NZR D class steam tank locomotives operated on New Zealand's national railway network.

[4] Four of the 1874 locomotives were named: The class was not particularly powerful and was employed on light duties, sometimes achieving speeds of 72.4 km/h (45 mph) on a level grade.

[1] They often saw service on commuter trains between Christchurch and Lyttelton until superior locomotives took their place,[5] and they were utilised at other major locations on the South Island's east coast.

Withdrawal began during World War I; the class had long since been superseded by newer and more powerful engines, but they were ideally sized for private sidings and bush tramways, so many were sold rather than scrapped.

This included D 137, which operated until 1963 on the truncated portion of the Hutt Valley Line that remained as an industrial rail siding for the Gear Meat Preserving and Freezing Company.