such as mines and torpedo boats. The breech-loading gun types were originally designed for the Royal Navy. An 1879 British Ordinance Committee had earlier identified the need for Britain and its colonies to be able to match arms developments such as those of the German Imperial Army and Navy (Krupp guns). The Ben Buckler Battery specifics The three guns that formed the outer defensive circle of Eastern Sydney in the late 1890s were established at Signal Hill Battery in , Ben Buckler Battery in North Bondi, and Shark Point Battery in . The single batteries consisted of a gun pit that incorporated a BL 9.2 inch (234 mm) Mk VI British-made breech-loading Armstrong 'disappearing' gun. The disappearing guns were prevalent at the end of the nineteenth century throughout Britain, its colonies and the United States. They were chosen because of their range and power, and upon firing and recoil, the gun retracted into its concealed pit and was therefore a lesser target to attacking naval vessels. The domed metal shield that covered the gun pit was devised to deflect incoming shells striking the battery. During the late nineteenth century, ten breech-loading "counter bombardment" guns of this type were established in Australia. These comprised three (3) at Sydney's eastern suburb batteries, plus a spare barrel; four in Victoria at Fort Nepean and Queenscliff, and two in South Australia (purchased in 1888). The Adelaide guns were never established into Fort Glenelg but were bought back by the British government in 1915. The Sydney guns were purchased with three hydro-pnuematic mounts and had the following serial numbers: Shark Point: #7317; Signal Hill: #7318; Bondi: #7319, and the spare: #7320. Of these guns, only the Signal Hill, Vaucluse barrel survived on public display at the Royal Australian Artillery Museum at North Fort, North Head before the museum closed in 2010. The Armstrong Foundry gun at Ben Buckler was cast in 1891 and established within its concrete casemate in 1893. The casemate allegedly had thick concrete walls. Transportation of the gun from the Victoria Barracks, Sydney, involved a team of thirty-six horses and took three weeks. The gun weighed and was installed on an EOC Hydro-pneumatic Mark "1" disappearing mount, operated by hydraulic power. The gun was fired through a slot in the iron "top" shield and could fire a armour piecing projectile to a range of . A report in The Sydney Morning Herald