The western linkspan ramp, which is used to load passengers and vehicles on and off ferries, was installed in the 1980s and is now at the end of its useful life.
Engineering work has already taken place to widen the concrete ramp and pedestrian tunnel, and work on the bridge is expected to start on 5 November. The project is likely to finish in February.
Condor has configured its winter timetable to ensure services are not disrupted by the work, which is being funded by the Ports of Jersey trading fund and not through central government cash.
