 The line was declared to conform to the standard C1 loading gauge on 14 March . The first passenger carrying train comprising C1 stock to use the line was a railtour on 15 March hauled by 50 025 Invincible . It was organised by the Southern Electric Group and ran from Paddington to Folkestone Harbour . A preview service of electric trains ran on 27 April 1986 and the full timetabled service commenced on 12 May 1986 . The next day , a wrong @-@ side failure occurred involving three signals between Tonbridge and Hastings . Contractors had made errors in the wiring of the signal heads . With the inauguration of electric services , a half @-@ hourly service was operated , with trains departing from Charing Cross at 15 and 45 minutes past the hour . Those departing at xx : 15 called at Waterloo East , Sevenoaks , Tonbridge , High Brooms , Tunbridge Wells , Wadhurst , Battle , St Leonards Warrior Square and Hastings , taking 84 minutes . Those departing at xx : 45 called at Waterloo East , London Bridge , Orpington , Sevenoaks , Hildenborough , Tonbridge and then all stations to Hastings , taking 99 minutes . The Royal Train visited the line on 6 May , conveying Queen Elizabeth the Queen Mother . It was stabled at Wadhurst whilst she ate lunch . The train was hauled by a Class 73 diesel @-@ electric locomotive . Upon electrification , services were operated by 4CEP , 4CIG and 4VEP electric multiple units . Class 508 electric multiple units also operated services on the line . When these units were withdrawn in the mid @-@ 2000s , they were replaced by Class 375 Electrostar , Class 465 Networker and Class 466 Networker units . 
