Source: John Morcombe, Manly Daily
The anti-tank traps at the southern end of an empty Dee Why Lagoon in June 1981. Photo Manly Daily
Tank trap at Dee Why still standing after all these years
IT IS hard to believe authorities thought timber piles at the southern end of Dee Why Lagoon might be enough to stop marauding Japanese tanks during World
Nevertheless, the piles were installed and remarkably have survived three-quarters of a century, although they are looking less sturdy by the decade.
But when World War II broke out, Sydney was only half-prepared.
Twin 9.2in batteries had been built at North Head and Cape Banks in 1936 and plans had been made to build other defences along the coastline but the outbreak
of war required quick action.
Two batteries of 4.7in guns were built at West Head to guard the entrance to Broken Bay and Pittwater, anti-tank traps were put in place along several
beaches and within Pittwater, and radar stations were established at North Head, Beacon Hill and Collaroy Plateau.
The anti-tank traps at the southern end of Dee Why Lagoon this week
Mile upon mile of barbed-wire entanglements, sandbagged foxholes, trenches and machine-gun emplacements were established along the beaches and inside Pittwater
and at the southern end of Dee Why Lagoon, the two rows of timber piles were driven into the soft mud to act as anti-tank devices.
A large trench was dug right across the northern peninsula from Bungan Beach to Winji Jimmi, where more timber piles were driven into the mudflats.
Anti-submarine nets were erected across the mouth of Pittwater and across the entrance to Sydney Harbour.
The biggest scare for locals was when three Japanese midget submarines entered the harbour on the night of May 31/June 1, 1942. Only one of the midget
submarines was able to fire its torpedoes, one of which hit the sea wall at Garden Island and sank a ferry being used to accommodate sailors, 21 of
whom were killed.
At the war’s end, most of the defence systems were pulled down or filled in, although some of the concrete tetrahedrons used as anti-tank devices can still
be seen at Fairy Bower and Bayview, along with the timber piles at Dee Why Lagoon and many of the installations at North Head and West Head.