). Railway Electrification in Australia and New Zealand. Sydney & Wellington: IPL Books. ISBN 0-908876-79-3.
  • Palmer, A. N.; Stewart, W. W. (1965). Cavalcade of New Zealand Locomotives. Wellington: A H. & A W. Reed. ISBN 978-0-207-94500-7.
  • Redward, Roger (1974). Railway Electrification in New Zealand: An illustrated survey. Wellington: Southern Press.
edit
Retrieved from "https://en.wikipedia.org/w/index.php?title=NZR_ED_class&oldid=1251985727"