Key facts
- The maritime facility was a central part of the islands’ economy, and it continues to be so even though it has long since been decommissioned as a naval base.
- The former dockyard now welcomes cruise ships at two berthing facilities – Heritage Wharf and King’s Wharf – supporting the tourist industry, one of Bermuda’s major economic sectors. But as cruise ships get bigger, expansion and strengthening of the docks are required.
- We were appointed to carry out site surveys, structural assessments, optioneering and detailed design services.
- The client was Bermuda Ministry of Public Works
Challenge
Bermuda was to be the place where the new Norwegian Breakaway, one of the world’s largest cruise ships, would start its working life in May 2014. The existing mooring structures weren’t adequately positioned or strong enough to cope with the increased vessel size. A serious upgrade project was needed, and fast.
Expanding the facilities called for four new piled structures called ‘dolphins’ – two for berthing and two for mooring. The dolphins consist of reinforced concrete decks, supported on steel tubular piles. Calcareous sands and the potential for karstic solution features such as underground caverns posed considerable challenges.
Investigation, design and construction needed to run in parallel to meet the schedule. We carried out site surveys, structural assessments, optioneering and detailed design.
Solution
Our early involvement during the tendering stage, and close collaboration with subcontractors, allowed design to make best use of locally available plant, expertise and construction techniques, enabling the construction programme to accelerate.
We used up to twice the number of piles per dolphin than the existing structures, which required larger pile caps: double the size of the originals for the mooring dolphins, three times the size for the berthing structures.
We tailored piling techniques to suit local contractor expertise and available equipment. The close proximity of many existing structures meant that we had to select the locations of the piles very carefully too. The composite pile caps were designed with precast and in situ reinforced concrete. In total, we utilised over 1100t of offshore grade steel piles, and nearly 800cu m of marine quality concrete.
Value and benefits
- Lengthening Bermuda’s berthing facilities held the key to welcoming the newest generation of cruise ships. We helped deliver the fast-track maritime upgrade.
- Our multidisciplinary capabilities meant we were able to provide additional services ranging from environmental impact assessment to passenger modelling and wayfinding to specialist concrete advice.
- Because of the success of this project, our team is now providing technical assistance and design services for further maritime works and coastal protection schemes across the country.