Breakwater construction nears completion

The 350m long Cowes breakwater structure in the UK is nearing the end of the construction process by contractor Boskalis Westminster.

Cowes Harbour Master, Captain Stuart McIntosh, said: “This new breakwater, along with the next phases of our harbour infrastructure, the extension to the Shrape and new Eastern Channel, are the key elements to achieving the Commission’s primary objective of providing a sheltered harbour environment for the benefit of all harbour users and stakeholders.”

Boskalis Westminster has continued to make good progress with the installation of the rock armour protection to the breakwater.

Rock armouring to the eastern end of the breakwater is already complete at a height of 6.7 metres above Chart Datum.

Approximately 10,000 m3 of surplus gravel remaining from the construction of the breakwater core has been moved to a holding position to the north of the breakwater; this will be removed once the rock armouring has been finished and before practical completion.

Trinity House has approved the installation of five navigation beacons on top of the breakwater, in addition to navigation marks and lights at the western and eastern ends.

Practical completion of the breakwater is due in the third week of October with removal of the barge dock piles and contractor de-mobilising in early November.

In addition, Hydrodynamic engineer ABPmer, lead consultants for all marine elements of CHC’s Cowes Breakwater Project and the HCA’s East Cowes regeneration project, have successfully completed the construction and verification of a new and technically advanced regional tidal model that will provide the platform and basis for the local Solent and Cowes model.

The next stage will see ABPmer use the new model to review the impact of the breakwater and optimise the harbour’s tidal flows and sedimentation regime in the design of the next phases of harbour infrastructure (Eastern Channel dredge and Shrape extension).

To feed into this process, it is also planned to undertake a further campaign of detailed tidal and sedimentation monitoring in the harbour, including sedimentation sampling and the deployment of fixed multi-function monitoring devices, as well as the possible use of drone video imagery.

Meanwhile, the East Cowes development is progressing well and the developers are now planning on commencing work on the construction of the proposed Victoria Marina in the winter of 2016 and towards spring 2017. The dredging of the new marina will most likely be carried out at the same time as the dredging of the harbour’s new Eastern Channel.

The next phases of the harbour infrastructure works (Eastern Channel dredge and Shrape extension) will also likely commence in the autumn/winter of 2016 to 2017, aligning with the HCA’s plans for the development.