George WINDLE began manufacturing in his back shed at 64 Vine Street, Prospect, South Australia, and the Windle Engineering Company was registered at this address in April 1937. It remained there in 1939 before shifting to rented premises at Manton Street, Hindmarsh where they were known to be from July 1941 until July 1944, when the company was registered at the premises of the Steamship Buildings in Currie Street Adelaide. They were still there in February 1946 when the company went into voluntary liquidation. However their fortunes must have recovered as the Windle Engineering Company was back in business at a new location, 44 Gilles Street, Adelaide by Jan 1947. They later built their own factory in Bacon Street, Hindmarsh and were known to have been there from at least February 1952 until its closure in 1978.
George WINDLE and the Windle Engineering Company were makers of the Windle Selfoil windmill, which was believed to have first been manufactured in 1936. It was a counter-clockwise running, single gear windmill encased in a welded gearbox. Other welded gearboxes of this era include the Fortescue Economy windmill made by Geo. E. Fortescue & Sons in Arncliffe, NSW, and the Webb Model T windmill made by Webb Bros of South Melbourne, VIC. The rear cover of the gearbox is fastened on by fourteen screws that need to be removed to view the internal gear and to check the oil level. Unlike the Webb Model T, the Windle gearbox was not galvanised.
The Windle Selfoil windmill had only three moving parts; a single pinion gear drove an internally toothed main gear, which had an eccentric driving a metal strap. The windmills were made with three legged towers and were available in 6, 8 and 10 ft sizes. Castings were done by E. J. KEEN & Co. of Adelaide, from patterns made by George WINDLE. The hub was a copy of the American Baker Monitor windmill.
In June 1937 an application was made by the Windle Engineering Company to register the design of a windmill head with the Australian Patent Office. The Design No. 16733 was approved and registered in October 1937. Designs differ from Patents in that a Design protects how a product looks, while a Patent protects how the product works. Put simply, a design patent protects an article's design - its unique external appearance - while a utility patent protects the article's function. It is not yet known which particular feature of the windmill head was the object of the Registered Design, but the number was stencilled on the tail of the Selfoil windmill.
The Windle windmill on display at the Morawa Museum has no windwheel or tail. It was donated by Chris SCHREIBER and Bill SLEEP of South Australia and restored by Helen and Patrick WALTER in 2026.