the reason I am posting this is that most people I have asked about this do not know that it happened I grew up at Rathmines ( used to play at the old air force base there ) and learnt about the attack in school even went to fort scratchley for a school excursion
not once have I seen any information about what I have put below on the history channel
this information is thanks to http://www.ozatwar.com/japsubs/japsshell03.htm
At about 2.15 am on 8 June 1942, Japanese submarine I-21 under the command of Captain Kanji Matsumura, shelled Newcastle in New South Wales. I-21 had travelled across Stockton Bight and positioned itself about 9 kms north east of Newcastle. I-21 travelled eastwards firing almost directly across the stern of the submarine. Their orders were to shell the Newcastle shipyards at Carrington. It is possible that it may have also targeted the BHP Works at Kooragang Island, Fort Scratchley and a large BHP-owned iron ore bulk carrier ship, the "Iron Knight" (4,812 tons), which was moored at the steelworks docks.
The Japanese gun crew broke out 20 shells (5.5" shells) from the ready locker. They also brought up another 14 rounds from the armoury below decks. 8 of the shells were "illuminators" or "star shells". All 34 shells were fired at Newcastle. After 13 minutes of firing, the guns at Fort Scratchley returned fire with 4 rounds. I-21 continued firing for another 3 minutes until all 34 shells had been fired.