NZR EO class (1923)

NZR EO class (1923)
Eo 3 running around a train at the Ferrymead Heritage Park.
Power type	Electric
Builder	English Electric Dick Kerr Works, Preston, United Kingdom
Build date	1923
UIC classification	Bo-Bo
Gauge	3 ft 6 in (1,067 mm)
Length	11.7 metres (38 ft 5 in)
Weight on drivers	50.0 tonnes (49.2 long tons; 55.1 short tons)
Locomotive weight	50.0 tonnes (49.2 long tons; 55.1 short tons)
Electric system	1500 V DC
Current collection method	Pantograph
Traction motors	4
Top speed	64 km/h (40 mph)
Power output	510 kW (680 hp)
Tractive effort	63 kN (14,000 lbf)
Class	EO
Number in class	5
Number	2 - 6
Locale	Midland Line between Otira and Arthur's Pass
First run	1923
Last run	1968
Scrapped	1969
Disposition	4 scrapped 1 preserved

The New Zealand Railways 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 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^{[citation needed]}. And so on the 10 April 1923, numbered EO 2 to EO 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 inch gauge, and is capable of pulling about six passengers with the driver.

See also

• Locomotives of New Zealand

External links

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

References

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