“It has been strongly emphasised in all recent communication from GOC, AIF Middle East , that it is essential that all future supplies of mechanical vehicles from Australia must be of the War Office four wheel drive type .....” (PC Spender, Minister of the Army, 28 Feb 1941).

The hardy Canadian Military Pattern (CMP) vehicles supplied to the British in the Middle East in 1939-40 were an immediate hit with prominent WWI and WWII figurehead General Blamey. He and the Minister for the Army recommended Australia procure the vehicles in quantity.

The Minister recommendation was twofold – firstly there would be an initial purchase of complete vehicles for direct supply to the Middle East for immediate use and limited numbers to Australia to use as patterns for the design of bodywork.

The second part of the procurement was for a large quantity of cab-chassis for direct supply to Australia, where they would be fitted with locally designed and manufactured bodies.

General Motors, under its Chevrolet brand , and Ford Canada built CMP vehicles, but the majority of early arrivals in Australia were Cab 12 type Fords in the three ton long wheel base class. They were assembled with locally built 'wood-steel' bodies and modified for Australian Army requirements.

Ford Motor Company of Australia (FMC) and General Motors-Holden (GMH) geared up for local cab manufacture, so when the advanced Cab 13 was introduced both were ready with locally manufactured cabs or cab parts built to satisfy Australian Army requirements.

There are numerous differences between both the Canadian built cabs and those produced in Australia, as well as differences between the FMC and GMH cabs themselves. GMH built the whole cab but with a number of unique Australian features, while FMC produced only parts of the cab.

The bolts were one of the unique traits of the Australian-built CMPs. The American National Coarse (ANC, now UNC) thread bolts were not available in Australia and GMH assembled vehicles used British Standard Whitworth (BSW) threaded bolts with head sizes machined to match the ANC sizes. For fine thread bolts, GMH manufactured the correct American National Fine (ANF) bolts. FMC used BSW bolts for assembly of the locally built cab parts.

Another unique feature of Australian CMPs is the cab floor. Chequer plate in 3/16th inch thickness was not available in Australia , so GMH used 1/8th inch flat sheet and spot welded 'skid strips' to required areas. In contrast FMC used the only chequer plate then available: 1/4 inch plate as used in locomotive construction.

The Army requirement for anti-aircraft defence meant that all Australian CMP cabs were fitted with a roof hatch and until 1943, a bracket for an Anti Aircraft Light Machine Gun (AALMG) mount. As the mount was seldom used and soon discarded, the mount was deleted from production late in 1943 – the roof hatch remained.

Rear bodies were initially 'wood-steel' construction but all-steel bodies soon began rolling off the production lines at GMH’s Woodville Plant near Adelaide . They served unaltered as GS bodies, or were fitted out with equipment for a number of specialised applications, such as machinery, stores, office and so on. These base bodies are different in design and manufacture to their Canadian equivalents.

In addition to the base bodies, Australian industry produced many specialised bodies. These included signals vans, field artillery and light anti aircraft tractors, and ambulances. Less common types included the dental surgery, field medical station, and recuperator. These were mainly manufactured by specialist builders such as Chettham and Borwick.

Small numbers of armoured vehicles based on CMP chasses were also manufactured in Australia. The Rover Light Armoured car and the Rhino Heavy Armoured car were CMP based as was the SC1 armoured car built for the United States Army.

CMPs were supplied to all three services as well as to US forces in Australia . They were retained in use for many years after the war, with some of the special bodied versions remaining in service until the late 1960s.

The procurement of CMP vehicles illustrated the Governments willingness to provide Army with the best vehicles available at the time, coupled with the prudent decision to manufacture as much of the vehicle as possible within Australia, thereby developing Australian Defence Industries and preserving Australian jobs in a way that was effective for the warfighter and efficient for the taxpayer.