Trying to follow up this statement, Google did not mention a railway but came up with the information that about 1967 there was a proposal to build a large dam on the Murray River not far from the border of SA.and NSW. A construction town was built in 1967 but the proposal was a political hot potato, and a government toppled in SA. Finally, after expenditure of some 12 million (dollars or pounds ?? ), the idea was abandoned.
My thoughts are that the railway was probably do do with the establishment of the construction town to build a five kilometre long embankment across the river valley.
Can any South Australian railpager confirm whether my supposition is correct, and provide any information about the railway. Was it dismantled with the construction town, or did it die a lingering death rusting away. I have not located the railway on any map.