Sandfly is historically significant to the Northern Territory as the first and longest serving locomotive to operate on the North Australia Railway (NAR).

Sandfly operated on the NAR between 1887 and 1950 and was instrumental in its construction. The NAR became a vital infrastructure link which directly facilitated the expansion of the mining and pastoral industries in the NT and the defence of northern Australia during WWII. Sandfly was the only locomotive of its class to operate along the NAR and is one of three remaining steam locomotives associated with the NAR left in the NT.

Following her retirement, Sandfly was relocated to SA in 1959 for restoration and display. In 2005, she was returned to the NT as a gift to commemorate completion of the Alice Springs to Darwin Railway. Sandfly is a symbol of the early pioneering and frontier Territory spirit that built the NAR. She is also a political reflection about the century of political manoeuvring required to complete the transcontinental railway from north to south and fulfil the 1911 contract between the Commonwealth, SA and the NT.