NZR M Class
Image courtesy of A P Godber Collection, Alexander Turnbull Library
Type and origin Power type Steam Builder Hunslet Build date 1875 Total produced 4 Rebuilder NZR Rebuild date 1888-1890
Specifications Configuration: ​  • Whyte 0-6-0T Driver dia. 42.25 in (1.073 m) Loco weight 27.7 long tons (28.1 tonnes; 31.0 short tons) Firebox: ​  • Grate area 8.6 sq ft (0.80 m2) Boiler pressure 130 lbf/in2 (896 kPa) Heating surface 583 sq ft (54.2 m2) Cylinders Two, outside Cylinder size 13 in × 20 in (330 mm × 508 mm)
Performance figures Tractive effort 7,200 lbf (32.03 kN)
Career First run 1875

The NZR M class were a series of four tank engines built in England for the Otago railways Bluff to Winton section. They were acquired by NZR in the late 1870s and rebuilt in the late 1880s. As rebuilt they were not very successful and were used in shunting duties until retirement in the 1920s.^[1]

They were rather ineffectual engines derisively called the Pullets by engine men. They were used on the Napier Express at the turn of the century; either in pairs or with a Baldwin N class when the duo was called a 'en and chicken. ^[2]