Gospel Oak to Barking Line

From the longer Wikipedia article

The Gospel Oak – Barking Line is a railway line in north and east London which connects Gospel Oak in North London and Barking in East London as part of the London Overground network. It is sometimes known as the Goblin (for Gospel Oak and Barking LINe), although this is a nickname rather than an official title. Unlike most railways in London, the line does not pass through the central Travelcard Zone 1. Traditionally the line has played a minor role in London's transport system; however, it is now receiving significant investment to increase its capacity. The line is part of the Network Rail Strategic Route 6, SRS 06.03 and 06.05. It is classified as a London and South East Commuter line.