Anti-submarine boom net (Sydney Harbour WWII) facts for kids
The Anti-submarine boom net was a special barrier used to protect Sydney Harbour in Australia during World War II. It was built to stop enemy submarines from secretly entering the harbour. This huge net stretched all the way across the harbour, from Green Point in Watson's Bay to Georges Head on the other side. It was an important part of Sydney's defences, which also included big artillery guns and patrol boats.
Building the Net
Australian defence forces started building the anti-submarine boom net in January 1942. It was a big job, and they finished it by August 1942.
For over three years, any boat, ship, or ferry wanting to enter Sydney Harbour had to pass through one of three special gates in the net.
A Night Attack!
On May 31, 1942, during World War II, three Japanese submarines tried to sneak into the harbour. The first submarine to try was called the M27. Lieutenant Jahai Chuma was the commander of this submarine.
The M27 followed a Sydney ferry through one of the gates. This ferry was on its way to Manly. However, the M27 got caught in the western part of the net's middle section. Lieutenant Chuma tried to free his submarine using a special tool to cut metal. But this only made the situation worse.
By 8:30 PM, James Cargill, a watchman for the Maritime Service Board, went to investigate. He rowed a boat over to where the submarine was stuck. Mr. Cargill was very surprised to find a Japanese submarine! He immediately called naval headquarters using his two-way radio. At first, the navy did not believe him. It took him two hours to convince them that a Japanese midget submarine was indeed caught in the boom net.
By 10:27 PM, Lieutenant Chuma knew his submarine had been discovered. He destroyed his submarine so it couldn't be captured. The two other Japanese submarines managed to get through the boom net. At that time, the net was not quite finished. These two submarines attacked ships in the harbour for several hours before they were also destroyed.
What's Left Today?
In August 1945, the boom net was taken away. By early 1946, only the dolphin structure was left. Today, the base of the winch house is the only remaining part of the anti-submarine boom net. You can still see it at Green Point.
