The Ekurhuleni Metropolitan Municipality's new R55-million "super" electrical sub-station at Isando has been completed.

It caters for Johannesburg International Airport's new domestic terminal, Caesars Casino, SAA Aircraft Workshops and Isando industry.

EMM's Mark Wilson said the project called for installation of an overhead line from the Kempton Park Main Substation, erection of the substation and provision of switchgear and feeder cables.

"A major challenge was the need for the electrical cables to cross the six parallel rails of the main Kempton Park-Germiston railway line," Wilson said.

"This was achieved by means of a 1,8m diameter round jacked cable tunnel installed about 2m below the railway lines."