Sydney Harbour defences

Sydney Harbour was protected by coastal batteries and other fixed defences from the early 1800s until the 1960s. These defences were constructed to protect the Australian city of Sydney from attack by enemy warships and submarines.

Sydney's earliest fortifications were built around Sydney Cove to protect the new colony of Sydney from attacks from non-British ships or convict uprisings. The first gun emplacement was built in 1801 on Middle Head (north of Obelisk Bay) during the Napoleonic wars. More permanent fortifications were built during the first half of the 1800s in response to feared foreign attacks and new threats to the British empire. In 1790 the Dawes Point Battery was meant to be the first line of defence against an attack by the Spanish Empire, Napoleon’s French troops in 1810, and the Russian Pacific Fleet in the 1850s (during the Crimean War). This was part of a line of defences that were concentrated on protecting the inner Harbour, these also appear to have been given a low priority. Construction of Fort Denison began in 1841, though the fort wasn't completed until 1857.

Sydney's defences were expanded following the withdrawal (Cardwell reforms) of British soldiers from Australia during the 1870s. This prompted the construction of four sets of fortifications on Georges Heights and around other parts of the harbour, the Middle Head Fortifications, the Georges Head Battery, the Lower Georges Heights Commanding Position‎ and a smaller fort located on Bradleys Head were constructed during this period and upgraded in the 1880s on the advise of British experts. They were designed to attack enemy ships as they attempted entry into Sydney Harbour. Some of these forts, were at the time, built of an out dated design.

A Submarine Miners’ Depot was constructed at Chowder Bay (Georges Head) in the 1880s. In 1888 the site was modified for the latest in harbour defences. The site was a strategic position and considered the best place to observe and fire mines which were laid underwater. Minefields were laid across the main shipping channels of Port Jackson from 1876 to 1922 and a base was built at Chowder Bay for the submarine miners (Clifton Gardens). From Georges Head, miners watched for ships entering the harbour. Their job was to explode the mine closest to an approaching enemy ship. Each underwater mine was attached to an electric cable that ran up the cliff to the firing post.

The work of the submarine miner was secretive, technical and dangerous. During a demonstration in 1891, a crowd of several thousand watched as a terrible accident killed four miners and injured another eight. The Submarine Mining Corps was dismantled in 1922.

Sydney's defences were expanded over the last decades of the 19th century and eventually incorporated a fort on Bare Island to defend the approaches to Botany Bay.

World War II

Sydney's defences were not expanded from their pre-Federation condition until the 1920s. During the 1920s a number of well-constructed fortifications were built to protect Sydney. Sydney's defences were further expanded following the outbreak of World War II and were considerably augmented once Japan entered the war. While Sydney's anti-submarine defences were not yet complete at the time of the attack on Sydney Harbour on the night of 31 May 1942, they were successful in sinking two of the three Japanese midget submarines which attempted to enter the Harbour.

The end of coastal defence

Following the end of the Japanese threat to Australia Sydney's defences were reduced from 1944. The last fortifications were not decommissioned until the 1960s, however. While Sydney is no longer protected by fixed defences, a high proportion of the Australian Defence Force is based within the greater Sydney region and could be called on to protect the city during an emergency. During the 2000 Sydney Olympics security for the Harbour was provided by Special Forces, Navy Clearance Divers and warships.

Current major ADF facilities in Sydney include:

• Air Force
  • RAAF Base Richmond
• Army
  • Holsworthy Barracks
• Navy
  • HMAS Kuttabul
  • HMAS Penguin

Bradleys Head Fortification Complex

The Bradleys Head Fortification Complex is a small fort located on the northern side of Taronga Park Zoo that formed part of a total defence system for Sydney Harbour and recalls a period when the colony of New South Wales became increasingly aware of its isolation and wealth. The fortification is located on Bradleys Head Road, Mosman, Australia.

The main firing wall of the Bradley's Head Fortification Complex.

Gun emplacement overlooking Port Jackson

History

Construction of the fort began in 1840-42 and consisted of a gun pit and firing wall that was built out of large blocks of sandstone and carved partly from the original rock that was located on site. The earlier stages of construction during this period were done with the supervision of Major George Barney, a Commanding Royal Engineer who used hired labour that was supplied by Governor Gipps.

In 1871 the fortification received an additional barracks. The barracks were constructed from large sandstone blocks and carved out of the existing rock on the headland. The 1871 barracks were designed and constructed under the direction of James Barnet, a colonial architect. This most recent addition consisted of three gun pits and had connecting galleries for the riflemen. The upgrade of 1871 was complementary to some of the larger fortifications being constructed during the same period on Middle Head, South Head, Georges Heights and Georges Head.

The site is now part of the Sydney Harbour Federation Trust.

