 The Small Arms Factory had been constructed as a central defence arsenal between 1909 and 1911 as part of Australia's general movement towards self sufficiency following Federation in 1901.This movement saw greater desire to manufacture and grow food, supplies and other needs at home rather than buying them from overseas.The Army concluded that any aerial attack on the Lithgow area would, because of the topography of the Lithgow Valley, be from either end of the valley rather than across the narrow valley.