 An electrical control room was provided at Cathcart.The suburban electric trains were equipped with apparatus to switch between line voltages, but when the main line electrification from Crewe to Glasgow was implemented, the Maxwell Park section of the Cathcart circle was designated as a diversionary route.The main line locomotives were not fitted with voltage switching mechanisms, and as the air clearance requirement had been relaxed in the intervening years, the 6.25 kV section was converted to 25 kV from September 1973.