Fort Denison

Fort Denison. C1855.

Formally known as Pinchgut Island and later as Fort Denison, the island sits in Sydney Harbour.

One of the last Martello Towers to be built in the world, following their proliferation in southern England after the design’s defensive capabilities had been proven at Cap Mortella, Corsica, in 1794.

The tower was built to defend Sydney against a possible attack by Russian warships, which never eventuated. Built from 8,000 tonnes of sandstone quarried near Kurraba Point, Neutral Bay, it was named after Sir William Denison, then Governor of New South Wales. By the time the fort was completed, it was redundant.

Plans in 1998 to turn Fort Denison into a restaurant necessitated the need to slow down the deterioration being caused by salt. This lead to the testing and development of the product now known as Cocoon. Working with National Parks and Wildlife and in conjunction with the CSIRO, trials were carried out to establish the efficacy of a Westox product sourced from the manufacture of pharmaceutical grade filter paper from the Westlegate factory at Revesby, a suburb of Sydney. Following successful trials which removed 87% of the salt from the test area in just 26 days, large areas of the fort were treated to lower the salt contamination. Due to the location of Fort Denison, continual desalination will always be required to hold the deterioration at a manageable level.