The lifting bridge will provide a third, more-southerly crossing over the River Yare, creating a new, more-direct link between the western and eastern parts of the East Norfolk coastal town.
Based on present designs the project is expected to cost £70-£75m. This includes design, construction and initial operating and maintenance of a new single-span opening bridge with a 50m navigable clearance, carrying a dual carriageway road across the River Yare.
Works also include design and construction of the associated approach roads and junctions.
Firms have until 23 March to complete prequals with formal invitations to bid due to be issued to shortlisted contractors on 20 April.
An application for a development consent order will be submitted in 2019 with construction then due start in 2020 for completion in 2022.
Documents are available from the county council website.
