Fort Scratchily stands on Flagstaff Hill in Newcastle, Australia. This was originally a signal position that was armed with two 32-pdr SB guns in 1866 served by local volunteers. In 1874 these were upgraded to two 68-pdr guns. With the end of the Crimean War, fears continued of Russian attack.
In 1877 Major-General Sir William Jervois and Colonel Peter Scratchley of the Royal Engineers visited New South Wales to advise on coastal defences. They also provided advice in respect of Bare Island Fort in Botany Bay. Detailed plans for the fort were prepared by Colonel Scratchily and it was eventually to bear his name. He also recommended the built of Green Hill Fort on Thursday Island.
The fort was built on a headland between 1878 and 1882. The main armament was three 9-inch RML guns in pits and four 80-RML guns in casemates with underground magazines and linking tunnels. In 1898 the four 80-pdrs were replaced with Nordenfelt 1.5-inch Quick Fire guns. In 1892 the RMLs were replaced with one 8-inch and three 6-inch BL Armstrong disappearing guns. In 1911 the three 6-inch disappearing guns were upgraded to with two 6-inch Mark VII BL guns. A seven-foot-deep dry ditch was built round the fort.