NZR EW class

NZR EW class
EW 1805 with DC 4611 near Paekakariki. Photo by Alan Wickens
Power type	Electric
Builder	English Electric, United Kingdom
UIC classification	Bo-Bo-Bo
Gauge	1,067 mm (3 ft 6 in)
Length	18.9 metres (62 ft 0 in)
Weight on drivers	76 tonnes (75 long tons; 84 short tons)
Locomotive weight	76 tonnes (75 long tons; 84 short tons)
Electric system	1500-volt DC
Current collection method	Pantograph
Traction motors	6
Top speed	97 km/h (60 mph)
Power output	1,340 kW (1,800 hp)
Tractive effort	104 kN (23,000 lbf)
Class	EW
Number in class	7
Locale	Wellington region
First run	1952
Last run	1988
Disposition	5 scrapped 2 preserved

The NZR EW class locomotive was a class of electric locomotive used in Wellington, New Zealand. The classification 'EW' was due to their being electric locomotives allocated to Wellington.

Introduction

The Jacobs bogie and bellows of Ew 1806.

They were built by English Electric in 1952 and hauled mainly passenger trains on the region's 1500 V DC electrification, and banked trains between Paekakariki and Pukerua Bay.

They were the first class of locomotive in New Zealand to utilise the Bo-Bo-Bo wheel arrangement, the other classes being the DJ class and the EF class. In both cases, this wheel arrangement was used to provide a lower axle-load due to track conditions. The EW class is different though, as the locomotive is articulated in the middle over the centre or Jacobs bogie whereas the two newer classes have sideplay in the centre bogie.

Withdrawal

Ew 1806 at the Ferrymead Heritage Park.

During the 1960s the tunnels on this section were lowered so that DA class diesel locomotives could handle trains all the way through to Wellington. With the introduction of the EM class units in 1982, the class was further displaced. An attempt was made to use two members of the class on the Otira - Arthur's Pass electrified section in the South Island, but the locomotives simply could not cope with the hash alpine operating environment including the steep 1/33 Otria tunnel. All were withdrawn from service by 1988. Two remain preserved today, one at Ferrymead in Christchurch and one at Mainline Steam in Plimmerton, north of Wellington.

Class register

Key:	In service	Out of service	Auckland Transport service	Preserved	Overhaul	Scrapped

TMS number	Original number	Notes
107	1800	Scrapped
113	1801	Scrapped at Woolston 1988
136	1802	Written off 1981, scrapped
142	1803	Scrapped
159	1804	Scrapped
165	1805	Preserved by Mainline Steam
171	1806	Preserved by Ferrymead Railway

See also

• JR Freight Class EH200
• JR Freight Class EH500

External links

• New Zealand Diesel and Electric Traction - Class EW