it was completed on 19 April. Design The fort was completed on 2 April 1882. It was designed by Lieutenant-Colonel Peter Scratchley, after whom the fort was named and included three 9-in Rifle Muzzle Loader (RML) guns and a casemated battery of four 80 pounders. In 1889 three 6-inch BL and one 8-in BL disappearing gun were installed. The 80 pounders were replaced by quick-firing Nordenfelt machine guns in 1898. Two 6-in BL Mark VIIs replaced the four disappearing guns in 1911. World War I During World War I, the fort was upgraded with the provision of a Battery Observation Post constructed in 1914. World War II During World War II, the fort was further upgraded with the extension of the Battery Observation Post and provision of Searchlight Directing Station and blast walls were constructed in 1942. The two 6-in BL Mark VII guns fired at the Japanese submarine I-21, which shelled the city on 8 June 1942. Post World War II After World War II the fort was home to 13 Medium Coast Battery RAA, a unit of the National Service Scheme, which was renamed 113 Coast Battery RAA in the 1960s. The army left the site in November 1972. The 6-in guns were relocated to King Edward Park, away, as a memorial. However, after extensive lobbying, they were returned to Fort Scratchley in 1978. In the first decade of the 21st century the site underwent a multimillion-dollar renovation and reopened as a museum. In 2014, History show TV presenter Sir Tony Robinson visited the Fort to produce a segment for his show Tour of Duty which was aired in 2015. In 2015, the Fort's sole Nordenfelt gun was restored to fully functional condition and is fired on special occasions from its position in the underground casemate. Cannon disposals Two 68 pounder cannons are now located at Stroud, New South Wales. An 8-in disappearing gun was sent to North Head Artillery School for training purposes. A Signal cannon was relocated to Georges Heights, Sydney, then relocated to Puckapunyal, Army Barracks in Victoria. The two Mk VII guns were decommissioned in 1965 and relocated to Obelisk Hill as monuments. They were returned to the Fort in 1978 and placed in their original positions. Both were restored by the Fort Scratchley Historical Society in 1992 and are capable of being fired on special occasions for ceremonial and saluting purposes. One of