Green Bridge rises above Brisbane as masthead installed

Onlookers caught a glimpse of history as the $300 million bridge's 180-tonne upright masthead - weighing the equivalent of four double-decker CityCat ferries - narrowly passed within a few metres of the city's iconic Story Bridge in challenging wet conditions on Tuesday afternoon.

Known as a "pyramidion" to bridge engineers, the masthead had to be transported from the Port of Brisbane to Kangaroo Point on a low tide to ensure enough clearance.

The masthead - the heaviest lift of the project - will be hoisted into position by a river-based tower crane on Wednesday.

"The fully assembled mast will sit at 95 metres above the water, higher than the Story Bridge, and will become a recognisable symbol of our city," Brisbane Lord Mayor Adrian Schrinner said.

The masthead will house 32 tensioned cables that will support the weight of the bridge deck.

The triangular steel structure is made up of four legs, manufactured locally using Australian steel, and was painted at a local business before being transported in two halves and assembled at the Port of Brisbane.

Due for completion next year, coloured uplighting will allow the bridge to be synchronised with other major bridges.

Council forecasts more than 6100 people will walk, ride or scoot across the bridge each day - taking 84,000 cars a year off the Story Bridge.

The bridge's cable-stay system and final over water spans will be installed as part of the next phase of construction.

Cr Schrinner said the bridge would connect the CBD with suburbs and provide somewhere for people to "stop, relax and eat while taking in stunning views".

"It will save people 15 minutes when travelling to the CBD from the eastern suburbs and will provide a new connection to the Gabba for sports and eventgoers for the 2032 Olympic and Paralympic Games and beyond," he said.

The bridge is being constructed by the consortium Connect Brisbane, led by BESIX Watpac, on behalf of council.