The only entrance to the battery constructed in 1871.	A feature inside the onsite barracks.	One of the barrack hallways with an entry point to the innermost chamber on the right hand side.	The innermost chamber of the barracks
Trenches leading to gun emplacements and into the underground chambers on site.	Large gun emplacement constructed 1840-42	Cannon and gun emplacement constructed 1871	Empty gun emplacement constructed 1871

Malabar Battery

Malabar Battery was a coastal defence battery built in 1943 during World War II at Malabar Headland, Malabar, New South Wales, Australia. The battery is also known as Boora Point Battery.

Four story observation post forming part of the Malabar Battery (below)

The battery was constructed to complement the existing coastal defence batteries at nearby Henry Battery, Banks Battery and Bare Island Fort.

Two 6 inch Mark XII guns in gun emplacements on mountings were constructed at the battery. An underground counter bombardment facility, with gun crew ready rooms, ammunition supply and engine room together with a narrow-gauge tramway which was cut into the sandstone and lined with sandstone and a large battery observation post were also constructed at the battery.

The tramway was a single track of 560mm (22in) and was to transport the 6" projectile munitions to the shell expense stores/magazines in the base of each gun emplacement. The tramway traverses through a deep continuous cutting lined with sandstone leads from the ammunition drop off point to the basement of the ammunition supply room and up to the two gun emplacements. Before reaching the gun emplacments the line enters a rectangular section concrete tunnel which is 94m (310ft) long.

Also constructed as part of the battery were northern and southern searchlight blockhouses with associated engine rooms and the battery barracks and toilet blocks.

Following decommissioning of the gun emplacements after the war, the site fell into disrepair.

Signal Hill Battery

Check out the video, it contains images of most Sydney bunkers

The Signal Hill Battery was constructed in 1892-3 at Watsons Bay and is adjacent to the Signal Hill Lighthouse on Old South Head Road. The Battery was one of a set of three coastal defense fortifications in Sydney, Australia, the other two being the Ben Buckler Gun Battery at Bondi, and the Steel Point Battery in Vaucluse. Each battery consisted of a gun pit that incorporated a BL 9.2 inch (234 mm) Mk VI breech-loading 'counter bombardment' British Armstrong 'disappearing' gun.

Pictured is the above portion of the fortification. This is one of two on this site.


The Australian government bought nine such guns and an extra barrel. The Signal Hill gun bore Serial Number 7318 and its barrel survives on public display at the Royal Australian Artillery Museum at North Fort, North Head.

This tunnel lies below ground and once led out to Old South Head Road
heading in direction of Gap Park.

These fortifications were the last link in Sydney’s outer defense perimeter, which was intended to defend Sydney from bombardment by an enemy vessel standing off the coast.

This tunnel is also part of the underground bunker


The fortifications built in the 1890's around Sydney's eastern suburbs were the culmination of some twenty years of construction of harbor defense installations that reflected the changing policy of the time to meet new technologies, threats and styles of warfare.

Above ground gun emplacement

The 9.2 inch (234 mm) breech loading gun was fired for the last time in 1933. It was removed and replaced in 1937 by two 6 inch (152 mm) Mk XI guns placed in each of two outer gun emplacements; these guns were removed after WWII. The fortification also has an underground complex that runs beneath Old South Head Road. It contains a maze of rooms and corridors including a mess room, elevator shaft and gunpowder magazines.

Ladder leading into the underground bunker


The entrance from the street has been tack welded and sealed. A memorial was placed there in November, 1992 by the Royal Australian Signal Corps Association on behalf of its members and two plaques were also placed on March 30, 1993 placing the reserve in proper historical perspective.

Illowra Battery, Hill 60, Port Kembla, New South Wales

This is the Hill 60 Bunker Located in Port Kembla, New South Wales. This fortifications formed part of the Kembla Fortress network. Its purpose was to defend Port Kembla in the event of a sea born attack by an enemy vessel standing off the coast during WWII.

The Australian Army took over occupation of the Hill 60 area and the Aboriginal people were forcibly removed from the land and were never permitted to return to the Hill.

Two large gun emplacements were constructed, housing BL 6 inch Mk XI guns and their shields held in storage from the decommissioned World War I cruisers HMAS Brisbane, Sydney and Melbourne. Two large tunnels were built and are steep in descent and have a small gauge tramway used for hauling shells to the guns located at the 2 gun emplacements.

A concrete bunker is connected to the underground tunnel system.

Pictured above is one of two gun emplacement at the Illowra Battery aka Hill 60. The large steel shell is a former gun shield that was taken from one of the decommissioned World War I cruisers HMAS Brisbane, Sydney or Melbourne before they were scrapped.

^{There would have to be about 15 to 20 separate rooms connected to these tunnels. Some of the rooms are quite large and were probably used as accommodation for troops and storage for ammunitions.}