In Carlisle, they operated the Border Union Railway (also known as the Waverley Line). Initially, access to Carlisle was being made difficult by one of their fiercest contemporaries, Caledonian Railway (CR), so they leased the Port Carlisle and Silloth Bay Railways, allowing them to reach the city via Port Carlisle Junction and later, via the previously constructed Caledonian Railway branch line from Carlisle Canal Basin to Carlisle Citadel station.
Also shown are the Port Carlisle & Silloth Bay Railway routes, the Solway Junction Railway, the Langholm Branch Railway and lastly, the Border Counties Railway, which linked the Waverley Line at Riccarton Junction with Hexham.