High Quality Content by WIKIPEDIA articles! The O class consisted of six steam locomotives that operated on New Zealand`s national rail network. Ordered from the Baldwin Locomotive Works of Pennsylvania in 1885, three arrived in time to begin work in December 1885, while two more were placed in service in January 1886 and the sixth in February 1886. After almost four decades of service, all six were withdrawn in May 1922. None survived to be preserved, although two engine frames and 5 tenders from O class locomotives are known to exist near Summit on the former Rimutaka Incline.