NZR EO class (1923)

The New Zealand EO class of 1923 were electric locomotives used on the steep Otira to Arthur's Pass section of the Midland Line. They were primarily for pulling trains through the 8.5 km (5.3 mi) Otira Tunnel to avoid the buildup of steam, smoke and soot.

Introduction

When the Otira tunnel was being built, steam locomotives were not considered for use in the tunnel, because smoke would build up in the tunnel and be difficult to clear. Tenders were received from English Electric, and a company in New York. Due to the economic situation at the time, the tender was given to English Electric. And so on 10 April 1923 six electric locomotives arrived, numbered E 2 to E 6 (1 was the Class E battery electric loco built in 1922).

They were later reclassified Eo to avoid confusion with the EC class locomotives.

Service

The locomotives coped well in service, and from 1942 it became standard practice to run three locomotives together with only two pantographs up, and have their pantographs linked by jumper cables. This was deemed dangerous however, and soon each locomotive ran with its own pantograph up. This often resulted in heavy sparking. Once it became normal to run three locomotives together, they were altered in 1940 to a single cab design.

Another view of EO 3

Replacement and preservation

There were replaced in April 1968 by the EA class locomotives. The EA class were later redesignated as EO class (of 1968).

EO3 was preserved at the Ferrymead Railway. There is also a scale model of EO3 in Nelson, New Zealand. It is 7 ¹⁄₄ in (184 mm) gauge and is capable of pulling about six passengers with the driver.

Class register

Key:	In service	On lease	Out of service	Preserved	Overhaul/Repair	Scrapped

Original no.	Reclassified classn	Introduced	Withdrawn	Notes
E 2	EO 2	April 1923	April 1968
E 3	EO 3	April 1923	April 1968	Preserved, Canterbury Railway Society.
E 4	EO 4	April 1923	April 1968
E 5	EO 5	April 1923	April 1968
E 6	EO 6	April 1923	April 1968

See also

• Locomotives of New Zealand

References

• Pasrsons, David, New Zealand Railway Motive Power 2002, (2002), Chapter 1, ISBN 0-908573-78-2

External links

• New Zealand Diesel and Electric Traction - Class EO (EE)