Next month the historic St Aubin's harbour in Jersey will undergo stabilisation work costing £1.2 million and lasting for 45 weeks.

Both the north and south piers of the Harbour and the breakwater at St. Aubin's Fort will be subjected to structural work.

Without the maintenance the walls would eventually be in danger of collapsing.

Sections of both piers will be closed for the duration of the works, causing some disruptions for pedestrians and boat owners.

The work will require scaffolding and a drill rig put in place so that holes can be drilled in the masonry to insert piles which will stitch the structures together and anchor them into the bedrock of the seabed.

Work will commence first on the breakwater before moving to the harbours north pier, sections of which will be closed to the public for the duration of the works. After this work is completed the rig will move to the south pier to complete the work.

Jersey Harbours Technical Services Manager, Ray Hine, said: "The stabilisation works will ensure that St Aubin Harbour and the Fort remain safe for future generations to enjoy. Once the works are complete careful dredging will be undertaken to achieve the optimum depth of water in the harbour."

St Aubin was the main port of the Islands commercial trade from the 17th to the early 19th century. The piers, which are proposed Sites of Special Interest, date from the 1760s with additions completed up to 1819 while work first commenced on the breakwater at St Aubins Fort in the 1680s. They are built of massive, dry-jointed granite masonry with parapet walls on the seaward sides.

The architectural heritage consultant for the scheme, Antony Gibb, said St Aubin Harbour and Fort rank among the Islands greatest architectural and engineering achievements.

He said: "St Aubin Harbour and the Fort are two of our finest historic monuments yet it is still very much a working harbour at the heart of a thriving community. Therefore, it is important to minimise any disruption and to keep the public informed at all stages of the project."

The Société Jersiaises Marine Biology Section was involved in the projects environmental assessment, alerting Jersey Harbours to the presence of two endangered species of molluscs that live in the north pier.

The selected method of construction was chosen to minimise the impact on the molluscs and to respect their habitats.