Redevelopment of No. 4 & 5 Berths at St Helier Harbour

Arup Rothwell were employed to provide Civil and Structural Engineering services on the Redevelopment of No. 4 & 5 Berths at St Helier Harbour.

The berths are used as a 24 hour holding area for St Helier Marina, house the RNLI All-Weather and Inshore St Helier Lifeboats and also provide a berth for a commercial pleasure cruise vessel.

The first phase of the project in- volved the removal of the existing pontoons and a Bailey bridge, which was the original vehicle ro-ro ramp for the Island, along with its reinforced concrete bank seat.

Once the site was clear, a jack-up barge was brought in to install new 1.2m diameter steel hollow section piles, which would act as foundations to the new bank seat and also as guides for the new pontoons.

The existing pontoon guides mounted on the Albert Quay were surveyed, repaired or replaced as required.

A combination of precast and in-situ reinforced concrete elements were used to create a new bank seat and also augment the existing St Helier Marina wind wall. Part of these works involved placing concrete underwater with the assistance of the Department for Infrastructure diving team.

A new pedestrian bridge was installed that spanned from the bank seat, at quay level, to the new main pontoons.

A dedicated pontoon was installed to house the two RNLI lifeboats with a pedestrian bridge link to the main pontoons.

Whilst on site, some degradation of the existing structural concrete to the St Helier Marina wind wall was noticed. These areas were subsequently surveyed and repaired concurrently with the original project.

Project Scope
• Removal of existing pontoons, Bailey bridge and bank seat.
• Installation of new piles, pontoons, two pedestrian bridges and bank seat.

Rothwells Scope
• Civil and Structural Design
• Site Supervision

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