The K-class was a class of steam locomotives of the Western Australian Government Railways

Western Australian Government Railways

Western Australian Government Railways was most common name of the Western Australian government rail transport authority from 1890 to 1976. It is, in its current form, known as the Public Transport Authority of Western Australia....

 introduced in 1893/94 to haul heavier loads in particular on the Eastern Goldfields Railway

Eastern Goldfields Railway

The Eastern Goldfields Railway was built in the 1880s to connect Perth, Western Australia with the rich goldfields at Coolgardie and Kalgoorlie. The narrow gauge Eastern Railway line already connected Perth with Northam, and the EGR extended this line through semi-desert to the goldfields...

. Their wheel arrangement was 2-8-4

2-8-4

In the Whyte notation, a 2-8-4 is a railroad steam locomotive that has one unpowered leading axle followed by four powered driving axles and two unpowered trailing axles. This locomotive type is most often referred to as a Berkshire, though the Chesapeake and Ohio Railway used the name Kanawha for...

T, which was a tank engine.

The locomotives required heavier rails, 39kg/m in lieu of 23kg/m.

The K class operated on narrow gauge

Narrow gauge

A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...

  lines.

Namesake

There is also a Co-Co K-class diesel locomotive

WAGR K class (diesel)

The K-class is a class of diesel locomotives of the Western Australian Government Railways first introduced in the 1960s for use on the new standard gauge lines. Their wheel arrangement was Co-Co. The K class was a hood configuration, which could be driven short end leading or long end...

of the 1970s.