Overview: Rob Bell explores the Waverley Route, which ran south from Edinburgh for 100 miles through the Scottish Borders to Carlisle, connecting with what is now known as the West Coast Main Line. After years of campaigning, the first stage of Rob's journey is aboard the new Borders Railway, the longest railway to open in over a century. It follows part of the old Waverley Route, making fine use of the 170-year-old, 23-arch Newbattle Viaduct. Rob also pays a visit to one of Hawick's surviving cashmere factories and discovers a First World War prisoner of war camp served by the railway.