Big Four tractors were produced by the Gas Traction Co. of Minneapolis, Minnesota. This company had started out in 1906 as the Transit Thresher Co., but in 1908 it changed its name to reflect its growing interest in tractor production. A number of different four-cylinder models were produced, but the most successful of these was the Big Four "30", a huge 30-60hp tractor with rear wheels eight feet in diameter and two feet wide. A second factory was opened in 1910 at Winnipeg, Canada to satisfy Canadian demands for big powerful tractors - this coincided with numerous successes in the Winnipeg Trials held nearby. In 1912 the Gas Traction Co. was taken over by Emerson-Brantingham, who continued to market the Big Four range of tractors for several more years.

(Click on images below to enlarge)

Big Four 30 (Gas Traction Co.) (serial no. 6) at the Best Show on Tracks, Woodland, California, USA in 2008.

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Big Four 30 (Gas Traction Co.) at WMSTR, Rollag, Minnesota, USA in 2004.

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Big Four 30 (Emerson-Brantingham) (serial no. 1550) at the Parkes Museum, New South Wales, Australia in 2006. Note the optional self-steering device in the foreground - this attached to the front of the tractor and followed the edge of the last furrow when ploughing, allowing a single person to operate both the tractor and plough.

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Big Four 30 (Emerson-Brantingham) (serial no. 1560) at the Stuhr Museum of the Prairie Pioneer, Grand Island, Nebraska, USA in 2011.