The New Zealand F class was the first important class of steam locomotive built to operate on New Zealand's railway network after the national gauge of 3 ft 6 in (1,067 mm) was adopted. The first locomotives built for the new gauge railways were two E class double Fairlies for the Dunedin and Port Chalmers Railway. The F class was the first class ordered by the Central government, and between 1872 and 1888, a total of eighty-eight members of the class were constructed.