The mainline starts from the English town of Barrow-in-Furness. Crossing over the rolling lift bridge across the Walney Channel, the line calls at Vicarstown before passing through Henry's Tunnel. After this, the junction to the Norramby branchline is reached. After Vicarstown, the line calls at Crovan's Gate, home to the Works and the Skarloey Railway. After stopping here, the line travels to Kellsthorpe Road, junction to the Kirk Ronan branchline. The line afterwards reaches Killdane, junction to the Peel Godred branchline.