The vessel, which is older than the famous Cutty Sark, which is a major tourist attraction in London, has been on a slipway in Ayrshire since 1992 while a debate continued about its future.
Trustees of the Scottish Maritime Museum struggled to raise cash to refurbish the vessel, and were on the point of scientifically deconstructing it so important features could be preserved in their collection.
But the voluntary group Clipper Ship City of Adelaide Ltd (CSCOAL) submitted a tender for the job based on relocating it in one piece to form the centrepiece of a new maritime heritage park.
Their proposal had won approval from a conference held in Glasgow that was organised by the Duke of Edinburgh.
A number of firms from across the state of South Australia have contributed components for a steel cradle which has been assembled on the quayside at Irvine.
The 450-tonne vessel will be raised and the cradle inserted under it, so it can be positioned on to a sea-going barge and moved to London.
There it will be berthed close to the Cutty Sark, before being lifted into the hold of a huge cargo ship which will take it to Australia for the first time in more than 125 years.
The ship is due to arrive by spring 2014.
A rival group based in Sunderland, where the vessel was built, had hoped to provide a new home for the clipper.
A campaigner from Sunderland has twice occupied the City of Adelaide to highlight its plight and to protest against the decision to send the ship to Australia.