Cockatoo Island Sutherland and Fitzroy Docks. Photograph by Janette Pelosi. Barney Kieran did much of his early training at Cockatoo Island where the Sobraon boys were able to go on land. The Fitzroy Dock (472 feet = 144 metres) was used as a venue for swimming races watched by Barney Kiernan and he used the Sutherland Dock for his swimming training. The Sutherland Dock, completed in March 1890, was 638 feet (194 metres) when built.