NZR E Class (1906) - Origin and Design

Origin and Design

The Rimutaka Incline opened in 1878, connecting Wellington with the Wairarapa region, and with the completion of the Wairarapa Line in December 1897, it provided NZR's main link to the north as the west coast route was then privately owned by the Wellington and Manawatu Railway Company (WMR). Six special Fell locomotives, the H class, worked the Incline, but after 1897, traffic increases necessitated additional motive power. Initially, two members of the B class were converted from tender locomotives into tank locomotives and reclassified as the WE class; W 192 was also transferred to assist on the Incline. These locomotives proved to be more expensive to operate and used more fuel than the H class. However, they were considered successful enough by Chief Mechanical Engineer A. L. Beattie that he authorised his Chief Draughtsman, G. A. Pearson, to design another, more powerful locomotive to work the Incline.

To meet Beattie's requirements, Pearson designed E 66 as a Mallet articulated locomotive with a wheel arrangement of 2-6-6-0T under the Whyte notation system. It's cylinders were placed at each end instead of one wheelset behind the other allowing one set to be driving forward at all times. It was a Vauclain compound, re-using materials left over from an unsuccessful experiment in the 1890s on N 27. The locomotive also used other surplus materials, such as modified F class wheels. The locomotive was built at the Petone Railway Workshops in the Hutt Valley under Pearson's direct supervision and entered service on 23 February 1906.