The Northern Power Station, presently under construction, is the third power station to be built at Port Augusta. Two previous stations (Playford A and B) were constructed during the 1950s, although investigations into the feasibility of using the site date back to 1947. The new station has a larger production capacity than the other two and because of its necessarily larger size will impose greater foundation loads. There is also an increased awareness of potential seismic activity in the region, and as a result great attention has been given to footing design and site investigations for the foundations. Playford A station, completed in 1957, is founded on driven timber piles. Footings for the Playford B station (completed in 1960) consisted of both pre-cast concrete driven piles and bored Franki piles, reflecting the increased foundation loads of a larger capacity station. For the new Northern Power Station rectangular piers of reinforced concrete, known as barrettes, were chosen. These can support much greater loads and show greater resistance to lateral forces generated by earthquake shock; they also match in with the diaphragm walling used for basement construction.