If ever there was a top heavy steamer, it was this one. Note her shallow draught of 20 ft. 8 in. to facilitate clearing sand bars at the entrances of ports along the Northwest coast. Koombana relied heavily on 900 tons of ballast water to keep her steady. She sailed into a tropical cyclone off Port Hedland, March, 1912, a month before the dramatic Titanic tragedy. 150 souls were lost.
The 13 broken plates referred to were sustained when when Koombana ran aground on Bar Flats, Shark Bay, 12 March, 1909. She was floated on Mort's Dock, Sydney (while Waratah was in port), three months later.
"She was evidently kept afloat only by the top skin of her ballast tanks"
This incident reminds me of Waratah taking the ground at Port Adelaide. In the case of the Koombana, the seriousness of the damage to her hull was not adequately assessed until she was sent to Sydney for repairs (by this time taking water in one of her tanks). It is naive to assume that Waratah sustained no serious damage to her hull plates and rivets before she departed Adelaide on her final voyage.