It was the trip home from our Peats Bite Christmas in July that got us talking.

Rounding back towards Pittwater, we cruised past the rust-streaked hull half-swallowed by mangroves at Cascade Gully, near Bar Point. Further along, we spotted what looked like old gun emplacements tucked into the cliffs.

It turns out these two discoveries are part of the same fascinating story, a reminder that the Hawkesbury River has been quietly watching over and protecting the nation for well over a century.

The Wreck at Bar Point

The wreck at Bar Point is the remains of HMAS Parramatta, the first ship built for the Commonwealth Naval Forces.

Launched in Scotland in 1910, HMAS Parramatta was one of six River-class destroyers that formed Australia’s first group of destroyers. During World War I, she served in Australian waters and also travelled overseas, including taking part in the Gallipoli campaign.

After her naval service ended in 1928, the ship was used for other purposes before a storm in 1933 pushed her onto the mudflats opposite Milson Island, where she has remained ever since.

Parts of the ship were later removed and preserved as memorials, but the remaining section of HMAS Parramatta is still visible today and has become a familiar landmark for those travelling through this part of the Hawkesbury River.

The guns above Broken Bay

The guns above Broken Bay

The emplacements you may have spotted at West Head were built by the Army in 1942. Two 4.7-inch ex-naval guns — the only battery of their kind in Australia — were positioned at the base of the headland, supported by an observation post, searchlights and an ammunition magazine cut into the sandstone.

Getting the guns into place was no easy task. A special inclined railway was built down the steep cliff face, using a counterweight system to move equipment and supplies to the gun positions below.

The battery had one important job: protect the rail bridge at Brooklyn.

Why Did a Railway Bridge Need Its Own Gun Battery?

The old Brooklyn Bridge was an important part of Australia’s railway network. Opened in 1889, it connected the rail lines of New South Wales with those of Victoria, South Australia and Queensland, making it a key link for travel and transport across the country.

Over time, the bridge developed serious problems. The foundations and concrete began to deteriorate, and by the 1930s one of the bridge piers had developed a large crack. Trains had to slow down when crossing, but the bridge remained a vital route, especially during World War II when supplies and troops needed to move north.

A new bridge began construction in 1939 and continued throughout the war, despite shortages of workers and materials. The original bridge continued operating until the replacement opened in 1946.

During the war, the bridge was considered an important target. After the Japanese midget submarine attack on Sydney Harbour in 1942, a map of the Hawkesbury rail bridge was found with one of the submarine commanders. This highlighted the need to protect the area, leading to the development of coastal defence sites, including gun batteries around West Head, along with minefields and submarine protection systems.

Today, the remains of the original bridge can still be seen beside the current railway bridge, a reminder of the important role this crossing has played in Australia’s history.

Next time you’re on the water

Today, the Hawkesbury feels like a place for cruising, celebrations and quiet moments on the water. But the landmarks around us tell a much bigger story.

The West Head guns, the remains of HMAS Parramatta, and the old Brooklyn bridge piers are reminders of a time when this river was carefully watched and protected.

Next time you cruise past West Head or travel beneath the Brooklyn rail bridge with us, take a moment to look a little closer ,there are stories hidden around every bend.