NZR O class

NZR O class

Type and origin Power type Steam Builder Baldwin Locomotive Works Serial number 7565–7569, 7572 (not in engine number order) Build date 1885

Specifications Configuration 2-8-0 Gauge 3 ft 6 in (1,067 mm) Driver diameter 36.25 in (0.921 m) Length 46 ft 3 in (14.10 m) Adhesive weight 25.2 long tons (25.6 tonnes; 28.2 short tons) Loco & tender weight 45.5 long tons (46.2 t; 51.0 short tons) Boiler pressure 130 lbf/in2 (896 kPa) Firegrate area 15.2 sq ft (1.41 m2) Heating surface 908 sq ft (84.4 m2) Cylinders Two, outside Cylinder size 15 in × 18 in (381 mm × 457 mm)

Performance figures Tractive effort 10,055 lbf (44.73 kN)

Career Operators New Zealand Government Railways Number in class 6 Numbers 31, 54, 59, 98-100 Retired May 1922

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 After almost four decades of service, all six were withdrawn in May 1922.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.

External links

• Baldwin Steam Trust statistics on the O class
• Plan of an O class locomotive by Derek Brown