Sydney Harbour defences facts for kids

Gun emplacements overlooking Sydney Heads & Watsons Bay

Imagine a giant shield protecting a city! For over 150 years, Sydney Harbour was guarded by strong forts and special defences. These were built from the early 1800s until the 1960s. Their main job was to keep the Australian city of Sydney safe. They protected it from attacks by enemy warships and submarines.

Early Defences: Before Australia Became a Nation

The Georges Head Battery (1871)

Sydney's very first forts were built around Sydney Cove. This was to protect the new colony from ships that weren't British. They also guarded against uprisings by convicts. In 1791, the Dawes Point Battery was planned as the first defence. It was meant to stop an attack by the Spanish Empire. Later, Fort Macquarie was upgraded in 1798.

More gun placements were built in 1801 during the Napoleonic Wars. One was on Middle Head and another at Georges Head. Fort Phillip was also built in 1804. This was to protect against a possible French invasion. It also helped after the Castle Hill convict rebellion.

Growing Threats and New Forts

During the first half of the 1800s, more permanent forts were built. This was because of new threats to the British Empire. These included Napoleon's French troops in 1810. The Russian Pacific Fleet also posed a threat in the 1850s during the Crimean War.

On November 30, 1839, two American warships quietly entered the harbour. This was just a friendly visit. But it showed how easily Sydney could be attacked. It made people realise how isolated and valuable the settlement was. Forts were built on Garden Island in the 1820s. Construction at Bradleys Head began in 1840. Building Fort Denison started in 1841. However, this fort was not finished until 1857.

British Soldiers Leave, Sydney Builds More

Sydney's defences grew after British soldiers left Australia in the 1870s. This led to building four sets of forts. They were on Georges Heights and other parts of the harbour. The Middle Head Fortifications, the Georges Head Battery, and a smaller fort on Bradleys Head were built then. They were improved in the 1880s. These forts were designed to attack enemy ships trying to enter Sydney Harbour. Some of these forts were already a bit old-fashioned when they were built.

The Beehive Casemate was carved into the cliff face at Obelisk Bay on Sydney Harbour in 1871

Underwater Mines and Brave Miners

From 1876 to 1922, special minefields were placed across the main shipping channels of Port Jackson. A base for the "submarine miners" was built at Chowder Bay (Clifton Gardens). From Georges Head, these miners watched for ships. Their job was to explode the mine closest to an enemy ship. Each underwater mine was connected to an electric cable. This cable ran up the cliff to a firing post.

The work of a submarine miner was secret, technical, and dangerous. In 1891, during a demonstration, a terrible accident happened. Four miners died, and eight others were hurt. The Submarine Mining Corps was eventually stopped in 1922.

Sydney's defences continued to expand in the late 1800s. A fort was even built on Bare Island. This protected the entrance to Botany Bay.

World War II: New Threats, Stronger Defences

The British aircraft carrier HMS Formidable passing through the Sydney Harbour anti-submarine boom net in 1945

Sydney's defences didn't change much until the 1920s. Then, many strong forts were built to protect the city. Defences grew even more when World War II started. They became much stronger once Japan joined the war.

On May 31, 1942, Japan attacked Sydney Harbour. Sydney's anti-submarine defences were not fully ready yet. However, they successfully sank two of the three Japanese midget submarines. These submarines tried to enter the Harbour. One submarine fired two torpedoes at a warship. Both missed, but one hit another ship.

The End of Coastal Defences

After the Japanese threat to Australia ended, Sydney's defences were reduced from 1944. The last forts were closed down in the 1960s. Today, Sydney is no longer protected by fixed forts. However, a large part of the Australian Defence Force (ADF) is based in Sydney. They could protect the city in an emergency.

During the 2000 Sydney Olympics, special security was put in place. Special Forces, Navy Clearance Divers, and warships guarded the Harbour.

Current ADF Facilities in Sydney

Here are some major ADF bases in Sydney today:

• Navy
  • HMAS Kuttabul
  • HMAS Penguin
• Army
  • Victoria Barracks, Sydney (Headquarters for Forces Command)
  • Holsworthy Barracks
  • Steele Barracks Moorebank
• Air Force
  • RAAF Base Richmond