Ab608, built by the New Zealand Railways Addington Workshops (maker's no. 163/15), was the first of the class when it went into service in October 1915. The Ab class went on to become the most numerous class of steam locomotive to run in New Zealand, totalling 151 locomotives by the late 1950s. The locomotives were also built by North British Locomotive Company, Glasgow, Scotland, and A & G Price, Thames, NZ.
The Ab was designed by chief draughtsman S H Jenkinson. It was a simple, superheated Pacific (4-6-2) locomotive, and introduced the cylindrical, Vanderbilt tender (adopted because of its light weight and economy of construction) to New Zealand. In their prime the Ab class hauled express trains in both islands, eventually becoming ubiquitous throughout the NZR network.
In 1925 Gordon Coates (the Minister of Railways) agreed to name a steam locomotive 'in memory of those members of the New Zealand Railways who fell in the Great War'. More than 5,000 railwaymen had served overseas between 1914 and 1918 (out of a total workforce of 14,000) and 447 had been killed. After considering the names 'Somme', 'Le Quesnoy' and 'Ypres', 'Passchendaele' was selected.
Ab608 was the locomotive selected to carry the name. 'Passchendaele' was exhibited at the New Zealand and South Seas Exhibition in Dunedin in 1925-26, and again at the Centennial of New Zealand Railways in December 1963.
The locomotive was retired in October 1967 when its boiler required heavy repairs. By the time it was withdrawn from service, Ab608 had steamed more than 2.4 million kilometers. It was subsequently given to the New Zealand Railway and Locomotive Society (http://www.railsoc.org.nz) for preservation, arriving at Ferrymead in 1978. It is currently undergoing restoration by Steam Incorporated (http://www.steaminc.org.nz) at Paekakariki, north of Wellington.
