A Stobie pole is a power line pole made of two steel joists held apart by a slab of concrete in the middle. It was invented by Adelaide Electricity Supply Company design engineer James Cyril Stobie (1895–1953) Stobie used materials easily at hand due to the shortage of timber caused by the arid and treeless nature of much of South Australia. In 1924 the pole was patented, Stobie describing his invention as
"an improved pole adopted to be used for very many purposes, but particularly for carrying electric cables, telegraph wires... [it] consists of two flanged beams of iron or steel, preferably rolled steel joist of 'H' or of channel sections, placed one beside the other with their flanges inward and preferably at a very slight angle one with the other and held together by means of tie bolts, the space between them being filled with cement concrete.
