Alex Coomber
A Class 313 25 KV AC/750 Volt DC Third Rail a dual voltage unit built at York in 1967-77. These units were the first of the second generation EMUs and the first dual voltage units. Initially designed for the Great Northern inner suburban services running over former London Tube Lines from London Moorgate to Welwyn Garden City and Hertford. Some served on the North London Line, West London Lines and the Watford DC lines out of London Euston until they were eventually replaced in 2010 by the new class 378 units. In DC Mode. No. 313017 leaves Dalston Kingsland and will follow the DC lines to Islington and Willesden Junction in July 1987. While in AC Mode. No. 313031 approaches Finsbury Park en route for Moorgate also in July 1987.