[russellw]

.. as a PS: we have 115 cases currently hospitalised nationally (75 of those in NSW) of which 28 are in ICU (18 in NSW).

There were 2,378 ICU beds in total at the end of 2019 (466 of which were private) and we haven't gone anywhere near saturating the health care system partly through good management (increasing capacity and managing outbreaks) and partly through sheer good luck. The latest COO from July 15th shows that there were 1,916 public ICU beds available (for COVID patients) nationally but that doesn't mean that they are evenly spread and it doesn't count 'surge' capacity which each state has some of.

NSW has the most with 842 or 1 per 8,400 persons;
NT has 24 or 1 per 10,270 people;
ACT has 37 or 1 per 11,500 people;
Victoria has 427 or 1 per 15,200 people;
Tasmania has 33 or 1 per 15,453 people;
QLD had 325 or 1 per 15,953 people;
WA has 138 or 1 per 19,326 people; and
SA has 86 or 1 per 20,590 people.

Some food for thought.

We have about 40% the population of the UK but if we had 40% of their current case numbers we'd be running at 20,000 cases a day so even if only the same 10% (as now) were hospitalised that's 2,000 new hospital patients per day and if the same percentage of those required ICU treatment (let's be generous and say only 20%) that's 400 per day and with an average ICU stay of 12 days before being downgraded to general care (or dying) it wouldn't take long for a big state based cluster to overwhelm the system. Also bear in mind that we have limited general ward capacity and with a non-ICU hospitalisation ranging anywhere from a few days to a few months that would also rapidly become an issue too.