Historic Car Brands

The Southern Cross was an innovative Australian car design, produced between 1931 and 1935 under the chairmanship of Sir Charles Kingsford Smith by the Marks Motor Construction Company.

Australian aviation pioneer, Sir Charles Kingsford Smith, had been a motorcycle despatch rider with the Australian Imperial Force (AIF) during World War I, before he learnt to fly with the Australian Flying Corps.

After the War, ‘Smithy’ owned a succession of British cars – mainly Triumphs – and ran a flying school. One of his pupil pilots, Jim Marks, owned a large Sydney harbour yacht, in conjunction with Stan Stranger. In the course of discussions when sailing aboard the boat, the three men decided to set up a car manufacturing business, with Smithy as chairman.

The concept of the car had been developed by Jim Marks’ father, Dr A R Marks and his business partner, A R Moir, who had built a prototype in the UK, using laminated wood construction in a radical, integrated body and chassis design. 

Wood construction was right up Smithy’s street, because of his aircraft construction background and he had also invested in a wooden aircraft propellor factory.

The original 1923 Mark-Moir wooden car was then eight years old and had travelled extensively throughout Australia, clocking up nearly 200,000 miles. In 1931, it was apparently showing no serious signs of wear and tear.

Its Wolseley engine was mid-mounted and a four-speed epicyclic transmission that may have been a modified Ford Model T gearbox, used chain drive to the rear axle, where one wheel had a simple form of limited-slip action, for improved traction in mud.

Birth of the Southern Cross brand

The 1930s weren’t the ideal time to enter the automobile business, because the Great Depression was killing off international car companies on almost a weekly basis.

In Australia, the Australian Six endeavour had collapsed, leaving enormous debts and Holden’s had been sold off to General Motors, following a staggering drop in Holden’s car assembly business, from more than 30,000 units in 1930 to less than 2000 in 1931.

Against this sombre background, the Southern Cross development went ahead, swallowing considerable sums of money.

The wooden bodywork differed from the UK-made Marks-Moir car’s ‘stitch and glue’ construction in using a newer system of 3mm-thick, laminated layers of Queensland pine and walnut, glued with aircraft casein adhesive over moulds, under 12 tons of pressure. 

This 10-layer plywood construction allowed compound curves to be incorporated in the design. The body sides were shaped in one compound curve and then the door skins were precision cut out of the body sides and mounted in place with metal hinges.

The engine, gearbox and suspension were mounted on steel frames that were bolted inside the body cavity. 

The selected front-mounted engine was designed by William Foulis, who had designed and built the two-cylinder motor for the 1917 ‘Roo’ car. It was a locally produced flat-four, with iron crankcase and two aluminium cylinder heads that displaced 2340cc. Initially, it put out 55bhp, but eventually developed 60bhp (45kW) at 3200rpm. 

Suspension from the beam front and rear axles was very thin, alternately-clamped, semi-elliptic leaf springs (18 leaves up front and 24 at the rear). The leaf clamping provided interleaf friction that did away with the need for shock absorbers.

The car weighed only 19 hundredweight (19cwt – 965kg) and had a 120-inch  (30498mm) wheelbase. The combination of a small engine, light weight and tall top gear ratio provided good performance and economy for the times. 

Although the original plan was for construction at the propellor factory, the first experimental Southern Cross was an open tourer with a body constructed by the Beale & Co Piano works. Several enclosed sedans were later built for test and development purposes. 

The prototype was introduced to the public at Mascot Aerodrome in June 1933, where it was displayed sitting under the wing of Smithy’s famous Southern Cross Fokker monoplane aircraft.

(A side legal issue was the fact that the name Southern Cross was registered in Smithy’s name for aeronautical, but not automotive, use and Triumph produced two contemporary Australian-market vehicles with the model designation Southern Cross.)

In January 1934, the Airline sedan version was driven to Melbourne by Smithy, Jim Marks and A E Nielsen, the secretary of the NZ Aero Club. Other people who drove and rode in the Southern Cross said that it had a smooth ride, with none of the jarring common in ‘square rigged’ cars built on ladder frame chassis.

The original plan for the Southern Cross car had at target price of less than 300 pounds, but the announced sale price was exactly double that figure – an expensive proposition in 1934. Nonetheless, the then-publicly-listed Marks Motor Construction Ltd company committed to an initial batch of 12 vehicles.

The engine was bolted to a four-speed transmission, but two of the cars built used an early form of automatic transmission that was developed in Australia. This was described as a frictionless system of centrifugal control, involving balanced weights and planetary gears, without need of a clutch or gear lever.

In an attempt to reduce costs, the Marks company imported a cheaper American powerplant and, to counter the scare campaign about fire risk from wooden construction, sheathed the bodies in steel.

However, the radical design of the Southern Cross, combined with its high retail price, discouraged buyers and, by early 1935, the company was in deep financial trouble.

Smithy’s demise

Smithy headed to the UK, in an effort to raise additional capital and was reportedly successful. However, his publicity-earning return flight to Australia ended in tragedy.

In November 1935, Smithy was in poor health, but with Tommy Pethybridge as navigator, set out from Lympne, to break the Britain to Australia speed record, in his Lady Southern Cross Altair aircraft.

After stops in Athens, Baghdad and Allahabad the aircraft disappeared after passing over Rangoon, Burma. An extensive search revealed nothing, but in 1937 an undercarriage leg, with wheel and tyre still attached, was found on a beach on Aye Island, in the Gulf of Burma. 

Despite subsequent searches nothing more was found and the Altair’s undercarriage leg is now held at the Powerhouse Museum in Sydney.

Whatever finance deal Smithy had done in the UK for the Marks Motor Construction Ltd company died with him in 1935 and no more Southern Cross cars were produced.

No Southern Cross cars remain

Records are unclear, but more than four and fewer than 10 Southern Cross cars were built. The best educated guess is around six or seven.

The open Tourer, which was christened by Lady Kingsford Smith at Mascot Aerodrome in 1933, was sold to a resident of Ryde or Parramatta, NSW, in 1936. It was reportedly chopped up for firewood in the 1970s. No Southern Cross cars are known to have survived.

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