 After the end of the war, the depot was surplus to requirements and the entire system was bought by Walker, who realised that the substantially larger Hunslet 0-4-0 well tank locomotives would be suited to his plans at Sand Hutton.Between 1920 and 1922 the existing miniature railway was converted to gauge and the extension to Warthill was completed.In April 1922 the first of the light railway were opened to goods traffic.