Soon after the 4x4 came the 6x6 version, a 5 ton truck using many of the same components as the smaller capacity 4x4, which minimised and simplified the supply of spares and replacement parts.

Following the end of the Second World War, much of the wartime equipment was declared obsolete and disposed of, with only small quantities retained for the post-war Defence Force.

In the early 1950s the Australian Army was faced with a deteriorating fleet of vehicles and a rapidly diminishing stock of available spare parts. A major re-equipment of the Army’s vehicle fleets was required.

Army’s vehicle working party met in August 1952 to begin discussing options put forward, with the least likely being to design and manufacture a wholly Australian tactical truck.

This radical suggestion, was explored and.initial meetings with local manufacturers in late 1952 provided some encouragement.

One company, International Harvester, showed particular interest in the suggestion of an Australian made vehicle. Using the Army’s broad specification and information discussed at length at a meeting in April 1953, the company mocked up a vehicle which was inspected by Army representatives in August 1953. During this time, the Army further refined the user specification which called for a four-wheel drive and a ‘cab over engine’ arrangement.

With the refined specification and close collaboration with Army design engineers, International went on to produce three pilot model vehicles. These were two-wheel drive vehicles which could be converted to 4x4. They were made as two-wheel drives because a transfer case and front driven axle assembly were not being manufactured in Australia at that time. It was the Army Design Establishment’s part of the project to design these components, and have them manufactured as ‘kits’ for installation into the prototype International trucks.

By July 1955, the first of the International prototypes, a two-wheel drive truck, was delivered to Army for testing. And, another Australian company, Coote Jorgenson had been contracted to manufacture the front axle conversion kits.

Over the next couple of years, the International trucks were tested under all conditions, and many refinements made.

Satisfied with the design, Army ordered 100 production vehicles, designated ‘Trucks, 2 ½ ton, General Service No.1 Mk.1’.

More testing and refinement ensued with very close collaboration between the Army’s design division, and the contractor. The result was the ‘No.1 Mk.3’ version which was introduced into service with the Australian Army in late 1963.

Shortly after, a 6x6 version was produced, and various body configurations followed over the next few years. These included a 6x6 dump truck, a semi-trailer tractor, hole boring truck and a garbage compactor. The International range of purpose-built military trucks would carry Australia’s troops throughout the Vietnam war and remain as Australia’s basic tactical truck until replaced by the 6x6 Mack and the 4x4 Mercedes Benz Unimog in the 1980s.

The development and manufacture of this range of military vehicles was very much a result of the close and successful collaboration between the Army, that knew what it needed, and a local industry that rose to the challenge of providing it.

Prototype 4x4 International 2 ½ ton General Service truck ‘P2’ gets put through its paces during a gruelling series of tests that saw many improvements made to the basic design. Close collaboration between industry and Defence resulted in an indigenous tactical truck that served the forces from the late 1950s to the late 1980s.