The M113A1 family of vehicles was introduced into service in Australia in the mid 1960s, and arrived in time to see service in Vietnam. Additional vehicle variants were added until 1979, and there are 766 M113A1 vehicles currently in the Australian Army fleet. By February 2005, however, only 520 remained in service.
A number of upgrades have been suggested for Australia’s APCs(Armoured Personnel Carrier) over the years, with a number of different reviews and upgrade proposals submitted. Many of Australia’s M113s remained in the old M113A1 configuration, though some had at least been repaired and overhauled at 25,000 km. Bushmaster wheeled mine-resistant vehicles have replaced some M113s in the ADF, but the M113′s lightweight, tracked, off-road mobility remains important to Australian mechanized formations, and to troops deployed in combat zones. A plan approved in the 1990s involved a “minimum upgrade” of 537 vehicles from 1996-1998, at a cost of about A$ 40 million in 1993 dollars, with a major upgrade to follow. That major upgrade did follow – along with schedule slips, and cost increases from around A$ 594 million to nearly A$ 1 billion.