Circle route
This was followed by the 25 kV AC overhead-power-lines electrification of the Glasgow and Paisley Joint Railway and the Inverclyde Line to Gourock and Wemyss Bay, completed in 1967. The WCML northern electrification scheme started on 6 May 1974. Part of the Cathcart Circle was upgraded to 25 kV AC supply in 1974, to provide a diversionary route; the whole of the Cathcart Circle route was later upgraded to that supply.