Wirrida Siding, looking south towards Tarcoola from the north end of the loop, concrete interlocking hut with searchlight repeater signal, point indicator, communications tower in the distance on the left and train control 'pillbox' on the right. Located at the 641 km from the 0 datum at Coonamia and 137 km north of Tarcoola between Carnes and Manguri on the Tarcoola - Alice Springs line. GeoData location. 16th April 2003.