The lifts and escalators at Brisbane's Central Station will begin to be replaced before Christmas and several of the platforms will be raised in a major three-year upgrade.

The work is part of the $65 million upgrade of Brisbane's busiest train station, announced in 2016 but delayed for the 2018 Commonwealth Games on the Gold Coast.

Brisbane Central Station is finally going to get its $65 million upgrade, three years after it was announced. Credit:Robert Shakespeare

More than 140,000 people catch a train to or from Central each day.

Rail unions questioned the progress of the project when little work had begun before May 2018.