It will be one of the most complex transitions in the history of the Canberra Hospital. And for patients, it will come down to a crucial minute.
Anyone who turns up at the emergency department at 7.29am on Saturday will be treated in the old ward. But from 7.30am, patients will be treated in the new emergency department, the centrepiece of the long-awaited critical services building.
As the doors shut to the old emergency department for the final time, the new emergency department will herald in a new era.
Over the day, August 17, it won't just be the emergency department moving but some of the hospital's core wards including the intensive care unit and operating theatres.
More than 160 patients will move throughout the day and staffing across the wards will be 50 per cent higher than normal levels to help facilitate the huge move. Some equipment has already started to be moved over.
Canberra Health Services deputy chief executive Janet Zagari said the decision to move the bulk of services in the one day was based on evidence from across Australia.
She said an extended transition tended to create confusion and this could result in unnecessary risk. It was also important to ensure critical services were near each other.
"When you have an extended opening it starts to create confusion around what exactly is in the new building and what is in the old building," Ms Zagari said.
"The other part of it is with these critical services they really are intertwined so they're dependent on one another. So if you move your ICU but not your theatres you've then got a much longer travel time between where theatres end up and where ICU ends up."
"The ability for people to move seamlessly between those critical care areas is actually one of the big drivers for it being all in one day."
The whole move is planned in five-minute increments and Saturday was chosen as there are fewer surgeries and other appointments meaning clinicians are freer to help with the process.
While the old emergency department will close at 7.30am patients in the ward won't be moved to the new department. For a time there will essentially be two emergency departments in operation.
But this plan is contingent on having no big emergencies. If there are several people receiving resuscitation at once or there is a mass casualty incident the plan can change. And the hospital has run simulations based on these very scenarios.
"If there was a big emergency involving lots of casualties immediately before the time we might take a decision that it would not change over at 7.30am," Ms Zagari said.
"We really need to be conscious of what's happening both within the hospital itself but actually in the broader territory.
"There will be decision-making right up until the moment."
For other wards, patients will be progressively moved through the day with the most complex moves involving intensive care patients. Some patient moves could take up to one hour, 30 minutes.
"The old ICU will be fully staffed and the ICU in the new building will be staffed at a lower level to start with and as patients move across staff will go with them," Ms Zagari said.
Visitors will be told when wards are expected to be moved and urged to stay away but some visitors of some patients, including those with a cognitive impairment like dementia, are being encouraged to be with them as the move is taking place.
As for the old building, the tower block as it's known, some wards will be repurposed while others will shut for good. The tower block will eventually be demolished to make way for the rest of the Canberra Hospital masterplan.