But the airborne tree brought smiles of pride and achievement to the faces of hospital management and construction workers.

The ``tree topping'' ceremony, an old Dutch construction tradition, marked the final height of the $390 million Stage Two Redevelopment of the hospital, proving that the long- awaited development is well on track.

The kauri pine was hoisted on to one of the two helipads for the new hospital.

The pine tree will later be moved into the gardens of the hospital.

Construction manager Nick Gaudry said more than 500,000 combined hours had been put into the project by workers so far, with the highest number of staff on any given day reaching about 387.

``It's very satisfying to reach this stage,'' Mr Gaudry said as the tree was placed on the helipad, overlooking all of Liverpool and surrounding areas.

By the end of next year, work will start on the ``milestone two'' area, which is the existing hospital.

Redevelopment co-ordinator Matt Sydenham said dust and sound-proofing restrictions would be put in place during this stage.

``You have to be mindful of the cost of things, too,'' Mr Sydenham said.

``The aim is to have no interference to services and for the hospital to still maintain full services, but it would be unrealistic to think there will be no interruptions.

``Things like entry points may change, but that's all a part of the process.''

The redeveloped hospital will have 855 beds, 23 operating rooms, 60 intensive care beds, a major new ambulatory care centre, additional parking, new education facilities and an elevated road and separate pedestrian bridge over the railway linking the eastern and western campuses.