Black Swan (dredge) facts for kids
The Black Swan was a special boat called a bucket dredge. It was the first one used in the Swan River Colony, which is now Western Australia. Its job was to make the Canning and Swan Rivers deeper. This helped bigger ships travel more easily.
The Black Swan worked from 1872 until 1911, when it was sunk on purpose. At first, people just called it the Government Dredge. But after it was fixed up and changed between 1887 and 1888, it got its new name, Black Swan. This name came from the black swans that live in the area, just like the Swan River itself. The work done by the Black Swan and other dredges changed the river's plants and animals a lot.
Building the Dredge
People realised as early as 1865 that the Canning and Swan Rivers needed to be deeper. This was especially true around Perth Water. The rivers were too shallow, which made it hard for ships to bring goods. Cargo had to be loaded and unloaded far away, near Fremantle.
So, in 1869, the government ordered a dredge from England. It arrived in pieces in Fremantle that same year. Workers then put it together in North Fremantle. The dredge was about 27 metres (90 feet) long and 7.3 metres (24 feet) wide. It had a 12-horsepower steam engine that could go up to 32 horsepower with help from a flywheel.
The dredge had 18 buckets on a ladder in the middle of the boat. These buckets could dig down about 2.7 metres (9 feet) deep.
By 1887, the dredge had not been used for several years. Its steel bottom had rusted in many places. So, between 1887 and 1888, it was repaired. The rusted bottom was replaced with strong Jarrah wood. At the same time, the bucket ladder was moved to the front of the boat and made longer. Four more buckets were added, which meant the dredge could now dig much deeper, down to about 4.6 metres (15 feet).
How it Worked
The Black Swan started working in 1872. At first, convicts helped with the work. Their first job was to dig a path between The Narrows and the William Street jetty. This allowed cargo boats to pass through. This path was later made longer, reaching up to Barrack Street, where King Cole's jetty was.
The dredge also worked around Fremantle several times. It removed sand banks and helped boats get to the jetty at Pier Street. In the 1870s, the Black Swan helped with land reclamation projects along the Perth foreshore. It used the mud and silt dug from the river channels. After these jobs, the dredge sat unused for a few years.
After its big repairs in 1887 and 1888, the dredge was officially launched and renamed the Black Swan on June 19, 1888. It was named after the Swan River, which got its name from the black swans living there. Its first jobs after being renamed involved making changes to the mouth of the Swan River.
In 1892, the Black Swan went to the Canning River. It dug a channel in an area called Muddy Reach. After that, the dredge returned to Perth Water. There, it dug a channel connecting Barrack Street in Perth with Mends Street in South Perth, near the Perth Zoo. Later, the Black Swan dug another channel between Barrack Street and Coode Street. In 1900, it made the Barrack Street – Mends Street channel wider. For the next ten years, the dredge continued to work on land reclamation projects in Perth.
End of its Journey
In 1911, the land reclamation work in Perth was finished. All the equipment used for the project, including the Black Swan, was taken out beyond the North Mole and sunk.
The changes made to the river, like making the shallow Perth Waters deeper, affected the plants and animals living there. Shallow parts of the river are important places where fish lay their eggs. They also provided food and shelter for the native black swans, which the Swan River was named after. When the river was made deeper, much of the swans' food, which was aquatic plants, became too deep for them to reach. This caused them to lose their habitat.
In 2000, the government made a plan to help the black swan numbers grow again. This plan aimed to fix their habitats and create new ones, to help them recover from the effects of dredging and other river changes.
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