The ARG L/3100 Class were the first 3300HP locomotives on Government Railway in Australia. They were initially used to haul Iron Ore, however they have been used to haul the Indian Pacific. They can be compared to the US SD40 class locos, albeit they are smaller.

When the Q class were introduced, half of the L class were withdrawn from service. A number of the L Class were sold to ATN Access for use on grain trains in the Riverina region of NSW to Appleton Dock in Melbourne, VIC. L265 and L271 were initially sold to Rail Technical Services (Dynon, Victoria), where they were overhauled and then on-sold to QRNational, L271 has returned to the ARG pool as LQ3122.