The six units converted by Commonwealth Railways to NF class were withdrawn between 1928 and 1945, with three of the class operating the line during World War II. NF6 was destroyed during the first Japanese air raid on Darwin in 1942 while shunting munitions on the Stokes Hill jetty. The locomotive was blown into the harbour and while both driver and fireman survived, the fate of NF6 remains unknown as it has never been officially salvaged or located.