The North Kent line runs from Charing Cross and Cannon Street, through London bridge, where the line splits into 3 branches, the Woolwich, Bexleyheath and Sidcup lines, all merging together again at Dartford, one of the busiest stations outside of central london on this route. Although most services on this line terminate here at Dartford, a few continue to Gravesend, and the Thameslink services continue all the way to Rainham, which in 2016 replaced the Charing X to Gillingham SE service. I think this route would work brilliantly on TS21 and would bring a significant and memorable part of the Southeastern Suburban Metro network to life.
