The line starts at Ulfstead and runs west, it goes over the top of the dam to Arlesdale End where it connects with Thomas' Branch Line. It then goes to Lower Arlesburgh and continues to Tidmouth Bay. It then merges with Duck's Branch Line and on to Bluff's Cove. Bertram also works at The Old Mine between Tidmouth Bay and Arlesdale Lake.
- In the CGI Series, Arlesdale End only has one track.
- This branch line is Toby's old tramway in the television series.