High Quality Content by WIKIPEDIA articles! The Watford DC Line is a commuter railway line from London Euston to Watford Junction. Services on the line are operated by London Overground. The line runs beside the West Coast Main Line (WCML) for most of its length. The London Underground Bakerloo line shares the track of the line from Queen`s Park to Harrow & Wealdstone. The London Overground rolling stock used on the line is Class 378 "Capitalstar".