South Channel Fort, also known as South Channel Island, is a 0.7 ha

artificial island An artificial island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those th ...

in southern

Port Phillip Port Phillip ( Kulin: ''Narm-Narm'') or Port Phillip Bay is a horsehead-shaped enclosed bay on the central coast of southern Victoria, Australia. The bay opens into the Bass Strait via a short, narrow channel known as The Rip, and is com ...

Victoria, Australia Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in ...

, 6 km north-east of the town of

Sorrento Sorrento (, ; nap, Surriento ; la, Surrentum) is a town overlooking the Bay of Naples in Southern Italy. A popular tourist destination, Sorrento is located on the Sorrentine Peninsula at the south-eastern terminus of the Circumvesuviana ra ...

. It was part of a network of fortifications protecting the narrow entrance to

. It is 122 m long, 76 m wide, and is 6.4 m above sea-level, and was built on a shoal, close to the main shipping channel of the bay, with 14,000 tonnes of

bluestone Bluestone is a cultural or commercial name for a number of dimension or building stone varieties, including: * basalt in Victoria, Australia, and in New Zealand * dolerites in Tasmania, Australia; and in Britain (including Stonehenge) * fe ...

boulders, concrete and sand. It was constructed during the 1880s as part of a defensive strategy to protect and control access by sea to Port Phillip and the cities of

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

and Geelong. Its principal purpose was to illuminate the main shipping channel at night, and to explode mines under attacking ships which had breached the defences at Port Phillip Heads. The fort still contains remnants of its original military equipment, including

disappearing gun A disappearing gun, a gun mounted on a ''disappearing carriage'', is an obsolete type of artillery which enabled a gun to hide from direct fire and observation. The overwhelming majority of carriage designs enabled the gun to rotate back ...

Construction

South Channel Fort was built with a protective ring of bluestone rocks which also provided a foundation. Concrete cylinders were then sunk through to the sandstone base rock below. Resting on these is a thick table of concrete and brick with atop the concrete structure of the fort. Sand was then placed on top of the gun emplacements to absorb impact from any projectiles.South Channel Fort - Visitors Guide
/ref>

Occupants

Between 1890 and 1916 over 100 officers and men lived on the island, serving as mechanics, artillery-men and maintenance. Gradually, the increased range, rapidity of fire and efficiency of coastal defence guns allowed the entrance to Port Phillip to be protected by guns at

Fort Nepean Fort Nepean is a former defensive facility occupying part of Point Nepean, Victoria, Australia. It was part of a network of fortifications, commanded from Fort Queenscliff, protecting the narrow entrance to Port Phillip. It is now part of Poin ...

and Queenscliff. This led to South Channel Fort becoming redundant and it was deserted by the military.

Layout

Gun emplacements

There are a number of gun emplacements whose function was for artillery defence of the shipping channel, artillery protection and defence against enemy landings.

Underground "Keep"

The layout of the underground keep is a labyrinth of passages, small lobbies, magazines and a kitchen, carefully designed to ensure the safe and efficient handling of ammunition and gunpowder underground. It was constructed with red-gum timber and mass concrete. Beneath the keep is the test room from which the minefield in the South Channel was controlled and tested. The mines were placed so that they would explode below attacking ships.

Battery Observation Post

The post was built to protect the fort commander from gunfire. Constructed in 1905, it contains a plinth for a range finder, and fire control positions. It also has the best strategic view of the island and Port Phillip.

Marine life

The waters of Port Phillip surround the island. The rocks that make up the fort provide a habitat for a range of marine organisms, including

kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwa ...

forests and

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s that attach to the rocks. Colourful

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

s and soft corals grow amongst the rocks and jetty structures. The small torpedo bay supports areas of

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...

, and many fish can be seen there as well as under the pier. Disappearing-gun-mount

South Channel Fort was listed on the now-defunct Register of the National Estate, both for its historic significance and its conservation importance as a breeding site for the

white-faced storm-petrel The white-faced storm petrel (''Pelagodroma marina''), also known as white-faced petrel is a small seabird of the austral storm petrel family Oceanitidae. It is the only member of the monotypic genus ''Pelagodroma''. Description The white-faced ...

. The site is within the boundaries of the

Swan Bay and Port Phillip Bay Islands Important Bird Area The Swan Bay and Port Phillip Bay Islands Important Bird Area comprises a cluster of disparate sites centred at the eastern end of the Bellarine Peninsula, and the southern end of Port Phillip, in Victoria, south-eastern Australia. As well as ...

, identified as such by BirdLife International. Other species visiting the island include little penguins, black-faced cormorants and Australian fur seals. Since 1995, it has been managed as part of the

Mornington Peninsula National Park The Mornington Peninsula National Park is a national park located in the Greater Melbourne region of Victoria, Australia. The national park is situated approximately south of Melbourne on the Mornington Peninsula. Together with the adjacent ...

. Public access is permitted during daylight hours and it is a popular diving site.

References

External links

* {{Recreational dive sites, reesit Islands of Victoria (state) Artificial islands of Australia Forts in Australia Military installations in Victoria (state) Sea forts Port Phillip Underwater diving sites in Australia 1880s establishments in Australia Victorian Heritage Register Greater Melbourne (region) Unincorporated areas of Victoria (state) Mornington Peninsula