RML 9 inch Armstrong Fortress Guns, Fort Gellibrand, Melbourne

These 9 inch (228mm) Rifled Muzzle Loading guns are 12 ton Armstrong Fortress guns (300 pounder guns - actual weight of shot was 256lb). With a 9 man crew, rate of fire was approx one round every 3 minutes with either solid palliser shot or exploding shell ammunition, cast in water cooled moulds to harden the tip to enhance armour penetration. Effective range approx 5000 metres

This pair are situated in Williamstown (near my parents' house), an inner suburb of Melbourne, and cover the final approaches to the port. These guns (Nos 1679 and 1683) purchased by Sir George Vernon in 1866 to upgrade the existing 32 pounder smoothbore guns at Fort Gellibrand, constructed in 1855 during the Crimean War "Invasion Scare", to cover the southern approaches to the harbour.  

The Point Gellibrand shore batteries were first developed as part of an immediate defensive system for the city and port of Melbourne. The strategy for the defence of the port of Melbourne at this time was based on a number of shore batteries inside Port Phillip Bay. 

From the Military History and Heritage of Victoria website here: http://www.mhhv.org.au/?p=2351

"1869 Sir William Armstrong rifled muzzle-loading fortress gun"
- Military History & Heritage Victoria

This pic appears to be the same location as the one above it - quite unchanged really for well over a century earlier (other than a fence!) 

The first permanent battery was built by penal labour on Gellibrand’s Point in 1855. Convicts from the hulks moored offshore were employed on these works and accommodated in an old military barracks at the Fort. The buried central magazine at the Fort dates from this period. Further gun emplacements were added by private contracts, along the foreshore in the 1860’s."

The importance of the Fort batteries declined from the 1890s with the advent of new technologies allowing enemy ships to stand further out and shell Melbourne at range. Accordingly, they were replaced by new outer harbour defences at Queenscliff and Point Nepean, though they were still used for gunnery practice. Local residents, through the Williamstown Town Council, complained to the Acting Minister for Defence that the concussion from the guns damaged windows, walls and foundations of buildings. 

When the cannons were relegated to garden ornaments

Now deemed not just obsolescent but also a public nuance, the Armstrong Cannons were moved from Fort Gellibrand to the Williamstown Gardens in 1906 as static displays, where they stayed until 1970 when the development of the Esplanade saw them taken to their current position.

"Williamstown cannons being fired in 1988" (assumed for the Australian Bicentenary celebrators).
This was the last time the guns were fired

In addition to coastal fortifications, this type of gun was also typically fitted to smaller British ironclads and as the secondary broadside armament on larger battleships. The primary ammunition was solid Palliser shot, primarily employed for Armour Piercing work. Initial design was 1865 and 3 successive upgrades were implemented.

http://www.mhhv.org.au/?p=2351

Two additional Armstrong guns, also originally emplaced at Fort Gellibrand, are displayed in another nearby Melbourne suburb where they were relocated in 1910.

https://historicalragbag.com/2024/07/

https://www.gleneira.vic.gov.au/our-city/history-and-heritage/our-monuments-and-sites/cannons-in-hopetoun-gardens