Plans for a fort were drawn up by the Colonial Architect's department, and government tender for construction was awarded to a building company led by John McLeod, who also built the Georges Head and Middle Head fortifications. McLeod won the tender in 1881 and commenced work on 7 April. His work was supervised by Public Works Department Clerk of Works Henry Purkis who was responsible for many other projects which called him away from Bare Island for extended periods. Following Scratchley's death in 1885 overall supervision of the project was delegated to Major Penrose.