 On 10 December 1961 electric power was switched on, and after trials a public passenger service started on 27 May 1962; Sunday trains ran for the first time.Three car units ran, strengthened to six at peak times; proposals to run nine-coach trains at the busiest times were considered impracticable because of the difficulty of extending the stations' island platforms.The electrification was at 25 kV 50 Hz, but limited overhead clearances required 6.25 kV to be used in the inner area.