The Cronulla train line will reopen as planned on Monday, July 15 after the successful replacement of the old rail bridge over Gannons Road, Caringbah.
A 750 tonne crane removed the bridge, built in 1939, on the weekend.
More than 20 pieces of heavy machinery, in addition to the crane, assisted in the operation.
Cronulla MP and Attorney-General Mark Speakman said the Sydney Trains operation involved "some very complex engineering work".
"The major structure is now securely in place with the rest of the pieces such as the rail tracks and overhead wiring to be installed this week," he said.
Mr Speakman said temporary traffic management and transport measures would continue until next Monday.
"Once this work is completed, Sutherland Shire Council can complete the next phase of the project, which is to add more road lanes, along with a footpath and cycle path," he said.
Buses will continue to replace train services between Sutherland and Cronulla and traffic will be detoured until Monday, July 15.
A shuttle service is provided for pedestrians between Kingsway and Denman Avenue.
